Roll Over Rube Goldberg

[Dougcole]

This is the infamous relay string that makes all three “standard” bilge pumps come on when the high water float switch is activated, a worthless, possibly dangerous feature in my opinion.
Since I have my port motor and fuel tank out of the boat, providing easy access to this panel, I took the chance to remove it.
For those of you at home who don’t feel like counting (and who could blame you), there are 7 (!) relays, 30 plus wires and a buss bar to make this work.
All of the pumps, float switches and alarms work fine without this mess. They just don’t come on all at the same time unless their floats all activate or you turn on the manual switches.

 

[jgwinks]

Yeah that sounds pretty dumb to me. My boat also has three pumps but each has it's own 3-way panel switch and float switch. They're in three separate non-connected bilge areas so there's no need for all of them to come on at once. Eventually real flooding would flow from one area to the others when it got deep enough but there's no benefit to running a pump in an area that's not flooded yet.

 

[Dougcole]

Yeah that sounds pretty dumb to me. My boat also has three pumps but each has it's own 3-way panel switch and float switch. They're in three separate non-connected bilge areas so there's no need for all of them to come on at once. Eventually real flooding would flow from one area to the others when it got deep enough but there's no benefit to running a pump in an area that's not flooded yet.

Exactly. Plus, about 5 or 6 years ago while we were 35 miles offshore crossing the Gulf stream one of those relays, or possibly a plug, failed and activated our high water alarm, which we could not turn off without clipping a wire. It scared the heck out of me.
I figured out how to deactivate this string back then, but the panel was so buried behind the motor and house bank that I left it in place until tonight.
Good riddance.

 

[KnotYet]

It is not obvious what problem they were trying to solve... but what nice connectors!

 

[Dougcole]

It is not obvious what problem they were trying to solve... but what nice connectors!

Lol. I know, right? It's some of the neatest wiring the factory did on the entire boat. It had a nice cover over it as well, which hid the relays and made it harder for me to find them.

 

[Comodave]

I would get rid of that unusual stuff and just wire them normally. Much simpler and easier to troubleshoot if you do have a problem.

 

[boomerang]

It is not obvious what problem they were trying to solve... but what nice connectors!

I know. right? Mainship obviously included these relays to be able to use smaller gauge wiring from the source to the switch and back down to the pump ,or they figured out after production had started that the wiring was too small and added relays close to the supply to remedy the problem. They (Mainship, Hunter/Luhrs) aren't known for their high-end wiring practices so to Doug, I would want to make sure that bypassing the relays will allow the pumps to work as they should.

 

[Comodave]

Yes, I would pull all that crap out and run new oversized wire to all the bilge pumps. I calculate for a 3% voltage drop and then go one size larger wire. I want the bilge pumps to have really good voltage so that they can perform extremely well. Also check that the switches are rated for the current. Put in automatic switches as needed and have a high water alarm.

 

[boomerang]

Whew, I can't imagine the undertaking of replacing all of the wiring concerning the bilge pumps on a Mainship 40! That would be my 1st choice, yes, but if it were me and my boat, I would just remount the relay panel contraption in a more accessible location and make sure all of the relays and connections are good. Sometimes ,at least on my junk, good enough has to be ok!

 

[psneeld]

I don't buy poorly designed or inadequately wired systems, but I certainly understand why all bilge pumps might/should be activated if a high water switch is activated and triggered by one float switch.

Assuming the high water switch is properly located and the bilge is not compartmentalized well.

If anything, it adds redundancy to all regular float switches in a real emergency (pretty much the function of the high water switch).

In this case it sounds over engineered and located in an inaccessible place which is not appropriate for emergency related equipment.

 

[boomerang]

Wait a sec. I reread the OP's first post and apparently the only thing that relay board does is turn on all of the pumps if the HW alarm comes on? Oh, heck no! I'd tear that thing out in a heartbeat! That's ridiculous, having every pump come on in the whole boat just because 1 bilge is potentially breached.

 

[psneeld]

If true that all pumps come on with just a falsely triggered high water alarm and not triggered by the high water switch AND a single regular float switch, then it is silly. Especially without a switch or means to disable.

If a system like that is desired, I see it a better idea if; the one for all and all for one concept is wired to require first a regular switch activation AND the high water switch activation.

 

[Dougcole]

Yes, the only function I can discern for them is to activate all four pumps when the high water float switch comes on. It is (obviously) all disconnected now and everything functions perfectly. I will take a look at the wire gauge for the pumps, but I don’t think that was their function, otherwise the pumps would not work when the relays are removed from the system.

 

[Shrew]

Under what conditions would I need a pump to be running that it (or the float) wasn't underwater?

Under what conditions would a pump not run when it or the float IS underwater.

Kind of stupid design. If you are in 'crash pump' mode, and need all the pumps, they will all already be underwater.

 

[KnotYet]

Under what conditions would I need a pump to be running that it (or the float) wasn't underwater?

Under what conditions would a pump not run when it or the float IS underwater.

Kind of stupid design. If you are in 'crash pump' mode, and need all the pumps, they will all already be underwater.

Exactly. One can imagine that a float switch can fail or be blocked by some debris.
But I think the proper way to deal with that is to pro-actively maintain and test the
systems, not implement a fail-safe mechanism that just adds another failure point.

 

[rslifkin]

Exactly. One can imagine that a float switch can fail or be blocked by some debris.
But I think the proper way to deal with that is to pro-actively maintain and test the
systems, not implement a fail-safe mechanism that just adds another failure point.

Agreed. I'd rather have a manual override switch to force a pump on than have an alarm force all pumps on.

 

[psneeld]

Rethink the all would be running if in the water and why maybe not scenario.

And why having all running might be important even if not currently in the water, especially if relying on manual "on".

Associate with auto engine shutdown with fire suppression.

 

[Wayne]

Rethink the all would be running if in the water and why maybe not scenario.

And why having all running might be important even if not currently in the water, especially if relying on manual "on".

Associate with auto engine shutdown with fire suppression.

On the Celestial (43' Albin destroyed by Hurricane Michael), the bilge pumps were wired as recommended here, but one Rule float switch stuck in the closed/run position. The wire had hardened, holding the switch in position. The continuously running pump overheated and melted the bearing holders - the armature then rubbed on the stater coils. The properly sized fuse finally blew but the pump and switch had to be replaced. I would never recommend running a pump dry on purpose - other than to test it momentarily.

 

[CaptTom]

My biggest concern with that arrangement would be having a single point of failure for all the pumps. Imagine if the "all on" logic got a false positive, burning out all the pumps. Or if it were triggered before the water got to some of them. Again, burning out some of your pumps when you need them the most.

 

[psneeld]

No system is perfect or maintenance free.

If worried about single point failures or dry running, install the pumps that can sense water and will only keep running if resistance from water is detected.

I guess I trust redundant systems over independent systems that seem to have a certain rate of failure too.

Not saying it "should" be done, but definitely worth thinking about.