Skip to content

LLI-750DC Live Line Indicator

5.0 (2 reviews)

  • Can be used on DC high voltage overhead lines up to 750V 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 be used on third rail installations
  • Battery check function
  • Standard Threshold: 250V DC
  • Resistor Chain: 1.5MΩ
  • Operating time: 5 minutes nominal


The LLI-750DC Live Line Indicator is a sophisticated, battery-operated electronic unit specifically engineered for precise testing of DC systems up to 750V, particularly in the context of Mass Transit Railway (Metro) and Tram models. It serves as a critical tool to ensure optimal safety during maintenance or installation procedures.

The kit includes:

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

While primarily intended for overhead catenaries, the versatile LLI-750DC can also be effectively utilized in “third rail” installations. Its primary purpose is to verify system de-energization, allowing for secure earthing and instilling confidence in both maintenance personnel and system security.

The instrument provides visual (flashing red LEDs) and audible (70 dB) alarms for live conductor indication during testing. It has a threshold setting of approximately 33% of the system voltage.

The unit features a test button. Pressing it activates the alarms, and releasing it changes the red LEDs to green for 5 minutes. If the threshold is exceeded, the warning alarms reactivate. The test button also performs a battery check.

A universal “star wheel” adaptor connects to various operating poles. Different clamps are available for different earthing systems, such as buried rail.

Selecting the LLI-750DC Live Line Indicator ensures meticulous testing procedures and an elevated level of safety. Suitable for both indoor and outdoor usage, this cutting-edge instrument functions optimally within an operating temperature range of -5°C to +50°C. Its remarkable immunity to interference fields and inclusion of a handguard with a viewing window further underscore its commitment to user safety.

Our partners, AcutestAlpha ElectronicsCuthbertson LairdNorwich Instrument Services, and PASS Ltd offer the LLI-750DC in the United Kingdom. If based outside of Great Britain, you can order the product through our worldwide distribution network.

LLI-750DC Operating Manual


LLI-750DC Datasheet


Additional information

Weight2 kg

2 reviews for LLI-750DC Live Line Indicator

  1. Martin Carter

    Perfect for requirements. Proved it’s worth multiple times over the years.

  2. Oliver Jensen

    We have quite a few and they work just fine. Not much maintenance is required to keep them working.

Leave a customer review

Your email address will not be published. Required fields are marked *

Back To Top