The Megger 210170 is all electronic; it generates a regulated dc high voltage and use low-zero-drift, high-accuracy circuit, with high current sensitivity. Designed for portability, it is enclosed in a molded, impact-resistance, flame-retardant case.
This unit provides high-resistance readings up to 20,000 MΩ. It features an analog meter movement calibrated directly in megohms, ohms and ac volts. Test voltages of 100, 250, 500 and 1000 volts dc are selected by a rotary switch. Insulation resistance measurements up to 20 GΩ can be made on all voltage ranges. The instrument is also equipped with a 0- to 5000 ohm continuity range and a 0- to 600 volt ac or presence of dc voltage measuring range. Power is supplied by an ac generator, driven by a hand crank, through a gear train.
Major Megger testers measure the insulation resistance of wires, power cables, motors, generators, transformers, switchboards and electrical controls. Both models offer multiple test voltages for performing spot and step-voltage tests. Typical applications include:
■ Acceptance testing at time of installation to check
conformance to specifications.
■ Routine preventive maintenance testing after installation.
■ Quality assurance testing by the manufacturer.
■ Diagnostic testing to isolate faulty components for
Major Megger insulation testers can be used for detecting high or low resistance grounds, short circuits in apparatus, cables, wiring, etc. whether caused by moisture, oil, dirt, corrosion, damage to insulation or natural deterioration. They can also be used to determine the presence of moisture, solvents and semiconducting foreign materials in wires, cables and other conductors, and in built-up insulation systems such as those found in motor windings.