Wired to provide a control sequence, relays may also be used for simple control schemes where a PLC would prove uneconomical. A PLC may be used to control the operation of a medium-voltage motor, perhaps 2,300V or 4,160V. The system controls the contactor on/off with temperature controller (PID regulator with relay control output) and intermediate relay and then controls the electric heater. The distinction of a relay as switching AC (almost always only single phase) or DC pilot/control signals vs a contactor actually switching the full line voltage and current (often three phase) to lights, motors, etc. The contactors is primarily used for switching larger power circuits (such as motors, for example), since the control logic components cannot meet the current & voltage duty of the power circuit. Contactors and relays perform the same task and operate under very similar principles. In general, an electro-mechanical contactor is rated for a specific However, a relay has a common contact that helps connect to a neutral position. A magnetic starter is a device designed to provide power to electric motors. Simply Buy Co., Ltd. is a leading new energy controls supplier, we major focus on electrical, pneumatic and automation controls for industrial and commercial. An electrical control signal triggers the opening or closing of the contact or contacts. Top 7 Difference Between Contactor And Relay: Relay and contactor are functionally doing same duty, but the major difference between relay and contactor is that, contactor can carry huge amount of current but relay can carry only less amount of current from 0.1 A to 20 A. Yet, a contactor is not normally called a “relay.” Rather, the term, “contactor” is used to describe a type of device that is used very much in the same manner as a relay. You can use a safety relay of that type in category B, 1 and 2 circuits too. January 24, 2019. Pinterest. The control terminals is operated by a single or multiple control signals to swtich the contact terminals. not surprisingly, the noise from a contactor is much louder than a small relay. They are provided with two auxiliary contacts – one NO (97-98) and another NC (95-96). By common usage, the term, “contactor” is applied to a special type of device that is functionally similar to the relay. A protective relay protects the electrical system by trying to determine what is normal and abnormal and tells the circuit breaker to open when a problem is detected. In a relay-based control system, relays are used to interface the input devices with the output devices. Types of relay… There are different types of Control Relays depending on the operating principle and structural features…Circuit Diagram…Contact Types…Differences between conductors The Basics. A control relay is, in essence, a switch that is controlled by electrical current.A control relay is an electrical component that opens or closes a switch in order to allow current to flow through a conducting coil, with the coil not coming into direct contact with the switch. A contactor has three components. For example, a safety relay rated to category 3 means that you can use it in your safety-related parts of your control system up to category 3. As known, contactor is used to switch higher capacity than relay. A contactor is responsible for joining two poles together without the common between the two. Here are a few of the basic differences that distinguish different types of relay and contactor switches. The contactor is the relay to use when a circuit must support an even heavier current load (typically 100-600 amps). Comparing PLC vs Relay tablewise! If you see from the application point of view, you would have seen contactors placed in control panels of industrial motors or other heavy loads. When you look in the data sheet for a safety relay you will find that it can be used up to a certain safety level. Chattering Relay Switch Noise Causes & repairs for clicking chattering relay switches in HVAC, Pump, & other controls. They are used for switching relatively high power circuits using low power signals. Relay-based Control System . Figure 3: Relay-based control system. Generally, a relay has several opening and closing contacts. They are used in large quantities for the indirect control of motors, valves, clutches and heating equipment. seems like a highly useful distinction. Examples of Motor Control Summary. It is used for switching an electrical circuit on and off. In general contactors are intended to control All magnetic contactors are a type of relay, but relays can be significantly more complicated than contactors. There are three areas of problems encountered with contactors and relays the contacts, the coil, and the mechanical linkage. A relay is an electrical switch that has a set of control terminal & contact terminals. Our CE Marked Series 300 & 310 contactors & control relays are available in reversing and non-reversing contactor types. The contactor is mostly used in applications where higher current carrying capacity is involved, while the relays are used for lower current applications. Installation contactor VSM220 The manual control contactors are designed