Key Features
27.6V dc output
EN 54 certified
Cost-effective switch mode technology
Energy efficient
LED indication
3 Year warranty


(Exc. VAT: £95.70)

Part Number: 28-021


The Elmdene STX range of switch mode power supplies are designed for EN 54 compliant fire systems and are certified to EN 54-4:1997, A1:2002 and A2:2006.

Elmdene STX power supply units are available in 1A and 2A versions with a range of enclosures to give the installer a choice of standby battery backup options with support for two 12V 1.2Ah batteries and two 12V 17Ah batteries.

These cost-effective fire alarm system power supply units provide a full rated current at 27.6V dc with additional current for battery charging. STX power supplies also support intelligent battery charging and monitoring using Elmdene’s EcoCharge technology and independent volt-free outputs to report mains failure and battery faults, charger faults or loss of output reports. These units also feature battery deep discharge protection in the event of a prolonged mains failure.

LED indicators provide quick diagnosis of the power supply showing the mains status, output fault, battery fault and charger fault indications.

Additional Features

  • Intelligent battery charging and monitoring
  • Deep Discharge Protection
  • Remote fault signalling
  • Full rated current to load plus additional current for battery charging
  • Mains transient protection


EN 54-4:1997
RoHS Compliant

Tech Specs


Mains input 93–264V ac
Output 27.6V dc
Maximum current See part codes
Operating temperature -10°C to 40°C at 95% RH


Product Dimensions (mm)
C Models 275H x 330W x 80D
E Models 420H x 400W x 80D

Part Codes

Part code Rating (A) Max Battery Size
STX2401-C 1A   2 x 12V 7Ah
STX2402-C 2A 2 x 12V 7Ah
STX2402-E 2A   2 x 12V 17Ah

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