The Whirlwind TLC (Tester-Line Cord) is a dedicated test device for Neutrik Powercon® and True One® three wire power cords. The TLC is a battery powered continuity tester that conveniently verifies the condition of power cables that are difficult to test without applying dangerous line voltage. Each of the three conductors is tested for continuity, shorts and incorrect connections. Six red LEDs indicate correct wiring or any fault conditions. A rotary switch applies test signal to each wire individually to easily determine if it is properly connected at both ends. To use the TLC, plug one end of the cable in to any of the Send connectors and the opposite end into the proper receive connector. Rotate the switch through the Line Neutral and Earth positions. The Send LED indicates that battery voltage is being applied to that wire. The corresponding Receive LED will illuminate if the cable is properly wired. If any other LED illuminates, shorted or miswired conditions exist. If no Receive LED illuminates, the wire is open. Adapters from one connector series to another may be tested by choosing the proper send and receive jacks on the rear of the TLC. The Whirlwind TLC is powered by a single 9 Volt battery located inside the unit. To install or replace the battery, remove the 4 case screws and connect the battery to the battery clip. Carefully slide the battery into the opening and confirm that the wires are not being pinched. Replace the bottom and close with the provided case screws. Do not use longer screws as they might puncture the battery. !!WARNING: DO NOT CONNECT ANY CABLE TO LINE VOLTAGE WHILE USING THE WHIRLWIND TLC TESTER!!