This section provides an overview for terminal relays as well as their applications and principles. Also, please take a look at the list of 12 terminal relay manufacturers and their company rankings. Here are the top-ranked terminal relay companies as of September, 2023: 1.Rockwell Automation, 2.PHOENIX CONTACT, 3.ASI.
Engaged in research on nitride semiconductor growth using the MBE method at Waseda University Graduate School. After graduating from graduate school in 2016, he joined a non-ferrous metal manufacturer.
Engaged in equipment maintenance and engineering work at metal smelting plants. Moved to a chemical manufacturer in 2022. Engaging in similar tasks.
A terminal relay is an input/output signal processing device that integrates multiple relays and terminal blocks.
It is used as an interface device to relay I/O of programmable controllers and solenoid valves. The main structure of a terminal relay, which plays the role of I/O interface device, is a terminal block on a pedestal with a built-in printed circuit board, and multiple independent single-pole type small relays can be mounted on this pedestal according to the application, as a compact relay structure while excelling in maintainability, This contributes to downsizing of equipment and reduced wiring.
Terminal relays are mainly used in industrial applications.
The following are examples of terminal relay applications:
Generally, microcomputers, PLCs, and other control devices are used to control large industrial equipment in complex ways. While these control devices are capable of complex internal processing, the allowable output signal current is often small. Conducting large currents through these devices may have adverse effects, such as accelerating failure frequency.
Therefore, if you wish to control equipment with large load currents or inrush currents, such as solenoid valves, isolate the outputs of the control equipment by means of relays. However, installing multiple power relays and other relays side by side occupies space and complicates control wiring.
Terminal Relays are a device that combines a terminal block and relay into a single unit, allowing a lineup of small, single-pole relays. Therefore, space and wiring savings can be achieved.
Terminal relays are composed of terminal block components and relay components.
The terminal block component consists of a relay socket and a terminal block. The part that conducts electricity is made of copper or iron screws, and the casing is made of hard synthetic resin. Many products are fixed by tightening the external wiring, which is processed with round terminals, etc., with iron screws.
Generally, most products have sockets that can accommodate four relays, with two inputs and two output terminals per relay. 16-point products are also available. Terminal Relay is sometimes referred to as a relay terminal.
A relay is a component that insulates and relays signals. Terminal relays are generally small, single-pole relays. It is often installed by inserting it into a terminal block component with a pin on the back side. Relay specifications are often printed on the casing on the relay surface, and products with various power supply specifications and signal types are sold.
When selecting a terminal relay, the following considerations should be taken into account:
The number of output points is the number of points that can be output by the terminal relay. Most general-purpose products have 4 output points, but there are products with 16 or 32 output points for connection to PLCs. In the case of a system that controls many devices, the more output points, the less wiring is required.
The input specification is the type of signal input to the coil portion of the relay. 100 VAC, 24 VDC, and other specifications are available. Select the input specification according to the output specification of the control equipment.
Output specifications are the specifications of the signals output by the relay. Factors such as signal type and rated energizing current are included.
Signal types are mainly classified into contact and non-contact. With contacts, the signal is transmitted by mechanically operating a metal section with an electromagnetic coil. It tends to have a large allowable current and has the advantage of being heat resistant. However, it has the disadvantage that the contact parts gradually wear out due to opening and closing operations.
The non-contact method uses semiconductors or solid-state relays to transmit electrical signals. Since there is no physical drive, it can withstand high open/close frequencies and high speed open/close operations. However, they are susceptible to heat and have drawbacks, such as semiconductor components that can fail if currents exceeding their rated currents flow through them.
The rated current rating is the amount of current that can be conducted. The larger the current value, the more capable it is of controlling large loads, but the larger the relay often becomes. Generally, when used as terminal relays, most products have a current-carrying capacity of 1 to 5 A.
*Including some distributors, etc.
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c3controls, founded in 1976 and based in Pennsylvania, is a leading manufacturer and supplier of electrical control products. Specializing in a wide array of offerings, c3controls delivers an extensive selection of push buttons, pilot lights, circuit breakers, motor starters, and control relays, encompassing crucial components for electrical control systems. Their product portfolio also encompasses switches, sensors, terminal blocks, and power supplies, catering to diverse applications within industrial environments such as machine control, motor control, power distribution, panel building, and industrial automation systems. Notably, c3controls holds certifications from the International Organization for Standardization (ISO) and Underwriters Laboratories (UL).
Phoenix Contact is headquartered in Blomberg, Germany, originally founded in 1923. Phoenix Contact’s Israeli subsidiary was founded in 2006 and located in Quadima Tzoran. Phoenix Contact provides tools and components for e-mobility, power, infrastructure, process industry, production manufacturing, system manufacturing, and others. Phoenix Contact’s product lines include automate including cloud computing, connect including PCB terminal blocks, “mark, assemble, and install” including hand tools, “supply, charge, and protect” including power distributors, and “switch, measure, and monitor” including relays and optocouplers.
Panasonic Industry, Founded in 1918, is an enabler that provides customer with unique strength through their material and process technologies. Panasonic Industry wants to make social demands strong and help in solving problems associated with such demands. Panasonic Industry manufactures numerous products such as capacitors, relays, connectors, sensors, etc. Such products are used in automobiles, solution modules, home appliances, health care, and other equipment. Their aim is to improve society and make it richer via new methodologies and technologies.
Eaton Corporation plc was founded in 1911 and is based in Dublin, Ireland. Eaton operates as a global power management company, providing electrical components, industrial components, power distribution and assemblies as well as industrial applications. The company’s vehicles segment also offers transmissions, hybrid power systems, and fuel vapor components for the vehicle industry. The company’s eMobility segment offerings include voltage inverters, power distribution systems, and commercial vehicle hybrid systems. The company also provides engineering and repair services.
Rockwell Automation, Inc. was founded in 1903 and is headquartered in Milwakee, WI. Rockwell Automation provides industrial automation and digital transformation solutions around the world. Rockwell Automation operates through their intelligent devices, software & control, and lifecycle services segments with both hardware and software products and services. The Intelligent Devices segment offers drives, motion, safety, sensing, industrial components, and configured-to-order products. The Software & Control segment provides control and visualization software and hardware, information software, and network and security infrastructure solutions. The Lifecycle Services segment provides consulting, professional services and solutions, and connected and maintenance services through independent distributors.
Wieland, established in 1910 and based in Bamberg, Germany, is a manufacturer and supplier of electrical connection technology. Their product range includes pluggable connections for seamless plug-and-play electrical device connections, insulated connectors that provide electrical insulation in device connections, cable glands for safeguarding cables and ensuring a watertight seal, terminal blocks used for connecting electrical wires, and contact systems facilitating connections between electrical components. Wieland's products find applications in diverse industries, such as building construction, electrical engineering, and automation.
Beckhoff Automation LLC is the American branch of Beckhoff Automation GmbH & Co. founded in Verl, Germany. The United States headquarters is based in Savage, Minnesota. The company serves industries such as automotive, marine, semiconductors, and alternative energy with hardware and software-based solutions. The company’s five hardware product segments are industrial PCs, fieldbus components for I/O, motion drive systems, MX systems, and system-integrated machine vision products. The company also produces software for automation-related tasks.