Bilge Pumps

[craigmc67]

I have only one bilge pump at the moment and have bought a second one as a back up which I’m going to fit.

my boat is 25ft long 

I have two batteries one leisure and one for the engine 

my current pump is wired directly to one battery and has bypassed the isolation switch so has power all the time but has an on off switch on the dashboard 

I have bought a new switch but was wondering what the correct way to wire both pumps would be, ie one on each battery 

and was wondering if I should buy two new switches 

 

[BrundallNavy]

One to each battery will give a belt and braces approach, You could buy a double switch so both are next to each other and easily noticeable. 
 

Are you back in the water yet ?

 

[craigmc67]

Not yet hopefully will be back in the water in a couple of weeks if all goes well 

been busy at home varnishing all the flooring on the forth coat now 

[Vaughan]

The idea is that the bilge pump is always fed from the starter battery as this is charged at all times, but the domestic batteries might be discharged.  Apart from the bilge pump, the only appliances connected to the starter battery are those which are only in use when the engine is running, such as horn, nav lights and wipers.

The bilge pump is also the only thing which is allowed to bypass the master switches.

But what is that alarm for on the switch panel?  What is it supposed to warn you of?  Not trying to be thick, but I have never seen one before.

[Smoggy]

I would guess the alarm is to tell you the pump is running, would be annoying on a leaky old biodegradable but ok on a grp boat, I've not seen one with alarm either so it is purely a guess.

Anything with a memory that requires power is also allowed to bypass the master switches as are diesel heaters due to the cool down cycle but must be fused, it would be too easy to switch off the master switch with the heating running and have it sit there at full temperature without the fan running.

[craigmc67]

The Osculati bilge pump control panel allows 3 settings for control of any bilge pump with an automatic float switch. The switch panel has control LED lights, a rocker switch with 3 positions (automatic, off or manual). The panel features a loud and bright alarm system to indicate the water level of the bilge. The bilge pump switch panel is made from black plastic and is fused.

[Smoggy]

32 minutes ago, craigmc67 said:

The Osculati bilge pump control panel allows 3 settings for control of any bilge pump with an automatic float switch. The switch panel has control LED lights, a rocker switch with 3 positions (automatic, off or manual). The panel features a loud and bright alarm system to indicate the water level of the bilge. The bilge pump switch panel is made from black plastic and is fused.

You mean just like the picture you posted earlier?

I've always found those switches easy to knock off by brushing past them as the bottom of the rocker protrudes when in the auto position, I prefer the auto side wired direct which I guess you could do on the back of the switch.

[annv]

Hi Craig Why do you need two bilge pumps? For a cert c you only need one fixed and one portable. otherwise as Vaughan said. If you feel that you need two wire them to a separate battery supply by a fuzed connection. John

[craigmc67]

The boat is left for periods of time alone so just belt and braces and advised this is good practice 

[mjt]

On 27/05/2022 at 09:10, Smoggy said:

I've always found those switches easy to knock off by brushing past them as the bottom of the rocker protrudes when in the auto position, I prefer the auto side wired direct which I guess you could do on the back of the switch

I made my own switch panel when I rewired the bilge pumps (the original wiring was a real Heath Robinson horror story). I fitted it in the side of the helm console and made up a windowed hinged cover to protect the switches from being knocked. One pump is fed from the engine battery, the other from the domestic. As they both bypass the isolators the OFF position of the switches is useful for maintenance and saves pulling the fuses.

In my wiring the main pump is fed from the domestic battery on the basis that if it were the engine battery and ran it flat I wouldn't be able to start the engine to recharge and keep the pump running.