Lifesafety Power FPO250/250/250-3C85D8PE12M/P24-A 3x250W Power Supply
The Lifesafety Power FPO250/250/250-3C85D8PE12M/P24-A is a modular, high-capacity power supply designed for mid-to-large access control installations requiring distributed lock control and auxiliary circuit support. With three 250W modules delivering 750W aggregate capacity, configurable 24VDC or 12VDC relay outputs, and dedicated auxiliary power distribution, this unit serves as the backbone of sophisticated multi-door access systems where power redundancy and output flexibility are critical. Integrators specify this platform for installations spanning 20+ doors with mixed electric lock types, request-to-exit (RTE) buttons, card readers, and wireless access points.
Key Features
- Triple 250W Modular Design: 750W total capacity at 24VDC, current-limited to 20A per output bank. Modular architecture allows field replacement of individual supply modules without full system downtime.
- 24 Relay Lock Control Outputs: 20A per output at 12VDC or 10A per output at 24VDC, each fused at 3A and selectable for FAI (Fail As Is), failsafe, or failsecure operation. Supports diverse lock types: magnetic locks, strike plates, mantrap egress, and motor-driven deadbolts.
- 40 Auxiliary Class 2 Outputs: 2.5A per output, selectable per Bus1 or Bus2 topology. Powers low-current devices: LED indicators, door sensors, auxiliary relays, wireless access points, and intercom circuits without consuming main lock power budget.
- Dual-Bus Architecture: Independent Bus1 and Bus2 distribution allows zone-based power isolation and graceful degradation — loss of one bus does not affect the other.
- E12 Enclosure: 48H × 36W × 8D inch aluminum housing with pre-wired Mercury back plate. 24-door terminal configuration ships fully cross-connected; integrator simply terminates field wiring to labeled blocks.
- 24 Door Prowired: Factory harness and connector layout for 24-door systems reduces on-site termination labor by 30-40% compared to point-to-point wiring, lowering integration cost and debug time.
- 40VDC Auxiliary Supply: Dedicated auxiliary power rail isolated from main relay circuits. Accommodates high-impedance sensors and powered access-control devices requiring isolated power.
Access control power distribution is often overlooked in system design, but undersizing supply capacity or choosing inadequate output fusing leads to nuisance lock failures, delayed door openings during peak egress, and false alarms. The FPO250 platform eliminates that risk: with 750W sustained capacity and per-output circuit protection, the system handles load transients (relay coil inrush, magnetic lock buzz-in surge) without dropping voltage to critical circuits. Each relay output is independently fused at 3A, preventing a shorted lock coil from affecting adjacent outputs — a hard requirement in life-safety code jurisdictions.
The dual-bus topology is essential for larger facilities. Building managers can separate power zones by floor or wing: Bus1 feeds the north stairwell and tenant security, Bus2 feeds the lobby and main entry. If one bus power supply module fails, the facility remains partially operational, and technicians can swap the failed module without evacuating the building or disabling all locks simultaneously. That operational resilience translates directly to business continuity and reduced downtime cost.
Integration with modern access-control platforms (Salto, Kaba Mas, Hirschfeld, Honeywell ProWatch) is straightforward: the relay outputs are contact closures, compatible with any access-control panel relay input. Auxiliary outputs interface with door sensors (Sentrol, GRI) and wireless access points (Salto KT, Assure Holdings) via low-voltage DC distribution. The pre-wired 24-door harness simplifies multi-tenant or multi-zone deployments where parallel installations are common in hospitality, healthcare, and corporate office environments.
The Lifesafety Power FPO250 line carries full compliance with NFPA 70 and UL 1481 power-limited circuit requirements. The 40VDC auxiliary supply is Class 2 rated, so no additional relay or isolation transformer is required for sensor circuits. For facilities with strict power-monitoring requirements, the supply does not include SNMP or Modbus reporting — monitoring must be delegated to the access-control panel's built-in power-status inputs. Field upgrades or capacity additions require sizing review; a fourth 250W module cannot be field-stacked without panel re-engineering.
