Sub panel question

[sid the squid]

First let me say MERRY CHRISTMAS EVERYONE. I appreciate all the help from you guys about how to run the electric circuits in the addition I am building, got that all straight now. The question I have now concerns sub panel sizes. Now I have a cutler hammer load center, 200 amp that is full, I am going to need a sub panel but the question I have is all the panels I have looked at that have about 12 single pole spots are rated for 125 amps. Can I swap out the main in the sub panel to say 50 amps to match the breaker feeding it in the existing panel. I will need the additional spaces for future circuits but don't know if I can feed a panel with a 125 amp main with a 50 amp breaker. Any suggestions? Thanks.

 

[divo]

Re: Sub panel question

If you get a subpanel with a main breaker it is ok to use it that way. The size of the main in the subpanel doesnt matter. It is not needed. You might find a main lug only (no main breaker) panel a little cheaper. You also can find one with more than 12 circuits. The most common in this area is 20 circuit. 12 circuits will get used up pretty fast if you have to move some over from the main panel. As long as the subpanel is rated for the same, or more than the breaker that is feeding it( in the main panel) you will be ok. Dont forget to use a ground bar, grounds on ground bar, neutrals on neutral bar, dont install the bonding jumper, and run a seperate ground from the main panel to the sub.

 

[--GQ--]

Re: Sub panel question

Inspector Divo the last time we met Mr. Sid asked the question you and I replied. Same sh*t different day i guess. This time i concur. Although i have a penny worth of thoughd to add. If your 200 amps panel is full using standard size breakers, it may be economically sound to replace them with slim size double breakers thus doubling the space available to be used. Just remember to get a "double double" breaker if you have a 240V load. Inspector you get the last word.

 

[OBJ]

Re: Sub panel question

GQ....slim size dougle breaker? Who makes them and are they common? I could use a few in my service box. Thanks for any info.....

 

[SS MAYFLOAT]

Re: Sub panel question

OBJ, In our neck of the woods they are known as piggy back breakers. Most eletricial suppliers carry them.

 

[crab bait]

Re: Sub panel question

yeah,, you can find a 20/24 space C/Hammer easily.. lowes/depot sell'um.. <br /><br />you still have to have a double space left in your main panel ( or make room with said 'slim' size breakers ) so you can install a 100 amp breaker to jump off/feed your sub-panel..<br /><br />get a MAIN LUG 120 amp ,no main breaker panel for your sub-panel.. <br /><br />just install a 100 amp breaker in your main panel an feed the MAIN LUGS of the sub-panel..<br /><br />like said..must have a separate groundbar ( 5 bucs,, on same shelf ).. all grounds go to it.. all whites go to the insulated neutral ( factory ) buss..<br /><br />throw the bonding screw/strap away..<br /><br />yeah, most manufactors have a half size/'slim'/piggyback breakers..

 

[divo]

Re: Sub panel question

If your main panel is a 40 circuit, tandem/piggyback breakers wont work. The maximun number of circuits allowed in a panel is 42. 40 circuit(+ 2 for the main) panels have little tabs that prevent the install of tandem breakers.