One for the pumpophiles

[nigelb]

I was dewatering my oil last night and left the pump running with the venturi fully open. When I got up this morning the pump wasn't running. I think it may have stopped a few hours after going to bed. The pump was hot and would not fire up. I unplugged it and went to work and started to dismantle after first trying it on the switch. All I got was a buzzing noise. This is what I found:







The pump is still free turning and there appears to be some BCB's in the input side but this could be an accumulation from when the pump stopped. What I'm getting at is I don't thing the capacitor melt down was due to a total pump blockage. It may have been a partial blockage as the flow wasn't brilliant when the venturi was closed. It did seem as though it was slightly slower than normal.

What I need to know is what sort of capacitor do I need to replace this one and where would be the best place to get it from? I could do with getting the pump running asap. The majority of infomation on it seems to have been destroyed in the meltdown.
I've tried to take photos of the pump plate but cant seem to get a clear image so here is the info:
Lowara CEAM 70/5-V
Cod 10261450       0.55W
Q 30-80l/min
H 29-22m

Motor 55M712     50Hz
          220-240v   42A
ClF IP55
C 18uF 450v

[therecklessengineer]

I got mine from eBay.

18uF and 250V minimum are the values you're looking for.

However - something has obviously overloaded your pump. I'd look at it carefully when you fire it back up with a new capacitor.

[julesandtash]

As James said, what you want are the values after the C in the details you posted (18uF 450V is the capacitor rating - eighteen microfarads and four hundred and fifty volts).
We have quite a useful electrical shop locally that keeps things like motor run capacitors in stock but at rather inflated prices. Great if you need one quickly but otherwise I would go for eBay.

May be worth buying two so you have a spare to get you going if that happens again in mid batch

Something like this http://www.ebay.co.uk/itm/DUCATI-18-uf-CAPACITOR-MOTOR-RUN-450v-18mfd-FLYING-LEAD-/250823126626?pt=UK_Irons_Presses&hash=item3a66392e62

There are cheaper ones but I would avoid anything with chinese writing on it - Chinese caps do not have a good reputation.

[nigelb]

James/Jules...a huge thankyou for your comments and replies.

I've ordered the one linked in your post Jules....and James, I'll most certainly keep a close eye on the pump when it gets fitted.

I had a look at the cap on a spare pump I have...on of JGS's. As luck would have it, bad luck in this case, it was a 20uF and with spade fittings....ah well it was worth a look.

[julesandtash]

I would pretty much guarantee that it would work with the 20uF - I have used slightly different rated ones in the past to make things work and seem to have been OK.

But, for something that is left running unattended for periods of time in close proximity to flammable liquids, it is best to do things properly.

[Tony]

Caps are +-20% tolerance of face value typically anyway, 20uF will be absolutely fine, so long as it is a run capacitor and not a start capacitor.

Basically it's a sliding scale between startup torque and long term running efficiency.  Given the extra viscosity of veg, having a larger rated cap is probably what you want anyway!

[nigelb]

Caps are +-20% tolerance of face value typically anyway, 20uF will be absolutely fine, so long as it is a run capacitor and not a start capacitor.

Basically it's a sliding scale between startup torque and long term running efficiency.  Given the extra viscosity of veg, having a larger rated cap is probably what you want anyway!

What's the difference between a run and a start....and have I ordered the right thing?

[julesandtash]

Motor start caps are used to get the motor turning but, once it is, they are taken out of circuit by some kind of switching (like a centrifugal switch) and the motor keeps on running.

Motor run caps do start the motor but they also remain in circuit all the time the motor is running.

You have ordered the right one, it says motor run capacitor in the title.

[nigelb]

Thanks bud.

[oakwoodtv]

Motor run capacitors are very well designed now to be self healing.
If the dielectric film fails the foil plates burn away under film.
Leaving the capacitor functional at a slightly lower value.
After time the capacitance will fall to low to start the motor.

I have saved run capacitors from old motors and use a meter
to select the value rather than the printed value.

Voltage rating must be the same or higher than the one to be replaced.

Richard         

[nigelb]

The new cap arrived on Monday...most impressed with that considering I didn't order it til late Friday afternoon. I wired it in and the pump lives to fight another day.

As a precaution I drained out all the oil last night and refiltered it through a finer strainer. It's now ready to process on Saturday.

Thanks for everybodies help and input.

Nige

[nigelb]

As a footnote I processed a batch today. The advice given by James earlier in the thread re keeping a close and careful eye on the pump when fired back up was taken into account. It performed as well it ever has with no apparant issues.

Even the slight leak from the main seal has been put to bed since the removal and refit of the impellor housing. Well happy with that.

[Chug]

good to hear you're all sorted Nige, it's great when you've had something unfamiliar apart and fixed it innit.

[nigelb]

good to hear you're all sorted Nige, it's great when you've had something unfamiliar apart and fixed it innit.

In my life Chug these things are little victorys. However, my biggest issues are not bio related ...as some on here and the VOD will bare me out. There's some real bad shit coming my way.

[Jamesrl]

good to hear you're all sorted Nige, it's great when you've had something unfamiliar apart and fixed it innit.

In my life Chug these things are little victorys. However, my biggest issues are not bio related ...as some on here and the VOD will bare me out. There's some real bad shit coming my way.

We were going to have chat about that at the last BBB but it didn't happen, keep y'chin up Nige.