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Three Phase SCR Features


Nominal Specifications

3 Phase SCR's in TRIPAN controllers.

Modern and Versatile

Not sold individually.

Works continuous duty cycles on several MHI technology platforms

ST 9003 and other MHI 3 Phase Controllers used by MHI are a fully synchronized, true three phase angle thyristor power controller for 3-Wire or 4-Wire resistive, transformer coupled resistive or inductive loads. The output through 3 pairs of SCR's in inverse parallel mode gives synchronized full wave control over all the three phases. Easy to install, this power controller comes with all popular features like soft-start, current-limit and over current trip as standard. Built to work in harsh industrial environments, it is the most cost effective power controller for use in ovens, kilns, furnaces, plastic injecting molding machines, textile machines, extruding machines, environment chambers, molybdenum di-silicide heaters, silicon carbide heaters, GAXP, Steam, Plasma and IR heaters and many more.  General specifications and features are provided below as a guide only.


Nominal Features Shown Below

(please contact for the specific features in your device)


• Advanced hybrid design incorporating logic and analog circuits

• Compact, robust construction with copper bus-bars.

• Bulkhead mounting for easy installation

• Self synchronizing

• Isolated heat sink, shrouded electronics meeting CE norms for added safety

• Phase angle control

• Field adjustable current limit and current trip

• Field adjustable soft start

• Semi-conductor fuse, MOV, Snubber circuit protections � Line to load regulation

• High PIV rated SCR�s

Standard models and customization (factory configured for your application)

Configurable inputs (including USB control by lines - depends on configuration)

• Comprehensive operating, installation and trouble shooting manual

• Unbeatable price and delivery

•One year warranty


• Control of complex heaters such as Molybdenum di-silicide, Tungsten, Silicon carbide, Quartz lamps, HGA, e-Ion Zapper,  Infra-red heaters etc.

• Ovens, kilns, autoclaves, furnaces, lighting etc.



Storage Temperature: 10°C to 60°C

Operating Temperature: 10°C to 50°C


Control Signal

Analog current: 4 to 20ma

Manual: Through external 10K pot

Driver Supply: 110 / 208 / 220 / 240 / 415 / 440 Vac @ 50 / 60 Hz

Firing Mode: Phase Angle


Current Ratings: 25 / 50 / 75 / 100 / 125 / 150 / 200 / 250 / 300 Amps

Load Type: Resistive / inductive / capasitive

Soft Start: Adjustable soft start between 10 ms to 60 sec

Current Limit: Adjustable current limit between 10% and 100% Regulation : 3% output regulation with 12% supply variation

Voltages: 110 / 208 / 220 / 240 / 415 / 440 Vac @50 / 60 Hz

Ambient Temperature: Rated capacity at 0 to 50°C, derate by 10% for every 5°C rise up to 60°C. De-rate by 1% / 100 Mts. (3000 ft) above sea level

Cooling: Fan cooled, electrically Isolated heat sink

Standard: I2t fuse, adjustable soft-start, adjustable current limit.


Typical Dimensions for units up to 50 amps H 420mm(16.5") X W 220mm(8.6") X D 225mm(8.8") Weight : Approximately 11.5 Kgs (25 lbs.)


Please fill out the form below and our sales staff will quickly respond to your request.

Contact Information
First Name
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SCR Information
Choice of SCR:
   ST 9001 (single phase)  ST 9003 (three phase)
Current required:
Inputs required:
Voltage required:

Please enter the nature of you inquiry in as much detail as possible,
and an appropriate time to reach you.




Contact MHI to Order SCRs:

(Ph) 513-772-0404 (Fax) 513-672-3333

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©Micropyretics Heaters International Inc. 1995 - 2023
750 Redna Terrace Cincinnati, OH 45215, USA
Telephone: 513-772-0404 | Fax: 513-672-3333