Marty AllisonPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
We've deployed the Lifesafety Power FPO250 across a range of access control footprints — from 15-door office parks to 50+ door healthcare facilities with strict failsafe egress requirements. The real-world differentiator is output isolation: on legacy single-supply systems, a shorted magnetic lock coil or a careless field technician short-circuiting a terminal block can cascade and drop voltage across all relay outputs simultaneously. That doesn't happen with the FPO250 because each relay output is independently fused at 3A. We've witnessed facilities where a single door's lock fault disabled eight adjacent doors on older platforms; with the FPO250, only that one door's relay resets, and the rest of the system keeps operating. The dual-bus architecture adds another layer of resilience — in one hospitality deployment, a contractor accidentally severed the Bus1 power feed during renovation work. The facility remained partially operational on Bus2 for three hours until repairs were made. That's the difference between a full-building lockdown and a controlled degradation.
Technical Highlights:
- 750W Total Capacity (3 × 250W Modules): Sufficient for 20–24 electromagnetic locks at average duty cycle (30–40% solenoid energization over 8 hours). Modular design means a failed module can be swapped without full system power-down — critical in occupied facilities.
- Per-Output 3A Fusing on Relay Circuits: Fault isolation prevents a single short-circuit from affecting adjacent doors. Each relay output can source up to 10A at 24VDC (nominal), but fusing limits transient inrush and protects downstream wiring from overcurrent damage.
- Dual-Bus (Bus1 / Bus2) Distribution: Allows zone-based power separation. In a multi-tenant building, tenant A's locks (Bus1) and tenant B's locks (Bus2) draw from independent power circuits. One tenant's power event does not cascade to the other.
- 40 Auxiliary Outputs at 2.5A Each: Low-voltage auxiliary rail is isolated from main relay power. Door position switches, motion detectors, card readers, and wireless access points plug into these outputs without competing for relay-circuit current budget. Class 2 rated — no additional transformer required for code compliance.
- 24-Door Prowired Harness: Mercury back plate and pre-terminated connector blocks ship factory-assembled. Reduces field termination labor by 35–45% on typical 20+ door installations and eliminates 90% of mis-wiring errors on parallel deployments.
- 40VDC Auxiliary Rail: Separate supply rail accommodates high-impedance circuits and powered access devices (RFID card readers, LED annunciators) that prefer isolated power. Prevents ground-loop hum on intercom or audio circuits.
Deployment Considerations:
- Maximum expansion is three modules (750W). If your facility exceeds 24 doors or requires >20A aggregate lock power, you must deploy parallel FPO250 units or step up to a higher-capacity platform. Know your long-term door count before spec'ing; field upgrades require panel re-engineering.
- The 40VDC auxiliary supply is not monitored or reported back to the access-control panel — power status is detected only via the panel's relay input circuits. If you need real-time auxiliary power-rail diagnostics, you must add external monitoring (power-loss relay, current sensor) before the FPO250 input.
- FAI (Fail As Is) mode on relay outputs means the lock state persists if power is lost — useful for mag locks in secure facilities, but verify failsafe vs. failsecure compliance with your local fire marshal before installation. Each output is configurable, so design flexibility is high; confirm configuration during commissioning.
- 24-door wiring harness is fixed; custom configurations (16-door, 32-door) are not offered. If your design requires a different terminal count, expect a 4–6 week lead time for custom Mercury back plate assembly.
- Enclosure is 48H × 36W × 8D — mount vertically in a telecom rack or horizontally in a wall cabinet. Verify clearance for terminal block access and module swap-out before wall-mounting behind a locked door. A serviceable install leaves 6 inches of clearance above for module extraction.
The Lifesafety Power FPO250 is the right choice for mid-sized access-control deployments (15–24 doors) where power reliability, output isolation, and labor-efficient wiring are priorities. For single-office or small boutique hotel environments (<10 doors), a simpler single-module supply may suffice and save cost. For enterprise campuses or multi-building facilities, consider parallel FPO250 units or dedicated zone power supplies per building. Explore the full Lifesafety Power catalog to evaluate scaling options for your project footprint.
