Technical library

Self-Powered-Relay (SPR) takes its supply from the CT-s connected and also the energy for tripping the breaker. SPR either have special CT made for the relay or are made to be used directly with standard CT-s.

 Self-powered relays will be animportant component for the protection of the smart grid.While they allow reducingthe cost of the protection system, they are definitely a challenge for relay test sets, that are required to provide the voltage and current signals to simulate the power system fault, but also the generatedsignals need to have necessary electric power to supply the protection relay.SVERKER 900 is designed to manage this task and this Technical Guide describes how two self-powered relays can be tested.This document guides through the testing of two self-powered overcurrent relaysfrom SEG GmbH (formerly Woodward), WIC-1 and WIP-1, with the relay test set SVERKER 900, for commissioning/maintenance purposes.The Technical Guide details on the principles adopted in the testing with reference to relevant IEC standards and to the relay manuals. In addition,basic instructions on the correct usage of the testing possibilities offered by SVERKER 900are described

Guide to Low Voltage Motor Testing

Earth testing and resistivity measuring requires sensitive equipment and sophisticated calculations. This guide makes these processes easier to understand for both large and small ground systems, with detailed studies of various relevant testing methods.

Transformers are subject to mechanical impact and vibration. Problems or faults occur due to poor design, assembly, handling, poor environments, overloading or poor maintenance. Measuring the polarity and turn ratio of a transformer winding assures that the connections are correct and there are no severe mismatches or opens. Many transformers have taps built into them. These taps allow the ratio to be increased or decreased by fractions of a percent. If any of the ratio changes involve a mechanical movement of a contact from one position to another, these tap changes should also be checked during a ratio test.

A comprehensive guide to testing power quality.

A complete guide to electrical insulation testing

this pocket guide we have endeavoured to cover the details of the 4th Edition - rather than clarify the changes – in an easy-to-read manner.

Gain insight into the different types of oil testing methods, including oil dielectric breakdown testing moisture content testing. This guide covers best practices for oil testing, the correct equipment to use, and the different IEEE/IEC standards to adhere to when testing.

This guide discusses the causes of insulation degradation on >1kV power cables, and the process of measuring degradation before a fault can develop. The guide also recommends the best equipment to use with reference to IEEE standards.