120% rule

I would like to know two different ways to install 60 amps of solar on my 200 amp service thanks

Comments

  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: 120% rule

    Welcome to the forum.

    First thing to do is check with your utility and see what they allow/require. Some limit GT solar to 10kW, and 60 Amps @ 240 VAC is 14.4kW.

    As it is a 200 Amp service would not be allowed that much connected in the usual manner, so you'd end up having to reduce the main breaker size or change the service or install via line-side tap (which may not be allowed).
  • solarixsolarix Solar Expert Posts: 713 ✭✭
    Re: 120% rule

    1) reduce main breaker to 175A (if available for that panel)
    2) install a 400A panel
    3) Do a line-side tap (if allowed by manufacturer of that panel)
    4) install conservation methods to reduce usage and max out the existing panel with 7.5kW inverter.
  • inetdoginetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: 120% rule
    njbelect wrote: »
    I would like to know two different ways to install 60 amps of solar on my 200 amp service thanks

    Would you settle for three?

    1. If the panel busbars are rated for 225Amp (some are, check the manufacturer specs) your 120% is 270 and you can directly add up to a 70 amp breaker while keeping the existing 200A main. (Be sure to install the backfed breaker at the other end of the busbar from the main breaker.

    2. If the panel busbars are rated for only 200Amp, then your 120% is only 240, so you would have to reduce the main breaker to 180 or less, and 175 is what is available.

    3. An electrician can do what is called a line side tap, bypassing your main panel completely to a dedicated panel or fused disconnect for whatever power level you want, up to 200 amps. The service wiring will not ever have to carry more than 200 amps in either direction, so it will be OK. Not all jurisdictions and power companies will allow a line side tap, even though it is recognized in the NEC.

    Not 4. An upgrade of your service to 400A will be expensive, and if you do not need the extra power, it will be a waste of money. The AHJ and POCO may not allow you to put in a 400A panel without upgrading your service.
    SMA SB 3000, old BP panels.
  • PhotowhitPhotowhit Solar Expert Posts: 5,209 ✭✭✭✭
    Re: 120% rule

    I always wondered if it would be fine to switch your main break to be at the pole, where many rural grounds are. Put a box up with a 175amp breaker going to the house, break the bond at the house making it a sub panel. If your array is closer to the pole this seems much easier than going back through the house breaker box? I'm no electrician, but this seems like it would be easier than some of the wiring I've seen... I'll run back to the off grid section now...lol.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: 120% rule

    Photowhit; in a lot of places it wouldn't meet code, even though it would work. They get funny about the locations of things sometimes. I can't even have my meter moved to the pole in the yard because of the ol' "it's not allowed" rule.

    I'd like to find someplace to live where the hopelessly ignorant aren't in charge. Okay, so I am just a bit sensitive about it right now owing to a recent run-in with code morons.
  • PhotowhitPhotowhit Solar Expert Posts: 5,209 ✭✭✭✭
    Re: 120% rule

    Thanks for the insite, our meters are on our poles in some situations, all the mains except one in our camping community are on the poles, and we have maybe 150 houses or cabins(all lots start as camping lots though). Mine new place the meter is on the pole as it was originally a mobile home. The wheels and tongue removed and skirted it became a module home and is taxed with the lot...

    If I ever become grid tied, I would hope to do it this way. My array is between the module and pole and breaker box is at the far end, think an extra 200 feet of wire. Along with our old codes and backwards ways, we also have "counrty Simple"and people here are more likely to vilolate codes and such if it makes sense and doesn't create a hazard.

    5" of snow and counting...
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
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