THERMOSTATS, THERMAL OVERLOAD PROTECTORS AND CUTOUTS Portex Technologies offers a wide range of thermostats and thermal overload protectors which are used in numerous industries and fitted in various applications. All our devices operate on the snap action bimetal principle, which ensures accurate and precise temperature sensing. Please see below our thermal overload protectors for different applications and our complete product list. I.S.I. Definition of Thermal Cut-outs -I.S. 302-1973, Para 2.37: A device during abnormal operation, limits the temperature of an appliance, or parts of it, by automatically opening the circuit or by reducing the current, and which is so constructed that its setting cannot be altered by the user. Self-Resetting Thermal Cut-out -I.S. 302-1973, Para 2.38: A thermal cut-out which automatically restores the current after the relevant part of the appliance has cooled down sufficiently. U.S. Standards are specified by U.L. 547 - PROTECTORS FOR MOTORS. Canadian Standards are specified by Canadian Standards Association (C.S.A.)