for auxiliary and power switching, have a front panel switch and have a manual forced boiler operation mode. In addition to the simplicity which they offer in project engineering, panel building, commissioning and maintenance, the high Contact of a relay can be used to connect or disconnect the coils of a contactor. In this, we are going to see the 7 difference between relay and contactors. Share. Using the test button, it is possible to test the control wiring. The control inputs are connected internally to an LED, which shines across an air gap to light sensors. In low-voltage (below 1,000 volts) industrial electricity, there is some overlap in these categories. Springer Controls offers a complete line of electrical controls including IEC contactors and starters, 22 mm & 30 mm pilot devices, power switching devices, crane & hoist controls, signaling devices, temperature controllers and terminal blocks. Symbol of an overload relay With voltage ratings from 12V DC up to 1200V DC, contactors are a cost-effective, safe, lightweight solution for DC high-voltage power systems. This article discusses control relay switch chattering or rapid, repeated clicking noises, their cause, meaning, and repair. Easy to install and mounted in multiple orientations. An electro-mechanical contactor is a device that opens or closes a contact, allowing electricity to be switched fully on and fully off. Control Relay also known as a relay, is an electromagnetic switch…. The contactor applies voltage to a contactor coil to close the contacts and to supply and interrupt power to the circuit. But there some relays can switch high current too, such as, some power relays can switch current beyond 100A, and there are contactors to switch only 160A. Test button. It is but one component of a starter and is rated by voltage. Quest: What is the difference between a switch, an isolator, a circuit breaker, a contactor, and a relay? What is the difference between a contactor and a relay? # Contents: PLC Relay: 01: Basic: Programmable Logic Control (PLC) is a solid-state computerized industrial controller that performs software logic by using i/o, CPU, memory. Relay is an electro-mechanical switching … The relay is usually used in the electrical control circuit, it's used to extend the contact capacity of a micro or small relay, so as to drive larger load. Contactor relays Contactor relays Contactor relays are often used in control and regulating functions. Linkedin. The contactor is larger and capable of carrying more amperage than a relay. The same procedures can be used to check both contactors and relays. So, if a relay has a same switching current with a contactor, which one to choose? A relay consists of a coil and switching contacts. NO contact is for trip signaling and NC contact is for disconnecting the contactor. This page compares Relay vs Contactor and mentions difference between Relay and Contactor.. What is Relay? >contactor has a hold on contact whereas relay has no such provision < Hold on contact is something that can be applied to either component. This includes power contacts, auxiliary contacts, and contact springs. Protective relays and circuit breakers must work together to isolate a fault. A contactor is really just an overgrown relay. Twitter. Get … Motion Control; Motor Control; Contactor vs. Relay. Control relays are an extremely important electrical part, and they play a vital role in today's electronic devices. The electromagnet (or "coil") provides the driving force to close the contacts.The enclosure is a frame housing the contacts and the electromagnet. It includes a contactor as an essential component, while also providing power-cutoff, under-voltage, and overload protection. The use of a contactor is similar to the relay . A contactor is a special type of relay used for switching an electrical circuit on or off. Contactors and Relays perform the same task of switching a circuit. Orig. Control relay switch chattering noises or chattering at contactor switches in air conditioners, heat pumps, water pumps. The relay contacts are operated when the relay coil is energized (24 V DC). If anything, it would more apply to the relay than the contactor because the hold is a smaller voltage to keep the coil engaged than what a contactor … But the device used for higher current carrying application is known as a contactor and the device used for lower current applications is known as Relay. I suspect this is because modern relays are very capable and in the field prove remarkably reliable. When a transistor is closed, current can flow freely through the relay, causing the load and power supply to be connected. It is a special type of relay, but there is a basic difference between the contactor and a relay. A relay is used to energize the starter, which, in turn, switches the motor voltage while the PLC controls the relay. Relay vs Contactor-Difference between Relay and Contactor. Any one of the the three areas can cause a contactor or relay to malfunction. Email. The light sensor is connected to the transistors which open or close, supplying the relay's load with power. 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