2016 RZX bilge pump question

[chpthril]

check-valve in the bilge outlet cures that. Many new pumps come with them and some pumps can have one installed in the outlet.

[IDBoating]

check-valve in the bilge outlet cures that. Many new pumps come with them and some pumps can have one installed in the outlet.

Agreed, which is why I said:

An alternative, if you want to share a single thruhull, is a check valve between each pump's outlet and its (usually) Y connection to the shared thruhull. This prevents either pump from using the other one as a path back into your bilge, and thus the water only has one place to go - overboard - even if only one pump is working.

If the pumps themselves can integrate the check valves, so much the easier!

EDIT: However, I still prefer the entirely separate pump approach. Bilge pumps can seem dull and uninteresting until you really need them. If you carry a standalone ballast pump (always a good idea in case a drain pump dies) it can double as an emergency bilge pump. We carry a standalone, 12V-outlet-powered Tsunami with a long hose for exactly these reasons. But how ever it's done, it's always a good idea to have an entirely separate method to get rid of ballast or bilge water if something unexpected happens.

[chpthril]

With a 3-wire pump, the auto side of each pump will be separate circuits all the way to the constant B+.

The manual side can easily be wired to be separate but yet powered by one manual bilge switch. This might be the best way to go when the manual bilge function is digital through a tige touch or similar, when there are no manual rockers at all.

[IDBoating]

With a 3-wire pump, the auto side of each pump will be separate circuits all the way to the constant B+.

Unless they share a fuse or circuit breaker back at the under-dash panel. In that case, a shorted pump motor could pop the fuse or breaker and take out power to both pumps. When water is rushing into the bilge is not the time to be scrambling around trying to solve a fuse or circuit breaker problem... many people won't be in troubleshooting mode.

The manual side can easily be wired to be separate but yet powered by one manual bilge switch. This might be the best way to go when the manual bilge function is digital through a tige touch or similar, when there are no manual rockers at all.

Agreed, if the available switch is a double-pole switch with one side uncommitted. Unfortunately, I've seen manufacturers use that "extra" side to turn on the switch illumination. That can be fixed, of course, by getting power for the switch indicator from the downstream side of the bilge pump side of the switch, but not everyone is as comfortable with such rewiring jobs!

Bottom line: Folks need to do what works for them and gives them the safety and security they feel good about. We each have our own standards for such things. To me, bilge pumps are safety equipment so I'm a bit less cavalier about how I wire and plumb them. It's all good!

[chpthril]

Unless they share a fuse or circuit breaker back at the under-dash panel.

If you are installing the 2nd pump, how would they. Also, with the auto-bilge circuit, you would want to wire battery direct to insure bilge function even if the main battery switch was off. So it would not be wired to the helm BUS. The auto side gets its own fuse and direct to battery or constant.

Switch failures are rare. Even with a single pole, you can supply 2 pumps, each with its own fuse right off the switch output. One pump failure would not effect the switch or the other pump.

With a PCB output like the medallion or murphy, use a relay to supply both pumps and a fuse for each, right off the relay. Same results.

[IDBoating]

Also, with the auto-bilge circuit, you would want to wire battery direct to insure bilge function even if the main battery switch was off. So it would not be wired to the helm BUS. The auto side gets its own fuse and direct to battery or constant.

Correct again, that's how the auto side of bilge pumps should be wired. But the switched (manual) side is not; normally it obtains its power from a fuse or breaker as described. And how many times have we heard of float/other auto switches in bilge pumps failing with the owner unaware for who knows how long? In a crisis situation, you want and need the ability to manually turn on the pump(s), which means you're dependent upon a fuse or breaker, and if you electrically parallel multiple pumps the shared fuse or breaker becomes a single point of failure affecting all pumps.

Switch failures are rare. Even with a single pole, you can supply 2 pumps, each with its own fuse right off the switch output. One pump failure would not effect the switch or the other pump.

Again, you are correct. The discussion above was not that using a double pole switch is unreliable, but that it's often a greater wiring challenge than many owners are able or willing to take on. I would trust YOU to wire two bilge pumps that way and I'd sleep well at night knowing it was right, but I can't say that about every boat owner I know! {grin}

With a PCB output like the medallion or murphy, use a relay to supply both pumps and a fuse for each, right off the relay. Same results.

Yes, that would work, but unless the boat in question also provides standalone switches that drive the PDM's aux inputs, controlling a bilge pump like that requires that the CAN network be operating properly (helm unit accepts user input, transmits command via CAN to PDM, PDM switches its output, relays changes state, pump gets power). Whereas the simple and reliable DP switch you mentioned, with power running directly through it, will work no matter what as long as the battery has charge. Dead helm, dead PDM, dead CAN network, dropped key that turns on the helm, none of that matters - flip the switch and the bilge pump(s) turn(s) on. It's just a question of what you're comfortable with. I like systems that degrade gracefully as opposed to fail catastrophically. Just my personal philosophy, doesn't mean it applies to anyone else!

[Drnodegree]

where is the circuit breaker panel in the 2016 RZX?

just above the batteries are "some" fuses, but no "breakers".... the kind that pop out and you have to reset them by pushing them back in.

Two bilges is a great idea!

[KoolAid]

no breakers like that on your year model of boat.