Water pump

spaceHopper

I went to use the camper for the first time in ages and I hadn't used the water tank in over six months the pump was not working and a 10 amp fuse was blown. After changing the fuse still no joy but the heater could have blown the fuse too.
I wired it directly to the 12V batter (fused of course) and it wasn't working so I took it out of the tank (it's a submersible pump) and was going to fit get a new one http://www.omearacamping.com/whale-water-pump-gp1352-1332-p.asp
But for kicks and giggles I spun the impeller with screwdriver and tested it in work on a power supply, it's now working. Could it have been gummed up or will it giver trouble in future? I refit it or get a new one?

I'd try it on the original setup again just in case it's something else. Broken wire, crusty connectivity etc.
I'd be inclined to get a spare depending on how hard it is to setup a gravity feed in yours worse case scenario.
I have the cheapo version myself http://www.omearacamping.com/whale-water-pump-gp1002-429-p.asp no problems ever, I think it's probably moved about 1500-5000 litres.

spaceHopper

I tested it in the van and ohm'd it out first so it wasn't wireing.

I tried it with a PSU before I moved the impeller by hand it wasn't working you could hear the moter kick a bit so I tried moving it. Think I'll set up a bucket of water and connect it to a battery for a while to see what happens. Then refit it.

Yeah I would too.

spaceHopper

spaceHopper wrote: »

...and ohm'd it out...

spaceHopper

Tried the pump, it's dead, it ran OK in the tank for 5 - 10 minutes but then the started to die. The wireing was getting hot too. When I ohm'd it out it read 3 or less ohm's so I reckon the motor windings must have shorts. It might be ok if it's only run for a min or two but if it was ever left on it could burn out some witing. So I'll bin it and get a new one. I'll add a 4 amp fuse in line too.

That doesn't sound off the mark.
I've 2.1Ω across my coils on a smaller version.

Possible ceased bearing or obstruction? If the motor was operating at max torque the wiring would get warm it's only 5amp cable if mine's anything to go by. Torque loss could be (by a long stretch of the imagination) increased resistance due to heat.
Fixing it may take you past the point of no return though, I imagine it's fully sealed.

Would it still lose torque if you run it at 15v?

Recommended fuse type for yours is 5A (motor inrush is about 5-10 times the operating current)

Just thinking....if it is just a blockage you might have more success blowing it out rather than sucking it through. You could try fully submerging the pump and running it backwards with reversed polarity, perhaps a boosted voltage may help too. I've run mine at >15v I reckon it'll take it, given it's application it should be able to withstand charging voltages.

spaceHopper

It's not blocked had it running in the tank with no hose connectedit was pumping fine for the first while the started to fade and no the battery is fine. It'll drive over to omeara tomorrow and get a new one

I understand, I meant restricted. An increase in friction would stress the motor and explain the heat, it'd also make it much harder to start as the first turn takes the most electrons..co-eff. of static friction and all that. Just a guess all the same.
The motor is likely isolated from the pumping mechanism so water would flow with the motor under duress...actually by that logic now that I think about it turning it either way may not help.

spaceHopper

Done new high flow submersible pump fitted. Also added a slow blow 5A fuse just to be sure to be sure

Happy days.

When I was installing mine way back when, the best solution I had for a fuseboard at the time was a 4-way extension lead with assorted ceramic fuses in the 13A plugs. To this day my water pump and hob igniters are still on these;