Electrical Relays

Introduction to Electrical Relays

What is it?

Relays are electrical switches that use an electromechanical component to switch high power loads with low power signals. They can be used to turn equipment on or off, regulate temperature, and trigger alarms or safety shutdowns.

Why we use it?

We use relays to improve system performance, optimize energy usage, and ensure safety by controlling the flow of electricity in HVAC systems.

How it works?

A relay typically contains a coil, which creates a magnetic field when energized. This magnetic field moves a set of contacts to open or close an electrical circuit to turn equipment on or off.

Major brands that manufacture it

Some of the major brands that manufacture relays include Honeywell, Schneider Electric, Siemens, and Square D.


There are different types of relays, including time delay, latching, and overload protection relays. Some models may also feature additional functions, such as surge suppression or communication protocols.

How do we select it?

When selecting a relay, consider factors such as voltage rating, current rating, switching capacity, contact type, and communication protocols. Also, make sure the device is compatible with your existing control and automation systems.

How to install it?

Relays should be installed according to the manufacturer's recommendations. They should be securely mounted using appropriate fittings or adapters, and any necessary wiring connections should be made to the building automation system or controller.

Wire connections required to receive the signals

The wire connections required to receive signals from a relay may vary depending on the specific device and building automation system. Typically, they will require a power supply connection and electrical wires that connect to the building automation system or controller. It's important to refer to the manufacturer's installation instructions for proper wiring connections.

Electrical Relays
Administrator December 22, 2023
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