Bilge Pump Wiring

[Martin S]

I want to wire two bilge pumps, each drawing 10A (recommended fuse 15A) on a 12 V circuit, directly to the battery bank. Rather than two cable runs, I was planning to run one cable from battery to a bus bar and then wire the two pumps to the bus bar.
I am correcting in assuming the single run from battery to bus bar needs to be sized for 20A and fused at the battery accordingly, say 25A.
Any other guidance welcome.

[a64pilot]

Yes, but being the paranoid type I would completely separate the systems, have no single point of failure, would even go to separate battery banks if possible.
I assume one pump is in case of failure of the other and not separate bilges?


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[cjester]

I would run two. Just say one blows the fuse. You just lost the benefit of redundancy for a little more cost and effort. Not to mention one may not blow the larger circuit breaker/ fuse and then you defeat the purpose of the fuse.


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[skipmac]

This is how I wired my emergency bilge pumps; two Rule 4000s. I ran a heavy cable, 50 amp fused at the battery to a bus bar. Bus bar feeds a two place circuit breaker panel, each one 25 amps (the rating for the Rule 4000).

I figure it's unlikely that I would blow the 50 amp fuse and each pump has it's own breaker.

[SunAndMoon2]

Fuse size is selected based on wire size. The fuse protects the wire. But you are right, it needs to be at least 20 amp. Read some compass marine articles for better understanding.

Compass marine articles are here:
http://www.pbase.com/mainecruising/boat_projects