Principle of Operation:
The Fenwal Thermoswitch controller is a strut-and-tube type thermostat comprised of two basic parts: the outer shell, made of high-expanding metal and the strut assembly made of low-expanding metal. A pair of electrical contacts is mounted on the strut assembly and installed in the shell under tension. The temperature at which the contacts “make” or “break” can be regulated by a temperature adjusting sleeve.
Fast Response:
Because the outer shell of the Thermoswitch controller is the active sensing member, and not merely a housing, response to temperature change is almost instantaneous.
Close Control:
The controller’s shell and strut arrangement has “anticipation” characteristics which substantially reduce the amount of overshoot and undershoot during conditions of rapid temperature change.
Extreme Sensitivity:
The strut and contact assembly operates by slow make and break. This means that every temperature change, no matter how small, causes a corresponding change in the space between the electrical contacts. Therefore, contact action can be produced by a very small temperature change, which accounts for the Thermoswitch controller’s excellent resolution os 0.1ºF (0.05ºC).
Agency Approval:
Various models are listed to component recognized by Underwriters Laboratories (UL) and certified by the Canadian Standards Association (CSA).

Specifications & Options:

• Shell dimensions: 5/8″ diameter, 3-9/16″ long (3″ long on units with threads)
• Standard lead wire: 8-10 inches
• Maximum volts: 240VAC / Vdc consult factory
• Maximum watts: 1200 AC / Vdc consult factory
• Maximum operating temperature: 600ºF / 316ºC
• Minimum operating temperature: -100ºF / -73ºC
• Contact action: slow make and break
• Options (call for pricing and applicability to specific models):
  • Special Marking
  • Extended Lead Wires
  • Factory Temperature Setting
  • Temperature Restraining Device
  • Tamper-Proof Cap
  • Dial and Knob
  • Moisture Resistant Seal & Moisture Resistant Tamper Proof Cap
  • Armored Cable (over lead wires)
  • Terminal Plug Connector
  • Extended Temperature Adjusting Sleeve
  • Protective Wells

01-017202-000 | 01-017223-000 | 17202-0 | 17223-0