Before you start to test any relay on equipment in service, it is important that you familiarize yourself with the relays and circuits involved. In situations where test blocks are used, be sure that a current transformer circuit will not be opened when you remove or insert plugs. Otherwise, voltage could build up and create a danger to people, property and equipment. Voltage build-up also could cause an important circuit to trip out. If you are testing relays on older installations where test blocks are not available, current transformer circuits must be short-circuited before the relay current circuit is opened. The transformer circuits can be short-circuited by jumpers with reliable clamping devices that will not come loose.
Obviously a good set of test equipment and relay tools are critical. You can count on Protec to maintain test equipment from the top manufacturers of portable relay test sets. Making your job easier is a central part of our mission.