Generator/Seperate Strucure Grounding

[al]

1. SDS gen set located 50' from seperate structure with utility service at the seperate structure.
2. Gen is 480/277 with gen neutral bonded at gen set. There is a service rated disconnect at the generator.
3. There are no L-N loads and therefore the conduit from the genset to the ATS has 3 ungrounded cond and one EGC cond. The ATS has no neutral switch.
4. Both the generator and the seperate structure have grounding electrode systems at there respective locations.

Question: Can the two grounding electrode systems be bonded together with a conductor running in the same trench as the generator conduit?

 

[RUWired]

Question: Can the two grounding electrode systems be bonded together with a conductor running in the same trench as the generator conduit?

Yes as long as like you said, the grounded neutral conductor is not ran with feeder conductors from the generator. In this case you are only creating a parallel path between the GEC and what i would call the equipment bonding jumper.

I think the grounding conductor between the generator and the ats is an equipment bonding jumper and should be sized per 250.30(A)2, 250.102(C),250.66.

Rick

 

[ceb58]

1. SDS gen set located 50' from seperate structure with utility service at the seperate structure.
2. Gen is 480/277 with gen neutral bonded at gen set. There is a service rated disconnect at the generator.
3. There are no L-N loads and therefore the conduit from the genset to the ATS has 3 ungrounded cond and one EGC cond. The ATS has no neutral switch.
4. Both the generator and the seperate structure have grounding electrode systems at there respective locations.

Question: Can the two grounding electrode systems be bonded together with a conductor running in the same trench as the generator conduit?

Why would you want to run a conductor back to the gen? The EGC from the service disco. and the EGC from the gen. disco. will need to be bonded in the ATS. This will connect the two grounding systems.

 

[al]

Al's Reply

Al's Reply

Why would you want to run a conductor back to the gen? The EGC from the service disco. and the EGC from the gen. disco. will need to be bonded in the ATS. This will connect the two grounding systems.

I am questioning this as this additional conductor is on the engineers plan.

 

[ceb58]

I am questioning this as this additional conductor is on the engineers plan.

Time for a RFI to the engineer. How and where dose he show the connection?

 

[cadpoint]

I am questioning this as this additional conductor is on the engineers plan.

Time for a RFI to the engineer. How and where dose he show the connection?

I concur
Most large installs like this that I've been around usually get an extra conduit or two to the generator service,
it is for signaling or control type wiring.