The GM-250 is the most advanced high voltage ground monitor on the market, available in both pilotless and pilot wire operation.  Offering a 45 ohm trip resistance, 250 ms time delay for reduced nuisance tripping, and immunity to DC and AC stray currents.  Easy installation and maintenance and approved to work with cable lengths to 10,000 feet, the GM-250 saves cable costs and repairs.

  • Pilotless or pilot wire operation.
  • Continuity monitor (45 ohm trip resistance)
  • Time delay (250 mS). Reduces nuisance tripping.
  • Immune to high and low voltage conditions. (+10%, -30%)
  • Immune to DC and AC stray currents.
  • Easy installation and maintenance.
  • Transient protection on all inputs and outputs.
  • Approved to work with cable lengths to 10,000 feet.
  • Saves cable cost and repairs.
  • Only MSHA – accepted high-voltage pilotless ground monitor.
Dimensions:6″W x 7.75″H x 8.5″D
(152.4mm x 196.9 x 215.9)
Weight:11.25 lbs (5.1 kg)
Enclosure Rating:Industrial Powder Coated Aluminum
Main Assembly Installation:Flush or Flange Mount
Operating Voltage:120 VAC
Current Consumption:250 mA
Operating Temperature: -20 to 70C
Humidity:0 to 90% R.H.
Phase Voltage Filters:7.2 kV, 15 kV, or 25 kV
Trip Resistance:Adjustable up to 75 ohms
Trip Delay:250 ms
Reset Mode:Auto
Transmitter Frequency:1000 Hz +/- 1%
Transmitter Output Current:200 mA
Outputs:(1) Normally open or Normally Closed Contact Relay
Contact Relay Rating:Form C – 120 VAC @ 10 A or 240 VAC @ 5 A
Contact Operating Mode:Fail Safe
Display:LED indicators, Analog Current Meter
Backup Battery:No
Test Feature:Yes
Option:Blocking Inductor-prevents parallel earth pass of signal
Warranty:90 Days

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12187 N Scenic Highway
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T:  +1-800-541-5583
F:  +1-276-928-1815

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1960 Valley Dale Street
Bluefield, VA 24605-9454

GPS > 700 Fincastle Tnpk

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