Old Parvalux motor not starting properly

Hello everyone;

I posted a few years ago asking for advice on a small watchmaker lathe I bought, my skill is hammering metal by hand but enjoy making small parts for vintage turntables and tonearms.

In essence, I know little about precision measuring and complex lathe work.

Moved to a small flat, a hovel, and the electrics are far from perfect. The lathe knocked the internet router off every time I switched on or off, so I plugged it in on a different circuit and all was well for a couple of hours.

The motor has suddenly started stuttering, it sounds as if it's about to start then slows down and starts again. This goes on cyclically but never spins properly.

It's a 220v 0.7 amps 1/15 HP motor, with a condenser.

I could really do with some advice and would be grateful for all suggestions.

Cheers,

Victor.

Edited By Victor francis on 27/09/2023 17:59:26

My first thought would be has the capacitor failed or dropped it's value ? A good multimeter may have a capacitance scale. Noel.

Agree with Noel you need a new capacitor, if it has the value marked get the same voltage and uf value, usually a motor rated 350v ac 5uf will run those fractional HP motors.

You may want to check the switch is passing volyage/current before buying the capacitor.

Emgee

Thank you. There is no external capacitor, so I am assuming it has an internal one?

Emgee and Noel, thank you both. I do hope it's just a capacitor and not burned windings.

I am trying to split the motor now in order to look inside, unfortunately it's not playing the game and won't open. Tried some hammer persuasion, with a block of wood between it and the spindle, but still no luck.

.

Forgive me please, Victor … I am a little confused

You originally stated : “It's a 220v 0.7 amps 1/15 HP motor, with a condenser.”

capacitor = condenser

MichaelG.

Edited By Michael Gilligan on 27/09/2023 20:26:43

Michael, I should have said Condenser motor. That's what it says on the label. No, there is no capacitor on the exterior.

This is the motor, the cover on the rear of the motor just covers the connection block. No capacitor visible there.

Fair enough, Victor … thanks for the clarification

MichaelG.

.

 Just had a close look at your photo:

. 

.

I can see no sign of any number stamped between CONDENSER and MFD

… perhaps that is a multi-purpose rating plate

[ which would be rather naughty of them ]

Edited By Michael Gilligan on 27/09/2023 21:44:21

Parvalux still exist (Bournemouth I think) and I found them very helpful people whilst I was still working, there is a lot of information on their website as well.

Might be worth a phone call?

www.parvalux.com.

I have just remembered that some Parvalux motors had what looked like ordinary mains leads but contained extra cores to connect a remote capacitor.

Edited By V8Eng on 27/09/2023 22:11:36

Yes, contacting Parvalux might be the next step.

Michael, so there is a capacitor in the motor? It's frustrating because these days online information mostly consists of someone trying to sell you something, rather than folk taking things apart.

Usually the type of motor has 3 wires from the casing, perhaps 2 white and 1 black. The 2 whites connect across a capacitor (approx 5uf) and the black is neutral, live incoming is connected to either of the white wires, swapping live supply to the other white reverses the motor direction.

If the motor is this type you should find equal resistance on each of the windings, measured each wh to bk.

The capacitor will be either in the connection box or external, not inside the motor casing.

Emgee

Edited By Emgee on 27/09/2023 22:16:12

If there is no internal capacitor I am buggered. Here are some photos of the wiring connector, no capacitor in sight.

Does the motor plate have a TYPE named/marked ?

Can you see where the 2 yellows connect ?

Emgee

Emgee,

No, no type, just a reference number: Ref n-SD 18/003696

I was reading about start and running windings, could it be that what I am hearing is the start winding kicking in over and over again?

This motor has been running really well for so long, but I have never been able to take it apart to service it.

Hi Victor

The connections I described earlier were refering to an SD type motor but yours seems to be quiite different from anything I have seen before.

The current Parvalux catalogue lists SD type all with capacitors for 220v AC operation, I will check the diagrams again to see if there is an arrangement that has 4 wires exiting the motor windings.

Emgee

Emgee, thanks for your efforts. It's greatly appreciated.

As far as the motor being different than you have seen before, it would be. Nothing in my life is straight forward.

Victor

There are 2 schematics that show 4 wire motors 220v AC but both are capacitor motors, if you can establish with a resistance meter where the yellow cables are connected it may help.

Emgee

Emgee,

I will have to crack the thing open to do that. The spindle is quite soft and even using some wood to protect it from the hammer, it mushroomed slightly.

Tomorrow I shall try a local mechanic for a puller, hopefully that will split the thing up.

I am now wondering whether the running coil is burned out or there is some mechanical part which has failed.

Give it the "sniff" test if it has burned out, there will be a smell of burnt bakelite / insulating material.

.

Sorry, Victor … I am out of my depth and can’t answer that ^^^
You already have wiser advisors than me.

I was simply observing that although the word CONDENSER appears on the ‘template’ there seems to be no value shown. … I found that simple fact worth mentioning.

MichaelG.

Edited By Michael Gilligan on 28/09/2023 07:08:16