Recently I installed 2 x12v 12000 BTU aircons on our catamaran. We currently have 1x harken 100amp breaker that runs all our 12v system. However when running both aircons, our 12v watermaker and all our 12v systems the breaker trips. I’m looking for a good 150amp or 200amp 12v breaker.
Anyone has any recommendations?
Best to use a Megafuse, rather than a breaker for this current.
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Thank you for your response. Any particular brand or specs. You recommend?
And do I just eliminate the 100amp breaker in place?
Use the breaker for a windlass or something that has a high amp draw and won’t run long. If you put a constant current on a breaker, it heats up and opens. They are also designed to start engines that may have 2-4 times the current draw of the cable rating.
For your other loads, look at getting a busbar and fusing each load. The fuse is there to protect the cable, so if the cable is rated 50A - 60A, for example, put a 40A fuse in there.
Install a fuse on the battery bank, such as an MRBF or ANL. Bussmann makes good stuff.
The 12v breaker the boat came with us just that type of breaker. Sorry for the edit it’s a 120amp hi amp but it does get hot if I’m running both aircons. Not if only running 1 aircon
They use a bimetallic strip that heats up as current flows through it. Under constant load, heat builds up over time. When the strip gets hot enough, it bends and mechanically opens the circuit. This is time dependent the higher the current, the faster it trips.
A regular fuse will not do that it will just hang in there take all the current even slighty over the rating.
see your Victron or Blue Sea dealer for parts.
So what type fuse and amps would you recommend? I’ve search through but there is so many different types. Want to make sure ik getting the correct one. Tia
You can read through this. They have a section on cable ratings and also fuses. When to use for voltage and current. On the battery, ANL or MEGA or even MRBF. They are all good. You can use a consumer unit like the one in the photo from Bussmann for the devices, or if you want to get really fancy, have a look at the Lynx distributor from Victron.