• Megger

Megger® WM6 Series

Hand-cranked Insulation Testers
Megger WM6 hand-cranked insulation testers


  • Pocket-sized, self-powered instrument -no battery maintenance problems
  • Tests at 500 V DC
  • Powered by an easy-to-turn, low-voltage, ac brushless generator
  • Stabilized electronic invertor
  • Resistance readings given directly on a moving-coil analog meter
  • Simple, two-position function selector switch
  • Robust ABS plastic case


The Megger® WM6 tester is a self-contained instrument designed to give rapid and accurate resistance measurements. The hand-operated generator is coupled with the latest electronic technology, thus allowing the WM6 to test insulation at 500 V d.c. up to 200 Mohms. A low-voltage, hand-cranked, a.c. brushless generator, which is easy to turn by hand, is the power source. It is connected to a stabilized electronic invertor to provide the test voltage. All resistance readings are given directly on a moving-coil meter with a rugged taut-band suspension movement, a white-on-black scale and an orange “dayglow” pointer. This gives goodlegibility in most lighting conditions.An electronic circuit is used to give a four-decade resistance scale for insulation measurement. There is a slider switch for selection of either the insulation resistance or continuity functions, and the strong ABS plastic case has a recess to accommodate the foldedaway generator handle for compactness. Two 4-mm terminal sockets are fitted into the side of the case for connecting the test leads.

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The WM6 tester is suitable for the direct measurement of insulation resistance and continuity of domestic and industrial wiring, cables, transformers, motors, generators, electrical machinery and appliances. It is suitable for use during installation and commissioning work as well as servicing and maintenance applications. The WM6 may be used to measure the insulation resistance of 415/240-V a.c. wiring installations to prove that they comply with wiring regulations.

  • Literature
  • Specifications
pdf icon Description
++ MJ159 Specification sheet
Insulation Ranges
WM6 0 to 200 MΩ and infinity
Measuring Range: 0 to 100 Ω
Terminal Voltage on Open Circuit (DC)
Insulation Range: <600 V
Continuity Range: 800 mV approx
Terminal Voltage at 1-MΩ Load (DC)
Insulation Range: 500 V +10%, -5%
Terminal Current on Short Circuit
Insulation Range: 1,3 mA approx
Continuity Range: 55 mA approx., Voltage Stability, 160 to 240 RPM
Insulation Range: < ±1% Ripple Content at 160 RPM on Open Circuit
Insulation 500 mV peak-to-peak approx
WM6 1,5 mm (0,060 in.) from any marked position on the scale when measured against standard resistors