Otis · DSD 412 Elevator System
This fault indicates that the DSD 412 drive has detected an open motor thermostat circuit, specifically between terminals A4TB3(2) and A4TB3(8). This condition does not automatically shut down the drive but is annunciated via the ALARM relay output K2.
Click steps to track your progress.
Check the motor thermostat between terminals A4TB3(2) and A4TB3(8) for an open circuit.
If the thermostat contact point is confirmed to be closed but the fault is still present, replace the power supply.