On Dec 9, 10:37 pm, John Davis wrote:
On 12/9/2011 1:37 AM, Bill Horne wrote:







On 12/8/2011 5:36 AM, David Ryeburn wrote:
This evening I checked the blog of VK1OD, which is always interesting.
The most recent posting there is "A medium priced generator set from
eBay". Worth reading.
http://www.vk1od.net/hardware/genset/index.htm
Another example of getting what you pay for.

Thanks for the link. One part caught my eye:

"Since this generator will be used with multiple appliances
of Class II, the neutral was bonded to the earth conductor
to allow the effective use of a portable RCD device."

... and I'm curious why that would be necessary. Of course, the author
is using 240 Volt, 50 Hz power, but I thought everyone kept neutral and
ground leads separate.

73,

Bill, W1AC

By code Neutral and Ground are bonded in the main service entrance box.

I have heard folks tell of portable generators where that is supposed to
"Cause Problems" however any portable generator or fixed generator
designed to supply power to a stick-build house.. Has got to be able to
deal with that.. Since many times a Generator transfer switch (Every one
I've seen) leaves neutral and ground bonded, and in fact cross
connected.. Only the "HOT" (L-1, L-2) Leads are switched.

--
Nothing adds Excitement like something that is none of your business.

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If the generator is dedicated to backup service, is located outdoors
or in another building, and the utility supply system is Multi
Grounded Neutral (MGN) then the neutral should be bonded to the fame
and to all of the available grounding electrodes required by the
electrical code in use in that locality in the same way a utility
transformer has the neutral bonded to the case and to ground. On new
installations done in an area that is governed by the National
Electric Code (NEC) here in the USA the connection to the building
should include all of the ungrounded conductors, the neutral
conductor, and an Equipment Grounding Conductor that is sized to the
generators overcurrent protective device ampacity. Additionally the
transfer switch should have a sufficient number of poles to transfer
the Neutral Conductor from the utility connection to the generator
with the connection to the utility side of the switch made on the load
side of the "Main Bonding Jumper." I don't know if Multi Grounded
Neutral electrical distribution is used outside of North America so
use extreme caution before applying these techniques elsewhere in the
world. When a portable generator is being used with a cord and plug
connection to the transfer mechanism's generator terminals than it is
not considered necessary to isolate the frame of the generator from
the neutral conductor. If you leave the generator plugged into such
an arrangement most of the time you would be well advised to set it up
with a bonding switch so that it can be closed when in portable use
and open when in standby use. If it is bonded in standby use then it
is a bond on the neutral of the buildings wiring on the load side of
the "Service Disconnecting Means" that is expressly forbidden by the
NEC.

--
Tom Horne