Delta MH300 Series - Page 752

Chapter 14 Fault CodesMH300
14-25
ID No. Display Fault Name Description
21
Overload
(oL)
The AC
motor drive detects excessive drive output
current.
Overload capacity:
 Normal duty:
Sustains for one minute when the drive outputs
120% of the drive’s rated output current.
Sustains for three seconds when t
he drive
outputs 150% of the drive’s rated output current.
 Heavy duty:
Sustains for one minute when the drive outputs
150% of the drive’s rated output current.
Sustains for three seconds when t
he drive
outputs 200% of the drive’s rated output current.
Action and Reset
Action condition Based on overload curve and derating curve (refer to the section 9-6)
Action time
When the load is higher than the protection level and exceeds allowable
time, the oL protection activates.
Fault treatment parameter N/A
Reset method Manual reset
Reset condition Reset in 5 sec. after the fault is cleared.
Record Yes
Cause Corrective Actions
The load is too large. Reduce the load.
Accel. / Decel. time and the
working cycle are too short.
Increase the setting values for Pr.01-12–01-19 (accel. / decel. time).
V/F voltage is too high.
Adjust the settings for Pr.01-01–01-08 (V/F curve), especially
the setting
value for the mid-point voltage (if the mid-point voltage
is set too low, the
load capacity decreases at low speed).
Refer to the V/F curve selection of Pr.01-43.
The capacity of the drive is too
small.
Replace the drive with a larger capacity model.
Overload during low-speed
operation.
Reduce the load during low-speed operation.
Increase the drive capacity.
Decrease the carrier frequency of Pr.00-17.
Torque compensation is too
large.
Adjust the torque compensation (refer to Pr.07-26 torque compensation
gain) until the output current reduces and the motor does not stall.
Check if the setting for stall
prevention is correct.
Set the stall prevention to the proper value.
Output phase loss
Check the status of three-phase motor.
Check if the cable is broken or the screws are loose.