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New Service Panel

Posted by mikec205 (My Page) on
Wed, Oct 27, 10 at 1:28

I have a detached studio on my property built in the 50's, I have removed the old "screw in" style fuse box and all of the wiring and want to install a new panel. The main power comes from a huge cable that runs about 100ft back to a 100amp knife switch.

What type of panel do I need: Main Breaker, Main Lug or transfer panel? I don't understand the differences.


Follow-Up Postings:

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RE: New Service Panel

A main lug only panel will be OK, though it may be cost effective in some circumstances (and perhaps convenient) to install a main breaker.

Things to check are to make sure your grounding electrode (rods typically) at the detached building is in place, that the 100A fuses in the feeder are in fact the right size for the size of wire used.


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RE: New Service Panel

If the panel has more than 6 breakers then you need a main breaker or a separate disconnect at the detached building.


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RE: New Service Panel

This sounds like an older installation. There are several considerations in upgrading such an installation - for example, the feed to your building may not meet current code grounding requirements.

At the very least, you'll need to be sure the feed is protected by an appropriately sized overcurrent device. A knife switch (!) isn't sufficient.

You may be getting into more than you bargained for here.


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RE: New Service Panel

i would use a squareD qo main breaker panel


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RE: New Service Panel

I just left a "knife switch" (enclosed type) in service as a disconnect for a residential furnace.

Charming contraption, original manufacturer (Trumbull) rated it to 30A, it's on a 15A circuit. It's in quite good condition.

I did replace all of the wiring on that circuit though. What a !@#$ working in a box that tight.


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