Bilge Pump wiring

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David of Essex

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Visited the boat yesterday to make sure every things ok. Put the circuit breakers on and the bilge pump started and pumped water for a short period, not to concerned about the water as last week, drained the fresh water system and pipes. My concern is it seems that the bilge pump is only active with the circuit breakers on. Is this the norm?.
David
ps the boat is a Merry Fisher 925
 
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Often the norm. Problem is, if you are away for a long time, with a small leak, you get a lot of water build up. On the flip side, if you're not on shore power, the bilge pump could run and flatten the battery, leaving you with some water build up, and a flat battery.
 
In my boat the power supply from the bilge pump (inclusive floating switch) comes straight from the battery, with a fuse in de positive lead. A clean connection, no switches, no other things connected in parallel

I have added a 'bilge pump alarm', to be warned when the bilge pump operates more then a few seconds, f.e. in the case of a cooling water hose damage
 
Think yourself lucky Jeanneau even bothered with the auto pump David, my 805 never had one.

Easy enough to change. Locate the fuse for the pump, remove and insulate the 12v feed wire. Run a new wire from the electronics battery to the fuse, or from the input side of the isolator, whichever is easier.
 
PaulGooch said:
Think yourself lucky Jeanneau even bothered with the auto pump David, my 805 never had one.
Click to expand...

yes I was quite surprised to find out that my uncle's Bene620 didn't have a electric bilge pump, only the mechanical emergency one, but it still remains a very nice boat (for my uncle ;))
 
Nope and forget my comments else where. At least your genuine and give out as much as you put in.

Your bilge pump and radio should be wired in before the master switches, so your bilge pumps are always live.

I'll tell you where we finally found MF's connections, yours may be some where similar.

MF's master switches are mounted on a block of wood, unscrew this and behind it, is a sort of buzz bar with a load of spade connectors. Seem to remember, one is positive and one neg, might be wrong. Anyway connect all the stuff for emergency use here. I'd also over rate the wiring and fuses. If it gets to the point that you need your bilge pumps in anger, I'd rather the pump smoked a bit and kept going rather than stop on a minor whim.
 
PaulGooch said:
Often the norm. Problem is, if you are away for a long time, with a small leak, you get a lot of water build up. On the flip side, if you're not on shore power, the bilge pump could run and flatten the battery, leaving you with some water build up, and a flat battery.
Click to expand...

:confused::confused:

So whats your solution to this, a sunk boat but a full albeit sunk battery, or a nearly sunk boat but flat battery.:confused::confused:
 
On my Prestige 32 I had two auto electric bilge pumps one fore, one aft. And a further manual one aft too. Both electric ones wired the same as OP desc. But, looking at what the pumps were - basically shower drain pumps operated by electronic solid state conductor type swicthes that are know not to be the most reliable (thought mine do work) I was not happy with their ability to cope (reliably) with anything major. And, the fact that if the elctrics were off I had no pumps at all. So, I fitted a large whale pump in the engine area with separate float switch and loud alarm and its own connections to the domestic batts. (leaving one engine batt alone) All fused properly with test and mute switches etc. This way if something major happens (whatever that might be!!) and we are not there, I have a bank of three large batts running a decent pump and an alarm screaming.

Additionally, I was concerned that if one of the main inlet hoses/connections failed whilst we were underway, the first sign would be engines stopping. At least with the additional kit I would know something was wrong earlier.
 
I've been discussing this very item with my sailing confrère of this parish.

I agree that an auto bigle pump should be left on when the boat is unattended, but we do have reservations about leaving it connected to the main batteries (the boat is on fore and aft moorings, so no marina-style recharge).

Making the assumption that there is only a small amount of water likely to income, and not a catastrophic failure of say an engine cooling inlet pipe (which would overwhelm any normal bilge pump anyway) we have considered the use of a spare 12v battery unconnected to any others, to power the pump.

Using say a well-charged 100 Ah battery, a bilge pump using around 5 amps could operate for about 6 hours before flattening the battery. That's enough to shift approx 6000 gallons, or 60000 lbs or 26 tons of water. If there is that much water needing to be shifted, it falls into the emergency planning zone anyway.

