Bonding

[SiddMartin]

Have a 600A Main, Service disconnect, PVC to trough, then 1-300A disc, and 1- 400A disc coming outta trough. PVC between disc, and trough. On the 300A disc, load side is rigid going down into concrete floor to feed another building.

Inspector says that the rigid pipe has to be bonded w/ ground. He said to bond it to the trough or the disc that it is going into. (Could use a grounding locknut).
He said this is req. because it is "within arms reach" of the Main disc.

I questioned him b/c I did not consider the 300A disc. service equipment b/c it is after the main disc.

Is he correct?

 

[tom baker]

The 300 and 400 Amp disconnects are feeders. Service bonding is not required.
However, if this is over 300 volts to phase to phase, concentric or eccentric KO's can not be used for bonding of the RMC.
But arms length is one I have not heard of. Ask him for a code section. There isn't one.

 

[SiddMartin]

If I had EMT or RIG complete from MAIN to trough and then to DISC, would all of them be req. to be bonded? w/ locknuts or whatever?

I'm just tryin to learn somethin here is there is somethin to learn.

 

[brother]

The 300 and 400 Amp disconnects are feeders. Service bonding is not required.
However, if this is over 300 volts to phase to phase, concentric or eccentric KO's can not be used for bonding of the RMC.
But arms length is one I have not heard of. Ask him for a code section. There isn't one.

Im not sure where you got the 300 volts phase to phase comment, but the article 250.97 NEC 2005 says 250 volts to ground check it out.

 

[tryinghard]

?Inspector says that the rigid pipe has to be bonded w/ ground. He said to bond it to the trough or the disc that it is going into. (Could use a grounding locknut)?
Is he correct?

It most definitely has to have an intentional effective ground fault path to source.