GFR Series Ground Fault Relays from Duncan Inst.

Product Announcement from Duncan Instruments Canada, Ltd.

GFR Series Ground Fault Relays from Duncan Inst.-Image

The GFR Series relays protect industrial electrical equipment such as motors, transformers and feeders, against the damage caused by low magnitude ground currents. GFR-2/3 work effectively on both high and low resistance grounded distribution systems. The package consists of: Ground Fault Protection Relay and Zero Sequence Current Transformer.


Technical Information

  • Power Supply: 115AC + 10% - 20%, 50/60Hz, 3VA
  • Tripping Range: See Ordering Information
  • Output Contacts: DPDT, 3A @ 115VAC or 28VDC
  • Repeatability Better than 1%.
  • Temperature Range: -10°C thru + 55°C
  • Operating Time: 50 msec. (typical)
  • Duty Cycle Continuous
  • Weight (approx.): 0.3 kg
  • Dimensions: 50 x 70 x 100 mm
  • Mounting Position: As required
  • Terminal Wire Size: 2 x 14 AWG (Solid)
  • Wide range power supply option


GFR-3 is an enhanced version of our GFR-2 with built-in self-test circuit and adjustable time delay. The self-test is activated by the TEST pushbutton. This test will trip both the Ground Fault Relay and the breaker. NO-TRIP pushbutton is also provided to test the Ground Fault Relay without tripping the breaker.

Technical Information

  • Power Supply: 115VAC, + 10%, -20%, 50/60Hz, 9VA max
  • Tripping Range: See Ordering Information
  • Repeatability Better than 1%.
  • Temperature Range: -10°C thru + 55°C
  • Output Contacts: DPDT, 10A @ 115VAC; 2 - N.O. in series - 1A @ 250VDC
  • Operating Time: 0.1 thru 1.2 sec., adjustable
  • Duty Cycle Continuous
  • Weight (approx.): 0.7 kg
  • Dimensions: 175 x 115 x 75 mm
  • Mounting Position: Semi-flush panel mount
  • Terminal Wire Size: No. 22AWG to No. 12AWG
  • Wide range power supply option


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