Technical library

A 21st century trend in electrical instrumentation has leaned toward smaller, lighter and easier to manipulate testers through microcircuitry. Being portable and easy to manipulate can be beneficial enough, but there’s much more to it. Size reduction is not just for ease of manufacturing or an advertising gimmick. Multiple instruments can be combined into a single handheld tester, so that an entire job can be completed with a single piece of test equipment. The user can benefit from notable cost savings and job improvement. This article will examine how many of the functions found in multiple different instruments can be included in just one handheld tester.

This is an easy solution to measure the impedance values for cables, the values are used for calculation of compensation factor in distance protection.The compensation factor is first theoretically calculated and these values can now be compared with the measured values.

The test and maintenance of electrical components on rolling stock is not an easy job to do. Some maintainers dismount some of the parts and bring them to a central location for revision and maintenance. This is a cumbersome and time consuming exercise. In many cases, the electrical parts are replaced only when they break down and are not subject to periodical testing. This of course holds a risk as some parts, e.g. circuit breakers, are crucial for safety reasons.

The MPQ software can be configured to automatically sync the remote MPQ to the network time periodically. This saves the expense of a GPS and removes the possibility of losing the GPS signal.

The MPQ can be controlled remotely using the Metrosoft PQ PC software. This app note shows how to do this.

A Comtrade Export feature is valuable when analyzing protection devices. It can help determine why a protection device is tripping or it can help determine if the protection device will trip under particular real world conditions.The MPQ analyzer can be left in the field for months or years at a time. During this time,it will record multiple real world events. These events can then be exported as a Comtrade file and then can be played back to protection devices tosee how they react.

The power measurement for a delta configuration uses a 2 wattmeter method even thoughthereare 3 phases.When measuring a wye all the voltages are referenced to neutral, referred to as line voltages. The measured currents are also line currents. Since both the voltage and currents are line values,the measurement does not introduce any phase shift.

The power measurement for a delta configuration uses a 2 wattmeter method even thoughtheyare 3 phases. When measuring a wye,all the voltages are referenced to neutral,referred to as line voltages. The measured currents are also line currents. Since both the voltage and currents are line values,the measurement does not introduce any phase shift.

The Metrosoft PQ software has a powerful data analysis feature. This feature allows you to automatically analyze the recorded data and see what parameters are out of requirements.To use this feature the nominal recorded voltage and frequency needed to be entered. However these values can change from recording to recording.A new AUTO option has been added to the data analysis screen.

Thermal imaging locates hot spots by examining the IR spectrum. Heat is the enemy of batteries.  A riseof just10°C willdeplete the lifeof a batteryby half. As molecules heat up,they move faster. This increases the rate of chemical reactions. This will increase the rate of oxidation that leads to corrosion. It will also increase the rate ofdry out in VRLA batteries. Heating will reduce the life of any battery regardless of the chemistry.