Phase Control Thyristor

AC Voltage Regulator

This Thyristorized Industrial AC Voltage regulator stack provides full seamless control of three-phase resistive loads. Signal control is by a DC signal. These burst firing control stacks use fast pulse zero volts switching technology to minimize flicker and eliminate RFI problems.

Salient Features

  • 40% smaller than conventional designs
  • Electrically isolated heatsinks.
  • Easy mounting – Easy service access
  • Quick-change I²T fusing system
  • Completely self-contained – No separate control voltage is required for standard voltages
  • Accepts all standard control signals.
  • Tin-plated all copper bus bar.
  • Standard ratings designed for 50°C maximum ambient
  • Steeples control for proportional electric power
  • Voltage Range: 10 to 440 VAC
  • Current Range: 50 to 200 Amps AC
  • Control Mode: Phase Angle Firing/Burst Firing as per requirement
  • Integral Fusing: Three coordinated I2
  • T fuses for semiconductor protection
  • Reference Signal: 0-5V, 0-10 VDC, 10K Pot
  • Feedback signal 0-5 V OR 4-20mA
  • Shutdown Contact: Lockout (inhibits firing)
  • Transient Voltage Protection: RC snubber with MOV.
  • Soft Start: Inrush Protection
  • Optional Features: RMS Current Limit, RMS Voltage Regulation
  • Mounting: Panel Mountable (standard)
  • Soft start Feature
  • Single phase / Three phase input options as per customer’s requirement.
  • With Programmable Logic Controller - PLC (as optional)


  • Suitable for 3-wire, 3-phase floating-star or closed-delta configured resistive loads. This includes the Heating, Ventilating and Air Conditioning (HVAC) market for air curtain applications, but also for furnaces, ovens, dryers and hot plates.
  • Temperature regulation is required in nearly every manufacturing process, typically for the purposes of material heating, melting, drying, or forming.
  • SCR power controllers, also called silicon-controlled rectifiers (SCRs), play a critical role in temperature regulation. Their primary use is to control the flow of electricity from the grid to a heater. This function regulates temperature to produce specific material effects or properties within an industrial furnace, oven, or other thermal processing equipment.
  • Compared to alternative devices, such as IGBT-based controllers, SCR power controllers provide much greater efficiency—up to 99.5%. SCR power controllers also replace contactors or relays due to the wear-free switching offered by thyristor devices. This characteristic greatly improves reliability and product longevity.

Function & Protection

  • Over temperature protection
  • When the sensor detects a heatsink temperature above 100ºC.

  • Over Current Protection
  • Fuses at AC input side provided. Fuse failure indicator with micro switch available (Optional)


  • Power/(current ratings): 60 KW (105 A) & 180KW (250A) @ a typical supply of 415V RMS
  • Input voltage: 415 RMS +/- 10%
  • Frequency: 50/60Hz
  • Control input options: 0 to 10V dc (set as standard) / 0 to 5V using 10 K Potentiometer.
  • Operation modes: Selection by input enable or auto (Burst Fire and Phase Angle).
  • Control Signal Logic: 5-24 VDC ( Opto –isolated Inputs).
  • Soft Start: 0-30 Sec.
  • Load Option: Resistive or Inductive.
  • Cooling Fan: 230 VAC fitted as standard – other options available.
  • Working Temperature: 0 - 55°C
  • Dimension: 240 (L) x 230 (H) x 250 (W) for 60KW for other KW rating it will customized
  • Weight: 6.5 Kg approx.

Product Applications

Phase Control Thyristor



Welding Machines & Inverters


Solar Inverters


Sugar Mills


EV Charging


Wind Energy



Power Plants

Power Plants



Medical Equipments

Medical Equipments

AC-DC Driver

AC-DC Driver