Gray Water Tank Wiring

[Dockhead]

My boat has two small gray water tanks, which are each evacuated by a Whale Gulper 220 activated by a standard bilge pump float valve.


The original float valve in my heavier used aft one of these setups lasted 18 years from the time the boat was built (2001) until last summer. I replaced it with a cheap Oscalati one last July and it failed already just now.


I have a hunch that this is not an oddball defective unit, but rather -- the type of float switches being made in 2001 used mercury to make the circuit, if I am not mistaken. Now that has been banned, so I suspect that although the thing is rated for 20 amps, the Gulper 220 is burning the contacts with the startup surge from the electric motor, and that I shouldn't hope for the new one to last more than 8 months in its turn, and this does not seem acceptable to me.


One approach to solving this would be to rip the whole thing out -- I don't like anything about this system anyway -- and put in one of the new tankless pumps, like this one: https://www.whalepumps.com/marine/pr...ndlyID=Grey-IC


But then you've got to believe in the reliability of that system -- not too sure.


Otherwise, what to do? Maybe it makes sense to wire this thing up with a relay and flyback diode? So the flapper switch is not carrying any significant current?


Any thoughts?

[slug]

Level sensor controls a relay , relay turns on the pump

[Dockhead]

Originally Posted by slug

Level sensor controls a relay , relay turns on the pump

Yes, that was exactly the solution I was asking about.

[tanglewood]

Does the Oscalati switch have an electrical rating? A slave relay shouldn't be needed unless the rating is close or not enough. But "should" is the operative word. Maybe the switch is just a POS.


And are you pretty sure it's a burned out contact, and not a fouled mechanism?

[Dockhead]

Originally Posted by tanglewood

Does the Oscalati switch have an electrical rating? A slave relay shouldn't be needed unless the rating is close or not enough. But "should" is the operative word. Maybe the switch is just a POS.


And are you pretty sure it's a burned out contact, and not a fouled mechanism?

Rated at 20 amps, and the pump needs a 10 amp fuse, so should be plenty of capacity.


Possibly the switch is just a POS. But is it not possible that the contacts get burned because of the inrush current? It's a fairly hefty electric motor.


This is the new one:





Different brand but looks like the identical article -- so these companies probably just stencil brand some ultra cheap Chinese article. Upside of that is that this one just snapped into the bracket of the old one, saving me a lot of time handling that nasty smelling contraption.

[billknny]

Dockhead,

A separate question from the float switch...

How long have those pumps lasted for you? I have had F----all luck with them. A year at best.

For the switch, I have had good luck with the WaterWitch models. Without mechanical parts, the don't get hung up even in gunky gray water. A bit of planning to be sure they are located right, but they are physically compact, and have been nothing but reliable in gray water application.

[Dockhead]

Originally Posted by billknny

Dockhead,

A separate question from the float switch...

How long have those pumps lasted for you? I have had F----all luck with them. A year at best.

For the switch, I have had good luck with the WaterWitch models. Without mechanical parts, the don't get hung up even in gunky gray water. A bit of planning to be sure they are located right, but they are physically compact, and have been nothing but reliable in gray water application.

The Rule switch installed in the original build in 2001 lasted until last summer, so 18 years. In heavy service switching a gray water pump used for galley, after heads, washing machine.


I believe it was a mercury switch which I guess is inherently more reliable.

[billknny]

Originally Posted by Dockhead

The Rule switch installed in the original build in 2001 lasted until last summer, so 18 years. In heavy service switching a gray water pump used for galley, after heads, washing machine.


I believe it was a mercury switch which I guess is inherently more reliable.

I was actually asking about the Whale pumps...

And yes, the old mercury switches did last essentially forever. As long as you didn't break the glass, or sink the float, or corrode the wiring.

[Dockhead]

Originally Posted by billknny

I was actually asking about the Whale pumps...

And yes, the old mercury switches did last essentially forever. As long as you didn't break the glass, or sink the float, or corrode the wiring.

Ah, the original Gulper 220 is still going strong after 19 years. I have a complete new spare in my spares inventory expecting it must be end of life sometime soon, but it keeps on ticking. I've replaced the diaphragm a couple of times, but since I figured out that bleach kills them and stopped putting bleach down the drains, they seem to last for years.


It's one of two on board -- the other one evacuates the forward gray water system which is, however, much less heavily used -- just one sink and one shower. The Gulper 200 there is original, and still has the original diaphragm in it, and the original Rule float valve is still working, 19 years on.




