A Relay Protection Tester is designed to simulate electrical quantities such as current, voltage, frequency, and phase, allowing engineers to test protective relays under controlled conditions.

Schweitzer Engineering Laboratories, Inc. (SEL) has announced wide-area-measurement-based control in a transformer relay for the first time. This enhancement to the SEL-487E Transformer Protection ...

Complex grids depend on equipment such as transformers, protection relays, switchgear, and cables—each of which can develop faults not immediately visible during normal operation. As a result, ...

Nov. 13, 2008, PULLMAN, WA - Schweitzer Engineering Laboratories, Inc. (SEL) is now taking orders for two new products, the SEL-787 and SEL-487E Transformer Protection Relays. These are the first ...

Among the various diagnostic methods used to assess transformer condition, capacitance and Tan Delta testing has gained broad acceptance as an effective means of evaluating insulation health. By ...

A range of manufacturing and production processes rely on current-operated relays to provide a continuously adjustable trip-current setting. They are able to protect mechanical apparatus from jam-up ...

Bob is a service technician who is well trained and nationally certified. However, he sometimes suffers from the same confusion that all technicians occasionally do - the facts that he gathers may or ...

Relays and contactors use a variety of technologies to switch signals and power connections. Many devices called relays use similar techniques and topologies, but the terminology can be confusing.

Liou Electronics’ product offerings encompass a variety of current transformer types, including the widely used Center Through Hole (Split Core) Current Transformers, precision PCB‑mount CTs, and ...