© 2014 Power-Tronics, Inc.
5
Note about Field Resistance
When measuring field resistance on a brush-type device, such as
a synchronous motor, measure the resistance through both the
field leads as well as directly on the slip rings themselves.
The readings you obtain should ideally be the same, but
no
more than 1% difference.
If you show more than 1% difference in reading your device has
brush and ring contact problems and will need cleaning or
maintenance before installing the PC1500BF.
Failure to correct brush and ring contact problems will
result in severe damage to the phase control as well
as possible PERMANENT damage to the slip rings
themselves!
NEVER
use emery cloth, carborundum stones, “comm
sticks”, or Tuner cleaner to dress or clean slip rings
!
They will make a bad problem much, much worse! Only use
Garnet or Flint sandpaper and clean with a clean rag soaked with
Acetone for best results!
