I have an apartment complex that im installing a 1300 amp meter bank assembly (13 meter sockets, 1 main disconnect)this will be an overhead single phase 120/240 service. The point of attachment for power co. is about 20' above the meter assembly. i would amuch appreciate any help here from the board on sizing the service and grounding conductor. im currently in the process of preparing the plans for this project.
One would need to know the size of the Service Entrance conductors to size the Grounding Electrode Conductor. When this is known use T. 250.66. You should not have to size this GEC larger than 3/0 cu or 250 KCMIL Alm. You may qualify for a smaller size based on the type of grounding electrode you find available. Ground rods(s) Max would #6 cu, Concrete encased electrode Max #4 cu.
Unless these apartments are huge or use a lot of electricity in electric baseboard heat, 1400 amps seems way too big to me. Did you do any calculations???? 13 apartments times 100 amps each doesn't cut it. What is the total square footage? any electric ranges?, electric dryers? kitchen small appliance branch circuits? figure in demand factor per 220 part III or IV.
Thanks for the reply, but its already been established what each unit is going to require, My question for the board was what size conductors are needed from point of attachment to line side of disconnect.
Re: sizing of service conductors
#170437 11/02/0708:57 PM11/02/0708:57 PM
I couldn't agree with earlydean more: 1400 amps seems to be an extremely large service for 13 apts. Thats more than 100 amps each. Who determined that the service should be sized to 1400 amps? Are these unusually large units with air conditioning, hot tubs, and other fancy power hungry appliances? I have seen large machine shops operating lots of huge machinery with many HID lights etc. on smaller services than that.