Video: AMPI-530-IT

Video transcript

What the MPI-530-IT measures, why it is ready for IT networks, and how it is connected for each test. Operating theaters, mines, and some industrial plants cannot afford an outage at the first insulation fault, so they are supplied by IT systems. Their protection still has to be verified, RCDs included, and a conventional tester is not prepared for that. In an IT system no live conductor is earthed at the source, and the exposed parts are earthed low.

A first fault to earth only lets a small current flow through the leakage capacitance of the network, and the supply carries on. That changes how loop and RCD tests are made. RCD tests in IT networks from 10 to 1000 milliamps, fault loop with 23 amps, insulation up to 10 gigams, and 4 earth methods with soil resistivity. The test sockets are on top. The rotary switch picks the function. The F keys set its parameters, and start runs the test.

The touch electrode next to start warns if the protective conductor carries voltage. In IT mode, it is switched off. It comes with a mains plug lead with its own start key, color-coded leads, probes and clips, reels and earth rods, the battery, and its power supply. Current clamps, the light probe, and a multi-core cable adapter are options. Before the first test, tell the meter what it is connected to. In the main menu, choose the earthing system. Choose the earthing system, TN, TT, or IT.

Then the nominal voltage and the mains frequency. From then on, every loop and RCD test follows that network. For the loop in an IT network, PE goes to the protective conductor, the N lead to one phase, and the L lead to another phase. The meter works from 95 to 440 volts and calculates the short circuit current from the impedance. RCDs in an IT network are tested downstream of the device, with the same connections PE to the protective conductor, N and L to two phases.

The test current returns through the leakage capacitance of the network. If PE can be connected upstream of the RCD, that is a second way. meter measures tripping time and tripping current of general and selective RCDs from 10 to 1000 mA of types AC, A and B. In TN and TT systems, it also gives touch voltage and earth resistance without tripping and the loop behind the RCD with 15 mA. In auto mode, one press of start runs the whole series. Insulation is measured with the circuit dead and the loads disconnected.

The RISO- lead goes to one conductor, the RISO+ lead to the other, and the far end stays open. Protective conductors are checked with 200 mA in both directions. Zero the leads first. Then one lead on the main earthing terminal, the other on the exposed part. The test starts by itself. For earth resistance, open the test link. E goes to the electrode, S to the voltage probe,

and H to the current probe, all in one line. Interference above 24 volts blocks the test. For poles, remove the lead resistance. Three poles plus a clamp measure one electrode without disconnecting it. Two clamps need no probes, and the winner method gives soil resistivity. also records a single-phase supply, voltage, current with clamps up to 3 kA, powers, power factor, and harmonics up to the 40th. It checks the phase sequence, and with an external probe it measures light.

Results go into a tree memory by client, object, and point, and transfer over USB or Bluetooth for the report. It runs on 5 LR14 cells or its rechargeable pack, charged inside the meter. Measuring Category 4 at 300 volts, and IP54 housing, 0 to 50 degrees, and about 2.5 kilos. Installations with IT earthing systems in hospitals, mining and industry, shock protection tests, and low-voltage installations RCDs, protective conductors, and earthing, and a first look at the supply.

Electrical installation testing from Amperis.