Description

PR3-E-86kW 120A Three-Phase Burst Fire Power Controller

A high-capacity thyristor stack designed for seamless control of three-phase resistive loads in HVAC and industrial heating applications. Using advanced two-thirds control and fast pulse zero-voltage switching, the PR3-E ensures stable, interference-free power delivery while minimising flicker and eliminating RFI.

Built for demanding environments, this controller provides precise heat management for air curtains, furnaces, ovens, dryers, and other large heating systems where reliability and smooth control are critical.

Key Features

• Seamless control of 3-phase resistive loads using two-thirds control
• Fast pulse zero-voltage switching to minimise flicker and remove RFI
• DC signal input or manual control via 5kΩ potentiometer
• Supports 0–10V, 0–5V, and 4–20mA control signals
• Auto-reset over-temperature protection
• Integral high-speed semiconductor fuses
• Heatsink with cooling fan fitted for enhanced thermal performance
• Voltage-free alarm relay with selectable NO/NC behaviour
• LED status indication with fault diagnostics
• Easy access rising-clamp terminals for straightforward installation

Technical Specifications

• Power rating: 86kW (120A) @ 415V RMS typical supply
• Input voltage: 400V RMS ±10%
• Frequency: 50/60Hz

Control inputs

• 0–10V DC (standard) or 0–5V (SW3 selectable)
• Manual control via 5kΩ potentiometer
• 4–20mA supported (SW I/V ON + 270Ω resistor across SIG±, SW3 to 0–5V)

Burst fire modes

• Slow burst: 1-second proportional time base
• Fast burst: variable, non-proportional time base

Protection & diagnostics

• Over-temperature trip: 90°C ±1°C
• Reset temperature: 85°C ±1°C
• Phase loss detection (slow LED pulse)
• Sensor loss detection (equal interval LED pulse)
• LED intensity tracks control signal
• Alarm relay: 125V AC @ 2A
• SW1 selectable relay logic (NO/NC on fault)

Terminations

• Phase power & earth: 35mm² rising clamp
• Reference phase (L2): 10mm² rising clamp
• Control signal: 2.5mm² rising clamp
• Auxiliary alarm: 2.5mm² rising clamp
• Terminal torque:
  • Power & earth: 3.2–3.7Nm
  • Reference (L2): 2.0Nm

Fusing

• 160EET (160A) high-speed semiconductor fuse

Environmental & mechanical

• Max operating temperature: 65°C
• Dimensions: 272mm (D) × 250mm (W) × 130mm (H)
• Fixing centres: 227mm (W) × 200mm (D) with 4 × 6mm holes
• Weight: 5.2kg

Applications

Suitable for 3-wire, 3-phase floating star or closed delta resistive loads:

• HVAC air curtain systems
• Industrial furnaces
• Ovens
• Dryers
• Hot plates
• Large industrial heating zones