What is the Use of Different Types of Relays: Contactors, Electric and Protection Relays?

1. What is the Use of Different Types of Relays: Contactors, Electric and Protection Relays? Relays can be defined as switches whose primary function is to close and open the circuits electronically as well as electromechanically. Relays essentially regulate the opening and closing of the circuit contacts of an electronic circuit. According to the dictionary, a relay refers to the action of passing something from one thing to another. This literal meaning can be applied to this device since the signal received from one side of the device regulates the switching operation on the other side. The different types of relays are explained below: Contactors When a relay is employed in order to switch a significant amount of electrical power through its contacts, it is assigned a specific name: contactor relay. Contactors generally consist of multiple contacts and those contacts are (but not always) normally-open to ensure that power to the load is shut off when the coil is in the de-energized state. Perhaps the most popular industrial use of contactors is the regulation of electric motors. Electric Relay An electric relay is an electromagnetically regulated electrical switch. A small current is employed to create a magnetic field in a coil within a magnetic core which is then consequently used to operate a switch that can control a much larger current. In this way, an electromechanical relay or electrical relay can make use of a small current to switch a much larger current and ensure that both circuits are electrically isolated from each other. Electrical relays come in different sizes and types based on their function, while they function and perform on the same fundamental concept. Protection Relay On the other hand, protection relays can be explained as a smart device that receives input, compares them to set points, and provides output. Inputs can exist in the form of current, voltage, resistance, or temperature while outputs can incorporate visual feedback in the form of indicator lights and/or alphanumeric display, communications, control warnings, alarms, and turning the power off and on. It can be stated that the concept of relays is critical in electrical power systems and in managing power distribution, whether in homes, commercial, or industrial settings. With the EMD monitoring relays, you can monitor important mains supply parameters and detect errors and/or irregularities early. When errors occur, you can report them to a controller or have targeted shutdown of system components. The EMD monitoring relays are a cost-effective solution for continuously monitoring current and voltage values, phase parameters, winding temperatures, motor loads, and liquid levels. In this way, you can spare yourself expensive bus systems or compact controllers that involve additional programming.

2. Thanks to the easiest of installations and startups, you willl be able to operate your systems in a cost- effective, smooth manner. Universal use : You can use the multifunctional monitoring relays worldwide in your applications – without additional power supply units. The following devices are available: 1. Monitoring relay with integrated wide range power supply for voltages of 24 to 240 V. 2. Monitoring relay with plug-in transformer to adjust supply voltage, graded in different voltage ranges from 24 to 500 V. Products by Application : Current monitoring Systems will be monitored for overcurrent in order to avoid overload situations or blockages. Lamp undercurrent monitoring With undercurrent monitoring, the function or open circuit of electrical loads can be monitored. If consumers fail, the current consumption drops. A signal is sent to the remote monitoring unit when the min. threshold value is reached; this can be activated by the service staff. Further examples of use: Current consumption by motors Monitoring of illumination systems and heating circuits Overload situations for lifting devices and transport equipment

3. Monitoring of locking devices, driving up to end stops and electromechanical brake mechanisms Monitoring of ventilation systems, in stables, for example Voltage monitoring (1- and 3-phase) Both over and undervoltage often have damaging effects: this is how a thermal overload can occur. Temperatures reach impermissible values, meaning that controllers, systems and machines may fail or even be destroyed. Undervoltage monitoring for a battery: With undervoltage monitoring, you can detect the minimum value of the battery voltage and communicate this, for example, to a controller. Further examples of use: DC motor speed monitoring Limit value monitoring in control cabinets Monitoring of machines and systems Controlling inverters in solar energy systems in the case of energy production that is too low or the detection of a voltage drop with cables that are too long Monitoring of the voltage supply for machines and systems Protection against destruction due to loads with unstable power supply networks Switch to alternative or emergency power supplies Phase monitoring In all three-phase mains supplies, all phase sequences such as phase failure, phase sequence and asymmetry should be monitored.

4. Phase failure monitoring: motor protection in 3-phase power supplies If one phase of a three-phase mains supply fails completely (for example, if the fuse is triggered), a connected motor draws the necessary current from the other two phases and may suffer damages from the uneven load. If the motor continues to operate under nominal load, the windings will overheat. Phase sequence monitoring: Rotation direction detection by conveyor drives If two conductors are swapped in a three-phase mains supply, the direction of the rotating field in electrical machines changes. This leads to a change in the rotation direction, which can lead to errors that can destroy the machine.

5. Phase asymmetry monitoring in motors The most frequent cause of asymmetry is an uneven load distribution in the individual phases. In this situation, a proportion of the energy is converted into reactive power. This causes the efficiency of the motor to drop, while the thermal load increases. Further examples of use: Protection against motor damage in the case of phase asymmetry or phase failure Protection of personnel and systems when rotation direction changes Movable/mobile three-phase load voltage monitoring Load monitoring (cos f) With the precise evaluation of power factors or effective power, you protect, for example, electric drives against damage from overloading, blocking or incorrect use. Application examples: Load and temperature monitoring for motors without additional sensors Monitoring filter contamination Detection of excess pressure in pipeline systems V-belts (for slippage and tears) Flow rates in air-conditioning and ventilation systems Real power monitoring in machines and systems Tool wear monitoring Pump dry run and flow rate Conveyor belt blockage or friction Motor winding temperature monitoring For motor winding temperature monitoring, the manufacturer will introduce temperature-dependent resistors into the motor winding. The PTC resistors in accordance with DIN 44081, are highly resistant at high temperatures and serve as sensors. They detect the heating of the motor and activate the relay for further processing of the message. Motor winding temperature monitoring for conveyor belt drives By monitoring the PTC resistors on the motor windings, the conveyor belt motor is protected against overload. Further examples of use: Protection of motor against thermal and mechanical overload, e.g., through insufficient cooling, heavy starting, undersizing Level monitoring

6. Level monitoring can monitor the filling levels and the electric resistance. In the case of conductive level monitoring, the wetting of the sensor probes is evaluated. The sensors are dipped in the medium to be monitored and record a change in resistance once they are wetted or dewetted. If the fluid level is below E2, the resistance increases and an alarm message is sent. Application examples Protects pumps against dry runs Tank overflow protection Filling level regulation Leakage detection Regulation of mixture ratios Wind power system brake system monitoring Visit https://aic.in/electronic-monitoring-relays/ for cable tray, starters for motors,cable glands, cat6 cable, patch cord, surge arrester, frls cable, cat6 cable price, shielded cable, motor starter single phase, siemens contactor, cat5e cable, flexible cable, double compression cable gland, control cable, Switchgears and Circuit Breakers India, SPD Protective Device.