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need help with sub-panel

need help with sub-panel

#1
12-14-04, 11:40 PM
uncle creepy
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need help with sub-panel

I have currently in my house 100amp service 120volts fuse panel.It is almost filled up.I have one empty slot left.Here is what I want to do.I want to run an 60amp 6 to 8 breaker sub-panel.To get power to the sub I'm going to run it off two 30amp fuses.Is this possible?I'm going to use 10-3 wire for the sub.Please help thanks

#2
12-15-04, 05:27 AM
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Join Date: Sep 2003
Location: Central New York State
Posts: 13,246
You can't use 10 gauge wire for a 60 amp panel, you need larger wire.

#3
12-15-04, 07:05 AM
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Join Date: Jan 2004
Location: Oregon
Posts: 1,104
1) Get a book on electrical wiring, and read about sub-panels. After you've read the book, then ask about the points that you don't understand; we'll be happy to help.

2) A subpanel in a home generally needs to be fed with _4_ conductors: two 'hot' conductors, one 'neutral' conductor, and one 'equipment grounding conductor'.

3) In the subpanel, the neutral and the ground are on _separate_ bus bars. They are only connected in the _main_ panel, and must be separate everywhere else.

4) A 60A panel is simply a panel that can be used at a maximum of 60A. If you only need 30A from this panel, and you feed the panel with 30A fuses, than #10 wire is fine. You could even use a '100A' panel if you wish. The point is that the #10 wires need 30A protection.

5) However you need to figure out what you actually _need_ from the panel. You do this with a 'demand load calculation', where you calculate the expected load placed on a panel. Search this forum for 'demand load calculation' and you will find lots of useful input. If your calculation says that a 30A feed is acceptable for this panel, then using 30A fuses or circuit breakers, and 10/4 wire would be fine.

6) You might wish to plan for future expansion, and install fuses and wire for the full 60A to the subpanel.

7) You should do a demand load calculation for your entire house, to make sure that your current service is sufficient for the load.

-Jon

Last edited by John Nelson; 12-15-04 at 07:47 AM.
#4
12-15-04, 07:30 AM
HVACELECT
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10-3 on 60 amps will not work at all. I gather from what you are saying is that your home has an 100 amp services with fuses. Is this correct? but you need more capacity, My suggestion is to up grade your whole service to 200 amps with breakers

#5
12-15-04, 07:52 AM
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Join Date: Sep 2000
Location: United States
Posts: 17,733
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(1) Do you really have fuses? Or do you have breakers?

(2) Please tell us the make and model of your main panel.

(3) Do you really have 120-volt service (very unlikely)? Or do you have 240-volt service with 120-volt fuses?

(4) In what year was your house built?

(5) If you need more circuits, a subpanel is a good solution. If you need more power, however, a subpanel is not the answer. How many square feet is your house and are your major appliances gas or electric?