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Acceptable Lightning Ground?
I would like to propose a grounding arrangement for my [hypothetical]
antenna and get some feedback on it. I have access to the solid-copper cold-water pipe that enters my home through the basement wall close to the basement floor. This pipe is used [in addition to cold water] for the service entrance [circuit breaker box] ground. I was thinking of putting an antenna outside on a pole and running the coax into the basement. Then I would strip back several inches of the outer jacket of the coax [axposing the braided shield] and connect the coax braid to the cold water pipe using several hose clamps. This should ground the coax directly to the service ground - the single point ground for the house. I would add an arrester near the ground point. I would then run the coax upstairs [about 10 feet] to the radio, where it would [via the PL-259] connect to the transceiver chassis. The radio chassis will be electrically bonded to peripheral equipment chassis'. It seems that in the unlikely event [low altitude, semi-urban area] that the antenna were struck by lightning, the energy [albeit significant] would have no reason to propagate up to my station. Even though it may elevate my house ground by thousands of volts [with respect to some other ground point], the station should ride up with it - and little current should flow in the coax at the station. Am I whistling Dixie? Thanks, -JJ |
Acceptable Lightning Ground?
wrote in message oups.com... I would like to propose a grounding arrangement for my [hypothetical] antenna and get some feedback on it. I have access to the solid-copper cold-water pipe that enters my home through the basement wall close to the basement floor. bad start This pipe is used [in addition to cold water] for the service entrance [circuit breaker box] ground. thats bad news I was thinking of putting an antenna outside on a pole and running the coax into the basement. nope, not the way to do it right. Then I would strip back several inches of the outer jacket of the coax [axposing the braided shield] and connect the coax braid to the cold water pipe using several hose clamps. This should ground the coax directly to the service ground - the single point ground for the house. except the single point shouldn't be 'inside' the house. I would add an arrester near the ground point. I would then run the coax upstairs [about 10 feet] to the radio, where it would [via the PL-259] connect to the transceiver chassis. The radio chassis will be electrically bonded to peripheral equipment chassis'. the radio chassis should be connected to the same single point ground, and not via just the coax shield. It seems that in the unlikely event [low altitude, semi-urban area] that the antenna were struck by lightning, the energy [albeit significant] would have no reason to propagate up to my station. Even though it may elevate my house ground by thousands of volts [with respect to some other ground point], the station should ride up with it - and little current should flow in the coax at the station. Am I whistling Dixie? |
Acceptable Lightning Ground?
Maybe read PolyPhaser | The Authority On Lightning & Surge Protection
http://www.polyphaser.com/ Happy New year -- CL |
Acceptable Lightning Ground?
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Acceptable Lightning Ground?
On 1 Jan 2007 04:40:29 -0800, "
wrote: I would like to propose a grounding arrangement for my [hypothetical] antenna and get some feedback on it. I have access to the solid-copper cold-water pipe that enters my home through the basement wall close to the basement floor. This pipe is used [in addition to cold water] for the service entrance [circuit breaker box] ground. Hi OM, You have the classic service ground connection. I was thinking of putting an antenna outside on a pole and running the coax into the basement. Then I would strip back several inches of the outer jacket of the coax [axposing the braided shield] and connect the coax braid to the cold water pipe using several hose clamps. This qualifies, in most respects, to code for grounding a continuous wire and employing a method prescribed by code, clamping. However, it would seem that clamping might deform the coax. You should investigate your local code for alternatives as well as for compliance. This should ground the coax directly to the service ground - the single point ground for the house. I would add an arrester near the ground point. Then you are breaking the run instead of just simply stripping the jacket. Check code. I would then run the coax upstairs [about 10 feet] to the radio, where it would [via the PL-259] connect to the transceiver chassis. The radio chassis will be electrically bonded to peripheral equipment chassis'. This is also classically known as a suicide connection. If you were holding the PL-259 shell in one hand, and touched any, poorly maintained metal chassis of the transceiver while plugging it in (or removing it); then you might just be the fuse in a circuit about to blow. I've seen my buddy draw sparks with just such an arrangement before I convinced him to run a real, separate ground. 73's Richard Clark, KB7QHC |
Acceptable Lightning Ground?
" wrote in
oups.com: I would like to propose a grounding arrangement for my [hypothetical] antenna and get some feedback on it. I have access to the solid-copper You haven't described here the antenna and its support structure, and they are relevant. One of the strategies for hardening a site against lightning is to divert as much of the strike current to ground rather than having it flow in the conductors within the facility. The value / necessity of this measure will depend on the antenna, its support structure, nearby structures that might protect your antenna to some extent, and the risk of lighting in your locality. cold-water pipe that enters my home through the basement wall close to the basement floor. This pipe is used [in addition to cold water] for the service entrance [circuit breaker box] ground. I was thinking of putting an antenna outside on a pole and running the coax into the basement. Then I would strip back several inches of the outer jacket of the coax [axposing the braided shield] and connect the coax braid to the cold water pipe using several hose clamps. This should ground the coax directly to the service ground - the single point ground for the house. I would add an arrester near the ground point. I would then run the coax upstairs [about 10 feet] to the radio, where it would [via the PL-259] connect to the transceiver chassis. The radio chassis will be electrically bonded to peripheral equipment chassis'. Lightning conductors need to be substantial enough to withstand the strike scenario without physical failure (eg melting). A common scenario is 20kA for 0.1s, but it does depend on the situation. Is your coax braid and your termination / bonding method sufficient to survive strike current? Equipotential bonding of the lightning protection ground and the AC service ground systems is important. Low resistance and more importantly low inductance conductors that will withstand the current are required. Depending on your coax shield as a bonding conductor from your equipment to the ground point as you describe sounds unwise for several reasons, but most notably because it uses coax connectors (and probably PL259s at that) for the connection, they are not reliable enough, and they would not be a permanent connection). If your equipment runs on low voltage DC, do not assume that the power supply provides a connection between the AC ground and the -ve DC lead, some powersupplies have floating output. In any event, bonding of the external metal of all equipment in your station to a single point ground is advisable to reduce the risk of substantial potential differences between equipments, and the risk that poses to life in the event of lightning or even an electrical fault. If addressing these issues seems extreme, it is probably a good indicator that many ham station earth systems are quite inadequate, offset by the low probability of an adverse event and not usually talked about when poor implementation exacerbated the situation. Like one of the other respondents, I recommend the Polyphaser site, it is a usefull source that canvasses many of the issues. Additionally, your wiring codes or standards may provide guidance or set requirements, they do here. Having done all that, and with better knowledge, review the risk, cost and measures. You may not want to resource a lightning hardened solution for 24x7 connection of the stations to antennas. Owen |
Acceptable Lightning Ground?
"Dave" wrote in message . .. wrote in message oups.com... I would like to propose a grounding arrangement for my [hypothetical] antenna and get some feedback on it. I have access to the solid-copper cold-water pipe that enters my home through the basement wall close to the basement floor. bad start This pipe is used [in addition to cold water] for the service entrance [circuit breaker box] ground. thats bad news I was thinking of putting an antenna outside on a pole and running the coax into the basement. nope, not the way to do it right. Then I would strip back several inches of the outer jacket of the coax [axposing the braided shield] and connect the coax braid to the cold water pipe using several hose clamps. This should ground the coax directly to the service ground - the single point ground for the house. except the single point shouldn't be 'inside' the house. I would add an arrester near the ground point. I would then run the coax upstairs [about 10 feet] to the radio, where it would [via the PL-259] connect to the transceiver chassis. The radio chassis will be electrically bonded to peripheral equipment chassis'. the radio chassis should be connected to the same single point ground, and not via just the coax shield. It seems that in the unlikely event [low altitude, semi-urban area] that the antenna were struck by lightning, the energy [albeit significant] would have no reason to propagate up to my station. Even though it may elevate my house ground by thousands of volts [with respect to some other ground point], the station should ride up with it - and little current should flow in the coax at the station. Am I whistling Dixie? Hopefully you are not really using the water pipe for a ground for your electrical service. Hopefully your plumbing is just bonded to the electrical ground. Dont even think about using this for lightning protection. Nothing like having lightning run in on your plumbing while taking a bath or have it run in on yor ground and eat about $7K worth of test equipment(my bad). Jimmie |
Acceptable Lightning Ground?
"Caveat Lector" wrote in message ... Maybe read PolyPhaser | The Authority On Lightning & Surge Protection http://www.polyphaser.com/ Happy New year -- CL THE BIBLE on grounding and bonding.as far as I am concerned. |
Acceptable Lightning Ground?
