Megger -
The Major Megger insulation and continuity testers MJ10 and BM12 are modern, portable, self-contained instruments designed to give rapid and accurate measurements.
They have four d.c. insulation testing voltages 100V, 250V, 500V and 1000V, and a single insulation resistance range of up to 2000MO. Similarly, continuity is measured, with either polarity, on a single 0-4 O range.
Power for the MJ10 instrument is derived from a low voltage, hand-cranked generator which has been designed to be easy to turn even under full load conditions. The low voltage generator is connected to an electronic inverter to provide a very stable test voltage.
- Standard d.c. test voltages 100V, 250V, 500V and 1000V
- Guard terminal
- Continuity range with polarity reversal
- Automatic capacitive circuit discharge facility
- Voltage range for indicating an energized circuit and monitoring discharge
Accuracy of measurement is unaffected by variations in the generator cranking speed and the test voltage is maintained at its rated value to as low as 1 MO at 1000V or 0.5 MO at 500V. The BM12 has a similar specification and circuitry to the MJ10 but it is powered by internal, replaceable batteries.
As a safety feature, the a.c. voltage range becomes effective as soon as the instrument is connected to the circuit under test. Thus, a warning is given that the circuit is not de-energized before the instrument is operated.
