911
SHORTED SCRS/DOUBLER FAULT
Otis · DSD 412 DC Elevator Drive
What does 911 mean?
One of the SCR/Doubler packs has a short circuit between the SCRs. This condition is checked only upon request through the PCU #998 Diagnostics CDU function. The optional handheld PCDU can also identify the specific SCR pair that is faulty. A DSD Power Down is required.
Common Causes
- A short circuit has occurred within an SCR/Doubler pack.
Repair Steps & Checklist
Click steps to track your progress.
- 1
Initiate a DSD Power Down for the drive.
- 2
Run the PCU #998 Diagnostics CDU function to identify the specific shorted SCR/Doubler pack.
- 3
If available, use the optional handheld PCDU to identify the exact shorted SCR pair.
- 4
Replace the identified shorted SCR/Doubler pack.
Verified technical data. Last updated: March 2026
Related Faults
Source: Otis DSD 412 DC Elevator Drive