About Thermal Controls

Bimetallic thermostats and thermal controls basically fall into two broad categories: 1) creep action devices with slow make/slow break switching action; and 2) snap action devices with quick make/quick break switching action.

Creep action devices are excellent in either a temperature control application or as a high limit control.  They have a narrow temperature differential between the opening and closing temperatures and generally have more rapid cycling characteristics than snap action devices.

Snap action devices are most often used for temperature limiting applications as their fairly wide differential between opening and closing temperature provides slower cycling characteristics.  We have been able to control the amount of differential in many of our snap action controls, that enables them to be used for temperature control applications, especially in dual voltage applications.

Snap Action Thermal Controls
Quick Make / Quick Break switching action. Ideal for over current and over temperature protection.

Creep Action Thermal Controls

Slow Make / Slow Break switching action best suited for temperature control applications.

Disc-Type Thermal Controls

Snap action controls available in automatic reset, manual reset, or self-hold types.

Valstat Thermal Controls
Snap action controls for inductive load applications where cost is a primary concern.

Self-Hold Thermal Controls
An extra degree of safety in over temperature applications. Integrated heat source for low profile design.


Customized Thermal Controls
Controls to fit the individual requirements of your application.

Choosing the right thermal control

The rate of temperature rise, location of the thermal control, the electrical load, and the mass of the application can each greatly affect cycling (operational) characteristics of a thermal control.  Because of these variables, we recommend that you conduct testing of our products specifically in your application.

Included in this web site are the specification sheets for each of our models of thermal controls.  These describe the basic features of our thermostats and thermal protectors.  We have included outline drawings which give the relative sizes of our controls.  Unless noted, all dimensions are nominal with English dimensions shown in black type and metric dimensions, given in millimeters, are shown in green.  We have also listed representative electrical ratings for each model, based on their use in the end application.