Author Topic: P323 Main Fuse  (Read 4718 times)


  • P323
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P323 Main Fuse
« on: February 13, 2024, 01:00:34 PM »
Hoping somebody can help...

Upgrading electrics in preparation for LiPO4, and better switching than 1-2-both. In my way is the main DC fuse. It has a big plastic cover over it - unfortunately wedged behind the water heater, so cannot be accessed/removed nondestructively. I therefore cannot see the original fuse rating (50,000 amps AC does not help!).

Does anybody have an idea of the correct fuse size for DC Main? I am assuming it is equivalent to a Class T fuse, and therefore needed in addition to the standard BlueSea 30A breaker.

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Re: P323 Main Fuse
« Reply #1 on: February 14, 2024, 09:08:17 AM »
on my 1990 31-2, mine was the same "shot gun shell" looking fuse, but only a 40A.  When I found it  (a screw had come loose and was shorting out the connection to my panel), I quickly replaced it with a newer 40A 2 prong push in fuse, like we use everywhere now, but it was MUCH bigger in actual size from an auto fuse.  I just took the 2 wires of the existing holder and joined them with the new 2 prong spade holder (just hanging freely, no mounting at all) and just plugged the new fuse in.  It was a 10 minute job for me as the fuse is located under my aft cabin with my batteries. Maybe you can remove/cut the 2 red wires off and move them to a more workable area. If I was going to do mine today though, I'd use this fuse holder and mount it and not have to join any wires:

I have also switched over to LiP04 batteries and no issues.  Good Luck!!