Commercial Defeciencies

[jar546]

What is wrong with this setup?

You are looking at a bank of sub panels that will be set up for vendors in an indoor flea market. Each will have a meter installed, owned by the landlord. The feeders for these subs come from a main panel right out of a new transformer (not installed yet). The transformer for this separately derived system is fed by the MDP.

 

[chris kennedy]

215.6.......

 

[chris kennedy]

I should add that my above reference also created a violation of 250.142(B).

 

[jar546]

One of the things I reminded him about was the fact that he cannot use the lugs in the meter base for the neutral as it is grounded to the box. The neutral will have to be feed through and he must add a ground.

 

[chris kennedy]

Very good, I was prepared to tell you thats legal, forgot about 250.142(B), requirement 2 of exception 2.

250.142 Use of Grounded Circuit Conductor for Grounding Equipment.(B) Load-Side Equipment. Except as permitted in 250.30(A)(1) and 250.32(B), a grounded circuit conductor shall not be used for grounding non–current-carrying metal parts of equipment on the load side of the service disconnecting means or on the load side of a separately derived system disconnecting means or the overcurrent devices for a separately derived system not having a main disconnecting means.

Exception No. 1: The frames of ranges, wall-mounted ovens, counter-mounted cooking units, and clothes dryers under the conditions permitted for existing installations by 250.140 shall be permitted to be connected to the grounded circuit conductor.

Exception No. 2: It shall be permissible to ground meter enclosures by connection to the grounded circuit conductor on the load side of the service disconnect where all of the following conditions apply:

(1) No service ground-fault protection is installed.

(2) All meter enclosures are located immediately adjacent to the service disconnecting means.

(3) The size of the grounded circuit conductor is not smaller than the size specified in Table 250.122 for equipment grounding conductors.