941
MOTOR THERMOSTAT FAULT
Otis · DSD 412 Elevator System
What does 941 mean?
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.
Common Causes
- The motor thermostat is open due to overheating or a circuit break.
- If the thermostat contact point is closed but the fault persists, there may be a problem with the power supply.
Repair Steps & Checklist
Click steps to track your progress.
- 1
Check the motor thermostat between terminals A4TB3(2) and A4TB3(8) for an open circuit.
- 2
If the thermostat contact point is confirmed to be closed but the fault is still present, replace the power supply.
Verified technical data. Last updated: March 2026
Related Faults
Source: Otis DSD 412 Elevator System