When selecting temperature switches for various applications, it’s crucial to understand the differences between a Temperature Control (Fan) Switch and a Limit Switch. Throughout our website, we use terms like “limit” and “control” or “fan,” which can sometimes confuse users about which temperature switch to use. Despite being mentioned together in our documentation, no relationship exists between a limit switch and a fan switch in terms of application. If you have any additional questions regarding our fan and limit switches, please contact us.
Temperature Control (Fan) Switch
A temperature control (fan) switch regulates the operation of equipment, such as fans, based on temperature changes in a system. When the temperature in an environment changes, the switch trips to control a piece of equipment, maintaining the desired temperature until it falls back to reset conditions. For example, in a wood stove, a fan switch activates a fan to move warm air when the stove reaches a specific temperature and deactivates when the temperature cools.
Temperature Limit Switch
A temperature limit switch serves as a safety device in redundant control systems to prevent over-temperature conditions. These switches meet approval agency standards, often by the Underwriter’s Laboratories (UL). They operate based on physical principles rather than electrical schemes or chip sets.
In critical heating and cooling applications, multiple switches often work together: one as a control switch and the other as a limit switch. The control switch activates and deactivates equipment at set temperatures, while the limit switch interrupts the process to prevent overheating and potential damage. For instance, in a hot water heater, the control switch manages the heating elements to maintain a specific temperature. Meanwhile, the limit switch prevents the elements from overheating and causing a critical failure.
When a limit switch trips, it remains in that state until the temperature falls back to a safe level, often requiring a manual reset or power removal to return to normal operation.
Applications and Manufacturing
Our STEMCO capillary style switches can meet both fan and limit conditions, providing reliable temperature control and safety in various applications.
Key Benefits of Temperature Control (Fan) and Limit Switches
- Precision Control: Temperature control switches offer precise regulation of equipment based on environmental conditions.
- Safety Assurance: Limit switches act as fail-safes, preventing equipment from reaching dangerous temperatures.
- Reliability: Both types of switches operate on physical principles, ensuring consistent performance without dependence on complex electronics.
- Versatility: Suitable for a wide range of applications, from wood stoves to hot water heaters and refrigeration systems.
Understanding the differences between temperature control (fan) switches and limit switches helps you select the right components for your specific needs, ensuring high performance and safety.
