If you want to use electrical control relays (also called control relays or electrical relays) as a control device in your electrical or electronic system, you must have sufficient knowledge about their types, installation and performance. If you are using a special relay such as a remote control relay, you must have information about other relevant technology such as remote sensing and interlinking of the relay system and the computer.

For industrial control relay distributors and manufacturers, it is always beneficial to train your employees on the latest technology in the field of electrical controls. For electrical relay control suppliers, understanding the relevant standards and compliance regulations is one of the key business factors.

To acquire information about different electrical control relays, you can:

1. Learn about the basics of industrial control relays
2. Search for courses that cover electric relays as a part of their syllabi
3. Read periodicals and journals that provide up-to-date information about electric relays
4. Keep track of updates about technical standards related to electric relays and other electric products

Action Steps
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Understand the basics of industrial electrical control relays and the relevant technology

If you have very little exposure to industrial electrical control relays and technology, you can learn the basics by browsing through different resources such as websites of electrical control relay manufacturers. Some reputable data publishing companies also provide the basics of industrial electrical control relays.

I recommend: OMRON Corporation, a manufacturer of electrical devices, provides a technical guide about electric relays. All About Circuits and Virtual Institute of Applied Science (VIAS) provide information about electromechanical relays, such as their construction, components and types. teamROCS is another information resource that provides relay basics.

Search for courses that provide information on industrial electrical control relays

Some institutions and associations offer courses for electronic and electrical control devices that cover control relays as a part of their syllabi. You can also search for self-study courses that allow the readers to learn about electric relays on their own.

I recommend: AIT Training and Technology, an industrial training provider, offers a self-study course on electrical relay logic. EandM offers various self-study courses, including a course called ‘Basics of Control Components’. You can also get hands-on training by attending the industrial electronics training course at Orion Technical Solutions.

Refer to different standards related to industrial electrical control relays

For electrical relay control suppliers, it is very important to be aware of updates in the technical standards on electric relays and relevant technology.

I recommend: ANSI (American National Standards Institute) offers technical standards related to various industrial products, including control relays. ISO (International Organization for Standardization) offers standards related to relays in the aircraft and automotive industry. You can also search for the standards related to control relays at IEEE, another organization that establishes and publishes technical standards.

Current control relays guard against disruption in the electricity powering your equipment and allow you to manage your electrical usage to guarantee smooth operations. And keeping the power flowing and machinery running is crucial to a successful business.

Electrical relays monitor and protect by constantly checking the current, frequency or voltage of your electrical system. The two basic purposes for electrical control relays are: to detect defective lines, apparatus or other power malfunctions and to control current and verify conditions in the power system. Protective relays serve the first function; monitoring relays the second.

Today most models of electrical control relays are programmable and monitored through a personal computer. As you plan your purchase of electric relays, be sure to take the following steps:

1. Investigate the key features of different industrial control relays.

2. Select relays that offer user-friendly features.

3. Research your business needs for electrical controls.

Action Steps
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Determine the key features of electrical relays

Protective and monitoring electrical controls function in several different ways: sensing overcurrent, undercurrent, phase disruption or differential changes. Your electrical control relay needs depend on your machinery and system configuration.

I recommend: AutomationDirect.com carries several models of control relays, including ice cube, plug-in, electromechanical and solid state. Check the specifications and applications of each type of relay to compare the features. You can find different relays by maker Smart Relays at Electrical Control Distributors. Compare your findings to note the differences in parameters, styles and prices.

Evaluate the user-friendly features of industrial electrical control relays

Suppliers stock electrical controls with several user-friendly features. Look for devices with automatic reset, visual readout, programmable time delay and latching controls. A remote control relay allows you to monitor and service the system through your personal computer.

I recommend: Check the Omron online catalog for electrical relays for control panels. They also carry solid state, plug in, and special purpose devices. Detrol Controls offers control relays with several mounting options including panel, bracket, socket and PC terminal. The web page includes sizes, specifications and additional details for each relay.

Purchase the right electrical control relays for your business application

Online catalogs contain information on the features and specifications of the wide variety of electrical control relays. Find listings for the ones that fit your needs from several distributors and compare them. Choose the devices that match your business applications.

I recommend: Siemens offers a variety of both protection relays and monitoring relays and a helpful video on substation solutions at its website. Broyce Control supplies four models of time delay relay, including dual and multifunction devices. They also have overvoltage control relays and three-phase relays to monitor voltage phases.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  Contact electrical control relay manufacturers and suppliers about free product trials and samples.

An electrical control relay (also called electrical relay) is an important component of an industrial electrical circuit. These relays perform various functions to protect the electrical components in an industrial circuit.

Whether you want to buy electrical control relays or you want to be a supplier, you will need to understand various technical terms. This guide will explain key terms relating to electrical control relays, such as AC, DC, volts, time delay relays and thermal overload relays.

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AC (Alternating Current) or DC (Direct Current)

AC is an electric current, in which the direction of flow is reversed at frequent intervals. In one cycle, an alternating current flows from zero to a positive maximum and then to negative maximum, before it again returns to zero. Unlike AC, DC is an electric current, in which the electron flow is unidirectional. DC might be constant or varying. Before selecting an electrical relay, you must have an idea about the characteristics of AC or DC flowing through the electrical circuit.

I recommend: You can read through the definitions for AC and DC at Energy Classroom, an informative Web site by Xcel Energy. In addition, Baldor Electric Company provides a glossary of technical terms, such as AC and DC.

Volts

Generally, specifications for electrical relays are expressed in terms of volts. It is the unit to measure electric potential between two points. One volt is defined as the potential (or electromotive force or EMF) required to produce a current of one ampere through a resistance of one ohm.

I recommend: For more information about this unit, read through the glossary at Tyco Electronics, a supplier of industrial electronic products.

Amperes

An ampere is another unit for specifying current rating for electrical relays. You must evaluate the current range for your applications and select the electrical relay accordingly.

I recommend: To understand the basics of this term, read through information at Maxim Integrated Products. Responsible Energy Corporation also provides a brief description about this term.

Time delay relays

Time delay relays are useful for applications that require time delay. If you require different time relays for each instance, you must use a time delay relay that has selectable time ranges. If the time delay is constant for your application, you can use a single time relay.

I recommend: All About Circuits, an online information resource, provides a description about time delay relays.

Protective relays

These relays provide a variety of protection and control functions. These instruments are very important for electrical transmission lines and power generation equipment, as the protective relays prevent accidents and damage to equipment and personnel.

I recommend: To learn more about electrical control relays, read through the description at GlobalSpec, a technical information resource.

Thermal overload relays

Sometimes, due to faulty components, an electrical instrument draws more current than its rating. This might result in overheating and subsequent burning of the instrument. Thermal overload relays or overload relays avoid overheating of electrical equipment.

I recommend: www.electronics-manufacturers.com offers information about thermal overload relays.