Jimmie D wrote:
Hopefully you are not really using the water pipe for a ground for your electrical service. Hopefully your plumbing is just bonded to the electrical ground. Dont even think about using this for lightning protection. Nothing like having lightning run in on your plumbing while taking a bath or have it run in on yor ground and eat about $7K worth of test equipment(my bad). Jimmie Electrical service grounding via water pipes is common and acceptable. Quoting from the 2005 NEC, which is the standard used in many or most jurisdictions in the US: 250.52 Grounding Electrodes. (A) Electrodes Permitted for Grounding. (1) Metal Underground Water Pipe. A metal underground water pipe in direct contact with the earth for 3.0 m (10 ft) or more (including any metal well casing effectively bonded to the pipe) and electrically continuous (or made electrically continuous by bonding around insulating joints or insulating pipe) to the points of connection of the grounding electrode conductor and the bonding conductors. Interior metal water piping located more than 1.52 m (5 ft) from the point of entrance to the building shall not be used as a part of the grounding electrode system or as a conductor to interconnect electrodes that are part of the grounding electrode system. I agree this is not a good solution for lightning protection. 73, Gene W4SZ |
Acceptable Lightning Ground?
"Gene Fuller" wrote in message ... Jimmie D wrote: Hopefully you are not really using the water pipe for a ground for your electrical service. Hopefully your plumbing is just bonded to the electrical ground. Dont even think about using this for lightning protection. Nothing like having lightning run in on your plumbing while taking a bath or have it run in on yor ground and eat about $7K worth of test equipment(my bad). Jimmie Electrical service grounding via water pipes is common and acceptable. Quoting from the 2005 NEC, which is the standard used in many or most jurisdictions in the US: 250.52 Grounding Electrodes. (A) Electrodes Permitted for Grounding. (1) Metal Underground Water Pipe. A metal underground water pipe in direct contact with the earth for 3.0 m (10 ft) or more (including any metal well casing effectively bonded to the pipe) and electrically continuous (or made electrically continuous by bonding around insulating joints or insulating pipe) to the points of connection of the grounding electrode conductor and the bonding conductors. Interior metal water piping located more than 1.52 m (5 ft) from the point of entrance to the building shall not be used as a part of the grounding electrode system or as a conductor to interconnect electrodes that are part of the grounding electrode system. I agree this is not a good solution for lightning protection. 73, Gene W4SZ Very common for local code to overide this and for good reason. You never know when a piece of metal pipe is going to be replaced with plastic so a ground rod has to be used with the electrical service.The plumber dont know it is being used as a ground. and the electrician doesnt know all the metal pipe has been replaced with PVC.Ground rods are cheap and easy to install. Jimmie |
Acceptable Lightning Ground?
In article .com,
" wrote: I would like to propose a grounding arrangement for my [hypothetical] antenna and get some feedback on it. I have access to the solid-copper cold-water pipe that enters my home through the basement wall close to the basement floor. This pipe is used [in addition to cold water] for the service entrance [circuit breaker box] ground. I was thinking of putting an antenna outside on a pole and running the coax into the basement. Then I would strip back several inches of the outer jacket of the coax [axposing the braided shield] and connect the coax braid to the cold water pipe using several hose clamps. This should ground the coax directly to the service ground - the single point ground for the house. I would add an arrester near the ground point. I would then run the coax upstairs [about 10 feet] to the radio, where it would [via the PL-259] connect to the transceiver chassis. The radio chassis will be electrically bonded to peripheral equipment chassis'. Please get a book on antennas to learn how to properly set one up. |
Acceptable Lightning Ground?
On Mon, 01 Jan 2007 11:14:20 -0600, Bob Miller
wrote: try http://www.w8ji.com/ground_systems.htm Although he doesn't say so, Tom's towers are on top of a mountain. bob Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair) www.rogerhalstead.com |
Acceptable Lightning Ground?
On Tue, 2 Jan 2007 00:33:03 -0500, "Jimmie D"
wrote: Very common for local code to overide this and for good reason. You never know when a piece of metal pipe is going to be replaced with plastic so a ground rod has to be used with the electrical service.The plumber dont know it is being used as a ground. and the electrician doesnt know all the metal pipe has been replaced with PVC.Ground rods are cheap and easy to install. Jimmie There was a time when the expression "water pipe ground" was common. Extra ground rods actually contribute to the risk unless the are tied together with at least #6 wire. (NEC) Allowing the grounds to be commoned through the power distribution will put appliances in the loop with expensive results. John Ferrell W8CCW |
Acceptable Lightning Ground?
John Ferrell wrote: On Tue, 2 Jan 2007 00:33:03 -0500, "Jimmie D" wrote: Very common for local code to overide this and for good reason. You never know when a piece of metal pipe is going to be replaced with plastic so a ground rod has to be used with the electrical service.The plumber dont know it is being used as a ground. and the electrician doesnt know all the metal pipe has been replaced with PVC.Ground rods are cheap and easy to install. Jimmie There was a time when the expression "water pipe ground" was common. Extra ground rods actually contribute to the risk unless the are tied together with at least #6 wire. (NEC) Allowing the grounds to be commoned through the power distribution will put appliances in the loop with expensive results. John Ferrell W8CCW Yep, that why we use "grounding" and "bonding" and why work should be done by a certified electrician. Grounding should be taken back to a single point so you dont get loops running through expensive appliances. Jimmie |
Acceptable Lightning Ground?
"John Ferrell" wrote in message ... snip There was a time when the expression "water pipe ground" was common. Extra ground rods actually contribute to the risk unless the are tied together with at least #6 wire. (NEC) Allowing the grounds to be commoned through the power distribution will put appliances in the loop with expensive results. John Ferrell W8CCW I had an upgrade (by professional electrician) about five years ago on my 35 y/o house. He upgraded the service level from 100A to 200A, added some outlets in the house and garage, etc ... stuff I've wanted since I moved in. The house was built with cold-water-pipe ground and it appears to be at least #8, maybe #6. The electrician said it could stay BUT he said code required an additional ground stake driven into the soil near the service entrance. This is San Diego County CA. "Your mileage may vary." One more thing, subject line "Yes, It's Really This Bad:" When I was a teenager, two families in the neighborhood went all-out at Christmas with the big outside lights. One guy said he kept blowing fuses (15A was the standard for all the branches in all the houses), so he "solved" the problem by substituting 25A fuses. Even as a snot-nosed kid I knew better. |
Acceptable Lightning Ground?
Jimmie D wrote:
"Dave" wrote in message . .. wrote in message oups.com... I would like to propose a grounding arrangement for my [hypothetical] antenna and get some feedback on it. I have access to the solid-copper cold-water pipe that enters my home through the basement wall close to the basement floor. bad start This pipe is used [in addition to cold water] for the service entrance [circuit breaker box] ground. thats bad news I was thinking of putting an antenna outside on a pole and running the coax into the basement. nope, not the way to do it right. Then I would strip back several inches of the outer jacket of the coax [axposing the braided shield] and connect the coax braid to the cold water pipe using several hose clamps. This should ground the coax directly to the service ground - the single point ground for the house. except the single point shouldn't be 'inside' the house. I would add an arrester near the ground point. I would then run the coax upstairs [about 10 feet] to the radio, where it would [via the PL-259] connect to the transceiver chassis. The radio chassis will be electrically bonded to peripheral equipment chassis'. the radio chassis should be connected to the same single point ground, and not via just the coax shield. It seems that in the unlikely event [low altitude, semi-urban area] that the antenna were struck by lightning, the energy [albeit significant] would have no reason to propagate up to my station. Even though it may elevate my house ground by thousands of volts [with respect to some other ground point], the station should ride up with it - and little current should flow in the coax at the station. Am I whistling Dixie? Hopefully you are not really using the water pipe for a ground for your electrical service. Hopefully your plumbing is just bonded to the electrical ground. Dont even think about using this for lightning protection. Nothing like having lightning run in on your plumbing while taking a bath or have it run in on yor ground and eat about $7K worth of test equipment(my bad). Jimmie Jimmie DE KB3OPR I am an electrician by craft. The US National Electric Code Requires that underground metal water piping on the premise be used as a grounding electrode for the electrical system. There is no way around it. No matter how fast people talk you cannot avoid using an underground metal piping system as a grounding electrode unless the electrical inspector is incompetent. -- Tom Horne |
Acceptable Lightning Ground?
On Mon, 02 Apr 2007 04:08:47 GMT, Thomas Horne
wrote: Jimmie D wrote: "Dave" wrote in message . .. wrote in message oups.com... I would like to propose a grounding arrangement for my [hypothetical] antenna and get some feedback on it. I have access to the solid-copper cold-water pipe that enters my home through the basement wall close to the basement floor. bad start This pipe is used [in addition to cold water] for the service entrance [circuit breaker box] ground. thats bad news I was thinking of putting an antenna outside on a pole and running the coax into the basement. nope, not the way to do it right. Then I would strip back several inches of the outer jacket of the coax [axposing the braided shield] and connect the coax braid to the cold water pipe using several hose clamps. This should ground the coax directly to the service ground - the single point ground for the house. except the single point shouldn't be 'inside' the house. I would add an arrester near the ground point. I would then run the coax upstairs [about 10 feet] to the radio, where it would [via the PL-259] connect to the transceiver chassis. The radio chassis will be electrically bonded to peripheral equipment chassis'. the radio chassis should be connected to the same single point ground, and not via just the coax shield. It seems that in the unlikely event [low altitude, semi-urban area] that the antenna were struck by lightning, the energy [albeit significant] would have no reason to propagate up to my station. Even though it may elevate my house ground by thousands of volts [with respect to some other ground point], the station should ride up with it - and little current should flow in the coax at the station. Am I whistling Dixie? Hopefully you are not really using the water pipe for a ground for your electrical service. Hopefully your plumbing is just bonded to the electrical ground. Dont even think about using this for lightning protection. Nothing like having lightning run in on your plumbing while taking a bath or have it run in on yor ground and eat about $7K worth of test equipment(my bad). Jimmie Jimmie DE KB3OPR I am an electrician by craft. The US National Electric Code Requires that underground metal water piping on the premise be used as a grounding electrode for the electrical system. There is no way around Ahhh...The water pipe must be bonded to the electrical system, but the main ground must be at the entrance. Here, we have plastic water pipe all the way to the main from the meter, yet we have to bond the meters which are metal with plastic running in and plastic running out. it. No matter how fast people talk you cannot avoid using an underground metal piping system as a grounding electrode unless the electrical inspector is incompetent. It's really easy to avoid here. We do not have metal piping available for grounding. Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair) www.rogerhalstead.com |
Acceptable Lightning Ground?
