Grounding

[JRumsey]

Above is a panel to be installed in a PDC (Power Distribution Center or Power House). This panel came with three separate ground bars; but with only one ground bar having a grounding electrode connection point. The two ground bars that do not have a grounding electrode point are screwed directly to the panel. Should these two ground bars be jumpered to the third ground bar or can the panel be used as the connection between these three ground bars?
Also, is there any educational literature or videos that deal with grounding that I could use as a training tool?

 

[infinity]

I see no need for a jumper. Is this actually a GEC or an EGC?

 

[texie]

View attachment 19673 View attachment 19674

Above is a panel to be installed in a PDC (Power Distribution Center or Power House). This panel came with three separate ground bars; but with only one ground bar having a grounding electrode connection point. The two ground bars that do not have a grounding electrode point are screwed directly to the panel. Should these two ground bars be jumpered to the third ground bar or can the panel be used as the connection between these three ground bars?
Also, is there any educational literature or videos that deal with grounding that I could use as a training tool?

As best I can tell from the photos those are just standard equipment ground bars and 1 just happens to have an optional lug for a larger conductor. Except for rare exceptions the GEC would not connect to an equipment ground bar. Is this an application that even requires a GES?

 

[DrSparks]

The metal enclosure electrically bonds the bus bars together. There is no need to install jumpers between them.

 

[GoldDigger]

The metal enclosure electrically bonds the bus bars together. There is no need to install jumpers between them.

Although there are those who feel that even though the little tiny sheet metal screw(s) are all the code requires, they are just not comfortable with that.

 

[romex jockey]

I see no need for a jumper. Is this actually a GEC or an EGC?

But that's the thing....

Milbank makes meters with GEC lugs inclusive in the N connection, or separate from it.

POCO's local to me require a 'solid connection' meaning not through sheet metal

I guess they've established a dif between 277 or 120V's and 1,000,000 volts

~RJ~

 

[electrofelon]

to expand on this a bit, am I correct on the following:

1. If the panelboard was in a remote separate structure fed via a feeder, the GEC would have to land on the same ground bar as all the EGC's
2. If N-G were bonded due to this being a service, the GEC would have to land on the same bar/bus as the grounded conductor.

edit: actually not sure about #1....

 

[DrSparks]

Although there are those who feel that even though the little tiny sheet metal screw(s) are all the code requires, they are just not comfortable with that.

The screws that are required must be sized number 10 with a minimum of 24 threads per inch. This has been evaluated by Testing Laboratories

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[DrSparks]

to expand on this a bit, am I correct on the following:

1. If the panelboard was in a remote separate structure fed via a feeder, the GEC would have to land on the same ground bar as all the EGC's
2. If N-G were bonded due to this being a service, the GEC would have to land on the same bar/bus as the grounded conductor.

edit: actually not sure about #1....

You are correct. If it is an external building fed by a feeder or a sub feeder from the main building the grounding electrode conductor would terminate on the equipment grounding bar and the neutral busbar would remain isolated from ground.

If you were to bond the neutral to ground in the subpanel the neutral current would take parallel paths back to the service equipment possibly creating a potential difference across grounded non-current carrying surfaces

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[ActionDave]

The screws that are required must be sized number 10 with a minimum of 24 threads per inch. This has been evaluated by Testing Laboratories

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How come all my SqD pk xxx ground bars come with 8-32 screws?

 

[electrofelon]

You are correct. If it is an external building fed by a feeder or a sub feeder from the main building the grounding electrode conductor would terminate on the equipment grounding bar and the neutral busbar would remain isolated from ground.

If you were to bond the neutral to ground in the subpanel the neutral current would take parallel paths back to the service equipment possibly creating a potential difference across grounded non-current carrying surfaces

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I know the grounds and neutrals must be separate. What I was asking was, does the GEC have to terminate on the same terminal or bus as the EGC's? In other words could the GEC land on its own bar bolted to the enclosure, then the source and branch EGC's land on a separate bus also bolted to the enclosure.

 

[DrSparks]

I know the grounds and neutrals must be separate. What I was asking was, does the GEC have to terminate on the same terminal or bus as the EGC's? In other words could the GEC land on its own bar bolted to the enclosure, then the source and branch EGC's land on a separate bus also bolted to the enclosure.

There is nothing in the code prohibiting you from terminating the the gec on a separate terminal bar or simply a log that is bolted through the chassis as long as you insure good electrical conductivity. But why wouldn't you just terminate the GC on the ground bar?

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[infinity]

I know the grounds and neutrals must be separate. What I was asking was, does the GEC have to terminate on the same terminal or bus as the EGC's? In other words could the GEC land on its own bar bolted to the enclosure, then the source and branch EGC's land on a separate bus also bolted to the enclosure.

Yes you can use the enclosure to connect the two EGC bus bars together.