• Mitsubishi Electric UN-FD, FD4 Fault Detection Units (Contact Weld Detection Relays)
1 1

Mitsubishi Electric UN-FD, FD4 Fault Detection Units (Contact Weld Detection Relays)

Mitsubishi Electric UN-FD, FD4 Fault Detection Units (Contact Weld Detection Relays)

Mitsubishi Electric UN-FD and UN-FD4 fault detection units detect main circuit contact welding of magnetic starters, cutting off power in combination with a circuit breaker or contactor to prevent load equipment runaway.

Key features

  • UN-FD for 200V main circuits (output 1c fixed, resets when the main circuit opens); UN-FD4 for 400V main circuits (output 1a or 1b selectable, also detects non-operation faults, resets by switching off the control supply)
  • Detection time 0.2 to 0.5s
  • CX types have CAN terminals
  • Not applicable to capacitor loads, star-delta starting, or inverter circuits
  • DC24V control supply versions available on request
UN-FD AC100V Fault detection unit UN-FD, 200V main circuit, AC100V | Main Circuit: 200V class | Control Voltage: AC100V (AC100-120V 50/60Hz) | Output Contact: 1c (fixed) | Terminal: Screw
UN-FD AC200V Fault detection unit UN-FD, 200V main circuit, AC200V | Main Circuit: 200V class | Control Voltage: AC200V (AC200-240V 50/60Hz) | Output Contact: 1c (fixed) | Terminal: Screw
UN-FDCX AC100V Fault detection unit UN-FDCX, 200V main circuit, AC100V | Main Circuit: 200V class | Control Voltage: AC100V (AC100-120V 50/60Hz) | Output Contact: 1c (fixed) | Terminal: CAN (CX)
UN-FDCX AC200V Fault detection unit UN-FDCX, 200V main circuit, AC200V | Main Circuit: 200V class | Control Voltage: AC200V (AC200-240V 50/60Hz) | Output Contact: 1c (fixed) | Terminal: CAN (CX)
UN-FD4 AC100V 1A Fault detection unit UN-FD4, 400V main circuit, AC100V, 1a | Main Circuit: 400V class | Control Voltage: AC100V (AC100-120V 50/60Hz) | Output Contact: 1a | Terminal: Screw
UN-FD4 AC100V 1B Fault detection unit UN-FD4, 400V main circuit, AC100V, 1b | Main Circuit: 400V class | Control Voltage: AC100V (AC100-120V 50/60Hz) | Output Contact: 1b | Terminal: Screw
UN-FD4 AC200V 1A Fault detection unit UN-FD4, 400V main circuit, AC200V, 1a | Main Circuit: 400V class | Control Voltage: AC200V (AC200-240V 50/60Hz) | Output Contact: 1a | Terminal: Screw
UN-FD4 AC200V 1B Fault detection unit UN-FD4, 400V main circuit, AC200V, 1b | Main Circuit: 400V class | Control Voltage: AC200V (AC200-240V 50/60Hz) | Output Contact: 1b | Terminal: Screw
UN-FD4CX AC100V 1A Fault detection unit UN-FD4CX, 400V main circuit, AC100V, 1a | Main Circuit: 400V class | Control Voltage: AC100V (AC100-120V 50/60Hz) | Output Contact: 1a | Terminal: CAN (CX)
UN-FD4CX AC100V 1B Fault detection unit UN-FD4CX, 400V main circuit, AC100V, 1b | Main Circuit: 400V class | Control Voltage: AC100V (AC100-120V 50/60Hz) | Output Contact: 1b | Terminal: CAN (CX)
UN-FD4CX AC200V 1A Fault detection unit UN-FD4CX, 400V main circuit, AC200V, 1a | Main Circuit: 400V class | Control Voltage: AC200V (AC200-240V 50/60Hz) | Output Contact: 1a | Terminal: CAN (CX)
UN-FD4CX AC200V 1B Fault detection unit UN-FD4CX, 400V main circuit, AC200V, 1b | Main Circuit: 400V class | Control Voltage: AC200V (AC200-240V 50/60Hz) | Output Contact: 1b | Terminal: CAN (CX)
AccessoriesMitsubishi Electric
12 product codes available in this family
Sourced direct from KoreaExport-ready supplyCompetitive pricing
RFQ List 0 Email about this

