Automatic Voltage Stabilizer (Linear Type)

LT Automatic Voltage Stabilizers holds potential for units having either LT supply or low capacity HT connection. The same can be manufactured for Balanced Supply for unbalanced load or Unbalanced Supply for Unbalanced Loads. The range of Input supply for which the stabilizer is designed depends upon the voltage condition at the supply point. However, some standard ranges for LT stabilizer are as under :

Technical Specification

Input Voltage 300-460V, 340-460V, 360-460V (Phase to Phase)
Output Voltage 400V /415V ±1% (Phase to Phase)
Type Suitable for Balanced Load & Balanced Supply
Application Indoor / Outdoor Type (Optional)
Phase 3 Phase, 4 Wires
Frequency 50Hz.
Response Time Fraction of Second
Speed of Correction 8-16V/Sec.
Mode of Operation Automatic/Manual/Hand Control
Suitability Suitable for all Power Factors
Wave Form Distortion Nil
Duty Cycle 100% Continuous
Efficiency 98%
Cooling ONAN (Oil Natural Air Natural)
IS Standard IS : 2026
Transformer Oil IS : 335
Operating Temperature 0° C to 50° C above ambient
Lamination Used CRGO Lamination – M4 Grade
Copper Used 99.9% Pure Electrolytic Grade
Carbon Rollers Used High Grade Graphite Rollers


The Rolling Contact Servo unit consists of the following :

  • Buck-n-Boost Transformer : Double Copper Wound, Open/Open connected.
  • On load Stepless Voltage Regulators having “Carbon Roller Assembly”: Copper Auto Wound and Delta Connected.
  • Automatic Control Gear : For automatic connection of fluctuating supply voltage, we shall provide Electronic Relay which in its simplest form, senses the Output Voltage and provide signal to the driving motor for necessary correction.
    • One electronic Voltage Relay
    • One Motor having Reversing Gear facility
    • Two limits switches in order to control over running at highest and lowest positions.
    • Chain Drive, Coupling device and all electrical connections.
  • Control Panel consists of :
    • IC bases solid-state, front loading plug in control cards for online serviceability, fitted inside of the panel.
    • Increase Decrease Push Button Switches with higher and lower limit switches.
    • Voltmeters to read Input & Output with help of selector switches.
    • Optional Ammeter with CT’s and selector switches.
    • Power indication LED’s and Auto/Manual selectable switch.
    • Hand wheel will be located on the front of the Regulator tank to be operative very conveniently.
  • Other arrangement: Cable Box suitable for input & Output armoured cable of appropriate rating. Suitable Aluminum bus bars will be provided with stem type terminals for auxiliary connections.
Rating Plate Lifting Lugs Drain Valve
Oil Level Indicators Earthing Terminals Thermometer Pocket