Description

PR3-E-27kW Three-Phase 27kW Power Controller (38A)

The PR3-E-27kW thyristor stack is a high-performance power controller designed for seamless control of three-phase resistive loads. Using a two-thirds control technique and fast pulse zero-volts switching, it delivers smooth power regulation while minimising flicker and eliminating radio frequency interference.

Built for reliability in demanding industrial environments, the unit includes automatic temperature protection, integral semiconductor fuses and a robust heatsink assembly. The 27kW model features forced-air cooling to maintain stable operation under high loads, while clearly accessible signal and power terminals simplify installation and maintenance.

Engineered for precision and durability, the PR3-E-27kW is ideal for HVAC systems and industrial heating applications requiring dependable three-phase power control.

Key Features

• Seamless control of three-phase resistive loads using two-thirds control technique

• Fast pulse zero-volt switching to reduce flicker and eliminate RFI

• DC signal control or manual control via 5kΩ potentiometer

• Automatic resetting over-temperature trip for built-in protection

• Integral semiconductor fuses for overload protection

• Forced-air cooling for reliable high-power operation (27kW model)

• LED status indicator tracking control signal and fault conditions

• Easy access terminals for straightforward installation

Benefits

• Smooth and stable power regulation for industrial heating systems

• Reduced electrical noise and improved system performance

• Enhanced safety with automatic thermal protection

• Reliable operation under demanding load conditions

• Flexible control options for integration into various control systems

• Simplified installation and maintenance

Typical Applications

The PR3-E-27kW is ideal for controlling three-phase resistive heating loads such as:

• HVAC systems and air curtains

• Industrial furnaces and ovens

• Drying equipment

• Hot plates and process heaters

• 3-wire floating-star or closed-delta load configurations

Technical Specifications

Electrical Ratings

• Power rating: 27kW (38A) at 415V RMS nominal

• Input voltage: 400V RMS ±10%

• Frequency: 50/60Hz

Control Inputs

• 0–10V DC (standard)

• 0–5V DC selectable

• 4–20mA selectable

• Manual control via 5kΩ potentiometer

Protection & Monitoring

• Over-temperature trip: 90°C ±1°C (auto reset)

• Phase loss detection

• Sensor loss detection

• LED status indicator with diagnostic signalling

• Integral semiconductor fuses

• Forced-air cooling fan (switch-on approx. 55°C)

Connections

• Power & earth: 10mm² rising clamp terminals

• Control signal: 2.5mm² terminals

• Auxiliary alarm relay: 2.5mm² terminals

• Terminal torque (power): 1.2Nm

Fusing (27kW model)

• 40A high-speed semiconductor ferrule fuse (14mm × 51mm)

Environmental & Mechanical

• Maximum ambient temperature: 40°C

• Dimensions: 150mm (D) × 240mm (W) × 100mm (H)

• Fixing centres: 220mm (W) × 130mm (D)

• Weight: 2.6kg