Siemens · SINAMICS G120
This alarm indicates that one phase of the inverter's output is disconnected, suggesting a break in the power path to the motor. This condition can lead to motor malfunction, reduced performance, or potential damage if operated under unbalanced conditions.
Click steps to track your progress.
1. De-energize the drive and measure the resistance of each motor phase (U-V, V-W, W-U) at the motor terminals; compare readings to specifications.
2. With power off, check all output cable connections for the motor (U, V, W) at both the inverter terminals and the motor terminal box for tightness and corrosion.
3. Measure the insulation resistance of each motor phase to ground and between phases using a megohmmeter (e.g., 500VDC or 1000VDC test voltage).
4. Verify the motor parameters (e.g., P0304, P0305, P0307, P0310) configured in the drive match the motor nameplate data exactly.
5. If using an output filter or reactor, inspect its connections and internal integrity for any signs of damage or open circuits.
6. Observe drive current output (e.g., r0027) on each phase using a clamp meter during a low-speed run to detect current imbalance.