PowerFlex Digital DC Drive User Manual -
Publication 20P-UM001C-EN-P - July 2008
Troubleshooting
4-13
The motor does not reach commanded speed.
The motor is turning in the wrong direction.
Drive Symptom
Action
The drive starts and the motor turns but does
reach the commanded speed.
The load may be too great for the motor and drive.
•
Remove the load from the motor and test for
the correct commanded speed. If the motor
reaches the commanded speed, then verify
that the measured armature current, using an
in-line current meter or DC clamp on meter,
equals the armature current feedback value
displayed in parameters 200 [Arm Current] and
199 [Arm Current Pct]. Increase the value of
parameter 7 [Current Limit], 8 [Current Lim Pos]
or 9 [Current Lim Neg].
•
Verify that the measured motor field current,
using an in-line current meter or DC clamp on
meter, equals the feedback value displayed in
parameter 351 [Field Current].
If the motor does not achieve commanded speed
continue with following tests:
•
Check the speed parameter limits: parameters
2 [Maximum Speed], 3 [Max Speed Fwd], 4
[Max Speed Rev] and 122 [Spd Feedback].
•
Check the analog voltage input and speed
reference values: parameters 1404 [Analog In1
Value], 1405 [Analog In2 Value], 44 [Speed Ref
A], 48 [Speed Ref B]
•
Check the setting of switch S9 and parameter
71 [Anlg In1 Config], S10 and 76 [Anlg In2
Config] or S11 and 81 [Anlg In3 Config].
•
Tune the analog input(s) using parameters
259-261 [Anlg Inx Tune] with the potentiometer
set at max.
•
The encoder pulse per revolution (PPR)
parameter (169 [Encoder PPR]) value is too
high.
•
The DC Tach Scaling is incorrect or the
jumpers are not properly set. Check parameter
562 [Anlg Tach Gain] and check the setting of
the DC Analog Tachometer DIP Switch S4 (see
).
Drive Symptom
Action
The motor is rotating in the wrong direction.
The motor is incorrectly wired.
•
Change the armature or field connections to
the drive.
•
The Polarity of the analog speed reference
signal is incorrect for the required direction.
!
ATTENTION: If the motor is turning the wrong direction and the drive is
using an encoder or DC analog tachometer for feedback and the speed
feedback is correct, then the feedback wiring must be changed. If using an
encoder, then two encoder connections must be reversed (A with A-Not or B
with B-Not). If using a DC analog tachometer, then the tachometer leads
must be reversed.
