F911
SHORTED SCR
Otis · DSD 412 Elevator System
What does F911 mean?
This fault is detected by the PCU Diagnostics function (Function #998) and indicates that one or more SCRs (Silicon Controlled Rectifiers) or doubler packs within the DSD 412 drive are shorted.
Common Causes
- Failure of an SCR or doubler pack, resulting in an internal short circuit.
Repair Steps & Checklist
Click steps to track your progress.
- 1
Remove power from the drive.
- 2
Identify and replace the shorted SCR(s).
- 3
Repeat the PCU Diagnostics function to confirm the issue is resolved.
Verified technical data. Last updated: March 2026
Related Faults
Source: Otis DSD 412 Elevator System