Help......Freshwater pump

ianybw

ianybw

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I have taken on a 25+ year old boat ( groan ) and I am trying to sort out the freshwater pumps. The one under the sink works for 10 seconds, pumps out water and then stops. The breaker is thrown at this point.

I have tried keeping the tap open and the pump still fails. Is this just a 20 year old pump losing interest, or something else I can actually fix.

Shouldn't the pump just cycle and pump when the tap is open, or did I just make that bit up. Its the original pump, I know because like the other three in the boat, the housing is corroded to hell.

Any help is appreciated before I just go and burn money on a new one..............while I am at it if anybody has managed to make one pump beer all the better.

Sylvester The Cat.
 
You need to use an amp meter to check the current being drained by the pump. Expect around 10 amps. You can then compare the urrent the pummp takes with the rating of the breaker.
It is possible the breaker is popping at a lower current than rated or the rating is just to low.
However it is also possible that corrosion or gunk has provided a mechanical loading on the pump which makes it go slow hence draws too much current. good luck olewill
 
[ QUOTE ]
The one under the sink works for 10 seconds, pumps out water and then stops. The breaker is thrown at this point.

[/ QUOTE ] I take that to mean that the circuit breaker trips on high current.

Normally these pumps are controlled by a pressure switch so that when the tap is opened they cut in and either run more or less continuously while the tap remains open or cycle on and off if the tap is only partly opened. (the plumbing may or may not include a pressure accumulator to reduce the degree of cycling)

A typical current consumption is approx 6 amps* so the circuit breaker (or fuse) must reflect that but you will have to refer to the manufacturers data for individual pumps. They will draw a bit more than that when starting so the circuit breaker will have to accommodate that as well.

* I would not dispute William H's figure of 10 amps. The ones I was able to get a figure for easily were all 6amps.
 
I agree with both Will and Vic but maybe you haven't got an ammeter capable of measuring amps up to those levels. The chances are better than even odds that the breaker is defective and is cutting out too early. You could wire it out and observe, maybe watching the amps on the main panel, but better still can you take the supply to the pump temporarily from another 10A breaker instead? If that works, leave it running from the 'wrong' breaker temporarily until you can get a replacement for the other one.

Since the pump is actually pumping it is very unlikely to be drawing a massive fault current but use a bit of commonsense!
 
Before you go fiddling with electrickery take the outlet pipe off the pump and see if it will pump freely into a bucket. If it does you may simply have crud in the pipes.
 
[ QUOTE ]
Before you go fiddling with electrickery take the outlet pipe off the pump and see if it will pump freely into a bucket. If it does you may simply have crud in the pipes.

[/ QUOTE ] Worth a try i suppose as its not difficult to do but if the pipes are blocked the pump will just shut down on its pressure switch in the same way as it does when the tap is shut. Assuming this is a pump controlled by a pressure switch.
 
It may have a duff pressure switch, in which case it could be stalling and then going overcurrent. Does it slow down obviously before it stops? You should actually hear the switch if you listen carefully. Assume it has an accumulator which has been recently "aired"?, in which case it should run for a few seconds after the tap is turned off, then stop abruptly.
 
[ QUOTE ]
You should actually hear the switch if you listen carefully

[/ QUOTE ] Above the noise of the pump? Good point though. Some of these pumps use a micro-switch actuated by the pressure sensor that is rated at such a small current compared with the pump current that you wonder they ever work more than a couple of times. More likely that the contacts would burn out but they could become welded "on".
 
Thanks for all the ideas, I am at the boat this weekend and I now have somewhere to start.

The breaker is rated 7.5A, that is probably the easiest ( driest ) place too start.

Much appreciated, excellent forum by the way.
 
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