bilge pump setup

[taz4]

Hello everyone,

its come time to fit an automatic bilge pump. Ive got an idea and was wondering if its the right thing to do or not.

Is it possible to setup the bilge pump to run once there is a gallon or two of water in the bilge and then run until its empty?

I was thinking of doing it that way (if possible) rather than having the pump run every few hours and drain the batteries.

Is this the right way to go or should I just sit the pump in the bottom of the bilge and let it run as soon as the switch activates?

Thanks in advance

Taz

 

[Kim Schoedel]

Taz4, are you sure that you are taking on 1-2 gallons every few hours? This may be excessive. Anyway,

Ours sits on the bottom of the bilge and when the float activates the pump, it clears most of the water out. When ever I go up to the boat, I hit the switch at the panel for a bit just to make sure things are emty and working fine. Old habits are hard to break.

I could always leave the charger on for the bilge pump. I installed a very nice 3 stage battery charger that is supposed to be "smart" and "will not cook the batteries", I have a very hard time leaving it on when we are not at the boat. Batteries are costly kritters. It's not a big problem with draining down the batteries with the bilge pump as even in the winter I go to the boat anyway for a looksee or a winter sail. And can put a quick charge on.

 

[Frank Langer]

Yes, there is such an arrangement....

I do recall reading about a system for the bilge pump--I think it was in Nigel Calder's Electrical and Mechanical Manual (the boat bible!), where he talked about two levels of circuitry, whereby the bilge pump would only come on when the level rose to a certain point, and then would drain the bilge, but not come on if there was a bit of water left in the hose or bilge until it got to that previous level. He explained that this was to protect the pump (and the night time sleeper), and it seemed very effective.
While i think that's where I read about it, if you don't find it there, do keep looking because I know it exists, and someone else may give you a better reference for it.
Good luck!
Frank.

 

[valentor]

There are a few things to consider. As earlier stated, if you accumulate several gallons, you need to address your leak problem. Normal would be more like a gallon or so after a few weeks when it has rained heavily. Once that is taken care of, then you can design a proper system.

Many people prefer a two pump system. One to keep the bilge dry, the other to address catastrophies. The catastrophy pump should be something like a 3000 gallon/hour capacity with a float switch mounted higher than the bottom of the bilge. It should also have a free path (no check valve) and a 1.5 inch hose going overboard.

The problem with relying on that pump for keeping your bilge dry is that when the pump shuts off, a lot of water (the length of the hose times the 1.5 inch diameter) drains back into the bilge. To solve this problem, add another small (500 GPH) pump with a built-in switch. Plumb it with 3/8 inch hose overboard - and make the hose as short as possible. Now when the pump shuts off, only a very small amount of water runs back into the bilge. Those few ounces of water will evaporate in a few hours on a hot day and your bilge will be bone dry most of the time. Having any kind of check valve in this system is not seamanlike and is not a good idea.

Both of the pumps should be wired directly to the battery with a fuse and properly sized wires - so that no switches need to be set to make them work and protect your boat from sinking. You can certainly add a switch to turn them on, but you should consider a momentary contact switch - so that you don't accidentally leave them on and run down your battery.

Finally, if your boat is not at a slip where you can leave a battery charger on, consider a small solar panel to trickle charge your batteries to replace the power used to run the bilge pump.

I have a system like this and it functioned very well when the hull spung a leak a couple of years ago. The ensuing repair was quite extensive (and that's another story), but the pumps ran every few hours, pumped out a few gallons, and kept the boat floating until I could haul it.

Best of luck and Happy New Year!

-Steve

 

[Tom Plummer]

I use a two pump setup.

The primary is a remotely located 5.5 GPM diaphragm pump with a cycle counter and the secondary is a 3700 GPH submersible centrifugal pump. I use the diaphragm pump as the primary because there is no back flow and the pump can be run dry. When the float for the primary activates it cycles the counter and the pump on the counter starts an alarm timer. If the float stays activated for more than 8 minutes the alarm timer times out and sounds a loud audible alarm and lights an eternal alarm light. If the float switch deactivates in less than 8 minutes then it starts a second timer which keeps the pump on for 45 seconds to pump the hose from the bilge pickup to the pump dry. The cycle counter lets me know if I have any controlled leaks so that I can fix them before they become a flooding problem. A high cycle count = a problem.

The secondary is located just above the float switch activation point for the primary and if it comes on the immediately sets off the alarms.

 

[ted_reshetiloff]

Wow thats probably the most elaborate bilge pump set-up I've ever heard of. I use a diaphram pump and have a manual backup. But I would not mind adding an "eternal alarm light"

 

[treilley]

Tom, can you give specific details(make, model) on that diaphram pump and what type of pickup you are using?

Thanks

 

[Tom Plummer]

All the date is on the boat will try to get up there in the next few days.