RE: Phase adjust

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Basura, Brian by way of Terry Fritz <twftesla-at-uswest-dot-net>" <brian.basura-at-unistudios-dot-com>

John,

I tried the Phase Adjust set-up with a couple 1/2hp SRSG motors (1800 and
3600RPM). Capacitance ranged from 135ufd up to 405ufd in increments of
67.5ufd. Both motors exhibited the same behavior.

Running with 135-270ufd caused the motor voltage to drop as soon as the
Variac was moved off the stop. The phase did vary but only by about
5-degrees before it dropped sync due to the low voltage. 

Running with 337.5-405uf caused the motor voltage to rise dramatically
(from 119 to 141 volts) as soon as the Variac was moved off the stop. The
phase varied some but again by only 5-degrees. This also caused the Variac
to groan and the higher than usual voltage made the motors produce more
noise. Another thing which happened, and was repeatable, was the motor no
longer coasted after the power was removed (it came to a stop like someone
had put on the brakes). This was so pronounced that the highest capacitor
caused the set screws to shear off due to the motor stopping so fast...

Hope this is of some assistance.

Regards,
Brian B.

 -----Original Message-----
From: 	Tesla list [mailto:tesla-at-pupman-dot-com] 
Sent:	Monday, December 25, 2000 10:09 AM
To:	tesla-at-pupman-dot-com
Subject:	Re: Phase adjust

<snip>

It will be good when we hear more reports from folks using
various sized motors, and what cap values they needed to
use.  I do have a 1/4HP modified induction sync motor, which
I have yet to try.  The bearings are shot and it makes a
horrific racket !

John Freau