Servo Voltage Stabilizer (AVR System)

Automatic voltage regulators (AVRs) are a proven technology originally developed to ensure steady regulated voltage regardless of the input voltage. AVRs are commonly deployed, where voltage is highly variable and where customers are subject to periodic brownout conditions. They are also used in urban areas where voltage often drifts upward past a point that shortens the lifespan of expensive equipments, UPS systems and batteries.

SurajStaar AVR System uses a combination of variable Auto-transformer, Fixed Auto-Transformer and flawless mechanism, all controlled by microprocessor. This design has been improved continually and perfected over a period of over 20 years.


Customized as per the site conditions and need of the user

Can be designed for extreme low voltage or extreme high voltage conditions

Protects sophisticated expensive equipments from fluctuations (sags) upto 35V per second per phase.

Does not have any control over spikes and surges



Equipment Type Servo Voltage Stabilizer - AVR system
Usage All 3 phases and single phase loads Industrial - (Factories, Hospitals, Movie Theatres, Hotels, etc) & Residential
Rating (KVA) 6 to 3000 KVA
Model Single / Three phase
Type of load Balanced / Unbalanced
Input Voltage Balanced / Unbalanced
Type of cooling Air / Oil
I/p voltage (widest possible range) 155V to 480V (on each phase 90V to 280V)
Output (each phase) 230V +/- 1%
Output (three phase) 410V +/- 1%
Input frequency range 47Hz to 53Hz
Panel indications Input OK, Output OK, Input / Output Voltage, High / Low indicators (can be customized)
Under / Over Voltage Protection Cut off through electronic circuit set at +5% / -10% of output voltage
Restart delay Optional through Electronic circuit
Restart mode Auto with 3 sec delay (upto 3 min optional)
Overload cutoff protection Optional through Electronic circuit / MCCB
Short circuit protection Optional through MCB / MCCB
Single phasing prevention Optional (if chosen)
Changeover (to Bypass equipment) Optional