bonding

[Hendrix]

I have a 200 amp. main breaker panel. Next to that there is a 100 amp. disconnect feeding a sub panel in an apartment. The #4 gnd wire is going to the water gnd. electrode. from the 200 amp panel. The Question is: Should the 100 amp switch have it's own gnd. electrode to the water? Or can the enclosures just be bonded together?

 

[augie47]

If the 100 amp disconnect is a service disconnect it should have it's own grounding electrode system unless the connections were made ahead of the two disconnecting means (at the meter, etc).
The GEC from the panel and disconnect could run to the electrodes (water pipe, etc) seperate or you could run a common electrode and tap off to each disconnect.

 

[infinity]

From where does the 100 amp disconnect get it's supply?

 

[Hendrix]

From where does the 100 amp disconnect get it's supply?

From the transformer through the meter.

 

[Dennis Alwon]

Let's get this right. You have 2 meters -- one feeding a 200 amp panel and the other feeding a 100 amp panel???? Is that correct?

 

[Hendrix]

Let's get this right. You have 2 meters -- one feeding a 200 amp panel and the other feeding a 100 amp panel???? Is that correct?

that is correct

 

[Dennis Alwon]

As Gus stated the 100 amp disco needs its own GEC to the water pipe.

 

[Hendrix]

As Gus stated the 100 amp disco needs its own GEC to the water pipe.

So, say there were 5 disconnects, they would all need separate GEC's to the water pipe ?

 

[kwired]

So, say there were 5 disconnects, they would all need separate GEC's to the water pipe ?

That is one option. Or run one GEC to the pipe sized for the equivelant size of all the service entrance conductors and make taps off it to each service disconnect. Another option is to run the GEC to a common point on the supply side of the disconnects.

See 250.64(D)

 

[Hendrix]

That is one option. Or run one GEC to the pipe sized for the equivelant size of all the service entrance conductors and make taps off it to each service disconnect. Another option is to run the GEC to a common point on the supply side of the disconnects.

See 250.64(D)

Which would be the meter socket ? 250.64 D is what I was looking for. Thanks

 

[Dennis Alwon]

Which would be the meter socket ?

Is there a trough or is this a 5 gang meter socket? If you run the gec to either place than only one gec is needed.

 

[kwired]

Which would be the meter socket ?

250.64(D)(3) says

in a wireway or other accessible enclosure on the supply side of the service disconnecting means.

Meter sockets generally are not considered accessible because the power company usually places a lock or seal on them. If that is only point available on the supply side then I say no you can not use it. If you had a junction box or wireway and nippled to the disconnects then you could run it to this point.

 

[Dennis Alwon]

Meter sockets generally are not considered accessible because the power company usually places a lock or seal on them.

This is true in some areas but certainly not all. I know NC and other states allow it. This is sometime ruled by the AHJ and more often by the POCO.

 

[infinity]

I would run one GEC and split bolt to the 100 and 200 amp service disconnects. Something like this: