# Grounding a 400 amp service with two 200s



## rgsgww (Jul 5, 2008)

I currently have a 400 amp service with two 200 amp service panels, the ground is a water pipe connected with what looks like 4 awg stranded. There is one rod with 6 awg solid.

If I were to update the grounding system, wouldn't I need to sink rods for each panel?
*Looks like I can install two rods and "tap" to both enclosures-250.62 (D)

Whats the code reference to gas bonding-Never mind, I have it 250.104 (B)

I don't think I will bother the system anyways as there is almost no space outside to sink rods. Just curious what I would do.

What size for the gas bond? It says to size it according to the circuit that is possible to energize it. So since furnaces are hooked up to it and are 15, I would use 14? It would make sense to size it to 12 since 20 amp circuit for the furnace might be installed in the future.

What about flexible gas tubing. Do I have to bond at each connection point or is a bonding the iron gas pipe enough?


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## Bob Mariani (Dec 1, 2008)

Bonding the iron gas pipe is all you need to do.
Service bond goes to the main disconnect, not each panel. From the main disconnect the neutral and grounding conductor are separated. So grounds in each panel tie back to the main grounding conductor in the main disconnection means.


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## Speedy Petey (Feb 1, 2004)

Bonding the gas line is done by the circuit ground to the appliances the gas feeds. Typically no additional bond is needed.
Flexible gas tubing is another story, typically they have their own codes for bonding. Mike Holt has some good info on this.

Bob, if you read the OP again you'll see he says service panels. I read this as two main-breaker panels. ALL bonding and grounding are done here. 

I usually run separate bonds and GECs from both panels. Basically treat it two 200A services.


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## Bob Mariani (Dec 1, 2008)

no way to run a 400 AMP service and not split it into two 200 amp panels unless some sort of main disconnect is used. This is where the grounding is done, not the two panels


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## Speedy Petey (Feb 1, 2004)

Bob Mariani said:


> no way to run a 400 AMP service and not split it into two 200 amp panels unless some sort of main disconnect is used. This is where the grounding is done, not the two panels


Bob, seriously? :huh:

Maybe your local codes prohibit this but it is a VERY common installation everywhere else. 
A 320/400A meter pan with dual lugs on the load side, to two 200A main-breaker panels fed in parallel. In fact you can have up to SIX main breaker panels before a main disconnect is needed.

Just a question and nothing else; are you an electrical contractor or a GC/builder?


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## wirenut1110 (Apr 26, 2008)

It most certainly can be done. They need to be grouped together, but as stated, it can be done as it is done very frequently.


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## rgsgww (Jul 5, 2008)

I will read up on flexible gas tubing, looks like thats the most important thing that needs to be updated.

If I were to sink rods, its kind of tricky. I will post a pic of the location.


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## Stubbie (Jan 7, 2007)

rgsgww said:


> I will read up on flexible gas tubing, looks like thats the most important thing that needs to be updated.
> 
> If I were to sink rods, its kind of tricky. I will post a pic of the location.


You do not have to use rods there are several electrodes that can be substituted. Even rods don't have to be driven vertical if the situation doesn't allow it. Vertical is certainly preferred. A plate electrode is not to uncommon.


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## wirenut1110 (Apr 26, 2008)

Stubbie said:


> You do not have to use rods there are several electrodes that can be substituted.


Ditto. If you're talking about CSST gas line. Just needs to be bonded to the grounding electrode system. 

Just finished a restaurant and the plumber ran about 150' of #6 all the way across the restaurant to the ground rods. I was like "sweeeeet" I cut it right where it came in the building and hooked it to a lug on the building steel. Now I have enough #6 bare copper to do many services:thumbup:


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## Bob Mariani (Dec 1, 2008)

Speedy Petey said:


> Bob, seriously? :huh:
> 
> Maybe your local codes prohibit this but it is a VERY common installation everywhere else.
> A 320/400A meter pan with dual lugs on the load side, to two 200A main-breaker panels fed in parallel. In fact you can have up to SIX main breaker panels before a main disconnect is needed.
> ...


