Power Relays

Relays are electromechanical devices used to control the flow of electrical power in a circuit. essentially operate as switches that control other switches within electrical circuits. They manage higher-power circuits using a low-power input signal. A key purpose of relays is to isolate the low-power control signal from excessive voltage or current from the higher-power circuit to ensure the safe operation of electrical systems while preventing damage to equipment.

What are Power Relays?

Power relays are commonly used in industrial and commercial applications in New Zealand to control large electrical loads, such as motors, heaters, and lighting systems. Power relays consist of a coil, which generates a magnetic field when a current flows through it, and a set of contacts mechanically switched by the magnetic field. When the coil is energised, the contacts close, allowing current to flow through the relay and to the load. When the coil is de-energised, the contacts open, breaking the circuit and stopping the flow of current.

Features of Power Relays

Power relays are available in a variety of configurations, including single-pole, double-pole, and three-pole versions. All of these are available in single-throw or double-throw versions, where the former can exist only in an open or closed state, allowing current to flow only in one of these positions. In contrast, the latter enables switching between two positions. Single-pole relays are the most straightforward contact type. With just one pole, this relay controls a single circuit. Meanwhile, double-pole relays can operate two separate circuits independently, and three-pole versions operate three circuits.

They may also include auxiliary contacts, which can be used to monitor the status of the relay or to control other devices in the circuit. This is because auxiliary contacts can indicate switching or malfunction states, and interlock circuits or logic and sequence controls with varying loads. They also relay data from the circuit to a programmable logic controller, which then instructs the connected devices to turn on or off.

Additionally, power relays may have features such as time delays or surge suppression to provide additional protection and control. Time delay relays are engineered to control events based on a predetermined time set within the device, activated by voltage or a signal. Meanwhile, the surge suppression feature helps mitigate the high voltage spikes produced when a relay or electrical contactor coil is de-energised.

Applications Where Power Relays are Used

Power relays are used in a wide range of applications where electrical power needs to be controlled. Some common examples of applications where power relays are used include:

• Motor Control: Power relays are used to control the operation of electric motors in various industrial and commercial applications, such as pumps, conveyors, and HVAC systems.
• Lighting Control: Power relays are used to control lighting systems, such as streetlights, outdoor lighting, and indoor lighting in commercial and industrial buildings.
• Heating and Cooling Systems: Power relays are used to control the operation of heaters and cooling systems, such as air conditioners and refrigeration units.
• Power Distribution: Power relays are used to switch power between different parts of an electrical system, such as between a main power source and a backup power source.
• Power Factor Correction: Power relays are used to correct the power factor in electrical systems, which helps to improve the efficiency of the system.
• Uninterruptible Power Supplies (UPS): Power relays are used in UPS systems to switch between different power sources, such as between a battery backup and a main power source.
• Security Systems: Power relays are used in security systems to control the operation of various devices, such as door locks, alarms, and cameras.

How to Order Relays in NZ from RS?

These are just a few examples of the many applications for power relays. Power relays are essential components in many electrical systems and are critical for ensuring their safe and efficient operation.

Understanding the importance of relay switches in ensuring seamless and safe operations for our customers, RS New Zealand offers a comprehensive selection of high-quality power relays. Our range includes products from well-respected brands such as Hongfa Europe GMBH, TE Connectivity, and our exclusive RS PRO line. With competitive pricing across our collection, you are assured of finding the ideal power relay to meet your needs without compromising on value.

Delivery Information for New Zealand

For the delivery of items stocked locally in New Zealand or stocked locally in Australia, please buy your items before 5 pm and 3 pm NZT, respectively, to enjoy next working day delivery.

RS is committed to delivering your electrical relays and other orders the next working day between 8 am and 5 pm local time. However, the following products will have longer lead times:

• Global Stock and Extended Range products.
• Orders containing hazardous products.
• Items weighing over 20kg, with a cubic weight over 20kg, or a length exceeding 1.5 metres.

Non-core products and deliveries to specific regional areas may also have extended lead times. For more information or to arrange a consolidated delivery, please contact Customer Service.