Table 250.66

Status
Not open for further replies.
Re: Table 250.66

Brian, there is more than capacitive grounding to consider.

Is this a viable or practical system? This has not been mentioned here.

We are talking about definitions and grounding methods.

I brought up isolation only for making a point for definition of SDS.

As far as backing a true iso system, we have AFCI and GFCI technology, so why not refine monitoring and guarding of an iso system? This would be the best system possible, wouldn't you think?

Roger

[ May 22, 2003, 09:27 PM: Message edited by: roger ]
 
Re: Table 250.66

Brian: Everyone in the industry, except Roger and myself, believe that applying the grounding procedures of 250.30 to a transformer, does not create multi-point grounding.

The premises wiring should be grounded single point, or within the window of a ground grid.

A transformer, on the premises, should be grounded to the service electrode. Not to building steel, or piping, that is not in the ground window.

This is from accepted engineering data from Federal Standards and Specs. not off the top of my head.

Edited for technical correctness.

[ May 23, 2003, 11:25 PM: Message edited by: bennie ]
 
Re: Table 250.66

Ist Roger Yes impedance grounding systems would be best, for limiting faults. BUT where is the neutral? Can't you see from the variety of questions and answers posted in various sites there are few that understand the installation of grounding as we have it now this would be multiplied undr your systems. Several times I have been to sites where electricians have attempted to ground impedance grounded systems.

The systems as required by the NEC are functional and operational.

AS for Bennie's statement that he and you are the only ones that truly understand "GROUNDING" well, I'll let that one rest.

I’m going to test a separately derived system with a four-pole transfer switch and ground fault protection. G-night
 
Re: Table 250.66

Everyone in the industry, except Roger and myself, believe that applying the grounding procedures of 250.30 to a transformer, creates multi-point grounding.

ANd this is because you are missing the boat...SO TO SAY. If properly installed there is no problem. It's when electricians mess up one has problems and this hold true for everything in life.
 
Re: Table 250.66

Bennie, this is eerie,
this is because you are missing the boat
Click to expand...
:D :D :D

Remember this one from a boat specialist


posted April 20, 2002 01:22 AM
--------------------------------------------------------------------------------
Ok Bennie,
Go ahead and laugh at the NEC and claim to have so many real alternatives but then never really offer any. Roger, it seems that you too wil probably spend the rest of your life following the NEC. There are dozens of good books to read on the subject and many hundreds of thousands of articles of reference to turn to. I only regret that I did not turn to them first. Thanks for nothing


--------------------------------------------------------------------------------

Did you notice the reference to books too? Wooooooo!!! :cool:

Roger
 
Re: Table 250.66

Brian: I am not laughing at the NEC. I present controversey on many topics to generate interest.

When I worked for the National Science Foundation, I wrote more technical manuals than many have read. I am still learning because of my interest.

I am trying to pass on some of my 53 years of experience. Some appreciate the fact.

Attacking my opinions is acceptable, attacking my credibility is not acceptable.
 
Re: Table 250.66

Bennie:

You have made a statement that I asked you to substantiate, I did not see a response to my request. I feel your beating a dead horse or at best playing with words, with the SDS argument. If you care to please give me some reasons why the term SDS bothers you and give some viable alternatives.
 
Re: Table 250.66

Brian: My problem is use of the term "Separately derived system" to describe a transformer.

250.30 gives the procedure for grounding a separately derived system, not a transformer.

By grounding a transformer as described for a separately derived system, creates multi-point grounding.

The definition of a separately derived system is that it is "a premises wiring system", not part of a wiring system for a premises.

The words premises wiring system is inclusive of all the wiring at a premises. Read the definition of "Premises wiring" in article 100.
 
Status
Not open for further replies.
Top