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Thurston Phoremost
 
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Default Fridge motor stuck

"Rheilly Phoull" wrote in message ...
"Thurston Phoremost" wrote in message
om...
I have a cyclic defrost fridge in near-new condition which was given
to me, the only problem was the defrost element open circuit.

Well, that fridge has been sitting there for a year, and now that I
decide to fix it, I find the compressor won't start. She hums, likea
the buzzy bee, then the overtemp protector clicks out.

Question - I know that the fridge mechs have a device that they
connect up to send a bit of a boost thru the compressor to unstick it,
but I'm a bit tight, and if I can rig up a relay and/or a capacitor
and/or a triac and/or an instantaneous switch or whatever to do it
myself, I will.

What's the general principle of it? Am I correct in assuming that the
idea is to connect a capacitor across the inductance of the start
winding to make a LC circuit whose resonant freq is close to mains
freq, so that you can get a lot of current flowing for a small
fraction of a second?

So... how do I make one of these gizmos? Can't be too hard, surely?

T.

Put the cap in series with the winding, note that start caps don't need the
full mains rating since they are in circuit for such a small time. See if
you can find one about 250 uF and about half your local mains voltage. You
can turn off the power if it doesn't get away in a second or so. Might take
a few "Hits".


Thanks for that. I'd imagine you'd have to be careful not to allow the
current to flow for too long. I'd say there must be some sort of
current limiting arrangement built into the kick-start machine that
the fridge mechanic uses, say, something that would limit the start
winding current to two or three times the current that the winding
would normally carry? Also, I'd guess that it would have a timer in it
to ensure that the high current was applied only for a short
predetermined time?

T.