Roger wrote:
On Mon, 02 Apr 2007 04:08:47 GMT, Thomas Horne wrote: Jimmie D wrote: "Dave" wrote in message . .. wrote in message oups.com... I would like to propose a grounding arrangement for my [hypothetical] antenna and get some feedback on it. I have access to the solid-copper cold-water pipe that enters my home through the basement wall close to the basement floor. bad start This pipe is used [in addition to cold water] for the service entrance [circuit breaker box] ground. thats bad news I was thinking of putting an antenna outside on a pole and running the coax into the basement. nope, not the way to do it right. Then I would strip back several inches of the outer jacket of the coax [axposing the braided shield] and connect the coax braid to the cold water pipe using several hose clamps. This should ground the coax directly to the service ground - the single point ground for the house. except the single point shouldn't be 'inside' the house. I would add an arrester near the ground point. I would then run the coax upstairs [about 10 feet] to the radio, where it would [via the PL-259] connect to the transceiver chassis. The radio chassis will be electrically bonded to peripheral equipment chassis'. the radio chassis should be connected to the same single point ground, and not via just the coax shield. It seems that in the unlikely event [low altitude, semi-urban area] that the antenna were struck by lightning, the energy [albeit significant] would have no reason to propagate up to my station. Even though it may elevate my house ground by thousands of volts [with respect to some other ground point], the station should ride up with it - and little current should flow in the coax at the station. Am I whistling Dixie? Hopefully you are not really using the water pipe for a ground for your electrical service. Hopefully your plumbing is just bonded to the electrical ground. Dont even think about using this for lightning protection. Nothing like having lightning run in on your plumbing while taking a bath or have it run in on yor ground and eat about $7K worth of test equipment(my bad). Jimmie Jimmie DE KB3OPR I am an electrician by craft. The US National Electric Code Requires that underground metal water piping on the premise be used as a grounding electrode for the electrical system. There is no way around Ahhh...The water pipe must be bonded to the electrical system, but the main ground must be at the entrance. Here, we have plastic water pipe all the way to the main from the meter, yet we have to bond the meters which are metal with plastic running in and plastic running out. it. No matter how fast people talk you cannot avoid using an underground metal piping system as a grounding electrode unless the electrical inspector is incompetent. It's really easy to avoid here. We do not have metal piping available for grounding. Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair) www.rogerhalstead.com That has nothing to do with not using an underground metal water pipe that is present on the premises. -- Tom Horne |
Acceptable Lightning Ground?
Thomas Horne wrote:
I am an electrician by craft. The US National Electric Code Requires that underground metal water piping on the premise be used as a grounding electrode for the electrical system. There is no way around Ahhh...The water pipe must be bonded to the electrical system, but the main ground must be at the entrance. Here, we have plastic water pipe all the way to the main from the meter, yet we have to bond the meters which are metal with plastic running in and plastic running out. it. No matter how fast people talk you cannot avoid using an underground metal piping system as a grounding electrode unless the electrical inspector is incompetent. It's really easy to avoid here. We do not have metal piping available for grounding. Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair) www.rogerhalstead.com That has nothing to do with not using an underground metal water pipe that is present on the premises. -- Tom Horne that would really depend on the local AHJ (Authority Having Jurisdiction).. For instance, in the City of Thousand Oaks, CA, only Concrete Encased Grounding Electrodes (aka Ufer grounds) are allowed in new construction. (other grounding electrodes are permitted, but you better have the Ufer ground, and, of course, they would need to be bonded together, per NEC). With respect to my house, built in 1998, I don't think there is a bonding jumper from water pipe to the system ground at the service entrance (which is a Ufer ground). Obviously, there IS a jumper from the telco drop, the cable TV drop, etc. to the ground at the service entrance (and all the "drops" are actually underground services in plastic conduit). Partly this is because the water service comes in on the opposite of the house from all the "wired" utilities. I'll have to go take a look, though. I believe the new code (which I don't have here to hand) does require that metallic water piping, if any, be bonded to the electrical system ground (presumably to eliminate "touch voltage"). I believe also, that the code prohibits use of a water pipe as the sole grounding electrode (NEC 250-(a)(2) in 1999 code, 250.53(D)(2) 2002,2005 codes). As always in code matters, what the AHJ says takes precedence. As a practical matter, a properly constructed Ufer ground is probably lower impedance and more reliable than rods, wires, and pipes. Jim Lux, P.E. W6RMK |
Acceptable Lightning Ground?
Jim Lux wrote in
: .... As a practical matter, a properly constructed Ufer ground is probably lower impedance and more reliable than rods, wires, and pipes. In this part of the world (Australia) an LV transformer usually serves many more premises (commonly 50 to 100), and the neutral wire (centre of the 3 phase 240/415 wye) is bonded to the premises earth electrode at each main switchboard (known as Multiple Earth Neutral or MEN), so premises earth systems are effectively paralleled using the neutral wire. The transformer neutral is connected to an earth electrode at the substation. The regulatory requirement for a MEN premises ground electrode here is just a 1.2m copper clad driven electrode, with no real performance requirement. Of course the earth system must be equipotential bonded to the metallic water service, and plumbers are at risk when they open up a metallic water pipe (they are supposed to jumper the gap to prevent electric shock). This approach is probably less suited to 110VAC distribution. Owen |
Acceptable Lightning Ground?
Jim Lux wrote:
Thomas Horne wrote: I am an electrician by craft. The US National Electric Code Requires that underground metal water piping on the premise be used as a grounding electrode for the electrical system. There is no way around Ahhh...The water pipe must be bonded to the electrical system, but the main ground must be at the entrance. Here, we have plastic water pipe all the way to the main from the meter, yet we have to bond the meters which are metal with plastic running in and plastic running out. it. No matter how fast people talk you cannot avoid using an underground metal piping system as a grounding electrode unless the electrical inspector is incompetent. It's really easy to avoid here. We do not have metal piping available for grounding. Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair) www.rogerhalstead.com That has nothing to do with not using an underground metal water pipe that is present on the premises. -- Tom Horne that would really depend on the local AHJ (Authority Having Jurisdiction).. For instance, in the City of Thousand Oaks, CA, only Concrete Encased Grounding Electrodes (aka Ufer grounds) are allowed in new construction. (other grounding electrodes are permitted, but you better have the Ufer ground, and, of course, they would need to be bonded together, per NEC). With respect to my house, built in 1998, I don't think there is a bonding jumper from water pipe to the system ground at the service entrance (which is a Ufer ground). Obviously, there IS a jumper from the telco drop, the cable TV drop, etc. to the ground at the service entrance (and all the "drops" are actually underground services in plastic conduit). Partly this is because the water service comes in on the opposite of the house from all the "wired" utilities. I'll have to go take a look, though. I believe the new code (which I don't have here to hand) does require that metallic water piping, if any, be bonded to the electrical system ground (presumably to eliminate "touch voltage"). I believe also, that the code prohibits use of a water pipe as the sole grounding electrode (NEC 250-(a)(2) in 1999 code, 250.53(D)(2) 2002,2005 codes). As always in code matters, what the AHJ says takes precedence. As a practical matter, a properly constructed Ufer ground is probably lower impedance and more reliable than rods, wires, and pipes. Jim Lux, P.E. W6RMK Jim I would hope you are aware that most concrete encased electrodes are not, in fact, a true UFER. In spite of that it is undoubtedly the most reliable electrode; which is not to say lowest impedance; commonly installed in homes. You are correct that an underground metal water piping electrode must always be supplemented with another electrode but the code still requires it to be used as an electrode were it is present on the premise. In my location the public water utility is entirely metallic, including the service laterals to buildings. It covers about fifty miles from north to south and more than thirty five miles east to west at it's widest point. That large an underground metal piping system has the lowest obtainable impedance to ground of any electrode on a premise served by the water system. -- Tom Horne |
Acceptable Lightning Ground?
