5 Troubleshooting 
 
 
5
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Er.620: Motor overload
Cause Conrming Methods Corrective Action
1. Wiring of motor and 
encoder is incorrect or 
poor.
Check wirings between servo drive, servo 
motor and encoder according to correct wiring 
diagram.
Connect wirings based on correct 
wiring diagram.
Prefer to use the cable congured 
by Inovance as standard.
When self-made cable is used, 
make and connect wirings 
according to hardware wiring 
guidance.
2. The load is too heavy. 
The motor keeps output 
of effective torque higher 
than rated torque for a 
long time.
Conrm overload characteristic of servo drive or 
servo motor.
Check whether average load rate (H0B-12) is 
greater than 100.0% for long time.
Replace a large servo drive and 
matching servo motor.
Reduce the load and increase 
acceleration/deceleration time.
3. Acceleration/
deceleration is too 
frequent or the load 
inertia is too large.
Calculate the load inertia ratio or perform the 
load inertia ratio auto-tuning. Then view H08-15 
(load inertia ratio).
Conform single running cycle when  servo motor 
runs in circular.
Increase acceleration/deceleration 
time during single running.
4. The gain is improper, 
causing too high rigidity.
Observe whether motor vibrates and generates 
noise during running.
Adjust the gain.
5. The servo drive or 
motor model is set 
incorrectly.
For IS650P series products, view serial encoder 
motor model in H00-05 and servo drive model in 
H01-02.
View servo drive nameplate and 
set servo drive model (H01-02) 
correctly and replace matching 
servo motor according to the 
IS650P User Manual.
6.  Locked-rotor occurs 
due to mechanical 
factors, resulting in 
very heavy load during 
running.
Check running reference and motor speed 
(H0B-00) by using the drive Inovance servo 
commissioning software or keypad.
Running reference in position control: H0B-13 
(input reference pulse counter)
Running reference in speed control: H0B-01 
(speed reference)
Running reference in torque control: H0B-02 
(internal torque reference)
Check running reference in corresponding mode 
is not 0 but the motor speed is 0.
Eliminate mechanical factors.
7. The servo drive is 
faulty.
The fault persists after servo drive is powered 
on again.
Replace the servo drive.
You can clear the fault or re-power on the system 30s after overload occurs.
Er.625: Brake applied abnormally
Cause Conrming Methods Corrective Action
1. The motor brake is not 
released.
Check whether the motor brake signal is active 
and whether the brake switch is damaged.
Perform the wiring again or replace 
the motor.