Lenze · i550 Protec Drive
This fault indicates a short circuit specifically in the motor cable. When detected, the inverter immediately disables the drive, leading to the motor coasting without torque.
Click steps to track your progress.
De-energize the drive and lock out power at the main disconnect.
Disconnect the motor cable from both the inverter output terminals (U, V, W) and the motor input terminals (U1, V1, W1).
Measure continuity between each phase conductor (U, V, W) of the motor cable using a multimeter; expect infinite resistance (open circuit).
Visually inspect the entire length of the motor cable for any external damage, cuts, or crushing that could compromise insulation.
Inspect inverter terminal blocks and motor terminal box for stray wire strands, debris, or improper wiring that could cause a short.
Measure the resistance between motor phases (U1-V1, U1-W1, V1-W1) at the motor terminals to verify winding integrity; expect balanced, low resistance readings.