Thermostatic Switches

Thermostat switches are used in temperature control systems to regulate air or liquids and can be used in commercial, industrial, and domestic applications. The two main types are capillary and bimetallic thermostats.

RS offer a range of thermostat switches such as enclosure thermostats, mechanical HVAC thermostats, digital and programmable HVAC thermostats, digital and smart thermostats with Wi-Fi.

What Does a Thermostatic Switch Do?

Thermostats regulate the temperature of liquid in a tank, or in conjuction with air conditioning units to monitor the air in a room or system. The thermostatic switch simply switches the system off or on whenever necessary so that a constant temperature can be maintained and controlled.

Types of Temperature Control Switches

Capillary Thermostat Switches

These consist of a sensor, capillary tube, diaphragms, a probe and an expansion medium. When the liquid heats up and expands, the temperature sensor is heated allowing for it to be converted into displacement in the diaphragm. The contacts within the closed circuit system can be opened or closed by this displacement due to pressure.

Due to their accuracy and easy installation, capillary thermostat switches are widely used to control air and water temperatures and are suitable for use in storage heaters, hot tanks and boilers to control hot water.

Bimetallic Thermostat Switches

These consist of a strip of two different metals with different coefficients of linear expansion. The bimetallic strip acts as an electric contact breaker in an electric heating circuit. When the desired temperature is reached, the circuit is broken.

The strips of metal are bolted together. A bridge is then created in the electrical circuit and is connected to your heating system. The strip carries electricity through the circuit when the heating is on. When the strips get hot, both of the metals expand but one more so than the other. The hottest metal bends and opens the circuit. Once the circuit is open the electricity switches off and the heating cuts out.

Once the heating is off, the room cools down which in turn cools down the strip of metal and allows it to go back to its original shape. When it cools, the metal goes back into the circuit and switches the heating back on as the electricity flow has been re-established. The metal strip takes a while to expand and contract so the heating is not constantly switching on and off every few seconds.

Benefits of Using a Thermostatic Switch

Thermostatic switches offer significant advantages over conventional switches by providing precise and automated temperature control, enhancing safety, efficiency, and convenience in various applications.

Precise Temperature Control

Thermostatic switches maintain a consistent temperature by automatically switching the circuit on or off as needed. This precise control is crucial in applications like heating systems, refrigeration, and industrial processes where temperature fluctuations can affect performance or safety.

Energy Efficiency

By automatically regulating temperature, thermostatic switches help optimise energy consumption. They prevent overheating or overcooling, reducing energy waste and lowering operating costs.

Enhanced Safety

Thermostatic switches act as safety devices by preventing overheating in appliances and equipment. They can automatically shut off power when a critical temperature is reached, minimising the risk of fire or damage.

Increased Equipment Lifespan

By preventing excessive temperature fluctuations, thermostatic switches help extend the lifespan of equipment and appliances. They reduce wear and tear caused by thermal stress, leading to longer operational life and reduced maintenance costs.

Automated Operation

Thermostatic switches automate temperature control, eliminating the need for manual intervention. This is particularly beneficial in industrial settings where continuous monitoring and adjustments would be impractical.

Industrial Applications of Thermostatic Switches

Thermostatic switches, with their ability to provide precise and reliable temperature control, find applications across a wide range of industrial sectors.

HVAC Systems

Thermostatic switches, including capillary thermostat switches, are commonly used in heating, ventilation, and AC systems to regulate temperature. They ensure comfortable indoor environments while optimising energy consumption.

Food Processing

Maintaining precise temperature control is crucial in food processing and storage. Thermostatic switches help ensure food safety and quality by regulating temperatures in ovens, refrigerators, and freezers.

Automotive

Thermostatic switches are used in automotive applications to control engine cooling systems, ensuring optimal operating temperatures and preventing overheating.

Appliance Manufacturing

Various manufacturing processes require precise temperature control. Thermostatic switches are used in ovens, furnaces, and other equipment to maintain consistent temperatures for optimal product quality.

Medical Equipment

Temperature-sensitive medical equipment, such as incubators and blood storage units, rely on thermostatic switches to maintain precise temperatures for patient safety and effective operation.

Aerospace

Thermostatic switches are used in aerospace applications to control temperature in critical systems, such as cabin temperature control and engine monitoring.

How to Choose the Right Temperature Control Switch

Selecting the appropriate temperature control switch, whether it's a thermostat switch or a capillary temperature switch, depends on several factors related to your application and desired functionality. Consider these key aspects to make an informed decision:

1. Temperature Range

Determine the temperature range over which the switch needs to operate. Ensure the switch's operating range encompasses the minimum and maximum temperatures required for your application.

Switching Action

Choose between "normally open" (NO) or "normally closed" (NC) switching action depending on whether you want the switch to close or open the circuit when the temperature reaches the setpoint. NO switches close the circuit when the temperature rises above the setpoint, while NC switches open the circuit.

2. Accuracy and Sensitivity

Consider the required accuracy and sensitivity of the switch. Applications demanding precise temperature control may necessitate a more sensitive and accurate switch, such as a capillary thermostat switch.

3. Mounting and Installation

Evaluate the mounting and installation requirements of the switch. Options include panel mount, surface mount, or capillary mount, depending on the installation requirements. Choose a thermostat switch with a suitable mounting style and connection options for your application.

4. Environmental Considerations

Consider environmental factors such as humidity, dust, or vibration. Select a switch with appropriate ingress protection (IP) rating to ensure reliable operation in the intended environment.

5. Electrical Ratings

Ensure the switch's electrical ratings, including voltage and current capacity, are compatible with your electrical system.

Common Issues and Maintenance of Thermostatic Power Switches

While thermostatic switches are designed for reliability, they can encounter issues that affect their performance or lifespan. Regular switch maintenance and prompt troubleshooting can help ensure optimal operation and prevent premature failure.

Issue 1: Inaccurate temperature readings or erratic switching behaviour.

Check for dust or debris buildup on the sensor or contacts. Clean the thermostatic switch carefully using a soft brush or compressed air. If the issue persists, the switch may need recalibration or replacement.

Issue 2: The switch fails to turn on or off.

Inspect the wiring connections for looseness or damage. Check the power supply and ensure the switch is receiving the correct voltage. If the wiring and power supply are intact, the temperature switch itself may be faulty and require replacement.

Issue 3: The switch trips frequently or prematurely.

Verify that the thermostatic switch's current rating is appropriate for the electrical load. If the load exceeds the rating, consider using a higher-rated switch or reducing the load. Also, check for any short circuits or overloads in the circuit that may be causing the switch to trip.

Issue 4: The switch is damaged due to exposure to harsh environments.

Choose a thermostatic switch with an appropriate IP rating for the intended environment. Ensure the switch is protected from excessive moisture, dust, or vibration. Consider using a protective enclosure if necessary.

Trusted Thermostatic Switch Manufacturer, Supplier & Distributor in Australia

RS Components is your trusted source for high-quality thermostatic switches, micro switches, and detector switches in Australia. We are a leading manufacturer, supplier, and distributor of a wide range of temperature control switches, catering to diverse industrial and domestic needs. We proudly offer products from top brands like Honeywell, Jumo, and Schneider Electric, ensuring reliability and performance.

Whether you need a capillary thermostat switch for precise temperature regulation or an adjustable thermostat switch for versatile applications, we have the perfect solution for your needs.

Explore our extensive range of thermostatic switches and experience superior temperature control for your applications.

Buy Thermostat Control Switches from RS

RS offers fast delivery of thermostatic switches and other detectors like door interlock switches and RF switches. For more details on delivery services and fees, please refer to our Delivery page.