Live Line Indicator

Live Line Indicators

High Voltage DC Live Line Indicators (LLI) are battery operated electronic units that have been specifically designed to test DC systems, with particular relevance to Mass Transit Railway (Metro) & Tram based models.

Each Live Line Indicator kit comprises the following components:

  • DC Live Line Indicator with earth lead & clamp
  • Bowthorpe Rod Adaptor incorporated into indicator case moulding
  • Universal Star-wheel Adaptor
  • Hook, Y and straight electrode
  • Polymer Cleaning Kit
  • Instruction manual
  • Carry Satchel

Three versions of Live Line Indicators are available to cover the most common system voltages of 750V, 1500V, and 3000V DC. Although usually applied to overhead catenaries they can also be used on “third rail” installations. Proving that the system is de-energised, and can thus be safely earthed, is important to both maintenance staff and system security.

High Voltage DC Live Line Indicators give both visual (high intensity flashing red LED’s) and audible (70 dB) alarm should a conductor under test indicate as live. Each version has a threshold setting of approximately 33% of system voltage, above which the line is deemed to be energised.

The unit is the first armed with the test button which will cause the alarms to activate and upon releasing the button the red LED’s will be replaced by green ones and the audible the alarm will stop. The green condition will remain active for about 5 minutes during which time the unit can be applied to the line under test and if the threshold is exceeded the Warning alarms will again be activated. Pressing the test button also performs a battery check.

A universal “star wheel” adaptor is also available to connect to other operating poles and alternative clamps are available to suit various earthing systems, e.g. buried rail.

Key Features

  • Can be used on DC high voltage overhead lines up to 3000V DC
  • Earth lead and clamp attached to long-length handle
  • Red LED indicators when voltage is detected
  • Loud 70dB alarm when voltage is detected
  • Audible indication: Buzzer, 3.1 kHz tone, modulated @ 2Hz
  • Can also be used on third rail installations
  • Battery check function
  • Standard Thresholds: 250V / 500V / 1000V DC
  • Resistor Chain: 1.5MΩ / 3MΩ / 6 MΩ
  • Operating time: 5 minutes nominal

Product Documents

This product and all its variants are available in the United Kingdom through our partners, AcutestAlpha ElectronicsCuthbertson LairdNorwich Instrument Services, and PASS Ltd. Alternatively, you can contact us direct by phone or request a quotation through our website.