On Apr 2, 8:07 am, Roger wrote:
Ahhh...The water pipe must be bonded to the electrical system, but the main ground must be at the entrance. Here, we have plastic water pipe all the way to the main from the meter, yet we have to bond the meters which are metal with plastic running in and plastic running out. ... It's really easy to avoid here. We do not have metal piping available for grounding. Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair)www.rogerhalstead.com Roger is correct here. Underground water pipe electrode is no longer sufficient as the earth ground in most locations for a long list of reasons. Yes, that water pipe must be bonded to the AC electric so that plumbing is electrically same voltages as everything else inside the house - human safety. Public utility water system may have voltages different from AC electric if the two are not bonded - as has been observed when a fault was created outside the building. Destructive currents entering on that water system must be eliminated by being bonded to AC electric. Many other reasons why AC breaker box must be bonded to the cold water pipe. Yes cold water pipe may act as an earthing electrode. But it is no longer sufficient as the earthing electrode. An earthing electrode - one that all utilities must use - is not the water pipe. All utilities must connect to a separate and dedicated earthing electrode defined by code (as defined in Article 250.52 A - paragraphs 2 through 7). The code defines 7 types of earthing electrodes. The only electrode not sufficient is cold water pipe - paragraph 1. For lightning, an antenna (or satellite dish) is typically treated as if a separate structure as demonstrated in this application note: http://www.erico.com/public/library/...es/tncr002.pdf Antenna wire must connect to the same building 'single point' earthing electrode. IOW any wire in any cable going to the station must first connect to that single point earthing electrode (either by hardwire or protector) before entering the building. Best is to have the antenna earthing also connected, by underground wire, to that same single point ground. This for lightning protection is beyond what is called for by National Electrical Code for numerous reasons. First, NEC only addresses human safety. The OP is asking about transistor safety. Second, the code does little to address impedance. Grounding for human safety is mostly about resistance - not impedance. Third, any grounding system dependent on some other trade (ie plumber) is no longer considered safe or sufficient. A ground system must meet NEC requirements. Then it must exceed those requirements. For lightning protection, a cold water pipe is not longer considered a good solution because that earthing electrode is just not sufficient. Also better is to earth lightning rods and antennas before that ground wire connects to a building's single point ground. Notice the underground wire connection between antenna earth ground and building earth ground. And finally a purpose of earthing that is beyond what the NEC requires. A station needs earthing that provided both equipotential and conductivity. Code concentrates on conductivity. But for equipotential, we do things beyond what is normally sufficient for human safety. We install Ufer grounds or halo grounds that completely surround the protected facility. We relocate all utilities so that each wire in each cable makes a 'less than 10 foot' connection to that common earth electrode. Any exception to the single point earth ground (as defined in code) is not permitted when also earthing for transistor safety. Route earthing wires to be separate from all other wires, no splices, no sharp bends, not inside metallic conduit, etc. All earthing wires remain electrically separate until all meet at the single point ground. Conditions beyond what code demands or permits. Consider with care information in that figure in: http://www.erico.com/public/library/...es/tncr002.pdf Things recommended are not immediately obvious. Reasons for this involve both equipotential and conductivity. Both are required for station protection. |
Acceptable Lightning Ground?
w_tom wrote:
On Apr 2, 8:07 am, Roger wrote: Ahhh...The water pipe must be bonded to the electrical system, but the main ground must be at the entrance. Here, we have plastic water pipe all the way to the main from the meter, yet we have to bond the meters which are metal with plastic running in and plastic running out. ... It's really easy to avoid here. We do not have metal piping available for grounding. Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair)www.rogerhalstead.com Roger is correct here. Underground water pipe electrode is no longer sufficient as the earth ground in most locations for a long list of reasons. As Thomas said, Roger is correct if the underground water service pipe is plastic. Missing is any of the “long list of reasons”. Many other reasons why AC breaker box must be bonded to the cold water pipe. Yes cold water pipe may act as an earthing electrode. But it is no longer sufficient as the earthing electrode. An earthing electrode - one that all utilities must use - is not the water pipe. All utilities must connect to a separate and dedicated earthing electrode defined by code (as defined in Article 250.52 A - paragraphs 2 through 7). The code defines 7 types of earthing electrodes. The only electrode not sufficient is cold water pipe - paragraph 1. The code says (250.50) all electrodes listed in 250.52-A-1 through 6 MUST (where present) be connected together to form the earth electrode system. 250.52–A-1, which is conveniently missing from w_’s list, is metal underground water pipe (at least 10 feet metal underground). ONLY if the pipe is not 10 feet long underground is bonding used instead. Water pipe requires a “supplemental” electrode. That is because the metal pipe may in the future be replaced by plastic. From the National Electrical Code Handbook - same publisher as the NEC “The requirement to supplement the metal water pipe is based on the practice of using plastic pipe for replacement when the original metal water pipe fails. This leaves the system without a grounding electrode unless a supplementary electrode is provided.” Requiring a supplemental electrode does not indicate there is any defect in metal pipe as an electrode. As Thomas indicates, it is likely by far the best electrode available in urban areas with metal supply. Earthing connection of other services, like the phone NID, may be made to the water pipe within 5 feet of the entrance to the building (the connection of the power earthing conductor is in the same 5 foot span). We install Ufer grounds or halo grounds that completely surround the protected facility. From http://www.lightningsafety.com/nlsi_...finitions.html “Halo Grounded Ring: A grounded No. 2 wire, installed around all four walls inside a small building, at an elevation of approx. six inches below the ceiling. There are drops installed from the halo to the equipment cabinets and to waveguide ports, interior cable trays etc. Halo rings serve as connector points to achieve ground references of interior metallic objects. These, in turn, are connected to the main ground bus bar.” Perhaps you mean “ground ring”? ---------------- The code now requires a Ufer electrode in new construction with concrete foundations or footings. -- bud-- |
Acceptable Lightning Ground?
Dave wrote:
"I would like to propose a grounding arrangement for my (hypothetical) antenna and get some feedback on it." Assuming the tower is not base insulated, start by grounding each leg of the tower with a no. 6 AWG or larger cable directly to its own ground rod. Best lightning protection comes from folded driven element antennas grounded directly at the tower top or other mounting point and connecting the antenna with coax which is grounded again at the tower base. If a folded driven element is not used, a short-circuited quarter-wave stub can be connected directly across the antenna drivepoint to supply the grounding to the tower that a folded element provides. Standard practice requires a no. 6 AWG or larger cable directly connecting the base of the tower to the ground connection used by the electrical service to the site. For enhanced protection, large RF chokes as used in tower lighting circuits in broadcast stations, are placed in each power wire, including the neutral, between the electrical service and the radio connected to the antenna. A-C capacitors are connected between each end of the high-current chokes and a common connection directly to the station ground. If there are 3 wires you need 6 caoacitors. Across each capacitor you need a metal oxide varistor appropriate for the line volts and the joules you may be called upon to dissipate when lightning strikes. We also shunted the capavcitors with conventional thyrite arrestors to back-up the MOV`s. This pi-filter with arresters worked like gang busters. It is not excessive but did prove necessary for solid-state equipment protection. Best regards, Richard Harrison, KB5WZI |
Acceptable Lightning Ground?
"Thomas Horne" wrote in message link.net... Jimmie D wrote: "Dave" wrote in message . .. wrote in message oups.com... I would like to propose a grounding arrangement for my [hypothetical] antenna and get some feedback on it. I have access to the solid-copper cold-water pipe that enters my home through the basement wall close to the basement floor. bad start This pipe is used [in addition to cold water] for the service entrance [circuit breaker box] ground. thats bad news I was thinking of putting an antenna outside on a pole and running the coax into the basement. nope, not the way to do it right. Then I would strip back several inches of the outer jacket of the coax [axposing the braided shield] and connect the coax braid to the cold water pipe using several hose clamps. This should ground the coax directly to the service ground - the single point ground for the house. except the single point shouldn't be 'inside' the house. I would add an arrester near the ground point. I would then run the coax upstairs [about 10 feet] to the radio, where it would [via the PL-259] connect to the transceiver chassis. The radio chassis will be electrically bonded to peripheral equipment chassis'. the radio chassis should be connected to the same single point ground, and not via just the coax shield. It seems that in the unlikely event [low altitude, semi-urban area] that the antenna were struck by lightning, the energy [albeit significant] would have no reason to propagate up to my station. Even though it may elevate my house ground by thousands of volts [with respect to some other ground point], the station should ride up with it - and little current should flow in the coax at the station. Am I whistling Dixie? Hopefully you are not really using the water pipe for a ground for your electrical service. Hopefully your plumbing is just bonded to the electrical ground. Dont even think about using this for lightning protection. Nothing like having lightning run in on your plumbing while taking a bath or have it run in on yor ground and eat about $7K worth of test equipment(my bad). Jimmie Jimmie DE KB3OPR I am an electrician by craft. The US National Electric Code Requires that underground metal water piping on the premise be used as a grounding electrode for the electrical system. There is no way around it. No matter how fast people talk you cannot avoid using an underground metal piping system as a grounding electrode unless the electrical inspector is incompetent. -- Tom Horne Tom you are confusing grounding with bonding, the plumbing should be bonded to ground but not used for ground, at least this is getting to be the rule in most places. I know that using the plumbing for ground is still acceptaable in places and in a lot of places it is still acceptable if if the local code permitted it at the time it was installed(grandfathering).. |
Acceptable Lightning Ground?
