SCR Power Controllers
MTC250A/1600V SCR Module with Three-Phase Power Controller
DREL MTC250A 1600V SCR module paired with the DREL three-phase power/voltage controller. A weak 4-20 mA signal governs strong three-phase heating loads with precise voltage or power regulation.
Specifications
- Rated Current
- 250 A
- Voltage Rating
- 1600 V
- Chip-to-Baseplate Insulation
- 2500 V AC
- Baseplate
- Nickel-plated copper
- Encapsulation
- Epoxy-resin potted, plastic housing
- Control Input
- 4-20 mA
- Control Modes
- Phase-angle (voltage) / Zero-cross (power)
- Adjustments
- Output limit P1, soft-start time P3
- Cooling
- Forced-air heatsink required
- Applications
- Industrial furnaces, injection molding, glass and chemical heating
Overview
The DREL MTC250A/1600V set combines an MTC250A SCR module with the DREL three-phase power/voltage controller - in industry usually called a power regulator. Its core job is precise temperature or power control of large three-phase electric heating equipment, using a weak control signal to command strong load power.
How It Works
The controller receives a 4-20 mA signal from a temperature instrument or PLC, processes it internally, and sends trigger pulses to the MTC module to control the thyristor conduction angle - regulating the voltage or power delivered to the load.
Two Control Modes
Phase-angle (voltage) mode changes the conduction angle of every AC half-wave for smooth, continuous voltage output, suited to processes that need precise temperature control. Zero-cross (power) mode adjusts the ratio of conducting cycles within a set period, which causes less harmonic interference on the mains and suits large-inertia heating loads. The SW1 switches select the mode; P1 sets the output limit and P3 sets the soft-start time.
Construction
The module's semiconductor chip sits 2500 V AC isolated from its nickel-plated copper baseplate. The plastic housing is epoxy-resin potted for insulation, moisture protection and mechanical strength. The controller uses a flame-retardant engineering plastic case with wiring terminals for the input signal, trigger output and alarm signals.
Typical Applications
Industrial furnaces and heat treatment: salt bath, quenching, annealing and sintering furnaces, tunnel kilns. Machinery: injection molding barrel heating, extrusion lines and heat sealing on packaging machines. Glass and chemical processing: melting furnaces, pipe heating and preheating systems. Also soft-start duty for large fans and pumps.
Installation Notes
The 250 A module must be mounted on a sufficiently sized heatsink with thermal grease - poor cooling will overheat and damage the module. The terminal studs are insulated from the baseplate, so one shared heatsink is acceptable; connect main electrodes with copper busbar and tighten fasteners flat. Match the 4-20 mA controller input with your instrument or PLC output, otherwise power regulation may be inaccurate. Contact us for model selection and quotations.