How to test a bilge non float switch

[RIN]

I have two of these on our boat. They are a very important safety fitting and I want to know if they work.

How can i test them in situ? I don't want to flood the bilge or remove them. I have tried leaving a saturated sponge across the terminals but no pump operation.

Are they a good idea or should i replace with an actual float switch?

Cheers
Richard

 

[Catalina36]

If they don't work with a wet sponge they probably don't work. I had a different make of electronic switch and that one eventually failed "on" and burnt the pump out. I've also had Rule float switches with a steel ball in them which don't always come on. It seems like it should be simple enough but doesn't appear to be.

Could you arrange a short length of plastic hose full of water to bridge the contacts?

 

[Rocksteadee]

Have you tried holding both the terminals on the left of pic with thumb and forefinger? Maybe licking finger and thumb to increase conductivity

 

[Portofino]

I wet sponge mine .Sets them off .

 

[Chris H]

Looks like there is only one screw holding it on, take it off and pop it in a bowl of water, checked all mine after I found this....

 

[PCUK]

Can't you just bridge them with a cable?

 

[RIN]

Thanks for the replies, I have bridged the terminals (not sure if I should) and nothing happened. I've just found one on the internet 180 EU! but interestingly it talks about a time delay to avoid chopping (google translated)
I know the pump works which is some distance from the sender. I think I will try and do what Chris H suggests and unscrew it and put the contacts in a shallow bowl for a few minutes and see what happens. Trouble is that the cable immediately goes into a tunnel and there does not appear to be any slack and I really don't want to cut the cable. Also I will try and find out if there is a 12v supply to the sender which will mean some needle and haystack fun upstream in the cramped part of the boat.

 

[Catalina36]

Can't you just bridge them with a cable?

Of course. Blimey I'm losing the plot! Sometimes I think on railway lines. How to make it wet...?

 

[Catalina36]

Thanks for the replies, I have bridged the terminals (not sure if I should) and nothing happened. I've just found one on the internet 180 EU! but interestingly it talks about a time delay to avoid chopping (google translated)
I know the pump works which is some distance from the sender. I think I will try and do what Chris H suggests and unscrew it and put the contacts in a shallow bowl for a few minutes and see what happens. Trouble is that the cable immediately goes into a tunnel and there does not appear to be any slack and I really don't want to cut the cable. Also I will try and find out if there is a 12v supply to the sender which will mean some needle and haystack fun upstream in the cramped part of the boat.

Deleted.

 

[Baddox]

Are they a good idea or should i replace with an actual float switch?

You could also look at a Water Witch as a similar replacement.
Bilge Switches – Water Witch Inc.

 

[girlofwight]

I‘m no expert but shorting the terminals, assuming its 12v or 24v, should set the pump off? Any delay function will be in the switch itself.

We’ve got a couple of these on board in grey water tanks, but suitable for bilge as well.

Whale Bilge Water Level Sensor BE9003

They do one with a delay as well. They can be tested with your fingers on two test points. We had some problems with them failing initially, and after 3 failed I complained. Whale promptly confirmed a known faulty batch and sent me a handful of replacements which have been trouble free. In a grey water environment they get used several times a day, and annually in the spring I take them out and clean them to get any winter slime off.