modelman wrote:
Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM
broadcast reception throughout my house. I also see snow on a TV
connected to an external antenna.

The radio noise occurs as soon as the draft inducer motor starts up;
the pitch of the interference is related to the motor speed. The draft
inducer motor is a dc motor driven by a PWM controller on the main
circuit board. It is well known that PWM systems generate strong
harmonics throughout the radio spectrum, resulting in radio
interference. However, properly designed PWM systems include filtering
and shielding to suppress the radio frequency currents from the wiring.

I contacted my installer, who is totally unfamiliar with the problem.
The electrician who was sent to my house to investigate the problem
also doesn't understand what's going on. I had to explain the
difference between an RF ground and dc or house ground to him.
Although everything appears to be well grounded from a dc perspective,
I suspect that portions of the system are radiating RF energy.

Several days ago I emailed Trane about the problem, but haven't
received any response.

Although there has been past discussion in this group about radio/TV
interference emanating from Trane high efficiency gas furnaces, I
haven't seen any definitive fix. Does anyone know if Trane has a fix
for this problem. Do they have a shielded cable and or rf filter kit
to suppress this noise? Since my system is under warranty, I won't
attempt any modiifcations to the system.

Has anyone experienced this problem?

Thanks.


Trane should be made to fix this and recall all the units that have
been installed. I can pick this interference up on a 2 meter receiver
in my car for blocks. The FCC should bust them if they don't fix it...

I cross posted this to some of the amateur radio groups.

Mark

Good point! There are FCC rules regarding interference / EMI and Trane may
have flagrantly ignored them. Maybe a threatening letter to the Customer
Service Department written with the help of those of us who are amateur
radio / electrical engineering types would force them to finally do the
right thing.


Smarty


"Mark" wrote in message
oups.com...
modelman wrote:
Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM
broadcast reception throughout my house. I also see snow on a TV
connected to an external antenna.

The radio noise occurs as soon as the draft inducer motor starts up;
the pitch of the interference is related to the motor speed. The draft
inducer motor is a dc motor driven by a PWM controller on the main
circuit board. It is well known that PWM systems generate strong
harmonics throughout the radio spectrum, resulting in radio
interference. However, properly designed PWM systems include filtering
and shielding to suppress the radio frequency currents from the wiring.

I contacted my installer, who is totally unfamiliar with the problem.
The electrician who was sent to my house to investigate the problem
also doesn't understand what's going on. I had to explain the
difference between an RF ground and dc or house ground to him.
Although everything appears to be well grounded from a dc perspective,
I suspect that portions of the system are radiating RF energy.

Several days ago I emailed Trane about the problem, but haven't
received any response.

Although there has been past discussion in this group about radio/TV
interference emanating from Trane high efficiency gas furnaces, I
haven't seen any definitive fix. Does anyone know if Trane has a fix
for this problem. Do they have a shielded cable and or rf filter kit
to suppress this noise? Since my system is under warranty, I won't
attempt any modiifcations to the system.

Has anyone experienced this problem?

Thanks.


Trane should be made to fix this and recall all the units that have
been installed. I can pick this interference up on a 2 meter receiver
in my car for blocks. The FCC should bust them if they don't fix it...

I cross posted this to some of the amateur radio groups.

Mark

Smarty wrote:
Good point! There are FCC rules regarding interference / EMI and Trane may
have flagrantly ignored them. Maybe a threatening letter to the Customer
Service Department written with the help of those of us who are amateur
radio / electrical engineering types would force them to finally do the
right thing.


Smarty


"Mark" wrote in message
oups.com...
modelman wrote:
Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM
broadcast reception throughout my house. I also see snow on a TV
connected to an external antenna.

The radio noise occurs as soon as the draft inducer motor starts up;
the pitch of the interference is related to the motor speed. The draft
inducer motor is a dc motor driven by a PWM controller on the main
circuit board. It is well known that PWM systems generate strong
harmonics throughout the radio spectrum, resulting in radio
interference. However, properly designed PWM systems include filtering
and shielding to suppress the radio frequency currents from the wiring.

I contacted my installer, who is totally unfamiliar with the problem.
The electrician who was sent to my house to investigate the problem
also doesn't understand what's going on. I had to explain the
difference between an RF ground and dc or house ground to him.
Although everything appears to be well grounded from a dc perspective,
I suspect that portions of the system are radiating RF energy.

Several days ago I emailed Trane about the problem, but haven't
received any response.

Although there has been past discussion in this group about radio/TV
interference emanating from Trane high efficiency gas furnaces, I
haven't seen any definitive fix. Does anyone know if Trane has a fix
for this problem. Do they have a shielded cable and or rf filter kit
to suppress this noise? Since my system is under warranty, I won't
attempt any modiifcations to the system.

Has anyone experienced this problem?

Thanks.

