Video: APQM-711

Video transcript

What the APQM-711 records, how it is connected to single-phase and three-phase networks, and how a week of recording is assessed against EN 50160. Dips, harmonics, flicker and transients trip drives, overheat transformers and damage electronics. Proving where they come from needs measurements made to a common method, over long periods, that hold up in a dispute with the supplier. Class A to IEC 61000-4-30. Five voltage inputs and 4 current inputs, with clamps up to 6 kiloamps.

Harmonics up to the 50th. And a transient recorder sampling at 10 megahertz, up to 8000 volts. The analyzer has 3 cable glands underneath: current inputs, voltage inputs, and the red power leads. The colour display and 4 keys start recording and check the connection. Wi-Fi and GPS are built in. It comes with marked voltage leads and crocodile clips, M4 and M6 voltage adapters, and a GPS antenna for indoor use.

Flexible clamps from one and a half to 6 kiloamps, hard clamps and piercing adapters are options. A campaign always follows the same routine. Configure the measurement point in the software: network type, nominal voltage, clamps and what to record. Mount the analyzer and connect it. Check the connection screen. Start the recording, and leave it for a week. On a single-phase supply, clip PE to the protective conductor,

N to the neutral and L one to the phase. Then the clamp goes round L one, with its arrow pointing towards the load. On a four-wire three-phase network, the clips go to PE, N, L one, L two and L3. Then one clamp per phase, and a 4th on the neutral if the neutral current is needed. All arrows point towards the load. Without a neutral, the voltage inputs are referenced to N, so the N clip goes to L3. L one and L two go to their phases. The L3 input is then only needed for transients, and PE goes to local earth.

Current can be measured with 3 clamps, or with two by the Aron method. Before leaving the site, look at screen one. It shows the phasor diagram and 5 checks: voltages, currents, voltage angles, current angles and frequency. A red mark means a wrong lead or a clamp the wrong way round, so it is corrected now, not after a week. EN 50160 sets what a low-voltage supply must deliver. Values are averaged over 10 minutes and assessed over one week.

For example, 95% of the ten-minute voltage values within plus or minus 10%. The software checks every parameter and writes the report. Every parameter group can be switched on or off, so memory goes where it is needed. Averages, minimums and maximums are stored at the chosen interval, and every event keeps its waveform and a half-cycle RMS graph. The 8 gigabyte card holds long campaigns. The transient module samples at up to 10 megahertz and captures pulses of plus or minus 8000 volts, from 650 nanoseconds.

Transients are measured against the PE input, so PE must always be connected to a local earth. The analyzer is configured, watched live and read out from the PC software or an Android tablet, over USB, Wi-Fi or the built-in LTE modem. GPS keeps the clock to class A, and a text message warns if the analyzer is moved during a campaign. Measuring category 4 at 600 volts, an IP 65 housing for outdoor and pole mounting, minus 20 to 55 degrees, and a battery that keeps recording through an outage.

Certifiable supply quality in industry and distribution, unattended campaigns in substations and long networks, photovoltaic and wind plants with four-quadrant analysis, and troubleshooting of harmonics and transients. Power quality analysis, from Amperis.