LEESON NEMA 4X SCR Control: 174903.00 (Obsolete) - Manual (Page 11)

10
TRIMPOT FUNCTION ADJUSTMENT
1. TURN DRIVE POWER OFF!!
2. Connect DC Voltmeter: + to +ARM, - to -ARM.
3. Set meter voltage range: (90VDC or 180VDC).
4. Turn power on. Set speedpot at 100%.
5. Adjust MAX trimpot to rated motor armature
voltage as shown on meter.
NOTE: A tachometer or strobe may be used in
lieu of a meter. Follow preceding steps, except
adjust MAX trimpot to rated motor base speed
indicated by tachometer or strobe.
1. Set speedpot to zero (fully CCW).
2. Rotate MIN trimpot CW until motor rotates.
3. Slowly rotate MIN trimpot CCW until motor stops.
NOTE: If motor rotation at zero is desired, rotate
MIN trimpot CW until desired minimum speed is
reached.
1. Set speedpot at 50%.
2. Observe motor speed at no load condition.
3. Apply a full load to the motor.
4. Adjust IR COMP trimpot CW to obtain the same
motor speed as with no load.
1. TURN DRIVE POWER OFF !!
2. Connect a DC ammeter between A1 on the
motor and +ARM on the control. This is in series
with the motor.
3. Turn power on.
4. Set speedpot at the 50% position.
5. Set CUR LIM trimpot fully CCW.
6. Apply friction braking to the motor shaft until
motor is stalled (zero RPM).
7. While motor is stalled, set current at 125% of
rated nameplate motor armature current by ad-
justing the CUR LIM trimpot.
1. CW rotation increases time of acceleration.
MAX
MIN
I.R.
COMP.
CUR.
LIM.
ACCEL
SETS MAXIMUM MOTOR
SPEED when speedpot is
set at maximum (100% rota-
tion CW). CW rotation of
MAX trimpot increases
maximum motor speed.
SETS MINIMUM MOTOR
SPEED when speedpot is
set at zero. CW rotation will
increase minimum motor
speed.
CALIBRATES SPEED REG-
ULATION - Provides a
means of improving motor
speed regulation in the ar-
mature feedback mode. If a
slowdown due to load
changes is of no concern,
rotate this trimpot fully
CCW.
LIMITS DC MOTOR ARMA-
TURE CURRENT (Torque) to
prevent damage to the mo-
tor or control. The current
limit is set for the rated mo-
tor current. CW rotation of
this trimpot increases the
armature current (or torque
produced).
ALLOWS ADJUSTMENT OF
ACCELERATION by user.
TRIMPOT ADJUSTMENT PROCEDURE