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Conflicting information from electricians... which is right?

Posted by anamehere (My Page) on
Thu, Feb 25, 10 at 22:09

Have a multifamily building that needs to have the fuses replaced with circuit breakers. Simple enough.

There's currently 200 amps coming in from the street and fuses have been historically unremarkable... I don't think a basement fuse has been changed in years. There's a gang with several connected meters in a row, with small 30 amp fuse boxes above them with cables which lead to the units.

One electrician tells me we need to install these massive boxes, each holding a meter and a 100 amp breaker, and run a cable to each apartment. Another tells me all we need to do is add a 100 amp breaker above the existing row of meters and run a cable to each unit. Which is proper?

Changing the fuses to breakers in the units will be pretty straightforward, and hopefully that's where the project will end. The building has knob and tube wiring. Is there anything else we might be required to do?

Another question, I think this one's OK but will ask anyways. With 200 amps coming in, the total of main breakers will be some 800 amps. Neither electrician thought we'd have to upgrade the 200 amp service. Sound right? Currently the basement fuses and existing breakers in the basement total around 300 amps.

There's a big difference in price between installing the large breaker/meter boxes in the basement and keeping the existing meter boxes and just adding just a 100 amp breaker above each.

Which route should we take? Each electrician says the other is wrong.

Anything else we should be aware of?

Follow-Up Postings:

RE: Conflicting information from electricians... which is right?

The one electrician probably plans to do the work without a permit. The meter cans are probably rated at 60 amps at best, and the main service condition is likely terrible/ nowhere near current code. With over 6 units, a main disconnect must be installed before all the meters killing all power. To determine the size of the main, a proper calculation must be done adding up all the units and appliances as a whole. Without electric ovens or dryers (sounds like you don't have), it is quite possible that even 10 units would only require 200 amps. However if you have thought in your mind of ever renovating them or adding dryers, etc, spend the money now for a bigger main or else every thing would have to be redone again. The combo meter assemblies/ disconnects are insanely expensive. I just priced some out for a 9 unit and came in near $10,000 in meter/disconnect supplies. The guys at the supply house didn't know what they were doing and had a 600 amp main which was a good portion of that cost but still. Probably cheaper to build the service with a main disconnect, electric gutter, separate meters each with their own disconnect. The point of the meter/ disconnect assemblies is to save labor and have everything in one neat assembly. Your guy that is avoiding upgrading the meters, main service, and required disconnect is saving himself thousands but avoiding code.

RE: Conflicting information from electricians... which is right?

Sounds like I should have been more descriptive. Sorry.

The main from the street is a 200 amp box. That, and the meter sockets are from the last upgrade from the 70's. There is an aluminum cable going from the main to the meters, my guess is about 2" x 3 1/2" in diameter.

Running a new cable from the 200 amp box to the meters would be challenging at best because of residential obstructions, and I'd be just as happy leaving that part alone if possible. The only intent on my part is to eliminate the fuses at the insurance company request.

Isn't a licensed electrician required to pull a permit to do this type of work?

I simply don't want to have someone start to do something of a limited nature and have it mushroom unexpectedly to a major task. And such conflicting information about the basement breaker boxes bewilders me. Don't know which path to take, or what additional work might be required.


Tried editing prior post, but it seems that's not possible.

Took a look at the meter sockets and they are Murray SC256AR which googled shows as "MTR SOC 4 JAW 2 POS 200A" so I assume that's OK to reuse. All the sockets are neatly connected in one straight run, and the 200 amp box at the front of the building does have a disconnect.

Hope that helps make things clearer.

RE: Conflicting information from electricians... which is right?


RE: Conflicting information from electricians... which is right?

It might be less troublesome to change insurers rather than than the electrical service.

RE: Conflicting information from electricians... which is right?

How many fuses in each 30 amp fuse box? And what amps are the individual fuses?

RE: Conflicting information from electricians... which is right?

I think any insurance company would require the changeover, if not now then not far into the future.

There is one 30 amp fuse in each of six basement boxes. In addition, there are two more boxes in the basement each with a 60 amp main breaker, and about six 15 and I think one 20 amp breaker in each.

There are about 6 fuses in each unit's fuse box, all non-tamp 15A.

I can't remember when a fuse had to be replaced, it's been a very long time.

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