Bilge Pump Functionality?

[Rhendry]

Hello Friends:

I recently took delivery of a 2003 sailing cat. Bilge pump wiring question.

Currently, the bilge pumps (6) do not activate unless the bilge pump switch is turned on at the distribution panel.

I beleive this is not correct.

I think the pumps should be wired to automatically activate whenever water is presnt to pump. And that the "on" switch att he panel is an override.

Can you confirm this for me?

A few months ago a whole new bank of batteries was installed by the prior owner. I feel somthing was missed on the connection to the new battery bank.

Your reply is appreciated.

Ralph Hendry
Sailing Cat Simplicity
48' St Francis

[sailorboy1]

Normally a boat will have at least 1 bilge pump that is float operated and controlled by an auto-off-manual switch.

It isn't hard to install a float in line with the pump. But if you want to be able to operate the pump- manually (without reaching down to the float) you will need to also get an HOA switch or do some creative wiring.

Personally I feel it is best to be able to manually operate any automatic bilge pump.

[DotDun]

Originally Posted by Rhendry

Currently, the bilge pumps (6) do not activate unless the bilge pump switch is turned on at the distribution panel.

I beleive this is not correct.

I think the pumps should be wired to automatically activate whenever water is presnt to pump. And that the "on" switch att he panel is an override.

Can you confirm this for me?

When I was shopping for a new FP 9 years ago auto bilge pumps were a factory option.

Mine had the same as yours, a switch at the panel. I added a circuit directly from the house batteries, thru a circuit breaker at the batteries and looped to a float switch at each pump.

[GrowleyMonster]

You MUST have a way of manually operating at least one bilge pump, at least one per hull for a multihull.

You SHOULD have a bilge pump in each hull that will operate automatically, no matter what. That one should be wired right to a battery. You could have a dedicated battery and a small solar panel for charging to be totally independant of shore power and charger.

Most small boat automatic bilge pumps have three wires, and the correct switch will have three positions... off, manual on, (usually you have to hold it on) and automatic, and it is common to bypass the DC power distribution panel and feed this switch straight from the battery bank or a separate battery. I usually stick a gob of red hand or other epoxy putty type product on the switch that prevents the switch ever being turned full off. It is easy to accidentally turn it all the way off right before leaving your boat for a couple of months. Don't ask me how I came to realize that, please.

[belizesailor]

What make/model of pumps? I suspect these are actually fully automatic pumps (with an integrated float switch/water sensor).

[Cheechako]

Your bilge pumps should have a manual/off/auto mode.

[DotDun]

Originally Posted by belizesailor

What make/model of pumps? I suspect these are actually fully automatic pumps (with an integrated float switch/water sensor).

Originally Posted by Cheechako

Your bilge pumps should have a manual/off/auto mode.

Not all manufacturers use big 'bilge pumps'. My boat has Gulper 220 squeeze pumps mounted 18-24" above the bilge. I added float switches.

[belizesailor]

Originally Posted by DotDun

Not all manufacturers use big 'bilge pumps'. My boat has Gulper 220 squeeze pumps mounted 18-24" above the bilge. I added float switches.

By "squeeze pump" do you mean a diaphragm pump?

Regardless, I think it is a much better idea to have them mounted above the bilge (as you have done). I've replace a disturbing number of failed bilge pumps, on many different boats, over the years (especially newer Rules which are just junk). You would think something intended to spend its days sitting in bilge water would actually be waterproof.

[DotDun]

Originally Posted by belizesailor

By "squeeze pump" do you mean a diaphragm pump?

Yes, a diaphragm pump.

[tamicatana]

To answer the man's question,

My bilge pumps have an on/off/auto switch (in the engine room above the pump itself), but to get juice to the pumps, there is a breaker at the main AC panel. I leave that on, and the switches in the rooms on 'auto.'

You may not want power to the bilge pumps direct-wired as you suggest - electrical safety issues (the AC panel switch is a breaker) come to mind. As in, I'd rather my boat sink than burn... Having a single electrical cut-off to all pumps also might be useful.

[DotDun]

Originally Posted by tamicatana

To answer the man's question,

My bilge pumps have an on/off/auto switch (in the engine room above the pump itself), but to get juice to the pumps, there is a breaker at the main AC panel. I leave that on, and the switches in the rooms on 'auto.'

You may not want power to the bilge pumps direct-wired as you suggest - electrical safety issues (the AC panel switch is a breaker) come to mind. As in, I'd rather my boat sink than burn... Having a single electrical cut-off to all pumps also might be useful.

AC panel? I assume your panel has both AC and DC.

