In article ,

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.



Actually, the NEC is very jumbled about exactly how this is supposed to

be setup. Mast Electrical Inspectors, and MANY Electrical Engineers,

still do NOT understand this area of the NEC as Published and Amended,

and it still isn't well understood, even with all the changes and

enhancements over then last TWO Decades. There are TWO basic Definitions

that MUST be understood BEFORE one can effectively communicate, about

the Neutral/Ground Bonding, REQUIREMENTS of the NEC.



1. Separately Derived Power Source

2. Portable Power Source



Once those are understood, then one can have a conversation about how

each can be connected to a Grid Tied Electrical Distribution System,

using a NEC REQUIRED and Approved Power Transfer System.



This section of the NEC is a relatively late addition to the Code, and

mostly was ignored before the Y2K Upgrades for Backup Power Systems. Now

with the number of Backup Power systems installations growing

exponentially, it is getting some PLAY, in the Inspection, and

Engineering, ends of the electrical world. there are some really good

explanations published over in the Generator and Motor Forums on

www.smokstak.com, as well as a good bunch of Resident SmartGuys, that

have MAN-Years of Professional Experience, in the Backup Power

Generation field. Just say'en.... This is NOT for the uninitiated, as

even many of those folks that should know and understand this stuff,

clearly do NOT.... YMMV....



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