Resettable thermal safety switch for heating appts. - uses spring immersed in wax to open contacts if wax melts and has external resetting button

摘要

The safety cut-put uses a spring loaded contact which is normally held in the closed position against the spring force by a wax material which is solid at safe temperatures and melts when the temperature is excessive. The wax is in the tip of a tubular rod in the space in which the temperature is being monitored. The rod extends through a hole in the wall of the heated space and has the electrical contacts and switch together with a reset-indicator button in a housing at the outer end of the rod. Inside the tubular rod a solid rod couples the wax immersed spring to the switch and the reset indicator button. The heating appts. may be an instantaneous water heater or liq. fuel heater.