Lifesafety Power FPO75-C8D8E6M1 75W Power Supply 8 Relay Lock Control
The Lifesafety Power FPO75-C8D8E6M1 is a regulated 75W AC-to-DC power supply engineered for access control and life-safety door lock systems. Offering dual-voltage output (6A at 12V or 3A at 24V), this supply delivers managed power to electromagnetic locks, strike plates, and request-to-exit (REX) devices across multi-door installations. Eight independently fused relay outputs with selectable failsafe/failsecure modes provide the switching logic for access decisions without additional control modules, reducing wiring complexity and component count on mid-scale projects.
Key Features
- Dual-voltage regulated output: 6A at 12V or 3A at 24V — select voltage at installation to match your lock hardware (12V for standard electromagnetic locks, 24V for power-hungry solenoids or long-run wire pulls).
- 8 relay lock control outputs: Each fused at 3A, individually selectable for FAI (fail-as-is), failsafe, or failsecure mode — no external relay panel required for small-to-medium door count systems.
- 8 auxiliary DC outputs: Fused at 3A per output, assignable to Bus1 or Bus2 for powering request-to-exit buttons, door position sensors, or secondary monitoring devices.
- Per-output fusing and isolation: 3A fuses on all eight relay outputs prevent a shorted lock from cascading; bus-selectable auxiliary outputs decouple critical exit monitoring from lock power rails.
- E6 enclosure (30H × 23W × 6.5D): Compact wall-mount form factor with Mercury back plate and door-mount kit included — fits standard electrical cabinets or surface-mounted security closets.
- Failsafe/failsecure per-door logic: Configure each relay output independently without reprogramming the supply — useful for mixed-mode deployments (e.g., emergency exits failsafe, office doors failsecure).
This power supply is purpose-built for access control integrators working with legacy or standalone door control systems that lack native relay outputs. Rather than daisy-chaining external relays and fuse blocks, the FPO75 consolidates lock switching, auxiliary monitoring, and fusing into a single enclosure. The dual voltage selection eliminates the need for separate 12V and 24V supplies on hybrid installations — a single unit handles both, reducing spare inventory and simplifying troubleshooting in the field.
The per-output selectable failsafe/failsecure mode is critical for compliance: emergency egress doors must fail unlocked (failsafe) under power loss, while secured tenant entries typically fail locked (failsecure). This supply lets you set that behavior at the output level rather than at the controller, which is essential when integrating with dumb locks or legacy access control systems that don't expose per-door failsafe configuration. Each relay output drives its own solenoid or strike plate independently, so a single failed lock doesn't affect adjacent doors.
The 8 auxiliary DC outputs are often overlooked but valuable in real deployments: use them to power door position sensors (to confirm the lock actually held against a push), request-to-exit buttons (with built-in LED feedback), or wireless bridge modules that report lock status back to the access control system. Bus1/Bus2 selection provides logical separation — for instance, all request-to-exit devices on Bus1, all position-monitoring on Bus2 — making troubleshooting and future expansion cleaner.
Total power budget is 75W DC, which supports up to 6 standard 12V electromagnetic locks (12–13W each) or 3 heavy-duty 24V strikes running simultaneously. If your site approaches that ceiling, you'll want to review the access control system's unlock schedule — typically not all locks energize at once, but staging or sequential unlock strategies reduce peak draw. The FPO75 includes short-circuit and thermal protection on the main supply line; individual fuses protect each relay and auxiliary output from lock shorts or wiring faults.
Mercury manufacturing (Lifesafety Power is owned by Anixter/Tech Data) means the enclosure, fusing, and relay contacts are built to industrial life-safety tolerances. This is not a commodity 75W PSU — it's a certified component for fire/life-safety systems, subject to regular testing and traceability. For installations subject to NFPA 101 or local fire code, the Mercury pedigree and per-door failsafe selection satisfy auditor requirements without additional engineering sign-off.
Marty AllisonPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
We've specified the FPO75-C8D8E6M1 on dozens of retrofit and new-build access control projects, and it consistently earns its place in the bill of materials. The key differentiator is the on-board relay logic: instead of mounting a separate relay panel (Altronix AL-RELAY8, for example) next to your power supply, the FPO75 combines fused DC power and relay switching into one enclosure. On a five-door retrofit where space in the security closet is tight, that consolidation is a game-changer. The dual-voltage flexibility — 12V or 24V, selectable at installation — also eliminates the need to stock two different power supplies. We've walked into sites where integrators had installed two separate supplies (one 12V, one 24V) when a single FPO75 would have done the job, wasting cost and cabinet real estate.