"Thomas Horne" wrote in message ink.net... Roger wrote: On Mon, 02 Apr 2007 04:08:47 GMT, Thomas Horne wrote: Jimmie D wrote: "Dave" wrote in message . .. wrote in message oups.com... I would like to propose a grounding arrangement for my [hypothetical] antenna and get some feedback on it. I have access to the solid-copper cold-water pipe that enters my home through the basement wall close to the basement floor. bad start This pipe is used [in addition to cold water] for the service entrance [circuit breaker box] ground. thats bad news I was thinking of putting an antenna outside on a pole and running the coax into the basement. nope, not the way to do it right. Then I would strip back several inches of the outer jacket of the coax [axposing the braided shield] and connect the coax braid to the cold water pipe using several hose clamps. This should ground the coax directly to the service ground - the single point ground for the house. except the single point shouldn't be 'inside' the house. I would add an arrester near the ground point. I would then run the coax upstairs [about 10 feet] to the radio, where it would [via the PL-259] connect to the transceiver chassis. The radio chassis will be electrically bonded to peripheral equipment chassis'. the radio chassis should be connected to the same single point ground, and not via just the coax shield. It seems that in the unlikely event [low altitude, semi-urban area] that the antenna were struck by lightning, the energy [albeit significant] would have no reason to propagate up to my station. Even though it may elevate my house ground by thousands of volts [with respect to some other ground point], the station should ride up with it - and little current should flow in the coax at the station. Am I whistling Dixie? Hopefully you are not really using the water pipe for a ground for your electrical service. Hopefully your plumbing is just bonded to the electrical ground. Dont even think about using this for lightning protection. Nothing like having lightning run in on your plumbing while taking a bath or have it run in on yor ground and eat about $7K worth of test equipment(my bad). Jimmie Jimmie DE KB3OPR I am an electrician by craft. The US National Electric Code Requires that underground metal water piping on the premise be used as a grounding electrode for the electrical system. There is no way around Ahhh...The water pipe must be bonded to the electrical system, but the main ground must be at the entrance. Here, we have plastic water pipe all the way to the main from the meter, yet we have to bond the meters which are metal with plastic running in and plastic running out. it. No matter how fast people talk you cannot avoid using an underground metal piping system as a grounding electrode unless the electrical inspector is incompetent. It's really easy to avoid here. We do not have metal piping available for grounding. Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair) www.rogerhalstead.com That has nothing to do with not using an underground metal water pipe that is present on the premises. -- Tom Horne Sure it does, what happens when a plumber replaces a piece of metal pipe with plastic and opens your ground. The plumber has no responsibility to see if the plumbing is being used for ground. Mrtal plumbing should be bonded to the electrical ground, not be the ground. |
Acceptable Lightning Ground?
Jimmie D wrote:
Hopefully you are not really using the water pipe for a ground for your electrical service. Hopefully your plumbing is just bonded to the electrical ground. Dont even think about using this for lightning protection. Nothing like having lightning run in on your plumbing while taking a bath or have it run in on yor ground and eat about $7K worth of test equipment(my bad). Jimmie Jimmie DE KB3OPR I am an electrician by craft. The US National Electric Code Requires that underground metal water piping on the premise be used as a grounding electrode for the electrical system. There is no way around it. No matter how fast people talk you cannot avoid using an underground metal piping system as a grounding electrode unless the electrical inspector is incompetent. -- Tom Horne Tom you are confusing grounding with bonding, the plumbing should be bonded to ground but not used for ground, at least this is getting to be the rule in most places. I know that using the plumbing for ground is still acceptaable in places and in a lot of places it is still acceptable if if the local code permitted it at the time it was installed(grandfathering).. An electrician confusing grounding and bonding - that is pretty funny. From the US National Electrical Code “250.50 Grounding Electrode System All grounding electrodes as described in 250.52(A)(1) through (A)(6) that are present at each building or structure served shall be bonded together to form the grounding electrode system.” “250.52(A)(1) Metal Underground Water Pipe” (10 feet or more metal in earth) Using underground metal water pipe as a grounding electrode is REQUIRED. And this has been a requirement for a very long time. Local codes may be different from the NEC, but it is unlikely they are different on this. And if you just "bond" metal water pipe it will work as a grounding electrode anyway. -- bud-- |
Acceptable Lightning Ground?
"Bud--" wrote in message .. . Jimmie D wrote: Hopefully you are not really using the water pipe for a ground for your electrical service. Hopefully your plumbing is just bonded to the electrical ground. Dont even think about using this for lightning protection. Nothing like having lightning run in on your plumbing while taking a bath or have it run in on yor ground and eat about $7K worth of test equipment(my bad). Jimmie Jimmie DE KB3OPR I am an electrician by craft. The US National Electric Code Requires that underground metal water piping on the premise be used as a grounding electrode for the electrical system. There is no way around it. No matter how fast people talk you cannot avoid using an underground metal piping system as a grounding electrode unless the electrical inspector is incompetent. -- Tom Horne Tom you are confusing grounding with bonding, the plumbing should be bonded to ground but not used for ground, at least this is getting to be the rule in most places. I know that using the plumbing for ground is still acceptaable in places and in a lot of places it is still acceptable if if the local code permitted it at the time it was installed(grandfathering).. An electrician confusing grounding and bonding - that is pretty funny. From the US National Electrical Code “250.50 Grounding Electrode System All grounding electrodes as described in 250.52(A)(1) through (A)(6) that are present at each building or structure served shall be bonded together to form the grounding electrode system.” “250.52(A)(1) Metal Underground Water Pipe” (10 feet or more metal in earth) Using underground metal water pipe as a grounding electrode is REQUIRED. And this has been a requirement for a very long time. Local codes may be different from the NEC, but it is unlikely they are different on this. And if you just "bond" metal water pipe it will work as a grounding electrode anyway. -- bud-- True enough but there is a difference, grounding is connecting to earth bonding is tying conductive structures together so they are at equal potential. Ground is a single point that everything else is bonded. Ground should be a stucture that the qualified electrician should be familar with not plumbing that may or may not be intact. If you dont believe me just try to get an electrical inspection on a new home without a ground rod installed. BTW the NEC is a minimum standard not a guide on how to wire your house.or perform grounding and bonding. You wouldnt believe what electricians dont know, like checking phase rotation before turning on a new 200KW UPS. or megging out lines before turning on new parking lot lights or making sure a generator is not backfeeding a line before working on it. All things I have seen electricans screw up in the past year. Jimmie |
Acceptable Lightning Ground?
Jimmie D wrote:
"Bud--" wrote in message .. . Jimmie D wrote: Hopefully you are not really using the water pipe for a ground for your electrical service. Hopefully your plumbing is just bonded to the electrical ground. Dont even think about using this for lightning protection. Nothing like having lightning run in on your plumbing while taking a bath or have it run in on yor ground and eat about $7K worth of test equipment(my bad). Jimmie Jimmie DE KB3OPR I am an electrician by craft. The US National Electric Code Requires that underground metal water piping on the premise be used as a grounding electrode for the electrical system. There is no way around it. No matter how fast people talk you cannot avoid using an underground metal piping system as a grounding electrode unless the electrical inspector is incompetent. -- Tom Horne Tom you are confusing grounding with bonding, the plumbing should be bonded to ground but not used for ground, at least this is getting to be the rule in most places. I know that using the plumbing for ground is still acceptaable in places and in a lot of places it is still acceptable if if the local code permitted it at the time it was installed(grandfathering).. An electrician confusing grounding and bonding - that is pretty funny. From the US National Electrical Code �250.50 Grounding Electrode System All grounding electrodes as described in 250.52(A)(1) through (A)(6) that are present at each building or structure served shall be bonded together to form the grounding electrode system.� �250.52(A)(1) Metal Underground Water Pipe� (10 feet or more metal in earth) Using underground metal water pipe as a grounding electrode is REQUIRED. And this has been a requirement for a very long time. Local codes may be different from the NEC, but it is unlikely they are different on this. And if you just "bond" metal water pipe it will work as a grounding electrode anyway. -- bud-- True enough but there is a difference, grounding is connecting to earth bonding is tying conductive structures together so they are at equal potential. Ground is a single point that everything else is bonded. Ground should be a stucture that the qualified electrician should be familar with not plumbing that may or may not be intact. If you dont believe me just try to get an electrical inspection on a new home without a ground rod installed. BTW the NEC is a minimum standard not a guide on how to wire your house.or perform grounding and bonding. You wouldnt believe what electricians dont know, like checking phase rotation before turning on a new 200KW UPS. or megging out lines before turning on new parking lot lights or making sure a generator is not backfeeding a line before working on it. All things I have seen electricans screw up in the past year. Jimmie Jimmie I can assure you I don't do that sort of careless nonsense. I can also assure you that whenever I'm involved before the foundation is poured or at least prior to it being back filled there will be no driven rods on that job. They are the single least effective electrode you can install. When I have to install driven rods, such as for a heavy up, I will stack them using rod couplers until I'm under twenty five ohms and perform a witnessed test for the inspector. I consider eight foot driven rods a complete waste of time. Mind you I'll install them when I'm forced to but you will usually find mine driven through the bottom of a three foot deep trench on at least twenty feet of bare copper number two AWG grounding electrode conductor. As for the US NEC being a minimum standard that is not always true. In at least ten states it is both the minimum and the maximum standard that a public electrical inspector may apply. So called "min max" states do not allow the local governments to amend the US NEC. Were the US NEC is the minimum standard you have to use underground metal water piping as a grounding electrode whether or not it jibes with your religious beliefs about what constitutes an electrode or not. If you were bonding the plumbing you could do that with a conductor sized for the largest branch circuit supplying an appliance that is attached to the plumbing. When you are using the piping as an electrode you must size the conductor to the size of the service entry conductors. People like W Tom cannot bring themselves to admit that underground metal water piping is an effective grounding electrode and worse still that it more effective then most of the other electrodes listed in the US NEC at least in homes. I always check the impedance of my grounding electrodes and that's what the measurements say to me. -- Tom Horne |
Acceptable Lightning Ground?
