Revision: 1.0
Status: Example
Approval: Operational Governance Review
1. Purpose
Define the controlled process for transferring a UPS system into maintenance bypass mode while minimizing operational risk to protected critical loads.
2. Scope
Applies to planned maintenance activities involving UPS systems supporting critical infrastructure environments.
3. Preconditions
- Approved maintenance window
- Change authorization completed
- Relevant stakeholders informed
- No active infrastructure alarms affecting redundancy
- Generator systems verified available, where applicable
- Operational monitoring active
4. Responsibilities
| Role | Responsibility |
|---|---|
| Operations Lead | Approve execution and supervise operational activity. |
| Authorized Technician | Perform approved switching or operational actions. |
| Verifier | Independently confirm each critical step before and after execution. |
| Control Room / Monitoring Function | Monitor alarms, load state and operational stability. |
5. Execution Procedure
| Step | Room/Tag | Action | Verification | Sign-1 | Sign-2 |
|---|---|---|---|---|---|
| 1 | ER-2 / OSL-DC1-ER2-UPS-001-01 | Verify UPS is operating in normal online mode with no active critical alarms. | Load percentage, bypass availability and alarm state confirmed. | ||
| 2 | ER-2 / OSL-DC1-ER2-MBP-001-01 | Confirm maintenance bypass path is available, correctly identified and ready for controlled operation. | Asset tag and bypass source verified by operator and verifier. | ||
| 3 | NOC / OSL-DC1-NOC-MON-001-01 | Notify monitoring function before switching activity begins. | Monitoring team confirms awareness and active observation. | ||
| 4 | ER-2 / OSL-DC1-ER2-UPS-001-01 | Transfer load to bypass according to approved manufacturer and site procedure. | Load remains stable and supported without downstream interruption. | ||
| 5 | ER-2 / OSL-DC1-ER2-MBP-001-01 | Engage maintenance bypass according to approved switching sequence. | Bypass state confirmed locally and through monitoring system. | ||
| 6 | ER-2 / OSL-DC1-ER2-UPS-001-01 | Confirm UPS is isolated for maintenance where applicable. | Isolation state confirmed before maintenance work begins. | ||
| 7 | NOC / OSL-DC1-NOC-MON-001-01 | Confirm monitoring systems show stable operating state. | No downstream critical alarms or customer-impacting events observed. | ||
| 8 | ER-2 / Operations Lead | Confirm maintenance activity may begin. | Operations Lead gives approval to proceed. |
6. Risk Considerations
During maintenance bypass operation, redundancy may be reduced. No unrelated maintenance activities should occur simultaneously.
- Reduced UPS protection may expose downstream load to increased operational risk.
- Incorrect switching sequence may cause interruption to supported load.
- All actions must be performed by authorized personnel only.
- Any abnormal alarm or unexpected state shall stop the procedure immediately.
7. Rollback
If abnormal alarms, instability or unexpected operational conditions occur, the procedure shall stop immediately. Further action shall be approved by the Operations Lead before continuation or rollback.
- Stop active work immediately.
- Notify monitoring function and affected stakeholders.
- Assess current system state before any further switching.
- Return to approved operational state if safe and authorized.
- Record alarm state, timeline and operational observations.
8. Post Verification
- System returned to approved operational state
- Alarm and monitoring status verified normal
- Operational logs and records updated
- Maintenance or change activity formally closed
- Stakeholders informed of completion status
- No unresolved operational exceptions remain
9. Operational Notes
This example intentionally avoids vendor-specific instructions, switching sequences and site-specific infrastructure details. Public examples should demonstrate structure and governance, not expose sensitive operational information.