# 800 amp 8 meter service grounding



## Techy (Mar 4, 2011)

for GEC's - 250.66
for EGC - 250.122


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## ponyboy (Nov 18, 2012)

Full sized ground in each pipe for parallel runs too. Just FYI


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## KGN742003 (Apr 23, 2012)

Might want to check your local utility's greenbook in addition to the NEC.


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## rrolleston (Mar 6, 2012)

KGN742003 said:


> Might want to check your local utility's greenbook in addition to the NEC.


Yeah since it's a large project I am sending all the plans to the POCO engineer and the inspector before we even start.


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## rrolleston (Mar 6, 2012)

Anyone know if I can use standard 5/8 ground rods or do I have to go to 3/4 rods


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## sbrn33 (Mar 15, 2007)

Or 1/2"


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## Magnettica (Jan 23, 2007)

250.24 Grounding Service-Supplied Alternating-Current Systems
250.28 Main Bonding Jumper and System Bonding Jumper
250.50 Grounding Electrode System


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## rrolleston (Mar 6, 2012)

Never done a service this large so I am confused with the code. Looks like I need a 2/0 GEC and 1/0 water bond. Service equipment will be three separate pieces but they actually bolt together and the bus makes contact to have basically one unit.


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## HackWork (Oct 2, 2009)

rrolleston said:


> Going to be an 800 amp disconnect before the meters and two 4 gang meter stacks. 7 100 amp breakers and 1 200 amp breaker.


Is it just me, or doesn't an 800A service seem a bit large for 7 apartments with 100A services (and I assume a 200A house panel?)? I'm just curious how that worked out.


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## rrolleston (Mar 6, 2012)

HackWork said:


> Is it just me, or doesn't an 800A service seem a bit large for 7 apartments with 100A services (and I assume a 200A house panel?)? I'm just curious how that worked out.


6 apartments 1 house panel and 1 200 amp pizza shop panel. House panel has a 3 washer 3 dryer laundry and heating is all electric in each unit. Current service is 600 amps. House panel may get an upgrade sometime.


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## Celtic (Nov 19, 2007)

HackWork said:


> Is it just me, or doesn't an 800A service seem a bit large for 7 apartments with 100A services (and I assume a 200A house panel?)? I'm just curious how that worked out.



Load calc brings it down ...check Annex D4(a)

EDIT:
I think I read your post wrong


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## rrolleston (Mar 6, 2012)

Celtic said:


> Load calc brings it down ...check Annex D4(a)
> 
> EDIT:
> I think I read your post wrong


If they did not have the pizza shop and a possible need to upgrade the house panel to 200 amps due to upgrades. Along with an all electric heat building. I would keep it at 600 but whole system is aging and I would like to replace the service planning for the possible upgrades.


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## rrolleston (Mar 6, 2012)

Am I correct that I need a 2/0 to my ground rods and a 1/0 bond to the water main or am I missing something?


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## ponyboy (Nov 18, 2012)

rrolleston said:


> Am I correct that I need a 2/0 to my ground rods and a 1/0 bond to the water main or am I missing something?


Never more than a 6 to ground rods I think


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## bkmichael65 (Mar 25, 2013)

No larger than 6cu to ground rod. Water bond would be from 250.66 from size of service conductors. Are you paralleling 500mcm? If so, then 2/0 would be the right size


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## rrolleston (Mar 6, 2012)

ponyboy said:


> Never more than a 6 to ground rods I think


I was wondering if I could just do that since it will just be grounding a few individual services only rule I have to worry about is POCO requires at least #4 for grounding.


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## Pete m. (Nov 19, 2011)

rrolleston said:


> Am I correct that I need a 2/0 to my ground rods and a 1/0 bond to the water main or am I missing something?


You do not need anything larger than 6 awg copper to the ground rods (per the NEC).

To answer the question of the size of the grounding electrode conductor to the water you will have to provide the size of your service entrance conductors.

Depending on your calculated load you could parallel 500 copper or 700 aluminum for an 800 amp service disconnect.

If you use either of the sizes I posted 2/0 copper or 4/0 aluminum would be the minimum to the water.

Pete


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## rrolleston (Mar 6, 2012)

bkmichael65 said:


> No larger than 6cu to ground rod. Water bond would be from 250.66 from size of service conductors. Are you paralleling 500mcm?


Paralleling 750mcm Al


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## bkmichael65 (Mar 25, 2013)

rrolleston said:


> Paralleling 750mcm Al


2/0 cu or 4/0 al for water bond


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## rrolleston (Mar 6, 2012)

bkmichael65 said:


> 2/0 cu or 4/0 al for water bond



Thank you everyone.

My brain is fried trying to do so much I can't always interpret the code properly when thinking clearly let alone on overload.


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## rrolleston (Mar 6, 2012)

I will just use some scrap 4/0 that will be a good way to get rid of some of my scrap.


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## Pete m. (Nov 19, 2011)

rrolleston said:


> I will just use some scrap 4/0 that will be a good way to get rid of some of my scrap.


Just for fun... let us know if the POCO and inspector you sent the plans to agree with us.

Pete


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