The D3/LLI Live Line Indicator is a resistive type voltage detector designed for use on overhead a.c. rail electrification systems operating at 25kV nominal voltage. The 'LLI' threshold is specified as 12kV ± 5%, however it should be. The unit is designed to be mounted on approved fibreglass earth poles with the pole immediately below the indicator being the primary insulator. The signal emitted b the D3/LLI is both audible and visible. Power is provided by a rechargeable battery, housed within the main unit. The battery can be charged in-situ using the charger.
The unit comprises a main unit and a contact probe. The contact probe is manufactured from lightweight fibreglass tubing and houses the calibrated resistor stack. The pole section is foam-filled to increase its voltage. The probe is connected to the overhead line by a replaceable aluminum hook. The top of the pole is coated in a special high reflectivity paint to ease visibility when applying the indicator in poor lighting conditions. The limit of contact with the overhead line is clearly defined by a red limit collar fixed to the pole. The contact probe screws into the main unit with a special screw connector to minimise flash-over.
** Approval Reference PA05/798
** Audible and visual warning
** Self-test function
** Fully interchangeable
** Insulation tested
** Compatible with primary insulator poles