The Metrohm LLI750DC High Voltage DC Live Line Indicator (LLI) is a battery operated electronic unit that has been specifically designed to test DC systems - with particular relevance to Mass Transit Railway (Metro) & Tram based models. 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.

Three DC Live Line Indicators versions are available to cover the most common system voltages of 750V, 1500V and 3000V DC.

Other pages:  1500V DC Live Line Indicator - LLI1500DC or 3000V DC Live Line Indicator - LLI3000DC

DC Live Line Indicator Features:

► Voltage Range: 750V DC
► Std Thresholds: 250V DC
► Resistor Chain 1.5MΩ.
► Operating time: 5 minutes nominal.
► Visual indication: LED's.
► Status: Alarm Red Flash @ 2Hz.
► Status: Safe Green Flash @ 2Hz.
► Audible indication: Buzzer, 3.1 kHz tone, modulated @ 2Hz, 70dBA @ 1.5 Metres.
► Battery life: 250 Operations minimum.
► DC Live Line Indicator Warranty: 1 year

For safety the DC LLI gives both visual (high intensity flashing red LED’s) and audible (70dB) 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 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 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.

Each DC Live Line Voltage Indicator KIt comprises:

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