Overview
The Haydon HAY-PSUEN54-1A is an EN54-4 compliant boxed power supply designed for fire detection and alarm systems. It provides an uninterruptible 27.6 VDC output with integrated battery back-up, battery monitoring and volt‑free fault outputs for system supervision.

• EN54‑4 +A1 +A2 certified for fire alarm use.
• Uninterruptible 27.6 VDC output with 1 A rated output (Imax with charging 1 A; Imax no charging 1.5 A).
• Accommodates 2 × 7 Ah sealed lead‑acid batteries; two‑stage charging with temperature compensation.
• Volt‑free GEN and EPS fault outputs for remote monitoring; LEDs for mains, fault and diagnostics.

Why choose this unit
This boxed PSU solves continuous-power and supervised-battery needs for small to medium fire alarm panels. It includes battery monitoring, deep‑discharge protection and fault reporting to integrate with alarm monitoring circuits—reducing false alarms and ensuring power continuity during mains failure.

Use cases
Suitable for internal installation with fire alarm control panels, conventional or addressable systems, and for installers and contractors requiring an EN54‑4 compliant PSU with built‑in diagnostics.

Safety & installation notes
Requires a dedicated fused mains isolation switch as part of installation. Refer to the official datasheet and installation manual for wiring diagrams, battery fitting guidance and national regulations. Check whether batteries are supplied by your reseller; the enclosure accepts 2 × 7 Ah sealed lead‑acid batteries (batteries typically supplied separately).