LINEMAN’S TOOLS & EQUIPMENT

Manual Reset (MR) URD Fault Indicators

Manual Reset (MR) URD Fault Indicators

Manual Reset (MR) Fault Indicators employ a magnetic principle using two magnetic elements. One is the yoke which is demagnetized by the fault current, allowing the other to act on the display
and cause a reflective red target to show. The target is held in place magnetically until the MR is reset using the Manual Reset Tool.

The MR is secured to the line by means of overcenter toggle clamps and may be applied or removed by a hot stick. MR Fault Indicators have a response time of 12 ms at the trip rating.
The display has a red reflective target area of 3.3 square centimeters.

Both MR and MB fault indicators have hermetically-sealed ultrasonically welded housings and stainless-steel, vinyl-coated clamping mechanisms that make them suitable
for use in harsh, submersed, and corrosive environments.

Specifications:

  • After a fault occurs, use an MR or MB before reclosing for inexpensive, efficient fault location.
  • Line-powered, battery free.
  • The MR model is available in a convenient kit to keep on a truck— three MRs and
    a reset tool in a sturdy, lightweight carrying case.
  • MR models are also applicable on overhead systems. MB models are only
    for underground applications.
  • More than 50 years of field-proven reliability.
  • Nominal Trip Ratings: MR 100 to 800 A
  • Trip Tolerance: ±10%
  • Overhead (MR only): Up to 38 kVL-L
  • Underground: Matches the URD cable rating
  • Maximum Fault Current: 25 kA for 10 cycles
  • Trip Response Time: 8 ms
  • Outer Diameter Clamping Range: 0.25″ to 1.4″ (please specify
    the clamping diameter or range when ordering)
  • Temperature Range: —40° to +85°C
  • Approximate Weight: 140 g (0.31 lbs)
    Linestar