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Underground Timed-Reset Fault Indicator

The TR is a timed-reset faulted circuit indicator (FCI) that provides indication for both momentary and permanent faults. It automatically resets at the end of a fixed-reset period, allowing time for crews to locate faults. You can apply the TR in underground distribution systems with low load and low voltage, and it is ideal for locations where false reset from backfeed is a concern.

The TR is available with a clamp-on timed-reset (TR) sensor or test point timed-reset (TTR) sensor for single- and three-phase applications. You can choose from a variety of remote display options that eliminate the need to access an enclosure cabinet or subsurface vault to determine the indicator’s status.

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Fault Troubleshooting—Apply the TR on distribution circuits to troubleshoot momentary and permanent faults. The TR provides identical indication for both momentary and permanent faults. The TR will hold the tripped status indication for a set time, regardless of the presence of current or voltage on the distribution circuit. TR fault indicators continue to lead crews to the fault location even after power is restored.  

Timed-Reset Intervals—A factory-set 2-, 4-, or 8-hour timed-reset interval will automatically reset the TR. You can also manually reset the units using the CRSRTT magnet tool. 

Industrial Backfeed—Circuits feeding large industrial equipment and rotating machinery can contribute energy into a fault past the FCI’s location within the fault path. Sometimes this energy is sufficient to reset a current or voltage reset-type FCI, misleading crews searching for a fault. You can use the TR in applications with backfeed to ensure FCIs in the fault path continue to display their fault indication for the timed-reset period, regardless of the duration or magnitude of the backfeed condition.

Why choose a TR FCIs in backfeed applications?

BTRI_IR system overview-01

Remote displays eliminate the need for line crews to open high-voltage enclosures or enter subsurface vaults during fault-finding patrols. The TR is compatible with a variety of remote display options:

  • BEACON bolt "B" display
  • Standard “V” display
  • Large “L” display
  • RadioRANGER Remote Fault Reader "M"
_FIS Displays
Power Source3.6 V lithium battery with a 20-year life
Replaceable Battery2.4 Ah Cell
Nonreplaceable Battery8.5 Ah Cell
Nominal Trip Ratings50 to 1,200 A
Trip Tolerance±10%
Maximum Fault Current25 kA
Reset Time2, 4, or 8
Trip Response Time1 ms (optional 24 ms with delayed trip)
Display OptionsBuilt-in flashing BEACON LED
Standard remote
Large remote
RadioRANGER Remote Fault Reader
Outer Diameter Clamping Range0.50" to 1.6"
Clamp MaterialStainless-steel clamp with a UV-stabilized rubber sleeve
Nominal Inrush Restraint Response Time300 ms
Temperature Range–40° to +85°C (–40° to +185°F)
Approximate Weight400 g (0.88 lbs)