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 ...

These speed safety relays provide overspeed, under speed and/or standstill detection for single- or three-phase motors by monitoring either external proximity sensors mounted on a rotating element of ...

The article discusses how the MSR57P from Rockwell Automation improves operator protection, simplifies control system operation, and improves productivity in hazardous areas. The MSR57P speed ...

SPO 1-1 Given information from discussion, handouts, and reading materials, explain the pump operator's responsibilities to pump a supply line, given the length and size of line, flow and desired ...

Power systems today operate in an environment where reliability and safety must be maintained despite rising loads, expanding ...

To be competitive, some electrical contractors often supply low-voltage (LV) service entrance switchboards and switchgear that meet the minimum safety requirements of the National Electrical Code (NEC ...

This chapter covers representative general-purpose relays used in the control circuits of most industrial, commercial, and consumer products. Relay names and terminology are in accordance with ...

What is a relay? What is zero voltage switching? How to create a zero-crossing relay driver with a simple external circuit. A relay is a device that allows for a smaller electronic switch to control a ...

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.

Relays usually are driven using optocouplers, which offer isolation between analog and digital grounds to ensure that switching currents in the relay coils do not affect the noise margin of the ...