My house batteries are located in the starboard engine room. At the same location are cut-off switches for the starboard engine, the house load, and negative. Also there is a 100amp 12v breaker for the windlass. I mounted a 5amp 12v breaker next to the 100amp and looped a 12v lead from the house batteries to each float switch. Yes, it's breaker protected, but the breaker is not located at my 12v distribution panel in the salon. On the distribution panel, there are (4) breakers, one for each bilge pump allowing manual operation. I mounted the float switches at the bilge pump pickup locations.

[fishtrap]

A power switch is good to have even on an automatic switched pump if for no other reason there may be something in your bilge water you don't want pumped overboard. Fuel or bilge oil comes to mind. Sooner or later, even the most anally conscientious skipper will have that problem. Other reasons would be to over ride a fuse or breaker that didn't blow or to rewire any problem that occurs between the power source and the pump. Best to have an on/off/auto switch. Mount it somewhere it won't be inadvertently bumped to the wrong setting.

[mcarling]

Regarding the specific case of the OP's catamaran, I would be uncomfortable with the wiring arrangement described. I would want to reduce the number of single points of failure.

Originally Posted by GrowleyMonster

You MUST have a way of manually operating at least one bilge pump, at least one per hull for a multihull.

You SHOULD have a bilge pump in each hull that will operate automatically, no matter what. That one should be wired right to a battery. You could have a dedicated battery and a small solar panel for charging to be totally independant of shore power and charger.

I agree 100% in the case of a monohull or catamaran. In the case of a trimaran, I agree about 98%. In my opinion, having at least one automated bilge pump in each hull of a trimaran is merely wise, rather than critical. In other words, the failure to provide one in a monohull or each hull of a catamaran is a greater degree of stupid than the failure to provide one in each hull of a trimaran.

[Wotname]

I am going to throw in a dissenting view - I don't automatically believe that one needs an auto bilge pump. I believe that auto bilge pumps can give a false sense of security and aren't always suitable to every boat however there are situations that I would recommend them.

Consider the following points.

1. Auto systems are designed to cope with slow ongoing leaks while boat is unattended
2. Auto pumps rarely cope with a large ingress of water
3. Auto pumps only operate as long as there is sufficent power supply available

Taking the last point first ; they are fine if you are normally connected to shore power while boat is unattended but if not, you have to calculate your available power to run the pump. Being conservative, I would suggest that you derate your nominal house battery capacity to 80 or 85% and that you assume a 80 to 85% charge capacity as being available. Let's say this becomes 68% of your nominal capacity.

Then measure your bilge pump current draw under your normal operating conditions. Divide this into the derated capacity to give you the number of hours your pumps will run before you have a totally flat house battery.

Now for point 2 above. Measure your pumping capacity in gallons per minute under real life conditions. Please disregard any marketing information about your pump. It's real capacity is dependant on the head it has to pump and the constrictions of the plumbing that is peculiar to your installation. It's actual capacity will be a LOT less than the marketing literature might suggest. Measure it yourself to know for sure.

With the figures calculated as above, you now know how much water your auto system will remove before it stops working and allows the boat to flood.

You may be able to add some extra capacity if you have a good solar panel installation but unless you have hard data to work with, I suggest you leave that aspect out of the mix.

Looking at point 1 above, where are you going to get a slow leak on your boat?

Slow leaks typically came hand in hand with wooden carvel hulls, poorly maintained stuffing boxes or decks leaks (rainwater ingress); sometimes from poorly maintained seacocks. Fibreglass (or metal / concrete) boats with well maintained shaft seals and seacocks just don't have slow leaks.

And unless you have massive pumping capacity and a very large house bank (or shore supply), your pumps won't cope with a large leak - say hose broken on an open seacock or siphon vent clogged on head plumbing etc.

Do your own figures, work out your capacity and the maximum time the boat is unattended; work out how many gallons per day that your slow leak has to be less than for your auto system to reliably save your boat and then compare that to the complexity of the auto wiring system and finally make a judgement call as to whether it is a good idea for you or not. In essence, it comes down to risk management but please don't blindly think that you must have an auto system and that having it with make you safe from sinking!

You might have guessed that I have decided not to fit an auto system to my boat - but I am always aware that I must ensure there is almost zero potential for slow leaks in my hull and deck.

[nhschneider]

We have three bilge pumps with float switches, two of them have momentary 0n/off/automatic switches at the nav station. On those two pumps, there are also pump cycle counters.

On the on/off/auto switch, I installed a green LED that indicates that the pump is in the Auto mode, the fuse hasn't blown and is connected to power. I suppose it's possible that I could leave the boat with one of the switches in the 'off' position but I know my panel wouldn't look right.

Fair winds and calm seas.