"Thomas Horne" wrote in message link.net... Jimmie D wrote: "Bud--" wrote in message .. . Jimmie D wrote: Hopefully you are not really using the water pipe for a ground for your electrical service. Hopefully your plumbing is just bonded to the electrical ground. Dont even think about using this for lightning protection. Nothing like having lightning run in on your plumbing while taking a bath or have it run in on yor ground and eat about $7K worth of test equipment(my bad). Jimmie Jimmie DE KB3OPR I am an electrician by craft. The US National Electric Code Requires that underground metal water piping on the premise be used as a grounding electrode for the electrical system. There is no way around it. No matter how fast people talk you cannot avoid using an underground metal piping system as a grounding electrode unless the electrical inspector is incompetent. -- Tom Horne Tom you are confusing grounding with bonding, the plumbing should be bonded to ground but not used for ground, at least this is getting to be the rule in most places. I know that using the plumbing for ground is still acceptaable in places and in a lot of places it is still acceptable if if the local code permitted it at the time it was installed(grandfathering).. An electrician confusing grounding and bonding - that is pretty funny. From the US National Electrical Code ?250.50 Grounding Electrode System All grounding electrodes as described in 250.52(A)(1) through (A)(6) that are present at each building or structure served shall be bonded together to form the grounding electrode system.? ?250.52(A)(1) Metal Underground Water Pipe? (10 feet or more metal in earth) Using underground metal water pipe as a grounding electrode is REQUIRED. And this has been a requirement for a very long time. Local codes may be different from the NEC, but it is unlikely they are different on this. And if you just "bond" metal water pipe it will work as a grounding electrode anyway. -- bud-- True enough but there is a difference, grounding is connecting to earth bonding is tying conductive structures together so they are at equal potential. Ground is a single point that everything else is bonded. Ground should be a stucture that the qualified electrician should be familar with not plumbing that may or may not be intact. If you dont believe me just try to get an electrical inspection on a new home without a ground rod installed. BTW the NEC is a minimum standard not a guide on how to wire your house.or perform grounding and bonding. You wouldnt believe what electricians dont know, like checking phase rotation before turning on a new 200KW UPS. or megging out lines before turning on new parking lot lights or making sure a generator is not backfeeding a line before working on it. All things I have seen electricans screw up in the past year. Jimmie Jimmie I can assure you I don't do that sort of careless nonsense. I can also assure you that whenever I'm involved before the foundation is poured or at least prior to it being back filled there will be no driven rods on that job. They are the single least effective electrode you can install. When I have to install driven rods, such as for a heavy up, I will stack them using rod couplers until I'm under twenty five ohms and perform a witnessed test for the inspector. I consider eight foot driven rods a complete waste of time. Mind you I'll install them when I'm forced to but you will usually find mine driven through the bottom of a three foot deep trench on at least twenty feet of bare copper number two AWG grounding electrode conductor. As for the US NEC being a minimum standard that is not always true. In at least ten states it is both the minimum and the maximum standard that a public electrical inspector may apply. So called "min max" states do not allow the local governments to amend the US NEC. Were the US NEC is the minimum standard you have to use underground metal water piping as a grounding electrode whether or not it jibes with your religious beliefs about what constitutes an electrode or not. If you were bonding the plumbing you could do that with a conductor sized for the largest branch circuit supplying an appliance that is attached to the plumbing. When you are using the piping as an electrode you must size the conductor to the size of the service entry conductors. People like W Tom cannot bring themselves to admit that underground metal water piping is an effective grounding electrode and worse still that it more effective then most of the other electrodes listed in the US NEC at least in homes. I always check the impedance of my grounding electrodes and that's what the measurements say to me. -- Tom Horne The point I am trying to make is that the ground system must be sufficent on its own and not need to connect to the buildings plumbing to improve the ground. You should never depend on the plumbing especially on residential work because you can not maintain control of modifications to that plumbing system. Good example is my in-laws home, for years the house connected to the well via 1 inch metal pipe and this was also the ground for the house as it was built in 1974. When the new well was drilled plastic pipe was installed to the new well with no groundwire going back to the well casing. A couple of years later a new HVAC system was installed and when there was an accidental short circuit the well pump was fried. This would not have happened if a proper grounding system had been installed at the house instead of relying on the plumbing. Professionals have a responsibility to idiot -proof there work as much as possible but you know how it is, sooner or later someone makes a better idiot. The fact that the water pipes may be effective or even better than the installed ground really have nothing to do with anything. Ground sytems are for grounding, Plumbing is for water. Electrians dont do plumbing and plumbers dont rewire homes. Jimmie |
Acceptable Lightning Ground?
Jimmie D wrote:
[big snip] ...and plumbers dont rewire homes. Jimmie They're not *supposed* to! :-( Bryan |
Acceptable Lightning Ground?
Jimmie D wrote:
"Thomas Horne" wrote in message link.net... Jimmie D wrote: "Bud--" wrote in message .. . Jimmie D wrote: Hopefully you are not really using the water pipe for a ground for your electrical service. Hopefully your plumbing is just bonded to the electrical ground. Dont even think about using this for lightning protection. Nothing like having lightning run in on your plumbing while taking a bath or have it run in on yor ground and eat about $7K worth of test equipment(my bad). Jimmie Jimmie DE KB3OPR I am an electrician by craft. The US National Electric Code Requires that underground metal water piping on the premise be used as a grounding electrode for the electrical system. There is no way around it. No matter how fast people talk you cannot avoid using an underground metal piping system as a grounding electrode unless the electrical inspector is incompetent. -- Tom Horne Tom you are confusing grounding with bonding, the plumbing should be bonded to ground but not used for ground, at least this is getting to be the rule in most places. I know that using the plumbing for ground is still acceptaable in places and in a lot of places it is still acceptable if if the local code permitted it at the time it was installed(grandfathering).. An electrician confusing grounding and bonding - that is pretty funny. From the US National Electrical Code ?250.50 Grounding Electrode System All grounding electrodes as described in 250.52(A)(1) through (A)(6) that are present at each building or structure served shall be bonded together to form the grounding electrode system.? ?250.52(A)(1) Metal Underground Water Pipe? (10 feet or more metal in earth) Using underground metal water pipe as a grounding electrode is REQUIRED. And this has been a requirement for a very long time. Local codes may be different from the NEC, but it is unlikely they are different on this. And if you just "bond" metal water pipe it will work as a grounding electrode anyway. -- bud-- True enough but there is a difference, grounding is connecting to earth bonding is tying conductive structures together so they are at equal potential. Ground is a single point that everything else is bonded. Ground should be a stucture that the qualified electrician should be familar with not plumbing that may or may not be intact. If you dont believe me just try to get an electrical inspection on a new home without a ground rod installed. BTW the NEC is a minimum standard not a guide on how to wire your house.or perform grounding and bonding. You wouldnt believe what electricians dont know, like checking phase rotation before turning on a new 200KW UPS. or megging out lines before turning on new parking lot lights or making sure a generator is not backfeeding a line before working on it. All things I have seen electricans screw up in the past year. Jimmie Jimmie I can assure you I don't do that sort of careless nonsense. I can also assure you that whenever I'm involved before the foundation is poured or at least prior to it being back filled there will be no driven rods on that job. They are the single least effective electrode you can install. When I have to install driven rods, such as for a heavy up, I will stack them using rod couplers until I'm under twenty five ohms and perform a witnessed test for the inspector. I consider eight foot driven rods a complete waste of time. Mind you I'll install them when I'm forced to but you will usually find mine driven through the bottom of a three foot deep trench on at least twenty feet of bare copper number two AWG grounding electrode conductor. As for the US NEC being a minimum standard that is not always true. In at least ten states it is both the minimum and the maximum standard that a public electrical inspector may apply. So called "min max" states do not allow the local governments to amend the US NEC. Were the US NEC is the minimum standard you have to use underground metal water piping as a grounding electrode whether or not it jibes with your religious beliefs about what constitutes an electrode or not. If you were bonding the plumbing you could do that with a conductor sized for the largest branch circuit supplying an appliance that is attached to the plumbing. When you are using the piping as an electrode you must size the conductor to the size of the service entry conductors. People like W Tom cannot bring themselves to admit that underground metal water piping is an effective grounding electrode and worse still that it more effective then most of the other electrodes listed in the US NEC at least in homes. I always check the impedance of my grounding electrodes and that's what the measurements say to me. -- Tom Horne The point I am trying to make is that the ground system must be sufficent on its own and not need to connect to the buildings plumbing to improve the ground. You should never depend on the plumbing especially on residential work because you can not maintain control of modifications to that plumbing system. Good example is my in-laws home, for years the house connected to the well via 1 inch metal pipe and this was also the ground for the house as it was built in 1974. When the new well was drilled plastic pipe was installed to the new well with no groundwire going back to the well casing. A couple of years later a new HVAC system was installed and when there was an accidental short circuit the well pump was fried. This would not have happened if a proper grounding system had been installed at the house instead of relying on the plumbing. Professionals have a responsibility to idiot -proof there work as much as possible but you know how it is, sooner or later someone makes a better idiot. The fact that the water pipes may be effective or even better than the installed ground really have nothing to do with anything. Ground sytems are for grounding, Plumbing is for water. Electrians dont do plumbing and plumbers dont rewire homes. Jimmie And my point is that your opinion does not jibe with the National Electric Code. -- Tom Horne |
Acceptable Lightning Ground?
