EMERGENCY · CONTROLLED DOCUMENT
AE-SOP-0212 — Power & Life-Support Failover
To preserve life support across the station when grid or generation fails, by shedding non-critical load and feeding the systems that keep stock alive first. The procedure guarantees that critical life support — circulation, aeration, and the pressure cascade — rides through any outage on reserve power, that loads are shed in a fixed priority before reserves are strained, and that the most sensitive systems never lose support, because the station's autonomy is measured in the hours its reserves can hold the critical bus.
ActiveEmergencyRev D
Doc Control AE-SOP-0212Revision DEffective 2090-04-22Next Review 2091-04-22Owner Engineering Dept.Approver Fleet AdmiraltyStatus ActiveClass RESTRICTED // TIDEWATER-EYES-ONLY
1. Purpose
To preserve life support across the station when grid or generation fails, by shedding non-critical load and feeding the systems that keep stock alive first. The procedure guarantees that critical life support — circulation, aeration, and the pressure cascade — rides through any outage on reserve power, that loads are shed in a fixed priority before reserves are strained, and that the most sensitive systems never lose support, because the station's autonomy is measured in the hours its reserves can hold the critical bus.
2. Scope
All station power events affecting life support across every zone.
- In scope: Outage detection, automatic failover, priority load-shedding, reserve management, and restoration to grid.
- Out of scope: Thermal-unit failure within an otherwise powered system, which follows AE-SOP-0211; pressure-cascade access discipline, which follows AE-SOP-0204.
3. Definitions
| Term | Definition |
|---|
| Critical Bus | The protected power circuit feeding circulation, aeration, and the pressure cascade, held up first in any outage. |
| Load-Shedding | The fixed-priority disconnection of non-critical loads to preserve reserve runtime for the critical bus. |
| Power Autonomy | The number of hours station reserves can sustain the critical bus with no external supply. |
| Failover | The automatic transfer of the critical bus to reserve power on loss of the primary source. |
| Black-Start | The ordered restoration of systems from reserves, bringing critical loads up before non-critical. |
4. Responsibilities
| Role | Responsibility |
|---|
| Engineering Dept. (Owner) | Owns the failover scheme; maintains reserves and signs the restoration sequence. |
| On-Call Responder | Confirms automatic failover, executes manual load-shedding, and monitors reserve runtime. |
| Husbandry Lead | Identifies the most sensitive systems and confirms they hold support throughout the event. |
| NEREID | Detects the outage, transfers the critical bus to reserve, sheds load by priority, and reports remaining autonomy hours. |
5. Load-Shed Priority Tiers
| Load Tier | Examples | Failover Action | Shed Order |
|---|
| Critical life support | Circulation, aeration, cascade | Hold on reserve | Never shed |
| Essential | Chillers, quarantine systems | Hold while autonomy > 12 h | Last |
| Operational | Imaging, comms, lab | Shed on failover | Second |
| Non-essential | Display lighting, offices | Shed immediately | First |
Note. The critical bus is never shed; non-essential loads drop the instant failover occurs, and essential loads hold only while autonomy stays above the 12 h floor — reserves protect living systems first, always.
6. Materials & Equipment
- Reserve power banks and standby generation, charged and fuelled
- Automatic transfer switch on the critical bus
- Priority-tiered load-shed control
- Reserve runtime and autonomy-hour readout
- Black-start restoration checklist
- On-call paging and dispatch kit
7. Procedure
7.1 Failover
- On loss of primary power, transfer the critical bus to reserve automatically.
- Confirm circulation, aeration, and the pressure cascade are holding.
- Page on-call and report the starting autonomy-hour figure.
7.2 Shed & Hold
- Shed non-essential and operational loads in fixed priority order.
- Hold essential loads only while autonomy stays above the 12 h floor.
- Never shed the critical bus; protect the most sensitive systems throughout.
7.3 Restore
- Black-start from reserves bringing critical loads up before non-critical.
- Return to grid only once the source is confirmed stable.
- File the outage report and recharge reserves to full.
8. Records
- Outage and failover event report (retained 5 years)
- Load-shed action log with timestamps
- Reserve runtime and autonomy trace
- Black-start restoration record
- Reserve recharge confirmation
9. References
10. Revision History
| Rev | Date | Author | Summary |
|---|
| A–B | 2086–2087 | Engineering Dept. | Initial issue; critical-bus failover and reserve banks established. |
| C | 2089-05-28 | Engineering Dept. | Added priority load-shed tiers and 12 h essential-load floor. |
| D | 2090-04-22 | Engineering Dept. | NEREID automatic failover and autonomy-hour reporting formalised. |