Non VW testing a capacitor

[Ian and Lins]

Sorry if this isn't quite the right forum but...I've got a log splitter with an electric motor to power the ,er, splitter. Tried to use it the other day and a bit of groaning and then nothing. It kept blowing fuses. The advice is the check the capacitor and then the stator. Could any one tell me how to check a capacitor? I do have a multi meter and know the difference between amps, volts and ohms but that's about it. Cheers.

[Cableguy]

Does your meter have a capacitance test capability?
Should have a setting giving readings in uf.
Set meter to setting applicable to your capacitor. Simply connect it up and press the button.
Make sure you have the polarity right

[badgerfax]

May help out

http://www.youtube.com/watch?v=iRt9WYK1wdQ" onclick="window.open(this.href);return false;


This guys capacitor was short circuit.

[icosahedron]

Please disregard the above video. The tester states that he is NOT familiar with capacitors and their working and his tests do not make sense. As for discharging one with a needle file!

You cannot test a capacitor with a multimeter, the only way is with an ESR meter. A capacitance meter will only measure the capacitance which is not an indication that the capacitor is good or not.

[camperclan]

You can test a capacitor for short circuit with a multimeter providing it has ohms or resistance check on it,depending on it's value you may need to discharge it first,best bet is to check it by substitution.

[Jeff J]

You can also test it for an open circuit, but only when the supply is applied. It should have the same voltage on each leg with respect to neutral or earth, if there is any difference then it is probably open circuit.Which is fairly common in this application ie. start capacitors for heavy duty motors.

[ghost123uk]

Motor start caps are so cheap you might be better off just replacing it and see if that fixes it

[Ian and Lins]

Ok and thanks. Would someone like Maplins sell them or would it be a fleabay thing?

[Jeff J]

Can you post the make & model of your log splitter or the details off the side of the capacitor. Or do a google search there are loads of options.

[Ian and Lins]

Motor start caps are so cheap you might be better off just replacing it and see if that fixes it

Thanks John. I have just tried that. The motor turns about 1/8 of a turn and then the fuse 'blows' again. Stator?

[ghost123uk]

Difficult to tell what it might be without actually being there with meter in hand. Was the cap you bought exactly the same ratings ? (I take it this unit is single phase ?)

[Ian and Lins]

Hi John,
Hope you don't mind me replying on the forum but I'm not sure if i could put images in an email.
This is the replacement diode; Does it matter which wire goes to which wire in the switch box?


This is the original;


I wondered if there might be a problem with the switch? It's a push and hold down button. The wiring is as in the next image. It has Brown/Blue input from mains into switch and two red cables that appear to go into the motor. Could I bypass the switch by connecting a mains input to the two red wires?


Thanks!

[ghost123uk]

Hi Ian, this is now slightly outside of my "hands on" experience

I know the basics of motor start caps having changed a few in my time, but my background is more "electronics" rather than this which is more "machinery" orientated "electrics", so I can not offer any further advice that is likely to be accurate.

p.s. = re the switch, from what you say it is a "push to make / release to break" type, so the motor will run only when the switch is held down, yes ?

If so then yes you could try bypassing the switch.

Sorry I can't be of more help and hope you get it sorted.

[Ian and Lins]

Thanks for keeping with me John. Bypassed the switch and still no go so deducing that the stator/motor is at fault. Will see what Screwfix have to say as it hasn't had THAT much use.
Thanks again.