Output Short-Circuit Detection

What does ALM4 mean?

This signal is output when an output short-circuit is detected, specifically when an E.GF (Output side earth (ground) fault overcurrent) occurs while Pr.249 is set to '2'. This indicates a severe fault on the output side that has triggered a restricted reset condition for earth faults.

• Output side earth (ground) fault overcurrent (E.GF) occurring when Pr.249 is set to '2'.
• Short circuit or ground fault on the inverter output terminals, motor, or motor wiring.
• Damage to the inverter's output power components causing a false short circuit detection.

Click steps to track your progress.

1. 1

   Immediately turn OFF the control circuit power to reset the E.GF condition as required when Pr.249 = '2'.

2. 2

   Inspect all motor power cables and connections for any visible damage, frayed insulation, or signs of a short circuit or ground fault.

3. 3

   Measure the insulation resistance of the motor and power cables to ground using a megohmmeter. Expect values >1 MΩ.

4. 4

   Check for continuity between motor phases and from each phase to ground. Verify no direct shorts exist.

5. 5

   Review Pr.190 to Pr.196 settings to confirm which terminal outputs the ALM4 signal, ensuring it is correctly assigned and monitored.