Video: AMZC-305

Video transcript

How the AMZC-305 measures fault loops and networks from 110 over 190 to 400 over 690 V, how it is connected for each loop and for a housing check, and what its high test current means. Not every plant runs at 230 over 400 V. Mines, heavy industry, and older plants use 500 or 690 V networks, and some use 110. The protection against electric shock has to be proven in all of them, with the same meter. Eight rated networks can be selected, from 110 over 190 to 400 over 690 V.

Phase-to-earth and phase-to-neutral loops are measured between 100 and 440 V, and phase-to-phase loops up to 750. Loop impedance from 0.13 to 1999 ohms, with a resolution of one-hundredth of an ohm. A no-trip mode behind RCDs, prospective short-circuit current up to 69 kA, and a voltmeter up to 750 V. The three sockets, L, P, E, and N, are on the top edge. The rotary switch selects the loop. START runs the test, and the touch electrode

next to it checks the protective conductor. ESC, setup, and SEL set the network and the lead length. Standard, red, yellow, and blue test leads of 1.2 meters, three pin probes, two crocodile clips, the case, the USB cable, straps, batteries, and the calibration certificate. Options include a plug adapter, a probe with its own start button, three phase socket adapters, and leads of 5 to 20 meters. First, set the rated voltage of the network, one of the eight,

since the short-circuit current is calculated from it. Choose the loop with the switch. Set the length of the phase lead. Connect, and press start. Wait at least five seconds before the next test. the L, N loop, the blue N lead goes to the neutral, and the red L lead to the phase. For a loop between two phases, the same leads go to two phases. That is where the 750 V range is used.

For the L, P, E loop, the yellow P, E lead goes to the protective conductor, and the red lead to the phase. The N lead is optional. RCDs and the circuit are bridged for the test, then restored and checked. same measurement proves the protection of a piece of equipment. TN network, the PE lead goes to the metal housing, and the L lead to a phase. The result is the loop through the housing and its connection to the P, E, N conductor.

Before an L, P, E test, touch the electrode next to start for about a second, standing on a floor that is not insulated. Voltage on the protective conductor is signaled with a continuous tone. Stop and repair the installation first. Loop measurements just downstream of inverters are not reliable. Behind an RCD, use the RCD position of the switch. TN-S network, L, PE and N go downstream of the device, or the plug adapter goes into the socket.

RCDs above 30 milliamps do not trip in networks from 100 to 440 volts. measuring current rises with the network voltage, 12.2 amps at 115 volts, 24.5 at 230, 21.3 at 400, and 36.7 at 690, each for 10 milliseconds. A firm current gives a firm reading of low loops. The prospective short circuit current is the rated voltage over the loop impedance, and is shown up to 69 kiloamps. The measuring range depends on the lead, from 0.13 ohms with 1.2 meter leads, up to 0.29 with 20 meters.

With the voltmeter, the meter reads up to 750 volts, with a tenth of a volt up to 250. Results go to 990 memory cells, 3,500 entries, and over USB to the PC. Measuring Category 4 at 600 volts, IP54, for AA cells for more than 3,000 loop tests, and automatic shutoff after 2 minutes without use. Shock protection in industrial networks of 500 and 690 volts, in low-voltage homes, offices and workshops, at socket outlets with a plug adapter, and in circuits protected by RCDs.

Fault loop testing from Amperis.