Subpanel Questions

[gjat]

I would caution you again to have an electrician do it and not rely on internet advice.
I've worked in industrial electric and have seen things go very bad. A mistake can be a life ending disaster, destroy your home... If you've done it yourself, a fire may not covered by your homeowner's insurance. Anybody buying your house would require a inspection and you'd have to pay for someone to repair what you've done.

[jseklund]

Thanks to all who replied. As much as I would like to upgrade the main, it really isn't in the budget.
Toolguy- all of my 120v breakers are already 1/2 size so that's not an option for me. My feeder line is definitely 6/3 black/red/white with no ground. I'll probably just strip off a length of left over neutral #6 and relabel it for the ground instead of using the #10 although I have been told that it is OK to downsize the ground by 2 sizes.

I am not sure why you are trying to do this, but if ALL of the breakers are already mini-breakers, you are probably already seriously overloading the box. MOST boxes specify something like 1/2 of the slots can be used as mini-breakers. Some boxes you can use mini-breakers in every slot, but if you're at that point, you are still at the box's limit and shouldn't go beyond.

If it is not in the budget to have it done right, by a qualified electrician, then this may be a case where you shouldn't do it at all. You could be making what already sounds like a bad situation worse.

[jseklund]

One side note - are you actually UTILIZING all of those seperate breakers? The fact that you have double-tapped each slot and aren't already having issues (such as serious dimming lights, etc) makes me wonder why you are in this situation?

In other words, you will need to have dedicated circuits to meet code on some items - such as a dryer or refrigerator - but do you have multiple circuits going to plugs that should have been planned more effectively?

Just curious and trying to help out, but I don't wanna see you burn your house down or kill yourself or someone in your family.

[mikemuirhead]

Jsec...
I appreciate your concerns. I am fully aware what can go wrong and I do have an electrician that I will be consulting with on the sub install. Now, I have a major concern with what you said about your install. I don't know if it is a typo or not but isn't #6 copper or #4 aluminum the MINIMUM required to feed a 60 amp circuit? Seems like the #10 would be two sizes too small, particularly over a 100' run. Someone correct me if I'm mistaken. I'm fairly certain that the NEC rates #10 for 30 amps.

[jseklund]

You are correct - I ran (4) #10 wires as a 220V circuit, feeding 30 amps at 220V and then split back to 110V. Good catch.

[mikemuirhead]

The only change I made to the main was to put a tandem 20 in so that I could put a dedicated circuit in for the Bt3. So I have only added one circuit since we bought the place 10 years ago. All of the other 120v breakers were already tandems. The house was built in 1978 by Ryan, so that should explain a lot. In our 10 years here, we've had one 15 amp breaker pop twice when my wife turned a space heater on hi. Works fine on low. One of the circuits I want to put on the sub is actually that single outlet that she has the heater plugged into. No other electrical problems with lights dimming or breakers popping. We did lose half of our panel once when Verizon was burying their FIOS lines and clipped one leg coming off of the transformer. Our neighborhood has all underground utilities.
In going over the numbers with my electrician, we are typically only using around 40 amps. He feels that the real issue is lack of space rather than lack of capacity. Remember it is only a 12 slot main and six slots are taken by the 240v appliances.

[toolguy1000]

Is romex allowed in NY now? Or was it just not in NYC?

romex is allowed in westchester county, but i don't know about NYC.

[LCHIEN]

Thanks for all of your replies. I have contacted several electricians and so far I would be well over $2000 for a panel upgrade. I would need to replace my meter socket to one with a higher rating and a disconnect, remove a large portion of my back deck/patio, retrench for the new wire, get approx 35 feet of wire from the meter to the panel underground, plus the cost of the new panel.
My original panel is a 12 position with six of those being used for 240 v service to the stove, A/C unit and Dryer. The remaining six are 1 tandem 20 amp and 5 tandem 15 amp breakers. Based on the loads being used, I'm at about 50-60 amps. An electrician I talked to said that a sub panel is a viable solution. I would move four circuits from the main to make space for the 60 amp breaker and add them to the sub. I want to add a 240 circuit for a compressor and heater(same plug so the will not be used at the same time). Any more thoughts?

I'd look at Woodturner's suggestion of using half size breakers if available for your box. They will allow say to replace the six 20A and 15A breakers with up to 12 breakers with a minimum of new wiring and boxes. Obviously you will have to look carefully at box loading and such but if you are using 50A on the box at present it might be possible.

[cabinetman]

I would caution you again to have an electrician do it and not rely on internet advice.
I've worked in industrial electric and have seen things go very bad. A mistake can be a life ending disaster, destroy your home... If you've done it yourself, a fire may not covered by your homeowner's insurance. Anybody buying your house would require a inspection and you'd have to pay for someone to repair what you've done.

+1. This is your best advice. The OP continues to ask for details as if he is proceeding on his own. With an electrician already in a consultation loop, that is the best source for qualified answers.

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