Inverter Overload shut-off (electronic overcurrent protection)
Mitsubishi Electric · A500 Inverter
What does E.THT mean?
This protective function activates to prevent damage to the inverter's output transistors. It triggers when a current exceeding 150% of the inverter's rated output current flows for an extended duration, typically if immediate overcurrent protection (for currents >200%) does not activate. The protection utilizes inverse-time characteristics, with an overload immunity of 150% for 60 seconds, leading to an inverter output stop.
Repair Steps
- 1
Measure the output current from the inverter (terminals U, V, W) to the motor and compare it against the inverter's rated output current.
- 2
Evaluate the mechanical load on the motor for any conditions that might cause excessive current draw on the inverter, and reduce the load if necessary.
- 3
Inspect the driven equipment for any signs of mechanical binding, excessive friction, or misalignment that could increase the power demand.