Table of Contents
Advertisement
12
Page
TROUBLESHOOTING
When a motor does not operate as expected, there
may be a valid reason other than that the motor is
bad. Troubleshooting involves looking at the
entire
system
of
environment. Problems that occur when a motor is
first put into service are most likely caused by
misapplication, improper connection or lack of
understanding. Problems that occur after a motor
has been in service for some time period may be due
to motor, control or environment.
These troubleshooting tips cover possible problems
as well as problems which were seen in the past.
PROBLEM
SHAFT ROCKS BACK AND FORTH
1. Motor leads T1, T2, and T3 are not connected to the
corresponding terminals on the motor control. T1 MUST be connected to
T1, T2 MUST be connected to T2 and T3 MUST be connected to T3.
2. Encoder cable is connected to control improperly . Check the
connections to the control per the card supplied w ith the control. The main
connections inv olv ed are the connections inv olv ing HS1, HS2, and HS3.
PROBLEM
ERRATIC SPEED
1.
Motor is going at or abov e base speed w hile cold. Allow
motor to w arm up before adjusting max imum speed.
2.
Feedback cable from motor to control is improperly shielded,
run w ith pow er cables, or defectiv e. Check the cable connections per the
card supplied w ith the control.
3.
Feedback signals are improper or missing. Check resolv er
signals against w av e forms on page 6. Check encoder w av eforms
against draw ing below . The draw ing below is for a four pole motor. An
eight pole motor w ill hav e the same w av eforms, but the interv al marked
as being 1/2 rev olution of the motor in the draw ing below w ill be 1/4
rev olution in an eight pole motor.
4.
Bearings are w orn. This w ill likely show up as increased
current and an ov erheating motor, but sev ere bearing problems may
affect speed control of the driv e.
5.
Sev ere load v ariations, such as a high inertia load changing
speeds quickly may result in speed being erratic. Consult POWERTEC.
6.
Driv e is unstable. Adjust gain and/or stability
Encoder waveforms
© copy right 2012 by P O WE R TEC Industrial Motors, Inc
POW ERTEC "F" Series Motor Manual
motor,
control
and
OFF
ON
OFF
ON
OFF
ON
OFF
ON
OFF
ON
PROBLEM
EXCESS END PLAY OF THE SHAFT
Check for excessive thrust loading on the shaft.
1. Check the tightness of the bearing retainer plate by checking
the bearing retainer plate screw s on the non-driv e end. (On some motors,
these screw s may be partially or completely hidden by the feedback
assembly .)
2. The bearings may be ex cessiv ely w orn.
3. The shaft bearing journals may be shot.
PROBLEM
EXCESS RADIAL SHAFT PLAY
*
Make sure radial loading on shaft is not
excessive.
1. The shaft may be loose in the bearing I.D.
2. The bearings may be ex cessiv ely w orn.
3. The bearing housing may be w orn.
PROBLEM
EXCESS VIBRATION
1. The load may be out of balance. Check the load balance.
2. The motor mounting bolts may be loose. Check for tightness.
3. The rotor may be unbalanced. Run the motor unloaded.
4. There may be ex cessiv e radial play . See abov e.
5. The bearings may be w orn. Listen for bearing noise.
6.
Noise on driv e speed reference.
PROBLEM
MOTOR RUNS HOT LOADED
DO NOT JUDGE MOTOR TEMPERATURE BY TOUCH.
USE A TEMPERATURE MEASURING DEVICE.
1. Check ambient temperature. It must be less than rated (40°C).
2. Check the load on the motor. Do not ex ceed rated current.
3. Check the duty cy cle of the motor. It may not ex ceed 100%
RMS.
4. The brake, if there is one, may not be releasing.
5. The bearings may be w orn. Run motor unloaded.
6. The rotor may be rubbing the stator. Listen for noise.
PROBLEM
MOTOR RUNS HOT UNLOADED
1. Check all items under Motor runs hot loaded.
2. The motor control may be misadjusted. Check motor control.
3. The encoder or resolv er may be improperly set up. See Page
6.
4. The motor may be demagnetized. Check terminal v oltages.
PROBLEM
MOTOR RUNS TOO FAST
1. Check the max imum speed setting on the motor control.
2. HS4 and HS5 on the encoder signals may be sw apped.
3. Resolv er or encoder misaligned.
4. Motor may be demagnetized. Check terminal v oltages.
Advertisement
Table of Contents
