Shallow Bilge Bilge Pump

[hurricanehole]

Hi-I've installed a new high volume bilge pump. Then noticed that the level of the pump and switch is almost at the same height as the batteries. The boat is a Prout cat Snowgoose. If the water level does set off the pump and then gets above the batteries will they short out and the whole rig become useless?

[Lepke]

The point of the pump is to keep the water below the batteries and other equipment. The pump should be at the lowest point in the bilge. If you have a battery charger /solar keeping the batteries charged, water overflowing the batteries shouldn't be an issue.
If water overflows the batteries they will fail. Faster in salt water than fresh.

[hurricanehole]

Yep. It's Homer head slap time

[Privilege]

Many boats have two pumps. Below my high volume pump, in the very lowest part of the bilge I have a small 500gph pump.
I've adapted the outlet so that it leads to a 3/8" hose instead of the normal 3/4". That way, there is limited water in the hose to drain back into the confined bilge when the pumps kicks off. Either way, your main 'oh ****' pump should be above your batteries.

[mottseng]

What make and model of bilge pump did you install. I am purchasing a shallow bilge pump this week for my CS30 which has a very shallow bilge. I am looking at the Rule LP900S which is only 2.3" high and ejects 900GPH.

[mottseng]

Also, I plan on connecting directly to the battery and not through a switch or circuit breaker. That way I am confident that it would work when I am not at the boat.

[tkeithlu]

This gets a little complicated; bear with me. Batteries are mounted low in boats for obvious reasons. Bilge pumps run off batteries. Batteries that go under water short out immediately. Large leaks mean no battery and no bilge pump. But, no radio or other electronics, either, including your most likely means of calling for help if out of cell phone range. You then have a problem. My answer, and I don't know that there are not better, is one battery mounted behind the instrument panel, normally in parallel with the house bank, but capable of being isolated from the bank with a rotary switch and then supplying the wheelhouse radios, etc. by itself for at least long enough to call for help. It's a matter of the main DC bus being supplied by the house batteries or by this one battery or by both (the usual situation). What I have not done, and should, is connect a bilge pump to this elevated battery.

[darylat8750]

Originally Posted by Privilege

Many boats have two pumps. Below my high volume pump, in the very lowest part of the bilge I have a small 500gph pump.
I've adapted the outlet so that it leads to a 3/8" hose instead of the normal 3/4". That way, there is limited water in the hose to drain back into the confined bilge when the pumps kicks off. Either way, your main 'oh ****' pump should be above your batteries.

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I hope you meant to say pump (or at least pump pick up) should be lower than the batteries.

I have a boat with a flat bilge also. Pain in the neck. I have 2 high volume pumps low and a third way aft that is still below the batteries. Then I added a Gulper diaphragm pump WHALE PUMPS Gulper 320 Pump | West Marine with a strainer WHALE PUMPS Plastic Bilge Strainers | West Marine with the strainer at the lowest point in the bilge. The switch is one that will leave the pump on for 15 seconds after the water level is below the switch hight. This will "vacuum " almost all the water out and empty the hose so there is no water running back into the bilge from the hose. Still not as nice as a deep small volume bilge but works pretty well.

[Privilege]

Originally Posted by mottseng

Also, I plan on connecting directly to the battery and not through a switch or circuit breaker. That way I am confident that it would work when I am not at the boat.

The problem with this setup, is that if the pump gets stuck on, especially if there is a piece of debris slowing the motor down, the wires can overheat and cause a fire. The fuse or breaker is there to protect the wire.

[mottseng]

Originally Posted by Privilege

The problem with this setup, is that if the pump gets stuck on, especially if there is a piece of debris slowing the motor down, the wires can overheat and cause a fire. The fuse or breaker is there to protect the wire.

Thanks and yes the plan is to install a fuse as well.

[hurricanehole]

Using an elevated battery is a great idea. My starting battery is already much higher up. I'm also going to get the pump down as far as possible. Thks for all the replies.

[Boatyarddog]

Consider a remotely mounted pump, an electronic sensing switch, and a bilge water pick up mounted as close to the bilge floor as possible.
The electronic switches can be mounted much lower than the mechanically actuated ones.
And yes, do fuse the system as close to the battery as possible. But above the battery so as not to corrode the contacts.


Sent from SV Cloud Duster

[hurricanehole]

Ha, yes great idea. This morning I was hand pumping out water from the bilge after taking on water from a fwd hatch that failed while getting through the cut there at Indian Cay near West End Bahamas. Many waves up and over into the cockpit. Anyway I had the same idea, you'd need a bilge pump that can have a hose pickup to reach further down,the new ones I bought from Rule don't have that feature. With the intake hose down in the bilge and the switch there also that would be ideal. Wonder why the pumps aren't made that way. The diaphragm pumps are but are pricy and don't pump fast.

[Boatyarddog]

Originally Posted by hurricanehole

Ha, yes great idea. This morning I was hand pumping out water from the bilge after taking on water from a fwd hatch that failed while getting through the cut there at Indian Cay near West End Bahamas. Many waves up and over into the cockpit. Anyway I had the same idea, you'd need a bilge pump that can have a hose pickup to reach further down,the new ones I bought from Rule don't have that feature. With the intake hose down in the bilge and the switch there also that would be ideal. Wonder why the pumps aren't made that way. The diaphragm pumps are but are pricy and don't pump fast.

I think there are some designs, that sit very low and horizontally in the bilge.
Most are to large for a small boat.
They also tend to have the switch internally mounted, to high for a shallow bilge.
Some water is necessary to keep the pump impeller lubricated so it doesn't burn out.


Sent from SV Cloud Duster