Multimeter adapter for interturn short-circuit tests

In addition to insulation defects between winding and housing, users can now also detect interturn short-circuits within a winding of an electric motor with this portable device for field use. In a surge test with 1kV impulse voltage, the METRAHIT IM and the connected coil adapter reliably recognise even those defects that occur only when operating voltage is applied.

The coil adapter is designed for windings with inductances from 10μH to 5H. This corresponds to rated outputs of about 160VA to 80 MVA for three-phase machines with 400V rated voltage. After connection to terminals U, V, and W, the semi-automatic test sequence is triggered by a rotary switch. Polarity reversal can also compensate for remanence effects in the rotor.

The new coil adapter is available as an optional accessory for the METRAHIT IM XTRA multimeter and the automotive version IM E DRIVE. These are the only available portable universal multimeters that also enable four-wire milliohm measurements for precise detection of minimal resistances with resolutions up to 1μΩ.

Their functional range includes insulation resistance tests with up to 1,000V, two-wire Rlow measurements with 200mA test current according to EN 61557-4/VDE 0413-4, TRMS current and voltage measurements up to ten or 100 kHz, high-precision temperature measurements with RTD and TC-K sensors, capacitance measurements, and measurements of the polarisation and absorption index.

To ensure protection from high short-circuit currents in electric vehicles, the battery-powered multimeters meet the demands of measurement categories CAT III (1000 V) and CAT IV (600 V). The devices are designed for convenient one-hand operation. Their 3.5" TFT color graphic display ensures readability.