What type of switch is a high limit switch categorized as?

A high limit switch is categorized as a normally closed switch (NC). This type of switch is designed to maintain a closed circuit during normal operating conditions, which helps to ensure the safe functioning of a system. The high limit switch remains closed until a set temperature limit is exceeded. Once this temperature is reached, the switch opens, interrupting the circuit and shutting down the equipment to prevent overheating and potential damage.

The operation of the high limit switch is crucial in safety systems, making it an integral component in heating appliances and gas furnaces. When the temperature drops back down to a safe level, the switch will close again, allowing normal operation to resume. This characteristic is essential for maintaining safe operational parameters in gas-related applications.