Safety is a major concern in a good many motor-driven applications. This is true in industrial applications where motion starts when power is applied and especially true when power is restored after ...

Many single-phase motors used with refrigeration-duty, semi-hermetic and hermetic compressors require an external relay to assist in starting. How much do you know about these necessary products? An ...

FIGURE 1: This electrical schematic diagram shows the cooler’s single-phase, R-134a capacitor start/capacitor run (CSCR) refrigeration compressor motor, and starting relay circuit section. July 6, ...

In Part 1 of this two-part series, we presented a 3-phase, 480VAC motor circuit with its associated controls (Figure). We stepped through a logical, systematic approach to troubleshoot the main power ...

The proper selection of 3-phase solid state relays for motor control application depends not only upon a comprehensive understanding of 3-phase SSRs, but also of the 3-phase power system and typical ...

Schweitzer Engineering Laboratories, Inc. (SEL) has introduced new features in the SEL-701 motor protection relay. These features include Acselerator QuickSet SEL-5030 software support and a ...

Relays continue to be useful and popular, but in low-power, battery operated applications they tend to be power wasters. The following relay economy circuits reduce coil power significantly by simply ...

The increasing need for modernization of substations is acting as a catalyst to boost the demand for motor protection relays. During the operation of a substation, if there is a fault, a motor ...

Last column, I wrote about various applications where fire alarm relays could be used to integrate a commercial fire alarm system with other electrical systems at a customer’s site to provide them ...