Residential 600 Amp Gas & Water Bonding requirement

[Aledrell]

Wiring a custom with single phase service. Exterior SES distribution to 3 separate 200 amp load centers. 1 located next SES on the exterior and the other 2 inside the home. Gas and water enter home on complete opposite side of the house. So here’s my question instinct and experience tell me to run 2/0 copper and loop at the gas to the water.
But sitting in on a commercial plan reveiw the other day guys were talking about bonding requirement being tied to available amps inside the home. So although it’s a 600 amp service, bc it’s broken down into 200 amp sub panels prior to entering the home does this lower the bonding wire requirement?
And why can’t the bond be terminated in a sub-Panel if you oversized the grounding conductor for that panel? Thanks for helping me better understand the code. Much appreciated. And any code thumping trolls, don’t beat me with the book too badly.


Sent from my iPhone using Tapatalk

 

[LarryFine]

Exterior SES distribution to 3 separate 200 amp load centers. 1 located next SES on the exterior and the other 2 inside the home.

The main disconnects are supposed to be grouped, whether inside or outside.

But sitting in on a commercial plan reveiw the other day guys were talking about bonding requirement being tied to available amps inside the home. So although it’s a 600 amp service, bc it’s broken down into 200 amp sub panels prior to entering the home does this lower the bonding wire requirement?

You can use a GEC sized for 200a, as long as you run one for each 200a panel.

And why can’t the bond be terminated in a sub-Panel if you oversized the grounding conductor for that panel?

Because the GEC is supposed to be run to the neutral in (or before) the main disco(s) with either no or irreversible splicing .

 

[Aledrell]

So I can either run #4 looped through each sub panel then bonded to the gas and water, unbroken or irreversibly crimped.....or run a 2/0 bond from the SES to the gas and water?


Sent from my iPhone using Tapatalk

 

[Dennis Alwon]

So I can either run #4 looped through each sub panel then bonded to the gas and water, unbroken or irreversibly crimped.....or run a 2/0 bond from the SES to the gas and water?


Sent from my iPhone using Tapatalk

No you must run 3 individual runs of #4 back to the water. Btw, the gas is usually bonded thru the furnace or any circuit that grounds a piece of equipment with gas

Other Metal Piping. If installed in or attached to a building
or structure, a metal piping system(s), including gas piping,
that is likely to become energized shall be bonded to any of the
following:
(1) Equipment grounding conductor for the circuit that is
likely to energize the piping system
(2) Service equipment enclosure
(3) Grounded conductor at the service
(4) Grounding electrode conductor, if of sufficient size
(5) One or more grounding electrodes used, if the grounding
electrode conductor or bonding jumper to the
grounding electrode is of sufficient size

 

[infinity]

Exterior SES distribution to 3 separate 200 amp load centers. 1 located next SES on the exterior and the other 2 inside the home. Gas and water enter home on complete opposite side of the house. So here’s my question instinct and experience tell me to run 2/0 copper and loop at the gas to the water.

Can elaborate on what this means? Where is the service disconnect(s)?

 

[Aledrell]

Disconnects are 3 fused 200 amp pullouts at the exterior SES. Load centers are MLO but could be made to have MB if needed.


Sent from my iPhone using Tapatalk

 

[augie47]

You can run one GEC from the service point (CT can ?) based on 250.66, or you can run individual GEC from each of your 200 amp pull-outs or you can "tap" from each tom a common GEC as shown.

 

[Aledrell]

So the pull outs are contained in one SES (same cabinet, same ground bar)
I’m a little confused, so we have a #4 ufer and ground rods at SES. I’m trying to see if there’s alternative to running 2/0 copper to the water incoming shut off bc it’s pex that’s what they require in AZ and/or gas which is right next to the water thankfully. So if that’s the requirement for the water running it to the gas is virtually nothing. Sorry I’m not understanding this part of the code has always confused me, meaning the difference between a ground and a bond. If you asked why I run this or that my answered bc that’s what we always do....


Sent from my iPhone using Tapatalk

 

[Aledrell]

Ok so I can either run #4 from each sub-Panel to the water or 2/0 copper from the SES?

And #4 from the subs must be separate runs, no looping or C crimps onto one number 4 trunk line run allowed if I’m understanding this right.


Sent from my iPhone using Tapatalk

 

[infinity]

Ok so I can either run #4 from each sub-Panel to the water or 2/0 copper from the SES?

And #4 from the subs must be separate runs, no looping or C crimps onto one number 4 trunk line run allowed if I’m understanding this right.

