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Generator ground bar

A

anbm

Senior Member
Location
TX
Occupation
Designer
Does generator actual have an equipment ground bar like electrical panel? I saw neutral bar not ground bar, so where will the circuit ground wire or GEC land to?
 
anbm said:
Grounding electrode conductor (system ground) will connect to this lug as well? How?
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I didn't know you meant that large, but residential generators usually don't require GECs, but if they do, there is an eternal GEC terminal.
 
anbm said:
Commercial - standby emergency generator - 408Y/277V, 3PH, 500kW and up... treated as a separately derived system.
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If it is ordered as an sds, usually it will have a buss bar where the generator neutral is connected and either solidly bolted to the frame, or a jumper to the frame. I’ve had to order insulator kits for that bar when the office ordered the wrong generator when used as a non-sds. And yes, the GEC would terminate there too if used as an sds.
 
anbm said:
Commercial - standby emergency generator - 408Y/277V, 3PH, 500kW and up... treated as a separately derived system.
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It should have an EGC bus setup within the generator connection point (like below) unless it supplied an integral disconnect(s).

Generator End Box.jpg
 
Here is a smaller 150KW generator. The one picture has the breaker and the mounting plate removed and you can see there are studs on the generator housing. The other pic has the breaker installed and you can just see the insulated neutral bar on the left of the frame.
 

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anbm said:
Commercial - standby emergency generator - 408Y/277V, 3PH, 500kW and up... treated as a separately derived system.
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To add, If the generator is connected via a transfer switch, then the generator has to be connected to a grounding electrode system such as a driven ground rod.
Otherwise, portable generators with receptacles mounted on the generator (with grounding conductor terminals, all non-current-carrying metal parts bonded to the generator frame) need not be connected to a ground electrode. The generator frame replaces the grounding electrode.
1926.404(f)(3)(i)
Portable generators. Under the following conditions, the frame of a portable generator need not be grounded and may serve as the grounding electrode for a system supplied by the generator:
1926.404(f)(3)(i)(A)
The generator supplies only equipment mounted on the generator and/or cord- and plug-connected equipment through receptacles mounted on the generator, and
1926.404(f)(3)(i)(B)
The noncurrent-carrying metal parts of equipment and the equipment grounding conductor terminals of the receptacles are bonded to the generator frame.
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infinity said:
It should have an EGC bus setup within the generator connection point (like below) unless it supplied an integral disconnect(s).

View attachment 2569888
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This is a great picture. I attached picture of one generator interior ... I saw at site, I have no clue where the ground bus is, only neutral bar stays next to generator main CB (I assume per code equipment ground wire and grounding electrode conductor will connect to the generator ground bus) if the generator is a separate derived system... downstream ATSs will be 4-pole, switched neutral.
 

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hillbilly1 said:
If it is ordered as an sds, usually it will have a buss bar where the generator neutral is connected and either solidly bolted to the frame, or a jumper to the frame. I’ve had to order insulator kits for that bar when the office ordered the wrong generator when used as a non-sds. And yes, the GEC would terminate there too if used as an sds.
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So if the generator is a SDS, the neutral bar is also the equipment ground bar and the bar won't be isolated from generator frame?
 
Fred B said:
What is the what looks like a CT on the A/B phase?
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Yes, not sure why there is only one on the A phase and not the B and C phases. There is also one on the EGC bus. :unsure:

I'm surprised no one noticed the black A phase. This was post pandemic and we could not get wire with the correct colors.
 
infinity said:
Yes, not sure why there is only one on the A phase and not the B and C phases. There is also one on the EGC bus. :unsure:

I'm surprised no one noticed the black A phase. This was post pandemic and we could not get wire with the correct colors.
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I missed the black conductor.
As meticulous as all your jobs are, I'm surprised you didn't re identify it.
Your pictures could serve as a "how to" booklet.
 
augie47 said:
I missed the black conductor.
As meticulous as all your jobs are, I'm surprised you didn't re identify it.
Your pictures could serve as a "how to" booklet.
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Actually I did not wire this one but I was involved with other aspects of the project. Yes I would have opted for a few rolls of brown tape. :)
 
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