Mostly remolding contractor now. But had an E1 license since 1968. Just always used a can with breakers in the same can for this purpose. In CT the inspector only allows 10' before a main breaker, so why use two separate 200 amp panels would be used in a residential application within these specs.


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## rgsgww (Jul 5, 2008)

Alright, this is what I'm talking about.


http://i428.photobucket.com/albums/qq5/rgsgww/100_5515.jpg


http://i428.photobucket.com/albums/qq5/rgsgww/100_5516.jpg


I suppose I would use the area above the existing rod?
http://i428.photobucket.com/albums/qq5/rgsgww/100_5517.jpg

http://i428.photobucket.com/albums/qq5/rgsgww/100_5518.jpg
Would it be ok to run the 6 awg through this hole that is used for the low voltage conduit?

Looks like my flexible gas tubing was not required to be bonded when it was installed. Would it be a good idea to bond my gas anyways?


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## Speedy Petey (Feb 1, 2004)

Things have changed a bit since '68 Bob.




Bob Mariani said:


> In CT the inspector only allows 10' before a main breaker, so why use two separate 200 amp panels would be used in a residential application within these specs.


Also typical in most areas. Actually most only allow 5-6 feet. 

You've never seen two 200A panels right next to each other?


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## Bob Mariani (Dec 1, 2008)

Speedy Petey said:


> Things have changed a bit since '68 Bob.
> 
> 
> Also typical in most areas. Actually most only allow 5-6 feet.
> ...


Not in a residence. But for electrical I have worked mostly on industrial work. Still seems more useful to have the two panels in different locations for house wiring. Like at my house, I have 400 amp but main breakers at the meter, then a 200 amp panel in the shop and one in the house. But my post only stated that the grounding is done at the main disconnecting means, which as you mentioned could be in both panels or could be as I have it here.


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## Speedy Petey (Feb 1, 2004)

Bob Mariani said:


> But my post only stated that the grounding is done at the main disconnecting means, which as you mentioned could be in both panels or could be as I have it here.


Actually you stated that you *had* to have a main disconnect and that the bonding/grounding could not happen in the two panels.


Bob Mariani said:


> no way to run a 400 AMP service and not split it into two 200 amp panels unless some sort of main disconnect is used. This is where the grounding is done, not the two panels


I just wanted to clear up that that was not the case; residential, industrial or otherwise. :thumbsup:


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## rgsgww (Jul 5, 2008)

What size do you guys bond gas with?


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## wirenut1110 (Apr 26, 2008)

Here we only bond the gas pipe(the black iron prior to the CSST) if CSST used and use #6. As I think Petey stated, if you're just talking about a flex connection to equipment, the EGC in the circuit is adequate.


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## Speedy Petey (Feb 1, 2004)

In all my years I have never externally bonded a gas pipe.
I never needed to. :thumbsup:

If I were to I'd also use a #6.


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## wirenut1110 (Apr 26, 2008)

I just saw this article and may shed some light on why we have to bond the CSST pipe as opposed to other states. It looks like states that are south of Pennsylvania and Md are requiring this because we're more susceptible to lightning strikes. It looks like there's been some lawsuits due to the CSST busting and/or exploding during this. We just started having to do this within the last 6 months or so.

It just missed you Petey...lol

http://www.gastite.com/include/lang.../pdfs/Gastite_LightningSafety_Distributor.pdf


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## rgsgww (Jul 5, 2008)

A very poor drawing...

Blue is CSST Brown is furnace. Shadow is unaccessible. Far right is meter. CSST feeds fireplaces.


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## wirenut1110 (Apr 26, 2008)

Bond at the pipe going into the house before it runs into the house, then tie that anywhere in your grounding electrode *system*. If the pipe is painted, scrape the paint off, bond it and repaint it. You don't want unprotected steel pipe.


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## rgsgww (Jul 5, 2008)

Sounds good, I'll need about 100 feet of 6 awg though


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