Need a different model, or a part not listed here? Send us your parts list →

Mitsubishi Electric UN-FD, FD4 Fault Detection Units (Contact Weld Detection Relays)

Brand Mitsubishi Electric·Accessories

Available part numbers (12)

UN-FD AC100V, UN-FD AC200V, UN-FDCX AC100V, UN-FDCX AC200V, UN-FD4 AC100V 1A, UN-FD4 AC100V 1B, UN-FD4 AC200V 1A, UN-FD4 AC200V 1B, UN-FD4CX AC100V 1A, UN-FD4CX AC100V 1B + 2 more — see full table ↓

How to order

Send the Mitsubishi Electric part numbers and quantities through our RFQ form or to info@prosourcemro.com. We confirm price, availability and lead time within 1 business day — no account needed.

RFQ List 0 →
View full details
Product codes & specifications
0 selected
RFQ List (0)
Product codeSpec
UN-FD AC100VFault detection unit UN-FD, 200V main circuit, AC100V | Main Circuit: 200V class | Control Voltage: AC100V (AC100-120V 50/60Hz) | Output Contact: 1c (fixed) | Terminal: Screw
UN-FD AC200VFault detection unit UN-FD, 200V main circuit, AC200V | Main Circuit: 200V class | Control Voltage: AC200V (AC200-240V 50/60Hz) | Output Contact: 1c (fixed) | Terminal: Screw
UN-FDCX AC100VFault detection unit UN-FDCX, 200V main circuit, AC100V | Main Circuit: 200V class | Control Voltage: AC100V (AC100-120V 50/60Hz) | Output Contact: 1c (fixed) | Terminal: CAN (CX)
UN-FDCX AC200VFault detection unit UN-FDCX, 200V main circuit, AC200V | Main Circuit: 200V class | Control Voltage: AC200V (AC200-240V 50/60Hz) | Output Contact: 1c (fixed) | Terminal: CAN (CX)
UN-FD4 AC100V 1AFault detection unit UN-FD4, 400V main circuit, AC100V, 1a | Main Circuit: 400V class | Control Voltage: AC100V (AC100-120V 50/60Hz) | Output Contact: 1a | Terminal: Screw
UN-FD4 AC100V 1BFault detection unit UN-FD4, 400V main circuit, AC100V, 1b | Main Circuit: 400V class | Control Voltage: AC100V (AC100-120V 50/60Hz) | Output Contact: 1b | Terminal: Screw
UN-FD4 AC200V 1AFault detection unit UN-FD4, 400V main circuit, AC200V, 1a | Main Circuit: 400V class | Control Voltage: AC200V (AC200-240V 50/60Hz) | Output Contact: 1a | Terminal: Screw
UN-FD4 AC200V 1BFault detection unit UN-FD4, 400V main circuit, AC200V, 1b | Main Circuit: 400V class | Control Voltage: AC200V (AC200-240V 50/60Hz) | Output Contact: 1b | Terminal: Screw
UN-FD4CX AC100V 1AFault detection unit UN-FD4CX, 400V main circuit, AC100V, 1a | Main Circuit: 400V class | Control Voltage: AC100V (AC100-120V 50/60Hz) | Output Contact: 1a | Terminal: CAN (CX)
UN-FD4CX AC100V 1BFault detection unit UN-FD4CX, 400V main circuit, AC100V, 1b | Main Circuit: 400V class | Control Voltage: AC100V (AC100-120V 50/60Hz) | Output Contact: 1b | Terminal: CAN (CX)
UN-FD4CX AC200V 1AFault detection unit UN-FD4CX, 400V main circuit, AC200V, 1a | Main Circuit: 400V class | Control Voltage: AC200V (AC200-240V 50/60Hz) | Output Contact: 1a | Terminal: CAN (CX)
UN-FD4CX AC200V 1BFault detection unit UN-FD4CX, 400V main circuit, AC200V, 1b | Main Circuit: 400V class | Control Voltage: AC200V (AC200-240V 50/60Hz) | Output Contact: 1b | Terminal: CAN (CX)

Need a different model, or a part not listed here? Send us your parts list →

Related products

All Circuit Breakers & Contactors →