Hi,
Is connecting the gec to building steel on a commercial job accpetable versus cold water bond?

it seems to me that you need both but parallel paths could be an issue.

i am looking at a riser diagram that calls for 3 3/4"X8' ground rods placed 10 feet apart and instructions to connect to building steel where possible..

it seems to me that you need a building steel connection and you need a cold water bond..200A service requires a #6 AWG GEC to a made electrode..and a #4 AWG GEC to cold water..correct?

thanks

mustang

thanks for any replies.

You must use all available electrodes. See 250.50

As far as the sizing goes, yes, you are correct.

250-50 says if available bond every thing together. sizes look good. #4 also to the steel.
Ryan you beat me

[This message has been edited by trekkie76 (edited 10-12-2004).]

so you are saying that there SHOULD be a cold water bond IF AVAILABLE?

i am asking because i am working from a set of plans that just ask to bond to three 3/4 X 8' ground rods and to the building steel. the building has copper piping installed. i always bond the copper at the point of entry into the building or first accessible loc

should i make a revision on the dwgs and call for a COLD WATER BOND using a #4 AWG? and should I revise the dwgs to call for a #4 AWG to the ground rods and the building steel? I though #6 was good for MADE ELECTRODES?

sorry if this is elementary to you...grounding is the most important part of any electrical system and it is one of the FUZZIEST too!

i am big on grounding!

thanks

mustang

This may help



The engineer is free to ask for more than code minimums.

The Power company around here asks for 4/0 to 3/4" 10' ground rods at transformer pads.

The NEC would say 6 AWG would be enough.

Bob

Yes, if it is there and meets the description of an electrode, you must bond it with (in your case) a #4.

yes that slide clearly shows the best means to accomplish a proper grounding system

That looks like the same slide on the first page of the NEC handbook

and thanks for the follow up comments regarding the #4

thank you very much!

mustang



[This message has been edited by mustangelectric (edited 10-13-2004).]

are the articles:

GEC:250.66
Bonding Jumper: 250.122

regards

mustang

[This message has been edited by mustangelectric (edited 10-13-2004).]

No, when we're talking about bonding jumpers within the grounding electrode system, they are also sized according to 250.66. (see 250.53(C))

to the made electrodes does only have to be #6. I was talking about to the steel being #4

Can parallel paths be an issue?

If you take a close look at the illustration provided by Bob, you will see that only the GEC is run back to the Service panel. Notice how the rest of the 'connections' are bonded to the GEC, using the different electrodes as connection points.
This helps to reduce if not eliminate the parallel paths.

Those conductors that are bonded to the GEC are not Grounding Electrode Conductors, they are bonding conductors.

Pierre