Servo Stabilizers - Three Phase Air Cooled

Salient Features

  • High efficiency & Fast response.
  • Wide input voltage range & Audiable alarm for trip conditions.
  • 99.99% failure proof control circuit.
  • No over under, shoots and hunting.
  • Built in bypass switch upto 100 KVA.
  • Less active component avoids failure ratings.
  • Special electronic circuit to operate on gensets.
  • No effect of power factor and frequency variations.
  • Single PCB for three phase sensing and correction.
  • Voltage at speed related to rate of fluctuations and avoids oscillations & hunting In DC motor drive.
  • Variable speed high torque DC servo motor proportionally controls corrections.
  • Rugged and smooth ac motor drive control through optoisolator circuit which is Highly reliable.
  • Separate isolated PCB for triac switching for motor.

High Reliability

  • High reliability due to digital monitoring and controlling using micro controller.
  • All components sourced from reputed manufacturers, confirm to IS / BS / VDU standards.
  • All raw material inspection as per internal components manual.
  • Individual assemblies and sub assemblies tested separately.
  • All electronic assemblies tested on full load at 55 deg c in oven for 48 hours to Minimize failure.
  • Final equipment tested for accelerated life test to identify and replace any weak links.


  • Input and Output Low Voltage protections.
  • Input and Output High Voltage protections.
  • Phase rotation/single phasing preventer.
  • Input protection using HRC fuse.
  • Control circuit protection using fast blow fuse.
  • Electronic overload protection.

Panel Control

  • VAF / VF 3 Phase Model Start, Select, Stop / Reset

LCD - Specification

  • 16*4 lcd display is used for easy reading of parameters.
  • True rms sensing and reading of voltage and current.
  • 100 event error log facilities for easy diagnosation of fault level.
  • Internal variable timer is adopted for on time delay and overload trip of scvs.
  • Selectable phase reverse function.
  • Selectable auto on function.
  • Less analog circuit and hence failure rate is reduced.
  • Built in digital meter for monitoring the voltage / current & frequency.
  • Separate isolated PCB for triac switching for motor.

Product Specification

Single phase capacity 1 to 25 kva
Three phase (air cooled) 3 to 150 kva
Three Phase (oil cooled) 3 to 2000 kva
Input voltage range 170-270 Single phase 295-465 volts three phase
195-270 Single phase 340-465 volts three phase
205-270 single phase 360-465 volts three phase
Special range As per customer requirements
Output voltage 220/230/240 V AC in single phase
380/400/415 V AC in three phase
System Unbalanced/balanced type
Connection Star/Delta or Star/Star
Output Voltage regulation (+/-) 1% from no load to full load
Servo motor drive model -A AC Servo Synchronous Motor - Small
Correction speed 35 V/sec-1 ph, 60 V/sec-3 ph
Response time Above 60 milli. sec.
Servo motor model-B DC servo motor
Correction speed Upto 105 V/sec.
Response time 10 milli.sec.
Operating frequency 47 to 53 HZ
Output waveform True reproduction of input
Insulation Class "B"
Short circuit percentage and period 300 % for 250 milli sec.
Overload capacity 120 % for 1 minute
Effect of load P.F on OP Volts Nil
Waveform distortion Nil
Duty Cycle 100 % continuous
Ambient Upto 45c max above ambient Relative humidity upto 90%
System construction As per IS:9815
Enclosure Powder coated
Efficiency Better than 98% (electrical consumption saved)
Environment Designed for indoor / outdoor tropical use
Mounting On wheels
Earthing Earthing terminals provided