Should Bilge pump be wired directly to battery?

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srah1953

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Greetings
My bilge pump is wired through the control panel with an ON/OFF/AUTO switch. It means that the domestic bank is never switched off. I am connected to shore power with a charger for a lot of the time so power consumption is not a particular problem.
My impression is that the "correct" way is for the pump to be wired directly to the battery. Should I change it or is that really necessary.
Thanks
 
Why do you need a permanent bilge pump in a modern yacht?

You have to be careful with bilge pumps that can turn a bucket of water in the bilge into a serious environmental offence.
 
I'm just getting one installed this week on my boat. I'm wiring directly to the battery by wiring it to the leads going into the battery switches.
 
srah1953 said:
Greetings
My bilge pump is wired through the control panel with an ON/OFF/AUTO switch. It means that the domestic bank is never switched off. I am connected to shore power with a charger for a lot of the time so power consumption is not a particular problem.
My impression is that the "correct" way is for the pump to be wired directly to the battery. Should I change it or is that really necessary.
Thanks
Click to expand...

Your 'main' bilge pump should be wired seperatly to you 'domestic battery' and the switch set to 'auto', this will enable you to switch everything else off when you leave the boat/go home.

I assume your electric bilge pump is either connected with a float switch or has a built in one.

That way worst case senario is it will drain your domestic battery (on you existing set up if shore power goes 'off' you have nothing) but a good domestic battery will run for a long time.

Mike
 
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It would be an idea to have a solar panel topping up the battery which runs the pump - and not all of us require domestic and starting batteries !

I'd prefer to wire the pump separately rather than leave everything live.

I knew someone with an old wooden boat which leaked from above and below; to try to establish how bad the problem was, they made up a counter which showed how often and for how long the pump was running.

In my experience float switches are one of those things where you definitely get what you pay for...
 
srah1953 said:
Greetings
My bilge pump is wired through the control panel with an ON/OFF/AUTO switch. It means that the domestic bank is never switched off. I am connected to shore power with a charger for a lot of the time so power consumption is not a particular problem.
My impression is that the "correct" way is for the pump to be wired directly to the battery. Should I change it or is that really necessary.
Thanks
Click to expand...
I'd suggest nothing should be wired directly to a battery without a fusible link.

My experience is that the float switch on the pump is always the first item to go home.
The most elegant situation is to have a solar panel (say 60 watt) charging the battery connected to the bilge pump.
 
charles_reed said:
I'd suggest nothing should be wired directly to a battery without a fusible link.

My experience is that the float switch on the pump is always the first item to go home.
The most elegant situation is to have a solar panel (say 60 watt) charging the battery connected to the bilge pump.
Click to expand...

No, the most elegant solution is a watertight boat which does not need the bilge pumped while on its mooring. I've been well involved with wooden boats where this is not going to be the case, but it should be the case for most GRP boats.
You will find several people on these forums who have had quantities of fuel or oil getting into the bilge. Having that automatically pumped overboard could lead to a very big fine these days.
I'm also not sure what failure a little Rule pump is going to save the average JenBenBavSterly from. Most of things that go through the hull will leak a lot faster than those things can pump, and most yachts don't have the battery capacity anyway.
 
lw395 said:
No, the most elegant solution is a watertight boat which does not need the bilge pumped while on its mooring. I've been well involved with wooden boats where this is not going to be the case, but it should be the case for most GRP boats.
You will find several people on these forums who have had quantities of fuel or oil getting into the bilge. Having that automatically pumped overboard could lead to a very big fine these days.
I'm also not sure what failure a little Rule pump is going to save the average JenBenBavSterly from. Most of things that go through the hull will leak a lot faster than those things can pump, and most yachts don't have the battery capacity anyway.
Click to expand...

Hmmmm .. suppose someone breaks into your boat ona mooring and leaves the window's open and then it pisses down for the next month whilst you're unable to visit the boat, how does your elegant solution deal with that scenario?
 
jimi said:
Hmmmm .. suppose someone breaks into your boat ona mooring and leaves the window's open and then it pisses down for the next month whilst you're unable to visit the boat, how does your elegant solution deal with that scenario?
Click to expand...

I've never left my boat on a mooring for a month without looking at it.
People who leave the hatches open will probably leave the lights on too, where is your elctric pump then?

I can see that a bilge pump is going to help if your boat leaks a certain amount of rain. One boat I sailed on, the mast drained into the shower, the shower sump pump was left on auto via its own fuse.

Some MAB owners seem much happier to fit auto bilge pumps than to keep the rain out. Are they addicted to the smell of mildew?
 
jimi said:
Hmmmm .. suppose someone breaks into your boat ona mooring and leaves the window's open and then it pisses down for the next month whilst you're unable to visit the boat, how does your elegant solution deal with that scenario?
Click to expand...

Hi Jimi,i think you would have a better chance of winning the lottery than have that happen to you,anyway most boats windows don't open.Ronnie.
 
Downside to leaving the domestic battery switch on is that you may have small leakages elsewhere through the domestic circuit or you may accidentally go home leaving lights left on (and no shorepower).

You say that it's connected via the on/off/auto switch but did you check where that gets it's power from - maybe it's direct from the battery.

Regarding the fuse - can we assume your switch panel has one built in?


Regarding the 'domestic battery will run the pump for a long time'.. I have some Johnson 4000 pumps installed.. needing a 20A supply each... perhaps I need an automatic engine start as well with remote pager warning :)
 
bigman1 said:
Hi Jimi,i think you would have a better chance of winning the lottery than have that happen to you,anyway most boats windows don't open.Ronnie.
Click to expand...

And, I assume , getting bashed by a boat leading to a leaking toerail is also an impossibility?
 
if you can borrow or buy a good clamp ammeter, you could tell if the domestic or engine battery bank is discharging even when switched "off" somewhere else.

Have a look at your battery terminals, and I bet you will see at least one mysterious wire tagged onto one of them.
 
For what it's worth, my domestic bank is always "on", in the sense that the busbar behind the panel is always live. There is no switch between the battery and the busbar (the connection on the battery is easy to access and remove if necessary for maintenance).

However, every single thing connected to that busbar is switched through the panel. So if all the panel switches are off, then I can be sure there is no leakage or live cabling anywhere else in the boat. This seems to me to be exactly equivalent to having one big "master" off switch. The only exception is the bilge pump, which is connected from the busbar through a control on the panel but has no "off" position (when would I ever want to select "off"?).

If you can examine your wiring and be sure that there are no sneaky taps off to things before the domestic busbar in the panel, then you could leave the master switch on, the panel switches off, and the only extra thing you've energised is the length of cable from the switch to the busbar. It's hard to see how that would cause any problems.

Pete
 
sarabande said:
if you can borrow or buy a good clamp ammeter, you could tell if the domestic or engine battery bank is discharging even when switched "off" somewhere else.

Have a look at your battery terminals, and I bet you will see at least one mysterious wire tagged onto one of them.
Click to expand...

It will be a very good clamp ammeter that is sensitive enough....
 
I have a Kew which specs at DC current 0 to 600A, to 1.5% accuracy with 5 digits.

Now that will tell the OP if there is a leakage of any significance, yes/no ?
 
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