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starcraft69's avatar
starcraft69
Explorer
Dec 07, 2018

inverter fuse/breaker

I am purchasing a 3000 watt inverter and wondering should i use a ANL 300amp fuse or a 300amp breaker between batteries and inverter?

29 Replies

  • No I don't think it's going to handle 8000 amps short
    Why should it
    You want it to trip at 300
  • starcraft69 wrote:

    This is what i was thinking Is 300amp breaker the right size?


    What size wire will you be using? That's the main purpose of the fuse--to prevent a fire from the wire overheating in the event of a short circuit.

    300A is a reasonable ballpark value, though larger might be better as most inverters have a surge capability somewhat beyond their nominal rated capacity. (Well, decent inverters do; all bets are off for questionable unknown brand inverters from overseas.)

    Edit: The inverter instructions may have some recommendations on power lead wire size and fusing.
  • What's the DC current interrupt rating of this 300 amp breaker? Can it handle the direct short capacity of your battery bank? Example: my bank is rated at 8000 amps direct short
  • KD4UPL wrote:
    I wouldn't use the ANL, the Class T is the fuse you want. But, I would prefer a breaker. It will act as a disconnect switch if you need to shut off power to the inverter for some reason. And, if it every trips, you can reset it instead of having to find/order and install a new fuse.
    Blue Sea, Outback, and Midnite solar (as well as others I'm sure) will have the breaker you need.



    This is what i was thinking Is 300amp breaker the right size?
  • I wouldn't use the ANL, the Class T is the fuse you want. But, I would prefer a breaker. It will act as a disconnect switch if you need to shut off power to the inverter for some reason. And, if it every trips, you can reset it instead of having to find/order and install a new fuse.
    Blue Sea, Outback, and Midnite solar (as well as others I'm sure) will have the breaker you need.
  • Neither ... at that amperage, go with a Class T fuse

    for background, read about interrupt rating and direct short rating on batteries.
  • Fuse. I guess I could look it up, but I didn't know DC used breakers.

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