Haydon HAY-PSUEN54-2A EN54-4 Power Supply | 24V DC, 2A, Small Enclosure
£107.72 (inc VAT: £129.26)
Key features
- GEN and EPS volt-free fault outputs
- 2A output and space for two 7Ah batteries
- Amber LED for engineer fault diagnostics
Downloads
Summary
The Haydon HAY-PSUEN54-2A is a 27.6V DC uninterruptible power supply (UPS) built to feed auxiliary devices on a compliant fire alarm system. It stands out by providing two separate volt-free fault outputs, GEN and EPS, so you can report mains loss and system faults back to the panel or building management system (BMS) independently, rather than lumping every fault onto a single contact.
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This separation saves you time explaining fault conditions to the client or a monitoring station, because the EPS output flags a mains loss over 10 seconds on its own, while GEN covers the wider fault picture. On a commercial install where auxiliary devices such as sounders, beacons or interfaces need their own regulated supply, this means fewer callbacks chasing down which fault triggered an alarm.
You get a 2A continuous output housed in the smaller enclosure, sized for two 7Ah batteries, making it suitable for installs where auxiliary load is modest and space is at a premium. The unit’s three-LED front panel (green mains, yellow fault, amber diagnostic) lets you read off the specific fault condition on site without opening a laptop or calling the manufacturer.
Features
- GEN and EPS fault outputs - report mains failure and general system faults separately to your panel or BMS without extra interface gear
- 2A continuous output - sized to run auxiliary fire system devices alongside two 7Ah battery standby in the compact enclosure
- Three-stage LED diagnostics - green, yellow and amber LEDs give you a fault code on the front panel so you can diagnose without extra test gear
- Deep discharge protection - batteries are automatically disconnected below 21V DC to stop damage from over-discharge
- Battery monitoring - continuously checks for low voltage, incorrect connection or short circuit on the connected batteries
- Overload protection circuit - protects the printed circuit board (PCB) from damage during a short circuit or sustained overload on the output
- Two-stage battery charging - constant current bulk charge to 80% within 24 hours, then float charge to full within 48 hours
- EN54-4:1997 +A1 +A2 compliant - certified for use on fire detection and alarm system installations
Specifications
| Rated Voltage And Frequency | 110-240V AC, 47-63Hz |
|---|---|
| Input Current | 0.5A |
| Mains Fuse Rating | F3A |
| Output Voltage Mains Power | 22.0-27.6V DC |
| Output Voltage Battery Standby | 20.0-26.0V DC |
| Ripple | <150mV |
| Output Fuse | F2A |
| Battery Fuse | F2A |
| Imax With Charging | 2A |
| Imax No Charging | 2.8A |
| Battery Capacity | 2 x 7Ah |
| Maximum Battery Internal Resistance | 5 Ohms |
| Minimum Current | 0.1A |
| Battery Charging | Two stage: constant current bulk charge to 80% within 24 hours, float charge to 100% within 48 hours |
| Constant Current Charge | 0.5A |
| Temperature Compensation | -30mV per degree C (0-50 degrees C) |
| Low Battery Voltage Trigger | 23V |
| Deep Discharge Protection Cut Out | 21V |
| GEN Fault Output | Normally closed, 0.5A at 60V DC, volt-free solid state relay contact |
| EPS Fault Output | Normally closed, 0.5A at 60V DC, volt-free solid state relay contact |
| Operating Temperature | -20 to +45 degrees C, 20-90% RH non-condensing |
| Storage Temperature | -25 to +85 degrees C, 10-90% RH non-condensing |
| Enclosure Material | 1.2mm steel, white powder coated |
| Enclosure Dimensions | 330 x 275 x 80mm (W x H x D) |
| Weight Excluding Batteries | 3.1kg |
| Approvals | EN54-4:1997 +A1 +A2, CE marked under EMC 2014/30/EU, LVD 2014/35/EU and RoHS2.0 2011/65/EU |
FAQ
This model uses the small enclosure and is designed for two 12V 7Ah batteries connected in series using the bridging wire supplied. With batteries fitted the unit weighs approximately 8kg, so check your wall fixings can take that load before mounting. Both are normally closed, volt-free solid state relay contacts rated 0.5A at 60V DC. You must ensure any circuit you connect to either output stays below 60V DC, and GEN opens on mains failure with battery voltage below 23V or a general power supply unit (PSU) fault, while EPS opens specifically on loss of mains for more than 10 seconds. The amber LED gives engineer-level fault codes from one flash up to five flashes, covering conditions such as batteries charging, batteries not detected, battery faults, charging circuit faults and temperature sensor faults. Cross-reference the flash count against the fault finding guide in the datasheet to identify the exact issue before replacing anything. No, this specific model is rated at 2A continuous output with charging (2.8A with no charging in progress). If your installation needs more current, speak to Huvo about the right model for the load you’re supplying. No, the two small white wires from the supplied temperature sensor can be connected either way round. They must be connected for the unit to monitor battery temperature correctly, and leaving them disconnected will trigger a fault code on commissioning. Within a minute the yellow fault LED should start flashing and the amber diagnostic LED will repeat a two-flash code indicating the PSU isn’t seeing the batteries. Reconnect the lead and both LEDs should stop flashing again within a few seconds, confirming the battery monitoring is working.What size batteries does the HAY-PSUEN54-2A take?
How do I wire the GEN and EPS fault outputs?
What does the amber diagnostic LED mean when it flashes?
Can the HAY-PSUEN54-2A run a higher current load than 2A?
Does the battery temperature sensor need to be connected a specific way round?
What happens if I disconnect a battery lead during testing?
Downloads
- Datasheet (Adobe PDF)
Additional information
| Output Current | 2A |
|---|---|
| Device Type | |
| Battery Charging | Yes |
| Maximum Batteries | 2 × 7Ah |
| Colour | |
| Mounting | Surface |
| Fault Relay / LED |






