Float switch with bilge pump, know-how needed.

[noswellplease]

I have a good sized electric bilge pump which was needed recently when problems arose with water ingress. I purchased a float-switch but I'm wondering what might be the best arrangement? Would I be better off buying a smaller secondary pilge pump and wire it up independently together with a relay or just do it without any relay?. And then the discharge water, any suggestions how I might get this water off the boat without having a major plumbing job on my hands. Floating floor-boards are not a pretty sight in a boat.
Suggestions most welcome! Russ

 

[Talbot]

normal bilge switch gives you two options - power through the float switch, or direct feed.

 

[Guest]

Float switches can normally cover most 12v / 24v bilge pumps even quite large ones ... so that's not normally a problem.
The question is really do you need this to attend to the bilges when you are not there ? Or is a switch on affair when you are there ?

I had the boat filled one toime and decided on the unattended route. Having no time to wire in properly - I actually connected direct to domestic battery via a fuse. That way it was always ready to activate.
The delivery water was fed to the sink overboard - a simple T piece was inserted into the overboard pipe from sink and valve left open. The bilge pump pipe was looped to sit right uup under the sink-worktop so that sink contents wouldn't flow to bilges.
Boat sat like that for a number of years without any trouble at all. In fact is still that way ... and it's on my list to wire it up properly with over-ride switches etc.

As long as you have a breaker or fuse in the power to the switch ... you are at laest protecting the boat electrically.

Someone I'm sure will jump in with diagrams and wiring advise ... great ... but it's well to remember that sensible cabling up with fuse etc. is often enough.

 

[Stemar]

I recently wired up a pump with float switch. I also used a 3 position 1 - off - 2 switch with +12v to the 1 terminal, the pump to the common terminal and the float switch connected between terminals 1 and 2. This gives me auto, off & manual options.

As an extra, I connected an alarm to terminal 2, so if the float turns the pump on, the alarm sounds. As an added bonus, the alarm will sound if the switch is in the off position and the float switch finds some water, so you'll get a nag before the floorboads start floating!

 

[Bergman]

I was going to do that but:

What is the purpose of the "manual" option?

If there is water there then the pump will run because float switch is closed

If float switch is open its because there is not water there - so no point in turning pump on.

If manual position is a reserve position for case of float switch failure you would have to look in bilges to see water to know it had failed so would then either mend it or use manual pump.

Most probable cause of failure will be fuse going which will disable system whther automatic or manual

Or am I missing something?

 

[Stemar]

What is the purpose of the "manual" option?

The float needs a couple of inches of water to operate, so you'll never get the last bit out on auto. If the pump comes on on auto, I flick it over to manual when it stops and get another gallon or so of water out (Jissel has flat bilges). I tend to turn it to manual every few weeks to empty out the little bit that seems to accumulate before we end up with enough to set the auto bit off.

I suppose that manual is what I usually use, auto is more just insurance.

 

[Billjratt]

I use a relay from the interior light circuit of a car. With a little common sense it can be arranged to give the pump "run-on" after the switch thinks the bilge is dry, thus clearing a bit more, and reducing cycling. It also means that heavy wire can be used from battery - inline fuse- relay -pump in short lengths, while the longer 'control' wires (manual,auto) can be lighter. If you use auto, it's good to have a squeeker wired in parallel with the pump so you know it's being activated. That way, you can take action if it stays on for a while......assuming you're there of course.

 

[ShipsWoofy]

similar circumstances to you with the last inch of water.

Also I had one of the float switches fail a couple of months ago so there is another need to override the system. The failed type was the float flicking a switch type, the replacement is a rolling weight in the lever which must make contact as it tips.

 

[oldharry]

There are 3 types of float switch on the market: the first flicks a switc as the lever drops, and is cheap and rubbish. Water gets in and it fails just outside guarantee. A mechanical float arm switch is useless unless it has a mercury switch in it. Because this is totally sealed the water can not get to it, so it is less likely to fail.

However boith types can be jammed open or closed if debris is washed down in to the bilges. I have more than once had batteries totally flattened because the float arm got stuck in the 'pump' position either because debris got caught under it, and once because the arm just got stuck.

The best type has an electronic sensor with no moving parts, and so far I have never yet had a failure with one of these comparatively expensive units. However they are quite difficult to find in the swindleries.

 

[Guest]

[ QUOTE ]
There are 3 types of float switch on the market: the first flicks a switc as the lever drops, and is cheap and rubbish. Water gets in and it fails just outside guarantee. A mechanical float arm switch is useless unless it has a mercury switch in it. Because this is totally sealed the water can not get to it, so it is less likely to fail.

However boith types can be jammed open or closed if debris is washed down in to the bilges. I have more than once had batteries totally flattened because the float arm got stuck in the 'pump' position either because debris got caught under it, and once because the arm just got stuck.

The best type has an electronic sensor with no moving parts, and so far I have never yet had a failure with one of these comparatively expensive units. However they are quite difficult to find in the swindleries.

[/ QUOTE ]

And the sealed typew with a metal ball that falls onto the contacts when lever raises ? Is that rubbish also ?? /forums/images/graemlins/wink.gif

Mines still working well after many years of being left alone fending for itself !!

 

[oldharry]

And the sealed typew with a metal ball that falls onto the contacts when lever raises ? Is that rubbish also ??

Mines still working well after many years of being left alone fending for itself !!

Obviously not! But a lot of the cheaper ones are......