Functionality and advantages of temperature limiters A temperature limiter is a thermal protection device designed to restrict the temperature of a device to a predefined maximum value. This component is used to prevent overheating, along with any associated damage and hazards. A temperature limiter interrupts the energy flow of the device or activates cooling mechanisms when the specified temperature threshold is reached or exceeded. It is therefore one of the most important safety features for electronic devices. How temperature limiters work Temperature limiters are used in a wide range of electronic devices. A common example found in almost every household is the coffee machine. In coffee machines, temperature limiters ensure that the water is heated to the correct temperature for brewing coffee while preventing overheating of heating elements or other electrical components. This not only reduces potential hazards like burns but also minimises damage. Temperature monitoring: Temperature limiters continuously monitor operating temperatures within the machine, especially in areas sensitive to heat. Predefined thresholds: Devices are configured to react upon reaching or exceeding predefined temperature limits, tailored to the machine type and its temperature control requirements. Circuit Interruption: When the temperature reaches a critical point, the temperature limiter interrupts the electrical circuit, stopping the energy supply to heat-sensitive components. Reset after cooling: Once the temperature drops below the defined limit, the temperature limiter can reactivate the circuit. In some cases, a manual reset may be required. Key advantages of temperature limiters Overheating protection: By cutting the circuit when a set temperature is reached, damage to the machine and its components is avoided. Enhanced safety: Reduces risks of fires or other hazards caused by overheating. Extended lifespan: Overheating accelerates material wear and aging; timely shutoff can prolong the machine’s lifespan. Cost efficiency: Avoids expensive repairs and component replacements, positively impacting long-term operating costs. The Limitor P and Y Temperature Limiters The Limitor P and Y temperature limiters can be deployed wherever overheating must be avoided - for instance, as winding protection for small motors, primary winding protection in transformers, or as general thermal protection in small electronic devices. Limitor, a leading manufacturer of temperature-based component technologies, is trusted by global electrical corporations like AEG, Siemens, Kärcher, and Philips. With over 50 years of experience, Limitor offers a broad product range from temperature monitors and limiters to thermal fuses and timers. P-Type Temperature Limiter The P-type limiter is a non-powered device that uses a bimetallic disc for temperature detection. This disc is pre-configured to snap at a specific cutoff temperature. When this temperature is reached, the disc snaps, opening a contact system and interrupting the electrical circuit of the device being protected. Y-Type Temperature and Current Limiter The Y-type limiter provides dual protection against both overtemperature and overcurrent. Unlike the P-type, the Y-type does not allow automatic resetting after cooling. Once triggered, it remains off until manually reset. This is achieved through a high-resistance element that prevents the bimetallic disc from cooling down until the power supply is disconnected. Advantages of the Y-Type: Enhanced safety and flexibility. Simplified installation as it doesn’t need to be mounted directly on the heat source. Cost reduction in development and assembly by allowing the use of less expensive materials in machine housings. Increased machine reliability and safety due to its hold-open function. Applications in Coffee Machines P-Type Limiter: Used to protect vibration pumps by shutting them off when temperatures exceed 100°C. The limiter resets automatically once the temperature returns to safe levels, resuming the pump operation. Y-Type Limiter: Provides protection for the brewing unit, preventing overheating caused by excessive cycles or lack of water. It also safeguards grinders from motor blockages due to foreign objects, shutting down within 3 seconds to prevent damage. Temperature limiters protect machines from dangerous overheating, enhance safety, improve reliability, extend component lifespan, and contribute to economic efficiency. If you have questions, feel free to contact our experts. Article published on: 2025. 02. 10. Article last updated on: 2025. 02. 10.