The Fenwal Series 18000 Coupling Head Thermoswitch can be inserted into a .625 in. reamed hole, except for the 18052 which can be inserted into a .750 reamed hole. Lightweight and compact, these units are economical temperature controllers or stand-alone high or low limit controllers. The Thermoswitch controllers control temperatures as low as -100ºF and as high as 600ºF with the proven dependability of over 60 years of service to satisfied customers.
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

  Fenwal Series 18000 Coupling Head Thermoswitch – Technical Data & Specifications Model No. Diameter Temperature Range Shell Material Corrosion Resistant Contact Operation on Temp. Rise Price 01-018000-000 5/8″ -100 to 400ºF Brass No Opens Discontinued, use 01-018002-000 below 01-018021-000 5/8″ -100 to 400ºF Brass No Closes Discontinued, use 01-018023-000 below 01-018002-000 5/8″ -100 to 600ºF 300SS No Opens $330.00 01-018023-000 5/8″ -100 to 600ºF 300SS No Closes $330.00 01-018052-000 13/16″ -100 to 600ºF 300SS No Opens $439.00 01-180020-029 5/8″ -100 to 500ºF 316SS Yes Opens $430.00 01-018002-021 5/8″ -100 to 600ºF 316SS Yes Opens $401.00 01-018023-007 5/8″ -100 to 600ºF 316SS Yes Closes $401.00

• 01-018002-000 | 01-018023-000 | 01-018052-000 | 01-180020-029 | 01-018002-021 | 01-018023-007 | 18000-0 | 18002-0 | 18021-0 | 18023-0 | 18052-0