Re: synchronous motor

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Anthony R. Mollner" <penny831@xxxxxxxxxxxxx>

Hey Doc.
  Looks like I'll need to buy the start capacitor 'cause mine are of a much
higher rating. I have a case of 35 uf caps but that would be to strong by
your advice. I was checking out McMaster-Carr and they have some that look
about right. What do you think of this? #7602K26
370 VAC, 7.5 Microfarad Rating AC Motor-Run Capacitor
In stock at $4.64 Each. Should I go a little higher?

Tony



-----Original Message-----
From: Tesla list [mailto:tesla@xxxxxxxxxx]
Sent: Monday, February 19, 2007 8:49 PM
To: tesla@xxxxxxxxxx
Subject: [PHISH] Re: synchronous motor


Original poster: "resonance" <resonance@xxxxxxxxxxxx>



Tony:

That was 4-12 uF not picoFarads.

This for a small 1/20th to 1/10th HP motor.  For a larger RTTY type
synchro motor the value is usually around 10-12 uF and sometimes
higher.  Values higher than this typically feature a disconnect
centrifugal switch inside the motor housing at the real
tailshaft.  If you operate the motor with more than this amount of
capacitance the high currents could damage the windings or burn the
motor up. Good idea to monitor the currents while you are testing to
be sure it is within the range stamped on the motor's plate.

Dr. Resonance


>Original poster: "Anthony R. Mollner" <penny831@xxxxxxxxxxxxx>
>
>I see now. Thanks Gerry, I hope to do some tests tomorrow. I dug out an old
>momentary push button that's perfect for this now all I need to do is to
get
>a Cap. that will work. I have a few but I think they are to high a value.
>Dr. Res. suggested 4 pf but what I have is in the 7-8 value. I might try
>them anyways and see what happens.
>
>Tony