Not only that, BUT IF you use copper pipe, you
may expect electrolysis , which will actually eat the pipe, in 4 or 5 years, in soil. If you go to your parts house (Lowes, or Home Depot), you will notice unions which are INSULATED for copper plumbing . I had a water line replaced with copper the plumber said with those unions, can get 25-30 years out of your new pipe, without, more like 5 years before holes appear! It ain't cheap replaceing couple hundred feet of water supply pipe! This also affects steel piping, tho not so rapidly! Jim NN7K Thomas Horne wrote: Jimmie D wrote: "Thomas Horne" wrote in message link.net... Jimmie D wrote: "Bud--" wrote in message .. . Jimmie D wrote: Hopefully you are not really using the water pipe for a ground for your electrical service. Hopefully your plumbing is just bonded to the electrical ground. Dont even think about using this for lightning protection. Nothing like having lightning run in on your plumbing while taking a bath or have it run in on yor ground and eat about $7K worth of test equipment(my bad). Jimmie Jimmie |
Acceptable Lightning Ground?
"Thomas Horne" wrote in message k.net... Jimmie D wrote: "Thomas Horne" wrote in message link.net... Jimmie D wrote: "Bud--" wrote in message .. . Jimmie D wrote: Hopefully you are not really using the water pipe for a ground for your electrical service. Hopefully your plumbing is just bonded to the electrical ground. Dont even think about using this for lightning protection. Nothing like having lightning run in on your plumbing while taking a bath or have it run in on yor ground and eat about $7K worth of test equipment(my bad). Jimmie Jimmie DE KB3OPR I am an electrician by craft. The US National Electric Code Requires that underground metal water piping on the premise be used as a grounding electrode for the electrical system. There is no way around it. No matter how fast people talk you cannot avoid using an underground metal piping system as a grounding electrode unless the electrical inspector is incompetent. -- Tom Horne Tom you are confusing grounding with bonding, the plumbing should be bonded to ground but not used for ground, at least this is getting to be the rule in most places. I know that using the plumbing for ground is still acceptaable in places and in a lot of places it is still acceptable if if the local code permitted it at the time it was installed(grandfathering).. An electrician confusing grounding and bonding - that is pretty funny. From the US National Electrical Code ?250.50 Grounding Electrode System All grounding electrodes as described in 250.52(A)(1) through (A)(6) that are present at each building or structure served shall be bonded together to form the grounding electrode system.? ?250.52(A)(1) Metal Underground Water Pipe? (10 feet or more metal in earth) Using underground metal water pipe as a grounding electrode is REQUIRED. And this has been a requirement for a very long time. Local codes may be different from the NEC, but it is unlikely they are different on this. And if you just "bond" metal water pipe it will work as a grounding electrode anyway. -- bud-- True enough but there is a difference, grounding is connecting to earth bonding is tying conductive structures together so they are at equal potential. Ground is a single point that everything else is bonded. Ground should be a stucture that the qualified electrician should be familar with not plumbing that may or may not be intact. If you dont believe me just try to get an electrical inspection on a new home without a ground rod installed. BTW the NEC is a minimum standard not a guide on how to wire your house.or perform grounding and bonding. You wouldnt believe what electricians dont know, like checking phase rotation before turning on a new 200KW UPS. or megging out lines before turning on new parking lot lights or making sure a generator is not backfeeding a line before working on it. All things I have seen electricans screw up in the past year. Jimmie Jimmie I can assure you I don't do that sort of careless nonsense. I can also assure you that whenever I'm involved before the foundation is poured or at least prior to it being back filled there will be no driven rods on that job. They are the single least effective electrode you can install. When I have to install driven rods, such as for a heavy up, I will stack them using rod couplers until I'm under twenty five ohms and perform a witnessed test for the inspector. I consider eight foot driven rods a complete waste of time. Mind you I'll install them when I'm forced to but you will usually find mine driven through the bottom of a three foot deep trench on at least twenty feet of bare copper number two AWG grounding electrode conductor. As for the US NEC being a minimum standard that is not always true. In at least ten states it is both the minimum and the maximum standard that a public electrical inspector may apply. So called "min max" states do not allow the local governments to amend the US NEC. Were the US NEC is the minimum standard you have to use underground metal water piping as a grounding electrode whether or not it jibes with your religious beliefs about what constitutes an electrode or not. If you were bonding the plumbing you could do that with a conductor sized for the largest branch circuit supplying an appliance that is attached to the plumbing. When you are using the piping as an electrode you must size the conductor to the size of the service entry conductors. People like W Tom cannot bring themselves to admit that underground metal water piping is an effective grounding electrode and worse still that it more effective then most of the other electrodes listed in the US NEC at least in homes. I always check the impedance of my grounding electrodes and that's what the measurements say to me. -- Tom Horne The point I am trying to make is that the ground system must be sufficent on its own and not need to connect to the buildings plumbing to improve the ground. You should never depend on the plumbing especially on residential work because you can not maintain control of modifications to that plumbing system. Good example is my in-laws home, for years the house connected to the well via 1 inch metal pipe and this was also the ground for the house as it was built in 1974. When the new well was drilled plastic pipe was installed to the new well with no groundwire going back to the well casing. A couple of years later a new HVAC system was installed and when there was an accidental short circuit the well pump was fried. This would not have happened if a proper grounding system had been installed at the house instead of relying on the plumbing. Professionals have a responsibility to idiot -proof there work as much as possible but you know how it is, sooner or later someone makes a better idiot. The fact that the water pipes may be effective or even better than the installed ground really have nothing to do with anything. Ground sytems are for grounding, Plumbing is for water. Electrians dont do plumbing and plumbers dont rewire homes. Jimmie And my point is that your opinion does not jibe with the National Electric Code. -- Tom Horne Please Tom, tell me in what way that the grounding system should be sufficent on its own and not having to rely on the plumbing to provide grounding for an electrical system in violation of the NEC. Also please tell me how you intend to prevent the scenario I discribed where the ground system was completely disconnected from the home when the well's metal plumbing was replaced with plastic. The Code is the min and max that an inspector can apply to an inspection This means that the inspector cant find fault with using plumbing for grounding if this is what the code says, it doesnt mean that the inspector can find fault if it is built better than code requirements, so again I say the code is written to a minimum spec. Your own definition of min max confirms this. Traditionally the NEC has the lowest minimum standard and the state and local codes usually have a higher standard., there may be some exceptions to this. I will will stipulate that using plumbing for ground may be "to code" in some places but it still is not a good way to ground your house and definately should not be used for a lightning ground. Jimmie |
Acceptable Lightning Ground?
Jim, NN7K wrote:
"Not only that, BUT IF you use copper pipe, you may expect electrolysis, which will actually eat the pipe, in 4 or 5 years, in soil." I don`t have my CRC Handbook here with its metal activity series but I was a sailor in WW-2 who replaced many zinc electrodes installed as sacrificial anodes to protect other metals on the ship. I`ve also built electrolytic cells which used copper and zinc as electrodes and sea water as the electrolyte. I guarantee it is the zinc which is eaten while the copper remains intact. Copper is poisonous to most sea organisms and thus is not likely fouled. Don`t worry about copper it does not waste away in the earth. I`ve worked in broadcast stations with radials buried in the 1930`s. They are still pristine. Zinc is the metal used to coat steel pipe when it is galvanized. Best regards, Richard Harrison, KB5WZI |
Acceptable Lightning Ground?