Trane should be made to fix this and recall all the units that have
been installed. I can pick this interference up on a 2 meter receiver
in my car for blocks. The FCC should bust them if they don't fix it...

I cross posted this to some of the amateur radio groups.

Mark




First, I would get a schematic of the electronics/wiring/specs/and
installation instructions for the specific model (web is a good place
maybe.) More of a chance the installer has made an error in the
installation, grounding, shielding, etc., could save you from the
possibility of "crying wolf" too soon... I suspect the engineers of
using more caution in the design of the unit, then the installers in the
installation of the unit.

JS

Nice thought, but I went a bit down that road--I'm fuzzy about the specific
details but for one reason or another the people that I spoke to didn't give
me anything positive. Something about the generation of RF interference not
applying to a product like a furnace. Since this has been a problem for so
long and Trane has not been mandated to fix it lends some weight to what I
was told. I did tell the Trane Rep that I was going to contact someone in
higher management (VP etc) and issue a complaint at that level----didn't
phase him. Then I put in my cable line and didn't follow up. For those of
you still aggravated by the RF noise why not try this route? I guess that
if you go the way of the Small Claims Court you probably have to sue the
installer as well as Trane and it would have to be for a complete
replacement (one without the problem)or a removal and money refunded.
MLD
"Smarty" wrote in message
...
Good point! There are FCC rules regarding interference / EMI and Trane may
have flagrantly ignored them. Maybe a threatening letter to the Customer
Service Department written with the help of those of us who are amateur
radio / electrical engineering types would force them to finally do the
right thing.


Smarty


"Mark" wrote in message
oups.com...
modelman wrote:
Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM
broadcast reception throughout my house. I also see snow on a TV
connected to an external antenna.

The radio noise occurs as soon as the draft inducer motor starts up;
the pitch of the interference is related to the motor speed. The draft
inducer motor is a dc motor driven by a PWM controller on the main
circuit board. It is well known that PWM systems generate strong
harmonics throughout the radio spectrum, resulting in radio
interference. However, properly designed PWM systems include filtering
and shielding to suppress the radio frequency currents from the wiring.

I contacted my installer, who is totally unfamiliar with the problem.
The electrician who was sent to my house to investigate the problem
also doesn't understand what's going on. I had to explain the
difference between an RF ground and dc or house ground to him.
Although everything appears to be well grounded from a dc perspective,
I suspect that portions of the system are radiating RF energy.

Several days ago I emailed Trane about the problem, but haven't
received any response.

Although there has been past discussion in this group about radio/TV
interference emanating from Trane high efficiency gas furnaces, I
haven't seen any definitive fix. Does anyone know if Trane has a fix
for this problem. Do they have a shielded cable and or rf filter kit
to suppress this noise? Since my system is under warranty, I won't
attempt any modiifcations to the system.

Has anyone experienced this problem?

Thanks.


Trane should be made to fix this and recall all the units that have
been installed. I can pick this interference up on a 2 meter receiver
in my car for blocks. The FCC should bust them if they don't fix it...

I cross posted this to some of the amateur radio groups.

Mark

MLD wrote:
Nice thought, but I went a bit down that road--I'm fuzzy about the specific
details but for one reason or another the people that I spoke to didn't give
me anything positive. Something about the generation of RF interference not
applying to a product like a furnace.

Anything that generates RF inside the USA is regulated by the FCC. If your
cat's butt emits RF in the USA it's regulated by the FCC.

--
"A man's country is not a certain area of land, of mountains, rivers, and
woods, but it is a principle; and patriotism is loyalty to that principle."
-- George William Curtis

"clifto" wrote in message
...
MLD wrote:
Nice thought, but I went a bit down that road--I'm fuzzy about the
specific
details but for one reason or another the people that I spoke to didn't
give
me anything positive. Something about the generation of RF interference
not
applying to a product like a furnace.

Anything that generates RF inside the USA is regulated by the FCC. If your
cat's butt emits RF in the USA it's regulated by the FCC.

Wrong. If the cat's butt emits RF, it's regulated by the FCC. But, digital
equipment used only in transportation vehicles - busses, cars, aircraft -
and equipment used in appliances - HVAC equipment mentioned specifically -
are exempt from Radio Frequency Device regulations. The rule says "....are
exempt from the specific technical standards and other requirements
contained in this part. The operator of the exempted device shall be
required to stop operating the device upon a finding by the Commission or
its representative that the device is causing harmful interference".

As to harmful interference, just because the noise floor rises 20db for 5
seconds on a 50 kHz segment of 20 meters when a bus passes your house, it
isn't going to be considered harmful interference. As much as you might like
to think that it is, a detectable signal from your neighbors Air Conditioner
isn't going to be considered "harmful interference". A carrier that
obliterates a specific, used - as in "there's a repeater 3 miles away
running 200 watts on 444.600, and the carrier from the Carrier (or Trane)
nukes it" - frequency might result in a letter. Just " 'cause you can hear
it" ain't gonna cut it.




