Unusual Grounding Issue!

[stuartdmc]

Here?s my scenario, we are wiring a 12,000 square foot home in Laguna Beach, CA that over hangs the cliff onto the beach we have a 400a 3ph meter / main breaker disconnect switch located at the street. At the street where the main switch is, we have provided a concrete encasement electrode and connected it to the neutral bus, bonding the enclosure etc. In the main house approx. 120ft away we have a 400a main distribution board (w/a main) where we have again a concrete encasement electrode and a cold water electrode conductor with in 5ft. from it entering the house. We are going to pull a full size grounded conductor from the main at the street to the main in the house, I think being that we have no coldwater at the street to bond to the neutral must establish in the main electrode system at the house and not at the street. Am I correct?
The inspector showed up and told the supper on the job that we can not have two (ufer grounds) concrete encasement electrode and that we need to isolate the neutral at in the house, does this make since?
Please advisee
Thanks.

Stu.

 

[electricalperson]

Here’s my scenario, we are wiring a 12,000 square foot home in Laguna Beach, CA that over hangs the cliff onto the beach we have a 400a 3ph meter / main breaker disconnect switch located at the street. At the street where the main switch is, we have provided a concrete encasement electrode and connected it to the neutral bus, bonding the enclosure etc. In the main house approx. 120ft away we have a 400a main distribution board (w/a main) where we have again a concrete encasement electrode and a cold water electrode conductor with in 5ft. from it entering the house. We are going to pull a full size grounded conductor from the main at the street to the main in the house, I think being that we have no coldwater at the street to bond to the neutral must establish in the main electrode system at the house and not at the street. Am I correct?
The inspector showed up and told the supper on the job that we can not have two (ufer grounds) concrete encasement electrode and that we need to isolate the neutral at in the house, does this make since?
Please advisee
Thanks.

Stu.

why not eliminate the CCE at the street and just use the ones at the house

thats what i would do. read 250.24

does the meter disco act as the service disco for the house?

 

[stuartdmc]

OK, But want I need some sort of electrode grounding system at the street, like a rod or something?

 

[Dennis Alwon]

Here’s my scenario, we are wiring a 12,000 square foot home in Laguna Beach, CA that over hangs the cliff onto the beach we have a 400a 3ph meter / main breaker disconnect switch located at the street. At the street where the main switch is, we have provided a concrete encasement electrode and connected it to the neutral bus, bonding the enclosure etc. In the main house approx. 120ft away we have a 400a main distribution board (w/a main) where we have again a concrete encasement electrode and a cold water electrode conductor with in 5ft. from it entering the house. We are going to pull a full size grounded conductor from the main at the street to the main in the house, I think being that we have no coldwater at the street to bond to the neutral must establish in the main electrode system at the house and not at the street. Am I correct?
The inspector showed up and told the supper on the job that we can not have two (ufer grounds) concrete encasement electrode and that we need to isolate the neutral at in the house, does this make since?
Please advisee
Thanks.

Stu.

If the building is 120 feet away you must have 2 electrodes. The CEE is a great electrode to use. I am assuming 2008 code-- and yes you must isolate the neutral and EGC run from the main at the street. The ufer would connect to the ground bar. Neutral bar must be isolated. Art 250.32(B)

 

[BryanMD]

OK, But want I need some sort of electrode grounding system at the street, like a rod or something?

wouldn't that be on PGE to engineer?
what are their protocols...

 

[electricalperson]

read 250.32 as well

i believe you need to make that panel in the house a sub panel and bond the waterpipe and the ufer ground to the EGC

 

[electricalperson]

If the building is 120 feet away you must have 2 electrodes. The CEE is a great electrode to use. I am assuming 2008 code-- and yes you must isolate the neutral and EGC run from the main at the street. The ufer would connect to the ground bar. Neutral bar must be isolated. Art 250.32(B)

you beat me too it!! i was reading the code as you posted that

 

[stuartdmc]

wouldn't that be on PGE to engineer?
what are their protocols...

The service provider is SCE and they do require that their service's be grounded.

 

[electricalperson]

The service provider is SCE and they do require that their service's be grounded.

well if they require the GEC at the meter socket/service disconnect you need to run a 5th wire back to your house and change it to a subpanel.

 

[Rick Christopherson]

You can have as many electrodes as you want, as long as they form a unified grounding system. You didn't say in your posting, but I get the impression you may not have carried the grounding conductor from the main back to the house. This would create two separate grounding systems. To the best of my knowledge, unless someone more familiar with this aspect of code chimes in, you need to bring a 5-wire (for 3-phase) from the street disconnect to the house.

 

[electricalperson]

adding that EGC could be an issue too. pulling out 120 of wire out then pulling it back in, removing all those ground wires and putting them onto a seperate ground bar could cost a lot of money but thats what he needs to do

 

[stuartdmc]

well if they require the GEC at the meter socket/service disconnect you need to run a 5th wire back to your house and change it to a subpanel.

Very well,
then what should I do with the coldwater ground at the house? Isn?t that part of my main electrode system? It is available! And as I read it, if it?s there it should be used and not considered a supplemental ground just to bond to.

 

[electricalperson]

Very well,
then what should I do with the coldwater ground at the house? Isn?t that part of my main electrode system? It is available! And as I read it, if it?s there it should be used and not considered a supplemental ground just to bond to.

attach it to the ECG bar in the panel. your just bonding it after all

 

[augie47]

Perhaps I'm missing something (I'm sure it will be pointed out) but, to me, it depends on what year Code he is under. <'08 he would be fine, 08, he would need to at the EGC and seperate the neutral/grounds-bond.

 

[Smart $]

Perhaps I'm missing something (I'm sure it will be pointed out) but, to me, it depends on what year Code he is under. <'08 he would be fine, 08, he would need to at the EGC and seperate the neutral/grounds-bond.

I agree. 2005 and earlier, the 5th wire (EGC) is not required, and without it, GES at house gets bonded to Neutral. However, the 2005 NEC does not prohibit running a 5th wire (EGC). If run then GES at house needs to be isolated from Neutral.