"Richard Harrison" wrote in message ... Jim, NN7K wrote: "Not only that, BUT IF you use copper pipe, you may expect electrolysis, which will actually eat the pipe, in 4 or 5 years, in soil." I don`t have my CRC Handbook here with its metal activity series but I was a sailor in WW-2 who replaced many zinc electrodes installed as sacrificial anodes to protect other metals on the ship. I`ve also built electrolytic cells which used copper and zinc as electrodes and sea water as the electrolyte. I guarantee it is the zinc which is eaten while the copper remains intact. Copper is poisonous to most sea organisms and thus is not likely fouled. Don`t worry about copper it does not waste away in the earth. I`ve worked in broadcast stations with radials buried in the 1930`s. They are still pristine. Zinc is the metal used to coat steel pipe when it is galvanized. Best regards, Richard Harrison, KB5WZI Richard, Thats not how it waste away. It is disovled from the inside by galvanic action. If you couple copper to galvanized pipe you must use a special coupler that electrically isolates the copper from the galvanized pipe. This is usually a brass union with a neopreme, I think, insulator. |
Acceptable Lightning Ground?
"Jimmie D" wrote in
: Richard, Thats not how it waste away. It is disovled from the inside by galvanic action. If you couple copper to galvanized pipe you must use a special coupler that electrically isolates the copper from the galvanized pipe. This is usually a brass union with a neopreme, I think, insulator. Hi Jimmie, Copper is higher on the Galvanic series than either Zinc or Iron. (Zinc is lowest in the series aside from Magnesium) While there is a possibility - though none that I know of - that for some reason that copper may corrode before Zinc or its iron substrate, usually the lower member of the series goes away first. Do you know what the effect is? I have heard of some low quality copper pipe that tends to spring leaks after quite a few years. Perhaps this is what we are talking anout? - 73 de Mike KB3EIA |
Acceptable Lightning Ground?
Jimmie D wrote:
Thomas Horne wrote: Jimmie D wrote: Thomas Horne wrote: Jimmie D wrote: Bud wrote: Jimmie D wrote: Hopefully you are not really using the water pipe for a ground for your electrical service. Hopefully your plumbing is just bonded to the electrical ground. Dont even think about using this for lightning protection. Nothing like having lightning run in on your plumbing while taking a bath or have it run in on yor ground and eat about $7K worth of test equipment(my bad). Jimmie Jimmie DE KB3OPR I am an electrician by craft. The US National Electric Code Requires that underground metal water piping on the premise be used as a grounding electrode for the electrical system. There is no way around it. No matter how fast people talk you cannot avoid using an underground metal piping system as a grounding electrode unless the electrical inspector is incompetent. -- Tom Horne Tom you are confusing grounding with bonding, the plumbing should be bonded to ground but not used for ground, at least this is getting to be the rule in most places. I know that using the plumbing for ground is still acceptaable in places and in a lot of places it is still acceptable if if the local code permitted it at the time it was installed(grandfathering).. An electrician confusing grounding and bonding - that is pretty funny. From the US National Electrical Code ?250.50 Grounding Electrode System All grounding electrodes as described in 250.52(A)(1) through (A)(6) that are present at each building or structure served shall be bonded together to form the grounding electrode system.? ?250.52(A)(1) Metal Underground Water Pipe? (10 feet or more metal in earth) Using underground metal water pipe as a grounding electrode is REQUIRED. And this has been a requirement for a very long time. Local codes may be different from the NEC, but it is unlikely they are different on this. And if you just "bond" metal water pipe it will work as a grounding electrode anyway. -- bud-- True enough but there is a difference, grounding is connecting to earth bonding is tying conductive structures together so they are at equal potential. Ground is a single point that everything else is bonded. Ground should be a stucture that the qualified electrician should be familar with not plumbing that may or may not be intact. If you dont believe me just try to get an electrical inspection on a new home without a ground rod installed. BTW the NEC is a minimum standard not a guide on how to wire your house.or perform grounding and bonding. You wouldnt believe what electricians dont know, like checking phase rotation before turning on a new 200KW UPS. or megging out lines before turning on new parking lot lights or making sure a generator is not backfeeding a line before working on it. All things I have seen electricans screw up in the past year. Jimmie Jimmie I can assure you I don't do that sort of careless nonsense. I can also assure you that whenever I'm involved before the foundation is poured or at least prior to it being back filled there will be no driven rods on that job. They are the single least effective electrode you can install. When I have to install driven rods, such as for a heavy up, I will stack them using rod couplers until I'm under twenty five ohms and perform a witnessed test for the inspector. I consider eight foot driven rods a complete waste of time. Mind you I'll install them when I'm forced to but you will usually find mine driven through the bottom of a three foot deep trench on at least twenty feet of bare copper number two AWG grounding electrode conductor. As for the US NEC being a minimum standard that is not always true. In at least ten states it is both the minimum and the maximum standard that a public electrical inspector may apply. So called "min max" states do not allow the local governments to amend the US NEC. Were the US NEC is the minimum standard you have to use underground metal water piping as a grounding electrode whether or not it jibes with your religious beliefs about what constitutes an electrode or not. If you were bonding the plumbing you could do that with a conductor sized for the largest branch circuit supplying an appliance that is attached to the plumbing. When you are using the piping as an electrode you must size the conductor to the size of the service entry conductors. People like W Tom cannot bring themselves to admit that underground metal water piping is an effective grounding electrode and worse still that it more effective then most of the other electrodes listed in the US NEC at least in homes. I always check the impedance of my grounding electrodes and that's what the measurements say to me. -- Tom Horne The point I am trying to make is that the ground system must be sufficent on its own and not need to connect to the buildings plumbing to improve the ground. You should never depend on the plumbing especially on residential work because you can not maintain control of modifications to that plumbing system. Good example is my in-laws home, for years the house connected to the well via 1 inch metal pipe and this was also the ground for the house as it was built in 1974. When the new well was drilled plastic pipe was installed to the new well with no groundwire going back to the well casing. A couple of years later a new HVAC system was installed and when there was an accidental short circuit the well pump was fried. This would not have happened if a proper grounding system had been installed at the house instead of relying on the plumbing. Professionals have a responsibility to idiot -proof there work as much as possible but you know how it is, sooner or later someone makes a better idiot. The fact that the water pipes may be effective or even better than the installed ground really have nothing to do with anything. Ground sytems are for grounding, Plumbing is for water. Electrians dont do plumbing and plumbers dont rewire homes. Jimmie And my point is that your opinion does not jibe with the National Electric Code. -- Tom Horne Please Tom, tell me in what way that the grounding system should be sufficent on its own and not having to rely on the plumbing to provide grounding for an electrical system in violation of the NEC. Also please tell me how you intend to prevent the scenario I discribed where the ground system was completely disconnected from the home when the well's metal plumbing was replaced with plastic. The Code is the min and max that an inspector can apply to an inspection This means that the inspector cant find fault with using plumbing for grounding if this is what the code says, it doesnt mean that the inspector can find fault if it is built better than code requirements, so again I say the code is written to a minimum spec. Your own definition of min max confirms this. Traditionally the NEC has the lowest minimum standard and the state and local codes usually have a higher standard., there may be some exceptions to this. I will will stipulate that using plumbing for ground may be "to code" in some places but it still is not a good way to ground your house and definately should not be used for a lightning ground. Jimmie I've seen this thread go back & forth. Back when my voice hadn't yet changed, my folks bought a small piece of land for weekend travel-trailer camping. At the time, there was power available but no water. We wanted AC power for the otherwise self-contained trailer, and followed the requirements set down by the county PUD. We installed a utility pole, with service entrance, weatherproof breaker panel, and weatherproof outlet. All we had available for grounding was an 8' rod driven into the ground next to the pole. There was NO water pipe with which to connect the ground wire. Fast forward to recent years (my voice has long-since changed, but now what graying hair I have left is falling out). When I decided to re-pour the concrete slab for my kitchen porch next to my service entrance, I found what was left of a 4' x 3/8" ground rod embedded in the old concrete (the entire #14 wire connected to it had also been embedded in the concrete.) There's no evidence of a connection to the water system. I replaced the rod with an 8" x 1/2" unit from the home improvement box store, and connected it to the service entrance with a #4 wire. Thankfully, when the utility pole that serves my house continued to lean away from my house (and the neutral opened), the ground rod kept L1 & L2 from swinging too wildly. There's a transformer on the pole that serves my house, with a ground rod next to the pole. I guesstimated the ground resistance at about 1 or 2 ohms. Of course, when they repaired their drop wire, the PUD had to inspect my service entrance to make sure it met the minimum requirement. The entire pole & guying has since been changed. Still, I keep an eye on the slack in the drop wire to my house! An interesting observation about ground rods... a 4'x3/8" rod = 56.55 sq. in surface area, while a 8'x1/2" rod = 150.80 sq. in surface area. Of course, more metal in the ground could only be better. Does anyone have a nice BIG copper kettle for sale? ;^) Bryan WA7PRC |
Acceptable Lightning Ground?
Jimmy D wrote:
"That is not how it wastes away." No. It would be the steel pipe which wastes away when coupled with copper. An insulated coupling may slow the process but the copper is not electrolytically eaten away. Best regards, Richard Harrison, KB5WZI |
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