A high limit switch is used in an electric heater to shut off the heating element when the internal air temperature exceeds a defined threshold. This prevents damage to internal components and reduces the risk of fire. For additional information on a high limit switch used in electric heaters, visit the product page or contact us.
Snap Disc Thermostats for Overtemperature Shutdown
Electric heater manufacturers install snap disc thermostats to serve as high limit switches. Each thermostat uses a bimetal disc to actuate a mechanical switch. When the temperature exceeds the set point, the disc flexes and opens the contacts. Once the temperature drops below the reset point, the disc returns to its original shape, closing the contacts and restoring operation.
Senasys produces snap disc thermostats with a range of temperature settings, mounting brackets, and terminal styles. Models include automatic reset or manual reset configurations, depending on the application requirements.
Application Overview
Heater assemblies position the snap disc thermostat in the airstream near the heating element. Two screws secure the switch to the housing. Wires connect the terminals in series with the heating coil. When air temperature rises past the cut-off threshold, the thermostat interrupts current to the heater.
This method provides a simple, mechanical solution for overtemperature protection. Snap disc switches do not require software, sensors, or external power. They respond quickly and maintain long-term performance across thousands of cycles.
Example: 2511L002-1983 Thermostat
The 2511L002-1983 is a ¾” automatic reset snap disc thermostat with an airstream bracket and two quick-connect terminals. It opens at 120°F and recloses at 105°F. It supports up to 25 amps at 240 VAC and operates in ambient temperatures up to 350°F.
This model represents one option in Senasys’ catalog of high limit switches used in electric heaters. Other configurations include different temperature ratings, bracket styles, and terminal layouts.
High Limit Control for Electric Heating Systems
OEMs and service teams use snap disc thermostats as a direct method to control maximum heater temperatures. These switches support code compliance and equipment protection with minimal complexity. Senasys offers U.S.-made models with short lead times and no minimum order quantities.
