Video: AMZC-304

Video transcript

What the AMZC-304 measures in 230 for 100 V installations, how it is connected for each fault loop and for continuity, and why a meter this small is sealed to IP67. In a fault, the protective device has to disconnect in time, and the fault current that makes it trip is set by the loop impedance. In homes, offices, and plants that loop is checked socket by socket and board by board, so the meter has to be small, quick, and robust. Loop impedance from 0.13 to 1999 Ω, with a resolution of one-hundredth of an Ω,

a mode that does not trip RCDs, the prospective short-circuit current, and continuity at 200 mA. test leads plug into a single connector on top, N, P, E, and L. The display shows the voltage before each test, and the result after it. START runs the measurement, SET/SEL, and the arrows change the settings, and the rotary switch picks the function. It comes with an angled plug adapter for sockets, red, blue, and yellow test leads of 1.2 m, pin probes, a crocodile clip,

hanging straps, a case, batteries, and the calibration certificate. Longer leads and three-phase socket adapters from 16 to 63 amps are options. Before the first test, set the rated voltage of the network, 220, 230, or 240 volts, because the short-circuit current is calculated from it. Then choose the loop with the switch, set the lead length, connect, and press start. For the L in loop, the blue in lead goes to the neutral, and the red L lead to the phase. Between two phases, the same two leads go to two phases.

The test current is at most 7.6 amps at 230 volts, and 13.3 at 400. For the LPE loop, the yellow PE lead goes to the protective conductor, the blue lead to the neutral, and the red lead to the phase. RCDs and the circuit are bridged for this test, then restored and checked. Before a loop test, touch the contact electrode for about a second. If the protective conductor carries voltage, the meter shows it and beeps, stop, and clear the fault first. Swapped L and N are signaled too, and the measurement still runs.

Behind an RCD, use the RCD position of the switch. TN-S network, connect PE, N, and L downstream of the device, or use the plug adapter. RCDs of 30 milliamps and above do not trip, and EV-type RCDs from 6 milliamps can be selected. meter always measures impedance and calculates the perspective short-circuit current from the rated voltage, or from the measured one if you choose. It recognizes a phase-to-phase measurement by itself.

Outside the voltage tolerance, it shows dashes instead of a current. For protective and bonding conductors, switch to RCONT. First short the leads and run AUTO-0. Then the red lead goes to one end of the conductor, and the blue lead to the other. The meter measures with 200 milliamps in both directions and shows the average. The RX position measures resistance with a low current, up to 1999 ohms, and beeps below about 30 ohms, which is handy to trace conductors. Both resistance functions are blocked if the object is live.

Results are saved in 990 memory cells and sent over Bluetooth to the PC software or to a mobile device, where they are archived for the inspection report. An IP67 housing, about 800 grams, measuring Category 4 at 300 volts, and 4 AA cells or rechargeable batteries for more than 5,000 loop tests. Short circuit protection in homes and offices, industrial plants with fault currents up to 4.4 kiloamps, circuits protected by RCDs, and the continuity of protective and bonding conductors.

Fault loop testing from Amperis.