No you do not need to run a #4 from the sub-panels to anything. The feeder to the sub-panels will contain an EGC. The GEC(s) land at the service disconnect(s). Since there are three you can run a single larger GEC and tap off to each disconnect as shown in Augie's graphic.

 

[kwired]

So the pull outs are contained in one SES (same cabinet, same ground bar)
I’m a little confused, so we have a #4 ufer and ground rods at SES. I’m trying to see if there’s alternative to running 2/0 copper to the water incoming shut off bc it’s pex that’s what they require in AZ and/or gas which is right next to the water thankfully. So if that’s the requirement for the water running it to the gas is virtually nothing. Sorry I’m not understanding this part of the code has always confused me, meaning the difference between a ground and a bond. If you asked why I run this or that my answered bc that’s what we always do....


Sent from my iPhone using Tapatalk

Is the underground water pipe metallic and at least 10 feet buried in the ground? That is what you are conecting to a "grounding electrode". If you don't have metallic pipe and at least 10 feet of it you have no qualifying electrode there and might not need any grounding line at all to the water pipe.

You may or may not need 2/0 copper as well - what is the size and type of conductor(s) supplying the MDP that has the three 200 amp service disconnects - it certainly does not have to be 600 amp conductor if the load calculation is less.

 

[augie47]

My misunderstanding.. If the 3 pullouts are in one cabinet, 1 neutral bar then you need only 1 GEC,
As kwired notes, if you have metallic undeground then the GEC must run to the point the piping enters the building. If there is metallic interior then you can bond it at any point (local rules may vary). Ifb its 100% PEX. obviouolsy nom water bond needed. In post #4, Denis addessed the gas (again. baring local rules)

 

[LarryFine]

Disconnects are 3 fused 200 amp pullouts at the exterior SES. Load centers are MLO but could be made to have MB if needed.

Then the 3 GECs should each land in one of these fused pullouts, unless you run one appropriately-sized GEC to the enclosure that houses the taps to those pullouts and hit the neutral ahead of the taps.

 

[tom baker]

The main disconnects are supposed to be grouped, whether inside or outside.


You can use a GEC sized for 200a, as long as you run one for each 200a panel.


Because the GEC is supposed to be run to the neutral in (or before) the main disco(s) with either no or irreversible splicing .

The GEC is sized based on the ungrouded service entrance size, not the panel ampacity. For example, this question can't be answered " what size ground for a 200 amp service".
See section 250.66

 

[Aledrell]

The GEC is sized based on the ungrouded service entrance size, not the panel ampacity. For example, this question can't be answered " what size ground for a 200 amp service".
See section 250.66

Thank you for clearing that up for me. I thought it was based upon available amps running inside the home. But it’s available amps running to the home.

Load calcs came in at 570 amps so essentially 600....

Idk if the water service is metal pipe underground between the shutoff and the meter. I’ve seen them use pex for this before. I’m pretty certain the plumber ran 1” rolled copper between the main house and the pool house (50ft) does this qualify GEC at that shut off? Sounds like it may, pool house is a 125amp sub off one of the 200s

So the gas I assume is considered metal throughout despite it not being typical cast iron, they ran a flexible trunk line that wasn’t the typical yellow it was black....


Sent from my iPhone using Tapatalk

 

[Aledrell]

But as far as the gas being bonded by the furnace, stove, or appliance using the gas. Here in AZ we have always been made to bond the gas with #4 on a typical 200 amp service homes. Depending on the municipality/inspector it may or may not be their preference that it be at the meter on the customer side.


Sent from my iPhone using Tapatalk

 

[infinity]

But as far as the gas being bonded by the furnace, stove, or appliance using the gas. Here in AZ we have always been made to bond the gas with #4 on a typical 200 amp service homes. Depending on the municipality/inspector it may or may not be their preference that it be at the meter on the customer side.

Not required by the NEC but certain types of CSST have bonding requirements as part of the national fuel code.

 

[Aledrell]

Here’s a 1 line from a 600 amp service replacement I did a year ago. Shows GEC detail, only difference is this was partially 3 phase delta high leg....


Sent from my iPhone using Tapatalk

 

[tom baker]

Thank you for clearing that up for me. I thought it was based upon available amps running inside the home. But it’s available amps running to the home.

No, size of GEC is based on section 250.66.
Nothing to do with amps.
Consider a 60 amp service fed with 500 kcml due to voltage drop.

 

[Greg1707]

The GEC is sized based on the ungrouded service entrance size, not the panel ampacity. For example, this question can't be answered " what size ground for a 200 amp service".
See section 250.66

Can you expand on this a little?

Suppose I have a small house with gas. The calculated load is no more than 100 amps. I install a 200 amp main/service panel. What size service entrance conductors are required?