Service upgrade of duplex

[jeff43222]

My neighbor has been bugging me to upgrade the service to his duplex. Currently each unit has 60A service. He wants 100A on each side, which should be enough. Each unit of the duplex is a one-bedroom apartment, 800-900 sq. ft. One electric dryer in the basement, and a few window A/C units. All other major applicances are gas.

I'm wondering about sizing the service cables for the job. There will be one service drop into a tandem meter enclosure. Do I have to base the size of the wire of the service drop on 200A (100A on each side), or can I do a load calc? I was planning on using 2/0 Cu from the service point to the meter pans, then #4 Cu from each meter to the main panels, but if it's legal to use smaller than 2/0, I'd be happy to do so, as 2/0 is not my favorite wire to bend.

 

[websparky]

Re: Service upgrade of duplex

I would do the calcs. I'll bet the total for each is less than 75A.

 

[peter d]

Re: Service upgrade of duplex

I agree. A load calc is in order.

As a point of reference, my relatives own a 3-family triple decker. It has electric stoves in each unit, oil heat, and gas dryers. The 3 gang meter socket has 2/3 SEU cable feeding it. (100 amp.) It's been that way for 35 or more years. The moral of the story is that the electric load for apartments is very light.