47CFR15.103

Mo Hoaner wrote:
"clifto" wrote...
Anything that generates RF inside the USA is regulated by the FCC. If your
cat's butt emits RF in the USA it's regulated by the FCC.

Wrong. If the cat's butt emits RF, it's regulated by the FCC. But, digital
equipment used only in transportation vehicles - busses, cars, aircraft -
and equipment used in appliances - HVAC equipment mentioned specifically -
are exempt from Radio Frequency Device regulations. The rule says "....are
exempt from the specific technical standards and other requirements
contained in this part. The operator of the exempted device shall be
required to stop operating the device upon a finding by the Commission or
its representative that the device is causing harmful interference".

Interesting. I've never heard that before. Thanks for the correction.

Not that that doesn't suck...

--
"A man's country is not a certain area of land, of mountains, rivers, and
woods, but it is a principle; and patriotism is loyalty to that principle."
-- George William Curtis

Yes, the FCC not only has cognizance, but quite legitimately does not want
to see products throwing a lot of EMI out which cause you and perhaps your
neighbors to have reception issues. If I were at Trane handling Customer
Service and was threatened with FCC action, I would react.

Smarty


"clifto" wrote in message
...
MLD wrote:
Nice thought, but I went a bit down that road--I'm fuzzy about the
specific
details but for one reason or another the people that I spoke to didn't
give
me anything positive. Something about the generation of RF interference
not
applying to a product like a furnace.

Anything that generates RF inside the USA is regulated by the FCC. If your
cat's butt emits RF in the USA it's regulated by the FCC.

--
"A man's country is not a certain area of land, of mountains, rivers, and
woods, but it is a principle; and patriotism is loyalty to that
principle."
-- George William Curtis

Mark,

I had a severe interference MF to HF from a neighbours gas heater unit. Not
sure what it was that was causing it but it was being effectively radiated
by the external cables, power and control. I traced the interference to the
unit using a portable rx. I silenced it by wrapping both cables tightly
around a 6 inch ferrite rod. The cables held in place by cable ties and
tape. Hope this helps.

73 Alan VK6BN


"Mark" wrote in message
oups.com...
modelman wrote:
Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM
broadcast reception throughout my house. I also see snow on a TV
connected to an external antenna.

The radio noise occurs as soon as the draft inducer motor starts up;
the pitch of the interference is related to the motor speed. The draft
inducer motor is a dc motor driven by a PWM controller on the main
circuit board. It is well known that PWM systems generate strong
harmonics throughout the radio spectrum, resulting in radio
interference. However, properly designed PWM systems include filtering
and shielding to suppress the radio frequency currents from the wiring.

I contacted my installer, who is totally unfamiliar with the problem.
The electrician who was sent to my house to investigate the problem
also doesn't understand what's going on. I had to explain the
difference between an RF ground and dc or house ground to him.
Although everything appears to be well grounded from a dc perspective,
I suspect that portions of the system are radiating RF energy.

Several days ago I emailed Trane about the problem, but haven't
received any response.

Although there has been past discussion in this group about radio/TV
interference emanating from Trane high efficiency gas furnaces, I
haven't seen any definitive fix. Does anyone know if Trane has a fix
for this problem. Do they have a shielded cable and or rf filter kit
to suppress this noise? Since my system is under warranty, I won't
attempt any modiifcations to the system.

Has anyone experienced this problem?

Thanks.


Trane should be made to fix this and recall all the units that have
been installed. I can pick this interference up on a 2 meter receiver
in my car for blocks. The FCC should bust them if they don't fix it...

I cross posted this to some of the amateur radio groups.

Mark

Mark wrote:
modelman wrote:

Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM
broadcast reception throughout my house. I also see snow on a TV
connected to an external antenna.

The radio noise occurs as soon as the draft inducer motor starts up;
the pitch of the interference is related to the motor speed. The draft
inducer motor is a dc motor driven by a PWM controller on the main
circuit board. ... SNIPPED ...

DC motors are notorious noise generators. Those of us who used to be mobile when
6 VDC was the value of a car battery, and alternators did not exist, will attest
to the facts of generator [DC motor] noise.

A DC motor uses brushes to contact windings within the motor. As the motor turns
the brushes continually make and break current in the rotating armature
[inductance]. This making and breaking creates a very wide HF and lower VHF
noise spectrum. [Lots of sparks].

The solution, in the olden days, was a coaxial capacitor mounted directly to the
frame of the motor with the DC power running through the capacitor. I recall the
capacitor was about 1 inch in diameter and 2 inches long. Sprague made such a
critter.

Hope this history helps.

/s/ DD, W1MCE