Multiple Service Entrances

[claus]

I have an existing industrial facility with two older 2000 amp (277/480 volt) service entrances and a newer (circa 1999) 3000 amp service entrance. The 3000 amp service was installed to serve new processes and was installed in the same area of the plant as the new processes, away from the older electrical room that houses the other two services. The two older services are heavily loaded, and the connected load on the 3000 amp service is only about 450 KW. The AHJ is reluctant to allow us to remove load from the existing services and refeed from the 3000 amp service, and he cites the safety issues involved with having power from multiple services serving equipment within the same area of the plant. The plant maintenance personnel are highly qualified and familiar with the plant. All services are labeled and have floor plan plaques showing locations of other services. All equipment will be labeled as to the source service. We have agreed to the AHJ's requirements for pushbuttons at the service entrance mains that would allow disconnection of the other (remote) services through shunt trip.

I feel that if load is divided in a clear, sensible, logical manner, there should be no violation of code or safety concerns.

Any comment on code violations or safety concerns?

 

[charlie]

Re: Multiple Service Entrances

Article 225 and 230 prohibit feeds from more than one place without a permanent plaque or directory to indicate the other feeds. In this case, you are in the same building and permitted by 230(C) and 230(B)(2) to have the additional service without firewalls. The permanent plaque or directory is all that is required for the services and a directory is required by 408.4 to be on a circuit directory located on the face or inside of the panel door in the case of a panelboard.

 

[charlie tuna]

Re: Multiple Service Entrances

we are presently working in a building that originally had only 208/120 volt services - since it is a printing plant the owner has requested 480 power on the new expansion to his facilty. they add a 1600 amp - 480 volt service away from the original service but required all breakers fed from this panel to have shunt trip capabilities and be connected to a shutdown button at the original service. by code it must be identified that it controls a remote service...

 

[claus]

Re: Multiple Service Entrances

Thanks for the input. Both posts support my feeling on the use of the third service. We will be working with the AHJ to ensure he is in the loop throughout design so there will be no problems when alterations are complete.