1080-HPT
HIGH POT TEST

The 1080-HPT performs a variety of tests on telephone lines, AC power lines, intercom lines and any other wire pairs. It generates up to 1,200 volts DC at 1+ mA to test for leakage caused by the semiconductors and other components normally used in wiretaps and room audio and data transmitters.
The unit detects back-to-back zener diodes, SCRs, TRIACS, DIACs, sidactors, thyristors, transistors, TVSs, varistors, and gas discharge tubes (including neon). Some of these devices have breakdown voltages of up to 700 volts.
OPERATION:
TELEPHONE SYSTEMS: When high-potting ANY wire pair it is imperative that both ends of the wire pair are free of known components or equipment. Once the operator is assured that no equipment is on the wire pair the telephone line plug may be plugged into either of the modular jacks. The clip lead cables are used if the wire is not terminated in a telephone plug. Rotate the voltage control knob fully counterclockwise. With hands clear of any wires, press the RED power button. Slowly advance the voltage control. If the meter immediately indicates current it indicates that the wire is not free of foreign devices. Again check the wire. If the telephone line is totally clear it should be possible to advance the control to the full 1,200 volts. Check both polarities by either moving the plug to the other modular socket or reversing the clip lead cable.

AC POWER LINES INCLUDING APPLIANCES: Unlike telephone lines, the AC power line is accessible at many points, normally the AC outlets. It is difficult, but not impossible, to clear the line of all appliances and accessories and then test the line. If the line can be cleared the power must be removed by throwing the circuit breaker or removing the fuse. Appliances, such as incandescent lamps, may, after removing the bulb, be tested individually. Clocks, instant on TVs or similar devices may not be tested. They require visual inspection.