Video: AMIC-2505

Video transcript

What the AMIC-2505 measures with its three test voltages, how it is connected on a power cable and on a transformer, and how to read its absorption coefficients. Power and control cables, motors and low and medium voltage switchgear are tested again and again, at commissioning, after repairs, and at every inspection. A light hand-held meter, set by a single rotary switch, makes long series of tests quick. test voltages, 500, 1000 and 2500 V, resistance up to 2 TΩ,

a nominal test current of 1 mA, and an AC and DC volt meter up to 600 V. The range depends on the voltage, 500 GHz at 500 V, 1 TΩ at 1 kV, and 2 TΩ at 2.5. Below the voltage divided by 1 mA, the converter limits its current and the accuracy is no longer specified. The three test sockets are on the top edge, plus, minus and the guard G. The rotary switch picks 500, 1000 or 2500 V, or the voltmeter. START runs the test, interlocks it, and the keys on the right set the parameters. set includes three test leads, 1.8 m long and rated 5 kV, in red,

blue, and shielded black, with a pin probe and crocodile clips. Also, the nickel metal hydride battery pack and its charger, the case, the harness, and the calibration certificate. Leads of 5 and 10 m and a USB cable are options. The Routine Make the object dead. Turn the switch to the test voltage. The meter shows the voltage on the object. Connect the leads. Hold start, or press enter while holding start to lock the test.

At the end, the object is discharged through 100 kΩ. On a power cable, each conductor is measured against the others, shorted and earthed. Bond and earth L1, L2, L3, and N. The red lead, RISO+, goes to the conductor under test, here PE, and the black lead, RISO-, to the bonded group. Between the two windings of a transformer, surface current over the bushings and the tank would add to the reading.

Connect G to the tank. The red lead goes to one winding. The black lead to the other, with the terminals of each winding bonded. On a cable in bad weather, surface current over the core insulation matters too. Wrap a metal foil round the insulation of the conductor under test and connect it to G. Between two conductors, the conductors not taking part go to G. The meter times the test at fixed points, 15 or 30 seconds, 1 minute and 10 minutes, with a beep every 5 seconds.

From them it calculates two absorption coefficients, or DAR and PI if chosen in the setup. After the test, the arrow keys step through the results, the resistance, the leakage current, both coefficients, and the resistance and current at each time point. The leakage current tells how much current really crosses the insulation. With the switch on U, the meter is an AC and DC voltmeter up to 600 volts, to check that the object is dead.

Between 25 and 50 volts of interference, it still measures and shows noise. Above 50 volts the test is blocked. Measuring Category 4 at 600 volts, IP54, 1.3 kilos, and about 900 tests per charge of the nickel metal hydride pack, recharged in about 3 hours. Power and control cables, motors, transformers, and switchgear in low and medium voltage, and the periodic checks of industrial maintenance.

Insulation resistance testing, from Amperis.