Pond pump Tripping MCB

ngoodson1969 · May 2, 2010

Hi,

I have a job to re-visit, a tripping MCB that protects kitchen lights and garden pond pumps.!!! Hmmmmm
Anyway, it's a 10A breaker and I have checked every junction box along the way of the SWA that runs for bloody miles in the garden. Everything seems OK, I have fixed the lights outside that were tripping this breaker also. Now it's just the 2 pumps for the pond. They last about an hour then trip the breaker.
It seems a very long run of SWA, maybe this is a factor, or maybe the breaker isn't larg enough. I don't know the rating of the pumps. The kitchen light total watts isn't high though.....
Some thoughts anybody?
Cheers

Nick

acat · May 2, 2010

If the breaker was not large enough I would have thought it would trip on start up not an hour later. Sounds to me like one of the pumps is breaking down can you isolate each pump to see which one is causing the actual problem.

Chris

ngoodson1969 · May 2, 2010

Yes, I agree, it would be immediate rather than after an hour or so.
Yes, I will disconnect one and try the other. Cheers.

Nick

UNG · May 2, 2010

Pump needs stripping down and cleaning, just sorted some pond pumps for a mate of mine they were full of crud causing them to jam as they warm up as the water is not running through them properly to cool them

lewlec · May 2, 2010

hi

might be an idea to stick a clamp meter on to see how much current is being drawn on that circuit with everything on, it just may be overloaded.

regards
gary

Madmole · May 3, 2010

If its a hozelock titan pump, its probably full of water, they always leak. before diving in, use a multimeter to test the PD between the pond water and a good ground earth. Should be zero, but its not uncommon for pumps that are going to put a charge into the water, which of course is normally fibreglass or rubber insulated so nothing happens until somebody sticks a mitt into it and provides an earth

Any UV lamps, they can corrode and overheat and do funny things

Hope they have an RCB on that circuit?

Also a good practice to hang a Stainless steel rod into the water and bond it to earth so that the pond water is always safe (dont use copper or aluminium as they are poisonous to fish), although water isnt a good conductor, there is normally enough gunk, algea etc for it to conduct a little

GT1 · May 3, 2010

had one similar..

UV lamp had corroded, MCB tripped when lamp plus pump turned on.. but not when operated separately..
swopped out the lamp and all was well.

ngoodson1969 · May 3, 2010

This happens when no lamps are on. I have even isolated the pumps nearby with their 20A DP switch and the MCB still trips after a time.
I think the switch is knackered though, but even still I bypassed the switch so circuit straight to pumps and MCB still tripped.
All that's left for me to try is to disconnect each pump and see if one is faulty. They run for a while and have been cleaned out and so didn't really think it was the pumps.
I'm gonna change 20A DP switch at distribution board outside near pumps, change MCB at CU as it may be faulty and finally disconnect each pump in turn and see what gives??????

Cheers Everyone