Installing a sub panel solely for outdoor Christmas lights/decorations. I will need approximately 120 amps now, with more to be added later. My current main panel does not have enough open slots for this since each circuit will be limited to 20 amps because of the outlet and switch ratings. Running a sub panel off of a 100 amp double pole breaker will not give me enough amps at the sub panel. Would it be better to connect two sub panels with lower amps to each, or does any one make a double pole breaker that will allow 150 amps through it? Already looking at #2 wire run inside conduit from the main to the sub. The circuits will all be on at the same time, for a few hours every night if that matters. Main service is 200 amps. Distance from main to sub will be approximately 50 feet. Thanks. Will be converting to LED lights in the future.

  • 3
    Do you actually need 120 amps? That is a LOT of lighting. Or do you just need 6 x 20 amp circuits? If you need 6 20 amp circuits but they won't all actually be using close to 20 amps each at the same time then you could do just fine with a 100 amp panel. Apr 10, 2018 at 22:34
  • Yeah, 120A of lighting in a subpanel would be an insane 28.8kW of lighting... My entire house only has 100A service, and I run an EVSE, electric stove/oven, and a heat pump. You definitely don't need a full 120A unless you're trying to be seen from space.
    – Hari
    Apr 10, 2018 at 22:43
  • Do you need 120A @ 120V or 240A @ 120V? Any panel over about 30A it behooves you to wire it 2-pole. So you get two banks of 120V at the panel amperage. A 100A panel actually can power 200A of 120V loads, or ten 20A circuits loaded to max (max being 16A/1920VA continuous or 20A/2400VA non-continuous). Reason that's worth thinking about is there's a big price jump going from 60A to 100A breaker and 100A to 125A (some 125s need FOUR spaces). Might pay for some of the LED upgrades. Also don't use copper wire, the lugs you'll be attaching to will be aluminum. Apr 10, 2018 at 22:46
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    Is your name Clark Griswald?
    – freshop
    Apr 10, 2018 at 23:52
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    @oldman Wow! Definitely time to switch to LEDs. Apr 11, 2018 at 0:43

1 Answer 1


It's obvious you take your lighting seriously. You would be better off applying for and setting temporary power rather than trying to upgrade you existing service. It really doesn't matter how long you lighting stays on if it runs over two hours unless you are planning not to run anything else while the lights are on. Something like this could put a lot of strain on your service.

So what I would do is set a temporary service in an unobtrusive area and have the utility company activate it and deactivate it every year.

Good luck with your project and your neighbors complaints.

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