Series 30000 Surface Mounting THERMOSWITCH Temperature Controller

THERMOSWITCH controllers control temperature as low as -100° F (-73° C) and as high as 600° F (316° C) with the proven dependability of over 75 years of service to satisfied customers. 

The THERMOSWITCH is a strut-and-tube type thermostat that operates on the principle of differential expansion between the outer shell and the inner strut assembly. 

As an unpowered mechanical temperature controller, the THERMOSWITCH has found wide acceptance in diverse applications requiring fast response, close control, extreme sensitivity and vibration resistance.

Fenwal Series 30000 Surface Mounting THERMOSWITCH® controllers operate on the principal of differential expansion of metals. 

A temperature increase causes the stainless steel outer case to expand at a greater rate than the internal bridge assembly. 

Because the case is in direct contact with the heated surface, a temperature change is sensed almost instantaneously. 

With an increase in temperature, the case expands. 

This results in a linear change of the internal bridge assembly causing the electrical contacts to open. 

A decrease in temperature closes the contacts. 

This is a field tried and time tested quality product in the Fenwal tradition.