Fixing a water pump cheaply
10:53am 1st October 2012
Our pool cleaner pump just died and I was able to fix it for $14...
Seems to be the week for things electrical to break.
We have a pool with a Polaris pool cleaner, which does a very effective job. Unfortunately I noticed the other day that the 'overload' fuse on the board powering the pump for the pool cleaner was out. I reset it and turned on the pump, was greeted with a loud hum and then the overload fuse reset.. Okay, the pump was not happy.
Now, being okay with fixing basic electrical items, I took the pump out of the system and hooked it up in my garage. Again apply the power and I get a hum, except this time I quickly removed the power to stop it tripping the garage circuit. So the pump was responding to the power just not doing anything.
So I did a little of dismantling - basically taking the fan guard off the back so I could easily spin the motor. Now in order to test the operation of the pump spinning under power I would give the pump a quick spin in the right direction and whilst it was still in motion apply the power - and surprise surprise the pump would run quite happily.
Now with simple mains pumps in order to get over the initial high 'start up' load it needs some assistance which is supplied by a capacitor of just the right size to give it a kick to get running. If that capacitor is 'shot' that initial kick doesn't happen and you end up with a pump making a large hum and overheating (which trips a safety switch in the motor).
So a quick trip down to my local Jaycar for a $14 replacement capacitor of the same capacity and voltage rating (at least 400v in Australia) fitted back into the same bracket in the wiring box on the top of the pump and I had the pump running again.. Now given these pumps usually cost around $200 a piece new, that was a saving well worth having.
Note: If you are not confident with electronics do not attempt this, mains is involved; if in doubt defer to a professional.