Description
PR3-O-150kW 415V Three-Phase Burst Fire Power Regulator
The PR3-O-150kW is a high-power three-phase burst fire power regulator designed for seamless control of resistive loads using advanced two-thirds control technology. Engineered for demanding HVAC and industrial heating applications, it delivers accurate power regulation while reducing flicker and eliminating radio frequency interference (RFI) through fast pulse zero-voltage switching.
Designed for continuous operation in high-power environments, the PR3-O Series combines integrated semiconductor fuses, automatic thermal protection, and a permanently running cooling fan to provide reliable performance and long service life. Flexible signal input options and configurable burst firing modes make it suitable for a wide range of industrial process heating systems.
With simple installation, comprehensive diagnostic features, and robust construction, the PR3-O-150kW provides dependable control for air curtains, furnaces, ovens, dryers, and other high-capacity resistive heating applications.
Key Features
- Seamless three-phase control using two-thirds control technology
- Fast pulse zero-voltage switching to minimise flicker and eliminate RFI
- Available in fast burst (flicker inhibited) or slow burst firing modes
- 0–10V DC, 0–5V DC, 4–20mA or manual potentiometer control
- Automatic reset over-temperature protection
- Integrated high-speed semiconductor fuses
- Voltage-free alarm relay with configurable operating modes
- Phase loss and temperature sensor fault detection
- Permanently operating forced-air cooling fan
- Easy-access signal and power terminals for straightforward installation
- Suitable for floating-star and closed-delta resistive load configurations
Technical Specifications
Electrical
- Power rating: 150kW (209A)
- Supply voltage: 415V RMS nominal
- Input voltage: 400V RMS ±10%
- Frequency: 50/60Hz
Control Input Options
- 0–10V DC (factory default)
- 0–5V DC
- 4–20mA input
- Manual control via 5kΩ potentiometer
Burst Fire Control
- Fast burst firing (flicker inhibited)
- Slow burst firing (1-second proportional time base)
Alarm & Monitoring
- Voltage-free alarm relay
- Alarm relay rating:
- 2A @ 125V AC
- Configurable relay operation (normally open or normally closed)
- Status LED tracks control signal output
- Remote alarm supply option (24V AC/DC)
Protection Features
- Automatic over-temperature trip activates at:
- 90°C ±1°C
- Automatic reset temperature:
- 85°C ±1°C
- Phase loss detection
- Temperature sensor loss detection
- Integral semiconductor fuse protection
Cooling
- Permanently operating 120mm cooling fan
- Standard 230V AC fan
- Optional 110V AC or 24V AC fan available
Terminal Connections
Phase Power
- M8 setscrew with nut and washer
Earth
- M6 stud with nut and washer
Auxiliary Alarm Relay
- 2.5mm² rising clamp terminal block
Control Signal
- 2.5mm² rising clamp terminal block
Torque Settings
- Power and earth terminals:
- 12–15Nm
Fusing
- 250A High-Speed Semiconductor Fuse (250MT or equivalent)
Environmental
- Maximum operating temperature:
- 65°C
Mechanical
Dimensions
- 260mm (D) × 245mm (W) × 215mm (H)
Fixing Centres
- 141mm (W) × 170mm (L)
- Alternative mounting:
- 141mm (W) × 100mm (L)
Weight
- 6.5kg
Applications
Suitable for 3-wire, three-phase floating-star or closed-delta configured resistive loads, including:
- HVAC air curtain systems
- Industrial furnaces
- Industrial ovens
- Dryers
- Hot plates
- Commercial heating systems
- Process heating equipment
- High-power resistive heating applications