The Gulper 220 is a fine pump. Some other Whale pumps are terrible, but I have high regard for this one.

[AndyEss]

There are solid state relays that might be used to change your float switch from the primary pump control to just a trigger for the relay. A 20A SS relay used to cost $10-15 each from Marlin P. Jones (US) but I bet they were made in China, so who knows what the supply chain looks like now.

I use solid state relays to offload the micro-switches in freshwater demand systems and to offload the mechanical relays in my old Autohelm 300 AP computer. I have been using them in these marine applications for only a year or so, and don’t know their longevity. If you pump enough power through them they do get hot, so get the heat sinks also.

[ggray]

I have a pair of gulpers servicing two small shower basins. They are (or were) controlled by float switches and manual switches.

I removed the float switches after one froze in the on position...when we were hauled out in the yard, and not on the boat.

We just push the button after taking a shower. The basin holds only about a gallon.

[a64pilot]

My shower sump has a gulper pump, original from 1987. I replaced the valves and diaphragm in it a few years ago.
Switch wise I won’t use anything except an Ultra Switch, it works by a float sliding up a rod, the float has a magnet in it and this magnet closes what is called called a reed switch. They last for decades, I know reed switches can have cycle lives well into the billions of times, they are often used on aircraft for squat switches and to tell where the landing gear position is etc.
Product-4

Oh, on edit I had to clean one of the switches once as nasty gunk built up in it and the float stuck but it was a very easy thing to clean.
Buy a new Whale pump or overhaul your old one and an Ultra switch and your done, for a very long time time.

Explanation of a reed switch, look under section on life, properly designed they last nearly forever partially because they are sealed like a light bulb is sealed
https://en.wikipedia.org/wiki/Reed_switch

The Ultra switches aren’t cheap, but you do get what you pay for.

Replace your bilge pump switch too.

[Dockhead]

Originally Posted by a64pilot

My shower sump has a gulper pump, original from 1987. I replaced the valves and diaphragm in it a few years ago.
Switch wise I won’t use anything except an Ultra Switch, it works by a float sliding up a rod, the float has a magnet in it and this magnet closes what is called called a reed switch. They last for decades, I know reed switches can have cycle lives well into the billions of times, they are often used on aircraft for squat switches and to tell where the landing gear position is etc.
Product-4

Oh, on edit I had to clean one of the switches once as nasty gunk built up in it and the float stuck but it was a very easy thing to clean.
Buy a new Whale pump or overhaul your old one and an Ultra switch and your done, for a very long time time.

Explanation of a reed switch, look under section on life, properly designed they last nearly forever partially because they are sealed like a light bulb is sealed
https://en.wikipedia.org/wiki/Reed_switch

The Ultra switches aren’t cheap, but you do get what you pay for.

Replace your bilge pump switch too.

I use Ultra switches for my bilge pumps. And even more importantly -- for my bilge alarm.


But my gray water tanks are full of all kinds of awful crap -- soap residue, fat, sludge, despite fanatical attempts to keep anything like that out of the drains. I don't think the Ultra switches would work very well in such a "chunky" environment.

[a64pilot]

Why do your sinks drain into the tank? Aren’t the sinks above water line?
My three sinks all have thru hulls and drain direct thru them.

The Ultra switch will actually work pretty well in that environment, the tube has a circle of holes in it of course and all of those holes would have to be clogged. Mount the switch on a stick so that all you have to do is pull the stick up to get to the switch, then it can easily be cleaned if needed.
I actually used a piece of angle aluminum but a stick would work.
we shower in the cockpit so only AC condensation and when the wife washes the bathroom floor does any water get into our sump, and that was why I had to clean the switch, stagnant water over a long time grew a bacterial slime

Is yours a tank or a sump? Mine looks to be a Kitchen trashcan, may not be, but sure looks like one. Anyway the top is open so the switch is easy to access, being a diaphragm pump, it’s in the engine room 8 feet or so away.

[a64pilot]

Oh, and I just remembered something we used to do with Powerboats, especially those with DD’s as they are a nasty motor. The bilge would get nasty and of course have an oily film and God knows what, so we learned to keep a couple of Dishwashing machine tablets in the bilge, tablets, but I guess powder would work, dishwashing machine as it’s a detergent that does no suds at all, but it does do a good job of emulsifying grease and cleaning things up with no suds.
If I would toss one or two in every month or so the bilge would be pretty close to spotless after a couple of months, the motion when the boat moved along with the detergent did it I believe.
You May try tossing in some tablets every now and again, it can’t hurt, but I bet it would help break down that nastiness