Cause : Switching operations too frequent comes when the power unit has executed too many switching operations for current limitation.

- closed-loop control is incorrectly parameterized.
- motor has a short-circuit or fault to ground (frame).
- U/f operation: Up ramp set too low.
- U/f operation: rated current of motor much greater than that of power unit.
- power cables are not correctly connected.
- power cables exceed the maximum permissible length.
- power unit defective.

Fault value (r0949, interpret bitwise binary):

Bit 0: Phase U.
Bit 1: Phase V.
Bit 2: Phase W.

1. check the motor data - if required, carry out commissioning.
2. check the motor circuit configuration (star-delta)
3. U/f operation: Increase up ramp.
4. U/f operation: Check assignment of rated currents of motor and power unit.
5.  
6. check the power cables for short-circuit or ground fault.
7. check the length of the power cables.
8. replace power unit.