"Brian" wrote in message
...
Graham wrote:
Hi, the timer on my heating hast stopped running, its a mechanical
driven by a small motor conected to 230Vac, the problem is a capacitor
(the only other component) that is in series with the motor. I shorted
the cap with a multimeter and the motor started running again.

The cap has the following info printed on it:

.1/10
250V ~
MKP1.70
.1/10
250V ~

What should I use as a replacement? What is the value exactly .1uF/10?
Which I assume is 10nF, true?

What exectly is the cap for?

Cheers Brian



If it's a clock then it will be a synchronous motor, and will have two
terminals only (no separate start winding).

I would have expected that the motor would be connected directly to the
supply, I can only suppose that the capacitor serves as a watt-less
voltage dropper.

Is there anything on the motor that suggests it runs on less than 230v?
120v maybe?


Graham,
looks like you are correct. It says 70V~ 50Hz on the motor. All the
start caps I have seen are pretty large things. The Motor here is very
small about 3/4 inch diameter and 1/2 inch deep. I assume that the
important point here is the frequency controlling the speed, not the
voltage. Is that correct?

I still haven't found a good replacement part yet.

Cheers Brian

Hmm interesting, yeah it sounds like the cap is just to reduce the voltage
then, and yes frequency is the important part. The cap should be non
critical, just don't go too big or you'll overheat the motor.