The GM-150 is pilotless and uses a 45 ohm trip resistance and a 250 ms time delay, which eliminates nuisance tripping from intermittent conditions in the cables and collector ring assemblies.

  • Monitors three phase, single phase, or DC power cables.
  • Requires no calibration even when cables are replaced.
  • Monitors reliably through cable reels for complete protection at all times.
  • Performs satisfactorily with all types of arc suppressors.
  • Current transformers and filters are easily installed with tie wraps.
  • By mounting only one compact unit, 5 monitor circuits are available. (Two units for up to 10 circuits, etc.)
  • With multi-circuit design and simplified installation the GM-150 is the most economical continuity type monitoring system available in the industry.


Head Office

PO Box 234
12187 N Scenic Highway
Rocky Gap, VA 24366

T:  +1-800-541-5583
F:  +1-276-928-1815

Hours of operation:
Monday - Friday
8:00AM - 4:30PM EST

Bluefield Facility

1960 Valley Dale Street
Bluefield, VA 24605-9454

GPS > 700 Fincastle Tnpk

T:  +1-800-428-7800
P:  +1-276-326-2611

Hours of operation:
Monday - Friday
8:00AM - 5:00PM EST

After Hours, Weekend & Holiday Service

+1 866-456-0231 (Toll Free)
* A technician will respond by phone within four hours of receiving your call.