Applicable Systems
DR-PRO 50t
Symptoms
The crane reports a motor protection trip. The motor protection relay has activated due to overload or fault.
Possible Causes
- Motor current exceeding the protection setpoint
- Motor thermal overload from high duty cycle
- Short circuit or ground fault in the motor
Troubleshooting Steps
- Step 1: Check motor current against the nameplate FLA
Current is within rated value - Step 2: Verify the duty cycle is within the motor rating
Duty cycle is appropriate - Step 3: Test motor insulation resistance
Insulation exceeds minimum standard
How to Reset
To reset: Clear the overload or fault, then reset the motor protection relay.
Source: Demag DR Rope Hoist Manual, Demag Cranes & Components GmbH
Category: Crane