Wesley BC-6200-8SA - Manual (Page 43)

Curtis 1268 Manual, Rev. D
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step 6. Set NEG FIELD MAX at or below the FIELD MAX setting.
If the controller is tuned such that the system is operating
outside the motor’s safe commutation region, there will be au-
dible and visual indications. Under normal operation, the mo-
tor will emit a whine with a pitch that increases with increasing
rotation speed. If a “scratchy” sound is also heard, this is usually
an indication that pin arcing is occurring in the motor and it is
operating outside its safe commutation region. This operation is
normally accompanied by a strong smell from the motor. If the
brushes and commutator bars are visible, arcing may be visible.
The further outside the safe commutation region the motor is
operating, the worse the arcing will be. Operation outside the
safe commutation region is very detrimental to the motor.
The
FIELD MIN and possibly also the FIELD RAMP should be increased
until the indications of arcing stop. Decreasing FIELD MAP START
will also help to move operation back into the safe commutation
region.
The typical default field map settings are as follows.
5 — TUNING GUIDE
Further tuning of the field maps is described in procedures 5,
7
, and 9.