Rockwell Automation 1391ES AC Servo Controller - Manual (Page 68)

Troubleshooting
Chapter 10
10-66
Table 10.C
General Servomotor Troubleshooting
Possible Cause
1. The motor connections are loose or open.
2. Foreign matter is lodged in the motor.
3. The motor load is excessive.
4. The bearings are worn.
1. The rotor is partially demagnetized causing excessive motor current.
2. Motor voltage is exceeding the maximum value.
3. The duty cycle is excessive.
1. Loose parts are present in the motor.
2. Through bolts are loose.
3. The bearings are worn.
4. GAIN setting is too high.
1. Phases A & B, A & C or B & C reversed
2. Sine, Cosine or Rotor leads reversed
3. Sine, Cosine, Rotor lead sets reversed
4. Combinations of 1, 2, 3
Condition
No Rotation
Overheating
Abnormal Noise
Erratic Operation - Motor locks into
position, runs without control or with
reduced torque
Test Point Descriptions Table 10.D describes the various test points found in the 1391B-ES
controller. Refer to Figure 10.1 for test point locations.
Table 10.D
Test Point Descriptions
Test Point Description
TP2 Resolver Amplitude (6.5V p-p sine wave at 9.3 kHz, 2.3V RMS)
TP3 Tachometer Output (2.0V/krpm or 1.2V/krpm)
TP6 I
D
(adjust using R45)
TP7 PWM Triangle (2.5 kHz, 11Vp-p)
TP8 PWM B
TP9 PWM A
TP10 PWM C
TP11 +5V DC
TP12 Signal Common
TP13 +12V DC
TP14 –12V DC
TP15 I
B
Reference
TP16 I
A
Reference
TP17 |I| Absolute Value
TP19 Buffered Velocity Command
TP21 Current Limit Calibration (adjust with R148, 3V DC=Rated Motor Current – TB2-5 Must be Grounded)
TP22 Current Command (3V DC=Rated Motor Current)
TP29 Current Feedback (Phase B, 2.5V Peak=Rated Motor Current)
TP30 Current Feedback (Phase A, 2.5V Peak=Rated Motor Current)
TP31 Regen I Limit (3.0V DC=Rated Motor Current)