24V 3A EN54-4 Switch Mode PSU

  • Certified to EN54-4/A2 by the LPCB and VdS.
  • A powerful 24V 3A switch mode/digital hybrid PSU that can be customised* to suit your exact requirements – see More Information tab for details.
  • Plastic cover on PSU PCB guards against touching live parts.
  • Includes a single-pole voltfree changeover relay that switches for any fault condition.
  • Multiple indicators – supply present, general fault, fault type & aux. equipment fault.
  • Two selectable battery charge currents.
  • Battery fault impedance limits can be optimised to suit load current (helps extend battery life)*.
  • Mains fail simulation mode.
  • Improved on-board temperature sensor with optional remote sensor.
  • Electronic functions comply with EN50131-6 grades 1-4 for security applications.
  • BF562-3/E encased version also available.


More Information


Ideal for powering beam detectors, auto-dial communicators, aspirating smoke detectors, auto-open vent systems, auxiliary sounder systems or any other device performing a mandatory function of a fire alarm system.


The BF562-3 can be customised to suit your exact requirements using a BF423 configurator & PC. Configurable parameters include float voltage temperature compensation, battery charge rate (mA), battery impedance and configurable Input/Output settings. *It is important to note changing the PSU’s parameters in this way is outside the scope of EN54-4 and any changes must be tested by the responsible person for correct operation.

PSU STATUS LED (located on the PSU PCB)

1 flash = Mains Failure.

2 flashes = Battery Voltage Low.

3 flashes = Battery Voltage Critical.

4 flashes = Charger Failure.

5 flashes = Charger OK (Battery is either actively charging, or in float charge).

6 flashes = No Batteries Fitted (indicating DIP Switch 4 position).

7 flashes = Battery Resistance Fault (Level set by DIP Switch 2 position).

8 flashes = Output Over Voltage.


The BF562-3 complies with EN54-4/A2 and therefore must monitor battery resistance. The fault threshold is directly related to the ability of the battery to deliver the rated current to the load. For example, batteries stored uncharged for long periods, during shipment and/or distribution, degrade leading to increased internal resistance. If a degraded battery is fitted, a fault will be shown by the PSU as mandated by EN54-4/A2.


Data on the BF562-3’s status can be extracted from the PSU’s bi-directional data port. The data available includes thermistor measurements; battery terminal voltage; system voltage at load terminals; battery charge current; load current; battery impedance and ASCII text string status messages. Extracting this data requires additional equipment and permissions – contact C-TEC for details.

Technical Specifications


Mains supply

Mains rated current

Total output current limited to


Battery charge capacity

Max battery size and type



Expansion connections

Product dimensions (mm)

Construction & finish

IP Rating


Operating conditions/temperature



BF562-3 24V 3A Boxed PSU Instructions – DFU0056230


5 SERIES EN54 PSUs Brochure – DML0549600


Dimensions & Mounting Information
Product dimensions: 404 W x 404 H x 110 D mm. Designed for surface mounting only.
Approval Certificates
LPCB Third Party Approval Certificate – BF560 Range PSUs & BF562 Range PSUs to EN54-4 168.06 KB Download
VdS Third Party Approval Certificate – BF562-3 & BF562-5 PSUs to EN54-4 1.60 MB Download
EU CPR Certificate of Conformity – BF562-3 (CoC) 195.05 KB Download
EU Declaration of Conformity – 5 Series Power Supplies (DoC) 1.29 MB Download
EU Declaration of Performance – BF562-3 & BF562-5 Power Supplies (DoP) 82.92 KB Download
UKCA CPR Certificate of Conformity – BF562-3 Power Supply (CoC) 194.71 KB Download
UKCA Declaration of Conformity – 5 Series Power Supplies (DoC) 426.90 KB Download
UKCA Declaration of Performance – BF562-3 & BF562-5 Power Supplies (DoP) 318.03 KB Download
BIM/CAD Drawings

BF562-3 BIM (RFA)