Power RelayDownload
A power relay is a device used to control the current in a circuit. They can be used to control both AC and DC circuits and are available in a variety of sizes and configurations. The three main types of power relays are miniature, PCB and industrial relays.
A power relay works by using an electromagnet to open or close a set of contacts. When current is applied to the relay’s coil, it creates a magnetic field that pulls the metal armature toward the coil. In turn, this moves the contacts closer or further away from each other, completing or breaking the circuit and controlling the flow of electricity.
As the need for uninterruptible power supplies increases, so does the need for reliable power relays. Our power relays are designed for durability and long-lasting performance. We have a variety of options to choose from to provide the perfect solution for your power needs.
They can be used in a wide range of applications including controlling motors, lights, heaters and other high power devices. They are also commonly used in automotive applications such as controlling headlights, windshield wipers and other electrical systems.
REH magnetic blow-out power relays are an excellent choice for DC motor loads.
RKF-LTS relays are designed for motor load applications with good performance.
RKE-LS sealed power relays are designed to provide good performance under harsh operating conditions.
RKM miniature general purpose relay with 2 pole 5A and 4 pole 3A.
Principle of Power Relays
Power relays use the principle of electromagnetic effects of magnetic-current interactions. A power relay usually consists of a coil, an armature and a set of contacts. When a voltage is applied to the coil, an electromagnetic field is created that attracts the armature to the coil. This movement of the armature causes the contacts to open or close, depending on the design of the relay.
Power relays are designed with either normally open (NO) or normally closed (NC) contacts. In a normally open relay, the switch is left open when the coil is unenergized. When current flows through the coil, it closes the switches and allows electricity to pass through. In contrast, a normally closed relay sees its contacts shut when no power reaches the coil. Upon same-state current being supplied to the coil, it opens up and stops any electricity from travelling through it.
Applications of Power Relays
Power relays are used as safety circuits to prevent inadvertent large currents from flowing into the circuit. In addition to safety circuits, it is also used as a main relay in products handling large charges.
It mainly includes the following applications:
Control Circuits: Power relays are often used in control circuits to turn motors, lights and other devices on or off.
Motor Control: Power relays can be used to control the start and stop functions of a motor.
Lighting Control: Power relays can be used to control lighting systems such as turning on/off lights in rooms, street lights and traffic lights.
Power Distribution Systems: Power relays are used in power distribution systems to control current flow and prevent overloading.
HVAC Systems: Power relays can be used to control heating, ventilation and air conditioning systems.
Industrial Automation: Power relays can be used to automate manufacturing processes to control the movement of machinery.
Automotive Systems: Power relays are used in automotive systems to control the operation of various components such as headlights, windshield wipers, and power windows.
Renewable Energy Systems: Power relays are used in renewable energy systems, such as solar and wind energy systems, to control current flow.
Causes of Power Relay Failures
Power relays have longevity because they have contacts that are mechanically operated by electromagnetic force. The service life in terms of the number of actions is about hundreds of thousands of times. If the life span is exceeded or excessive shock is applied, the following malfunctions will occur.
Some common causes of power relay failure are:
Overheating
If a relay is exposed to high temperatures for an extended period of time, the coil insulation will degrade, resulting in failure.
Mechanical wear
Due to repeated switching, the contacts of relays can wear or become dented over time, causing them to fail.
Corrosion
If the relay is exposed to moisture or corrosive substances, the contacts and other parts of the relay can corrode, which can lead to failure.
Voltage Spikes
Voltage spikes or surges can occur in the circuit, causing the contacts of the relay to fuse together, resulting in failure.
Contamination
If dirt, dust, or other contaminants get into the relay, it can cause the contacts to stick or become damaged, leading to failure.
Coil burnout
If the relay’s coil is exposed to excessive current or voltage, it can overheat and burn out, causing it to malfunction.