It would be very comforting to know how many times the pump operated between visits, so one of those fancy monitors may be on the shocking list. :)



Does anyone know of a device which can identify a low voltage on a battery and set off an alarm by mobile phone ? I guess there will be security systems that do this, but I can't find a standalone one.
 
Best setup I have seen, so far :-

Battery switch, normally left on, small battery distribution panel, with breakers for various loads, bilge pumps included, big breakers for other switch panels, also left on. from there to a normal distribution panel, stuff like lights, instruments etc.


3 bilge pumps fitted, fore, aft & high level.


fore & aft have the usual on/auto switches + indicators.

High level has the float switch mounted a few inches higher than the others (deep bilge)

This is wired to an indicator, a loud alarm & a bright strobe light mounted on the radar arch.

If you are marina based, easy to spot there is something amiss, even at a casual (marina staff) glance.
 
hlb said:
:confused::confused:

So whats your solution to this, a sunk boat but a full albeit sunk battery, or a nearly sunk boat but flat battery.:confused::confused:
Click to expand...

Stop looking at the nurses bums Haydn and read all the posts. :)

I wasn't offering a solution, i was answering if it was the norm (the OP's original question). It is surprising the number of boats where the isolators do kill the auto pumps.

My solution was in post #5, the same as your solution, funny enough :)
 
My solution. Bilge pump controlled by a small microcontroller. Tests the pump ( by running it once every so often ) and the bilge switch ( by checking the current draw when pump is run and can take over if the switch fails ). Monitors battery voltage and talks to my phone via SMS messages. :) Reports on number and time of runs, battery voltages, charger operation, shore power presence. Also when away from the boat a loud alarm is set off if the pump runs too long ( make the marina earn their keep ) and when aboard a quieter onboard alarm.
 
Thanks for all your ideas, quite a few to ponder over. Hayden's idea with the radio and bilge connected on there own sounds good. The problem I have have is not being electrically minded.
David
 
PaulGooch said:
Often the norm. Problem is, if you are away for a long time, with a small leak, you get a lot of water build up. On the flip side, if you're not on shore power, the bilge pump could run and flatten the battery, leaving you with some water build up, and a flat battery.
Click to expand...
Personally I'd settle for the flat battery. My pump draws about 4A pumping 700gph. So in order to flatten my 110AH battery it would have to pump about 15000 gallons.

Which would you rather find - a flat battery or 15000 gallons in the bilges?
 
bedouin said:
Personally I'd settle for the flat battery. My pump draws about 4A pumping 700gph. So in order to flatten my 110AH battery it would have to pump about 15000 gallons.

Which would you rather find - a flat battery or 15000 gallons in the bilges?
Click to expand...

Try reading what i said, in both posts. Particularly the part about the boat not being on shore power, being left for a long time and the battery going flat. I didn't say the flat battery was especially undesirable, per se, but when it's flat, what do you suppose is powering the bilge pump ?

By the way, if you think a 110ah battery will pump 15,000 gallons of water, you need to think again.
 
PaulGooch said:
Try reading what i said, in both posts. Particularly the part about the boat not being on shore power, being left for a long time and the battery going flat. I didn't say the flat battery was especially undesirable, per se, but when it's flat, what do you suppose is powering the bilge pump ?

By the way, if you think a 110ah battery will pump 15,000 gallons of water, you need to think again.
Click to expand...
I think I read what you wrote carefully enough. The figure of 15000 is an approximation based on the manufacturers figures for flow and draw with a 4' head, and assuming I could draw about 80AH out of the battery before it was dead - all reasonable enough assumptions (although it assumes that battery started off well charged).

You might quibble with the figures - but they aren't going to be that far out. Anyway, IIRC 1000 gallons of water would weigh 5 tons so whether you would find 15000 gallons, or 5000 gallons is rather academic, 5000 would be more than enough to sink most boats.

In fact on my boat I have the bilge pump connected directly through to the engine start battery (as it is usually fully charged). It is wired through a dedicated CB bypassing all the isolation switches and fuse panel. When the boat was on a swinging mooring I used to have a small solar cell on board that I reckoned would go a long way to replenishing the drain from the pump, and the self-discharge
 
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