Product Specifications

3/4 Inch Disc Heater-Biased Control

The 69T line of 3/4 (19mm) bimetal disc temperature controls from Therm-O-Disc offers multiple temperature operation in a unique, cost effective design. The snap action bimetal disc provides high speed contact separation resulting in exceptional life characteristics at electrical loads up to 25 amps at 240 VAC. By utilizing heaters mounted internally, the open or close calibration of the bimetal disc can be biased lower. The more power applied to the internal heaters - the more supplemental heat is generated to bias the operating temperature of the control. The 69T is a cost effective alternative in applications where multiple temperature control is required.

Features and Benefits of the 69T:

• Internal heater construction for consistent temperature depression.

• Available in automatic reset SPST and SPDT switch configurations.

• Snap action bimetal disc for high speed contact separation.

• A wide variety of terminal and mounting options for design flexibility.

• Exposed or enclosed bimetal disc for either increased thermal response or protection from airborne contaminants.

Switch Action and Typical Applications:

SPST - In this design, the switch can be built to either open or close its electrical contacts on temperature rise. Once the temperature of the bimetal disc has returned to the specificed reset temperature, the contacts automatically return to their original state. The SPST switch action is typically used to regulate clothes dryer drum temperatures.

SPDT - This design is the same as the SPST described above with the addition of an auxillary set of contacts that open and close in opposition to the main contacts.

Mounting Brackets:

Airstream Mounting - This mounting configuration positions the bimetal disc through a hole in the mounting surface to sense temperature within an enclosure such as a heater box or air duct. The standard configuration positions the bimetal disc .39 inches (9.9mm) into the airstream while an optional version positions the bimetal disc .78 inches into the airstream. Airstream configurations may be specified with a flange or without a flange to suit your application needs.

Surface Mounting - This optional mounting configuration positions the bimetal disc firmly against the mounting surface to sense the actual mounting surface temperature.

Stud Mounting - This optional mounting configuation positions the bimetal disc within a 1 inch hex brass base with a 1/4 x 18 NPT stud to sense temperatures of the mounting area or liquids contained within.

Tube Mounting - This optional configuration positions the bimetal disc within a machined brass base to sense tube temperatures. Mounting is available for 5/8, 3/4 and 7/8 inch tube sizes.