What matters operationally: per-output failsafe/failsecure selection without needing a smart access control panel. Many standalone systems (older Honeywell, Salto, or even 3rd-party wireless lock controllers) don't expose per-door failsafe configuration — the controller fails one way globally. The FPO75 lets you override that at the power supply level, which is essential for mixed-mode sites. We've used it on parking garage retrofits where the ingress points must failsecure (security), but the emergency stairwell must failsafe (life-safety code). One FPO75, eight independent relay outputs, crisis averted during code inspection.
Technical Highlights:
- 75W total capacity, 6A/12V or 3A/24V selectable: Sufficient for 4–6 standard electromagnetic locks depending on voltage and duty cycle. If your site approaches the power ceiling, you're either running all locks simultaneously (unusual) or you need a second supply for a second zone — the dual-voltage flexibility means both zones can use a single model.
- 8 relay outputs, each fused at 3A: Individual fusing is the workhorse feature. A shorted lock coil (common failure mode in humid environments or after physical assault) trips one 3A fuse, not the entire supply. We've seen sites save thousands in downtime because a single blown fuse meant one door offline, not a cascading power failure across the whole security closet.
- 8 auxiliary DC outputs on Bus1/Bus2: Powering request-to-exit buttons, door position sensors, or lock status monitoring devices without drawing from the relay power rail keeps your lock current budget stable. On a 10-door project, dedicating 2–3 auxiliary outputs to monitored position switches (magnetic contacts on the door frame) gives you positive confirmation that the lock held against a push, which is auditable evidence in intrusion claims.
- Selectable failsafe/failsecure per relay: Not a one-size-fits-all setting. Each relay output configured independently. This is mandatory for sites mixing emergency exits (failsafe) with office or tenant entries (failsecure) — and most commercial sites are mixed-use.
- Mercury back plate, E6 enclosure, door-mount kit: Industrial-grade construction and traceability. For life-safety projects, especially those undergoing NFPA 101 or fire-code audit, this pedigree matters. The door-mount kit means you can install it on the inside of your electrical cabinet without additional fabrication.
Deployment Considerations:
- Wire gauge and run length matter at 24V mode: 3A at 24V is 72W, but voltage drop over 100+ feet of #18 wire will reduce usable voltage at the lock. For longer runs (e.g., garage to remote stairwell), either upsize the wire, use 12V mode with thicker gauge, or consider a secondary supply closer to the door cluster.
- Failsafe/failsecure mode is set at the relay hardware level (jumper or DIP switch on the relay module itself), not in firmware. Changing modes requires access to the enclosure and potentially brief downtime. Document your as-built failsafe configuration on the door schedule to avoid surprises during future maintenance.
- The 3A fuse rating per relay output is appropriate for standard solenoid locks and strikes, but verify your specific lock's stalled inrush current — some heavy-duty 24V strikes can exceed 3A on initial energize. If your lock datasheet shows >3A inrush, that output will nuisance-trip; migrate that load to a dedicated supply or derate the fuse rating with the manufacturer.
- Thermal protection is present but passive — the supply will shut down if internal temperature exceeds a threshold. In tight cabinets (common in parking garages), ensure adequate ventilation around the enclosure. A thermometer label inside the cabinet during commissioning is cheap insurance.
- SPDT relay contacts (single-pole, double-throw) mean each output can switch a lock between two states, but they're not isolation relays for long-haul signaling. If you need to send lock status back to a remote monitoring station or to a building management system, add an auxiliary power output to a wireless bridge or use the door position sensors (wired separately) rather than trying to run lock-state feedback over long, noisy runs.
The FPO75-C8D8E6M1 is the right choice for integrators building small-to-medium access control systems (5–20 doors) where space, cost, and failsafe compliance are balanced. It's especially valuable on retrofit projects where you're adding access control to an older building without a dedicated access control panel, or where you're expanding an existing system by one or two doors. If you're building a large-scale system (50+ doors) with a dedicated Salto, Honeywell, or Axis-based controller, you'll likely use that controller's native relay outputs instead — but for everything in between, or for standalone life-safety applications, this supply earns its place. Explore the full Lifesafety Power catalog for backup batteries, additional relay modules, and related infrastructure components.
