Generator Connection to Switchgear via Cablebus

[neerajbhatia]

A 1000kW DG set is located in the generator room . The generator room is located adjacent to the switchgear building, in which the 480V switchgear is located. The generator(without breaker) feeds the 480V switchgear (without incomer breaker through a busway of approximate 30 Feet length.
Do we require an overcurrent protection device as per the code requirements?

 

[bwilson]

Re: Generator Connection to Switchgear via Cablebus

IMO Art. 445.13 would allow this if 445.18 were complyed with

 

[caj1962]

Re: Generator Connection to Switchgear via Cablebus

My first thought is why you would not want a disconecting means located with your gen set. Code would be a secondary issue for saftey to those charged with working on the emergency system with no disconecting means other than turning off the gen set. Next question is what kind of EPSS do you have legaly required or optinal, also is this a healthcare facility. Lokking through the code article 225.30 would indicate that you would have to have one in both of the buildings

225.30 Number of Supplies.
Where more than one building or other structure is on the same property and under single management, each additional building or other structure served that is on the load side of the service disconnecting means shall be supplied by one feeder or branch circuit unless permitted in 225.30(A) through (E). For the purpose of this section, a multiwire branch circuit shall be considered a single circuit.

 

[bennie]

Re: Generator Connection to Switchgear via Cablebus

This is a 1200 amp capacity power source. Switching the load with one switch is not practical.

This bus duct probably feeds multi transfer switches.

Generators, of this size, will use the exciter to control overcurrent or ground faults. The current in the exciter is relatively low compared to the line system.

The generator shut down serves as a positive disconnect system.

This same concept is used on all large power houses.