Electrical Relays & Thermal Overload Relays

What are relays?

Simply put, relays are switching devices. Relays come in multiple types with varying constructions. In general, though, they are switches that open and close circuits electromechanically or electronically. Relays are designed to allow a low power logic signal to control a much higher power circuit, controlling one circuit by opening and closing conducts in another circuit.

As well as current control, relays play an important role as protective devices. Certain protective relays can detect electrical abnormalities such as overcurrent, undercurrent or reverse current. The proper maintenance of relays can help prevent expensive equipment damage and ensure the proper operation of an electrical system.

What are common types of relays?

As electrical contacts, relay may come as normally closed (NC) or normally open (NO). The term normally refers to the state the relay is in when something else is not affecting it. To understand the difference, remember that a “closed” state allows a current to flow, while an “open” state does not. A relay in an open state needs to be energized, or actuated, to allow for the flow of electrical current. Which type of relay chosen, NC or NO, is determined by how it must regulate for the proper function of the electrical part, system or application.

Another important distinction in relay types is latching versus non-latching relays. A latching relay maintains its state once actuated. A non-latching relay, conversely, maintains its state only while being actuated. Our electrical technicians are experienced in using these two types of relays and a large host of other relays used in Electrical Contracting.

The electrical contracting team at American Electric will help you solve any electrical issues you may be experiencing related to relay damage or failure. We’re your North Florida and US Southeast relay experts. Our experience extends to many types of relays and contactors:

General Purpose Plug-in or “ice cube” Relays
Lighting Control Relays
Impulse and Alternating Relays
Thermal Overload Relays
Control Panel Relays
Electronic Timing Relays
Wye Start / Delta Run
Definite Purpose Contactors
Non-reversing Contactors
And many more . . .

What is the difference between an EMR and a PLC, and should I upgrade to PLC?

Electromechanical relays (EMRs) use electricity to operate and can be found in a multitude of electronic devices and applications. Commercial and industrial processes have long relied on electromechanical relays, also called armature relays, as circuit control devices. As relays have moving internal components, they are susceptible to electrical or mechanical failure. Also, keeping pace with competitors can be tough when relying on the speed of a conventional relay.

Programmable logical controllers (PLCs) may offer a solution to issues of relay reliability, speed, or even noise level. PLCs are specialized devices that use computer technology to control automated processes in commercial and industrial systems. Upgrading to PLCs or “smart relays” can result in overall lower costs over time, greater efficiency and process speeds, and greater functionality. They may even lower noise levels.

As a solid-state device, a PLC has no moving parts, so troubleshooting and diagnostics can be easier with PLCs. If you are considering upgrades from EMRs to PLCs be sure to ask if the Electrical Contractor has the specialized training to install and maintain this upgrade in control and automation applications.

Why choose American Electric as my Electrical Contractor or Service Provider?

At American Electric – Jacksonville, our expert electrical technicians handle many types of relays and contactors. We can test, diagnose, and replace any circuit control devices that may be causing electrical, equipment or system application problems.

Call or Contact American Electric of Jacksonville, Inc.