12, 24 and 48 VDC, 300 Watt,
Complete DC Power System

The Site Power System (SPS) series provides a complete DC power system solution that integrates quickly with batteries, loads, and monitors. Available in 12, 24 and -48 volt, 300 configurations, the compact assembly contains: power supply with temperature compensated, automatic boost/float battery charge cycle; low voltage disconnect; and programmable alarm contacts. High operating temperature rating with convection cooling make the unit ideal for remote site shelters, railroad wayside bungalows, and pole mount enclosure applications, as well as private network base stations and microwave sites.


  • Well regulated noise free output – no interference with sensitive electronic loads
  • Separate Battery Charger output with remote temperature compensation sensor
  • Automatic Boost voltage output after AC power failure quickly recovers battery
  • Low voltage disconnect protects batteries from over discharge
  • Output current indicator LEDs
  • Wide temperature operating range (-40 to +70╦Ü C), convection cooled, meets AREMA standards
  • Alarm contacts interface with remote monitor systems

Specifications: Site Power System Series Wall Mount DC Power System

Models Voltage Range Voltage Adjustment Range Output Amps
SPS 12-20 13.6V 11-15V 20
SPS 24-10 27.2V 22-30V 10
SPS 48-6 54V 44-60V 6

AC Input

Nominal: 110/220V, 50/60Hz
Voltage Range: 100-275V AC (full power output), 85-100V AC (reduced power output)
Frequency Range: 45-66Hz
Power Factor/Efficiency: >0.99 (full load)/87%
Input Fuses: Fuses in phase & neutral
Maximum Input Current: 300W Models: 4A


Input Voltage: Automatic shutdown, restarts automatically when correct voltage restored.
Input Rush: Weight: 3.4 lbs.;1.5kg


AC: IEC 320 universal connection, 3 foot power cord provided, NEMA 5-15
Output to Load & Batteries: 4 way lumberg macromodule, screw style
Temperature Sensor: 2 way lumberg macromodule, (pre-installed on 6 foot cable)
Monitor Connection: RJ45

Standard Features

Output Current Indicator: Ten segment red LED “dot” display
Auto Float/Boost: Rectifier enters boost mode at power up. When battery current reduces to float threshold limit (adjustable from 0.1A to 40% MRC), unit reverts to float voltage. When in boost but out of current limit, rectifier automatically switches to float after four hours. If battery current exceeds float threshold when rectifier in float mode, it automatically switches to boost mode.
Alarm and Indicator Controls: Positive V out, Load share signal (in/out), External shutdown, Open collector ‘off normal’ alarm (OSVD, over temp. limit), LVD synchronisation signal (in/out) Temperature compensation input signal, Open collector rectifier fail (via 4k7 resistor), Open collector mains fail, Negative V out.


Low Voltage Disconnect: SPS 12-20 SPS 24-10 SPS 48-6
Voltage Adjustment Range: 10-12V 19-24V 39-48V


Internal Alarm Card: 4x N.O or N.C (selectable) relay contacts with single common for rectifier fail, off normal, float low, float high. 1x VF changeover relay contact for mains fail. Relay contacts rated at 100V DC 1A. Connections┬ávia “mini combicon” connector accepts 16 AWG (1.5mm diameter) wire.
LED Indicators: Green – AC on. (primary converter operating) Green – Temperature probe connected and within normal limits.

Red – Rectifier ‘failed’.
Green – Rectifier in ‘float’ mode.
Yellow – Rectifier in ‘boost’ mode.
Yellow – Rectifier in ‘current’ limit.
Red – Rectifier ‘off normal’.

Internal Adjustments

Float voltage, Boost voltage, Over voltage shut down, Current limit, Temperature compensation slope, Auto boost to float threshold limit, Load disconnect voltage, Load disconnect hysteresis voltage

Design Standards

Electrostatic Discharge: CISPR24, Radiated Radio Frequency: CISPR22, AC
Harmonics: EN61000-3-2, AC
Flicker and Fluctuation: EN61000-3-3, CE MTBF 358,540 Hours, calculated to Telcordia Standards