Help Pool Pump Problem

[Bugsy]

Went outside this morning and I thought my pool pump sounded a bit noisy. I found the back of the black electrical box that sits on top of the motor had blown off. I removed what was left of it and found the aluminium cylinder shown in the photo (empty). I looked behind the sand filter and found the other part which had clearly 'fired' itself out through the plastic box pulling out the wires as it went.

I really know nothing about electrics so would appreciate advice as to what it is - what does it do - and what do I need to do to sort it.

The motor casing was also, a lot warmer than usual.

Thanks guys.

[IMG]http://i129.photobucket.com/albums/p211/Bugbear2/P1010137.jpg[/IMG]

[Pierre ZFP]

That is a capacitor that the motor uses when it starts up to avoid putting a huge current load on the supply until it spins up and starts generating back EMF.   Anyway, the do blow from time to time, it's rare but I've had one go on a large-ish electric motor.  Good news is that they are cheap and readily available.  I'll have a search for you later or you can search for 16 micro Farad Electrolytic capacitor (400 or 450 volt , not critical)

[Pierre ZFP]

There you go, something like THIS

[Théière]

Maybe not on a slow boat from China though! or you'll have more problems with your pool at this time of year. Bugsy stick extra javel in to keep the pool clear whilst you sort this or pull the cover over.  This time of year pools can turn green v quickly

 

[Bugsy]

Thanks for that - awesome response.

One further question.

How is it wired in ?

I have the standard brown/blue/ yellow to the plug, thats no problem.

When it exploded it took the wires with it and I can see no evidence of where they came from.

[IMG]http://i129.photobucket.com/albums/p211/Bugbear2/P1010138.jpg[/IMG]

On the black block are the following marks - top to bottom - left to right.

V2 - W1

U2 - V1

W2 - U1

The old capacitator has just two identical brown wires and no markings to identify them.

Help . [:)][:D]

[Bugsy]

I've just located this diagram which suggests that it was wired to the two (now bent) tabs on the left of the picture.

[IMG]http://i129.photobucket.com/albums/p211/Bugbear2/Pumpwiring1copy.jpg[/IMG]

The only problem if this is right is that the old unit has just two brown wires with no markings.

The new one I've ordered has one blue and one brown.

Edit: I've just checked for continuity and

U1 - U2 = makes a circuit

V1 - W2 = makes a circuit

On this basis am I right in thinking that the BLUE wire goes to U2 and the BROWN one to W2.

Confused, moi  [8-)]

[Chancer]

its been years since I changed a capacitor on a decent sized motor but I frequently get to do them on VMC's, I am fairly certain that they are just wired in parallel across the motor winding, dont worry about the lead colours they are not polarised.

When it is a reversing motor such as on electric gates you have 2 motor terminals and one common, if say the resistance of each winding is 6 ohms then the common terminal will have 3 ohms to each motor terminal if that makes any sense, on one of these motors the capacitor is wired across the two motor winding terminals and not the common, I dont know if a pool pump has a reversing action though, if it does it would explain the multitude of terminals.

[Pierre ZFP]

From the diagram it looks like it was using a unipolar capacitor which can't be right as the picture you gave was clearly polarised.  By convention, the diagram shold have a small '+'  or a hollow box. on the pos side   In fact, the reason for observing the polarity is that if fitted the wrong way round, it can lead to the internal insulation breaking down in a DC circuit, it can also happen over time in an AC circuit (which is probably why yours failed in the first place).  So, since you will be apply an AC voltage across the capacitor (if only for a very brief time, the motor switching takes it out of circuit for running) it doesn't matter too much which way round but I would do as you suggest and go BLUE to U2, BROWN to W2.

Just a note of caution, these capacitors can hold a charge for many hours after the supply is taken away so be very careful of touching one of the wires even if the supply is disconnected - I know, I once got a helluva belt 6 hours after switching off a motor [:-))] 

[Théière]

[quote user="Bugsy"]The old capacitator has just two identical brown wires and no markings to identify them.

Help . [:)][:D]
[/quote]

Therefore a non electrolytic capacitor (AC motor)

What type of connectors are on the ends of the leads of the capacitor Bugs? Would expect to see a crimped on lug as they are a replaceable part and are normally clamped on, ok for U2 but for W2 it must have been soldered so there should be something remaining of the solder joint. Your picture is good but too much flash has taken out some of the detail.

What pump is it?

[Bugsy]

Those two twisted lugs next to U2 & W2 are all there is.

The wire ends are just bare as they were ripped out when the innards shot through the electrical box and into the wall.

I was planning on a ring connector for U2 and solder joint on W2.

[IMG]http://i129.photobucket.com/albums/p211/Bugbear2/P1010138-1.jpg[/IMG]

.

[Théière]

Zooming right in on those lugs, they look as if they are crimped around the remains of a lead right where your coloured lines end.