ByPyramid Electronics


1 KVA to 60KVA RDSO/PE/SPEC/TL/0023-2001 Rev.0 Amendment No.1

General Description

The 1kVA UPS is designed to provide a conditioned power supply with battery backup for trackside ticketing machines within Indian Railways. The UPS uses MOSFET and IGBT technology to produce a regulated 230V, 50Hz output from a variable input supply. In the event of an input supply failure the UPS sources the output power from 48V DC batteries.

The system provides seamless changeover between mains and battery ‘stand-by’ supply and contains an active bypass, which activates during sustained overload and fault conditions, and a manual bypass for servicing purposes.

A battery charger supplies power to charge the batteries as well as to provide auxiliary power to the system controller.

The UPS contains a power factor correction (PFC) front-end rectifier to maintain a near unity power factor. The PFC stage establishes an intermediate dc link voltage which is pulse width modulated through a single-phase IGBT bridge and output filter to produce a regulated 230V, 50Hz single phase output.

The battery supply is boosted through a current fed push-pull (CFPP) converter and connects to the intermediate dc link voltage in parallel with the PFC output. This enables the CFPP to seamlessly take over supply of the power to the output inverter when the input AC supply is unavailable.

The UPS has an LCD and keypad for set point configuration, dynamic operating condition display and fault checking as well as indicator LEDs that show the current state of operation. In addition a USB port is provided on the front of the UPS for downloading of Fault Status data to a USB Memory stick.

Technical Features
• IGBT Based inverter section
• Filtered AC Output with 1kVA capacity
• Input current limiting capability
• Input and Output Over Current protection
• Over temperature protection
• Output short-circuit protection (and lockout)
• Input Under Voltage & Over Voltage Protection
• DC link voltage monitoring
• Low losses & hence high efficiency operation
• Fused Input
• Modular design, hence easy maintenance
• Provision of fault memory recording for diagnosis & subsequent analysis
of faults
• Provision of USB port for USB Memory Stick data downloading
• Auto-restart on fault elimination (dependent on fault type and frequency of
Technical Specifications  
 Input Side
 Maximum Voltage 300V AC
Voltage Operating Range 140V – 280V AC 1 phase, 50 ± 3Hz
Output Side
Rated Output VoltageI : 230V AC ± 1%, 50 ± 0.5Hz
Output Current : 4.5A
Output Power  : 1kVA @ 0.8pf
Overload maximum 125% load for 10 minutes
150% load for 1 minute
General Data
 Efficiency  More than 90%
Operating Temp. Range  -5°C to 55°C
Cooling Medium  Fan forced air cooling
Construction Modular
Dimension in mm
US Cubicle
468(L) x 200(D) x 275(H)
Protection IP 20 for US Cubicle


The 1kVA UPS unit has the following major functional elements:

  • Input Fuses
  • Power Board
  • Battery Charger Board
  • Front Panel Display/Keypad Board
  • EMI Board
  • DSP Controller Board (permanently attached to the Power Board)
  • Series Resistor
  • Batteries
  • Bypass Switches

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