Otis · DSD 412 Elevator System
The contactor did not close or opened unexpectedly, or the motor voltage exceeded 30% of rated motor voltage #7 during Self-Tune #997. This fault sets the Severe Fault flag and forces the DSD 412 current reference to zero, leading to a drive shutdown.
Click steps to track your progress.
Check the contactor auxiliary feedback circuit to TB1-7.
Check contactor and LPR coils for proper operation.
Verify power is being applied to LPR from the power supply at TB3-5.
If no power at TB3-5, replace the A4 Power Supply PCB, as an internal relay failure is suspected.