THERM-O-DISC - 20MAA3FA - Motor Protection Temperature Sensor Switch, NC Contacts.

THERM-O-DISC - 20MAA3FA – Normally Closed Contacts Motor Protecting Temperature Sensor Switch. The Therm-O-Disc line of Motor Protectors offers accurate and reliable protection against hazardous overheating in single phase/single voltage A/C motors. This motor protector employs a snap-acting, current and temperature responsive bimetal disc for proven performance over life. An internal resistance heater utilizes the effects of current to bias the operation of the bimetal disc for added thermal response. A wide range of bimetal and heater combinations are available to cover specific design requirements. This design flexibility and proven performance has made Therm-O-Disc Motor Protectors a popular choice among the leading manufacturers of fractional horsepower motors. The operating mechanism inherent to all Therm-O-Disc Motor Protectors is the snap-action bimetal disc. During abnormal conditions, heat generated by resistance and/or motor ambient causes the bimetal disc to snap at the specified calibration temperature. This allows the circuit to open within the maximum safe limits of the motor windings. Once the motor returns to a normal operating temperature, the bimetal disc resets automatically. This closes the circuit and re-energizes the motor. This same snap-action principle is utilized in millions of Therm-O-Disc products applied in the appliance, heating and air conditioning industries. The Motor Protector features include: • High-speed contact separation ensures long contact life. • Current and temperature responsiveness for excellent design flexibility. The Motor Protector series has been rated by major agencies throughout the world. The agency ratings can be used as a guide when evaluating specific applications. However, the mechanical, electrical, thermal and environmental conditions to which a control may be exposed in an application may differ significantly from agency test conditions. Therefore, the user must not rely solely on agency ratings, but must perform adequate testing of the product to confirm that the control selected will operate as intended in the user’s application. This is an over temperature motor protector which opens its contacts (SPST) when excessive temperature is sensed. Bimetal Resistance: 0.0015 Ohm, Heater Resistance: 0.0320 Ohm Temperature: Opens @ 110 C (230 F), Closes @ 45 C (113 F) Current Rating: 50A @ L.R. 120V, 37 A @ L.R. 240V Dimensions: 1.38" Wide x 1.32" X R2.50 Radius Curved 0.38" Thickness. Weight: 0.5 Ounce (15 Grams) Termination: Two Side Entry 1/4" Quick Connect Terminals. Applications: Commercial, Industrial, and Residential, Including Several Whirlpool, Maytag, Kenmore Dryer as a motor fuse. New Old Stock Made in USA