UL Standard for Safety Dehumidifiers - Section / Paragraph Reference: Supplement SB Subject: Alternative Path for Electronic Controls (Edition 9: July 8@ 2009)
"Throughout the Supplement@ when reference is made to requirements in ""this Standard@"" the reference is to requirements in the main body of the Standard and not to other requirements of the Supplement. These requirements provide an alternative path for investigation of electronic controls used in appliances covered by this standard. In the context of this Supplement@ an electronic control is a circuit incorporating at least one electronic component and that causes the intended output of the appliance energy source(s) (e.g. heaters@ moving parts@ humidity@ radiation) to vary. In the context of this Supplement a motor speed drive would be considered an electronic control. Circuits that transmit or receive signals (analog or digital)@ transform or convert electricity to supply other circuits (e.g. power supply) or simply switch an electrical load (e.g. electronic relay) are not controls but are subject to the requirements of this Supplement when they are integrated (physically or functionally) with a control. A self-regulating PTC heater is not considered a control from the perspective of this Supplement. When a thermistor is used as a sensor or as part of a thermal management function of a control@ it is investigated as part of the control. Thermal motor protectors in direct contact with motor windings and intended for direct control of the motor supply are outside the scope of this Supplement even if they incorporate one or more electronic components. Exception No.1: Electronic circuits that provide thermal motor protection but only have a thermal sensor in direct contact with motor windings are within the scope. Exception No. 2: Electromechanical thermal motor protectors in direct contact with the motor windings where the protector is connected to electronic circuits that provide the motor load control are within the scope. Electronic circuits that provide control functions intended to prevent special hazards such as an explosion or whose failure could directly cause a hazard in the appliance are outside the scope of this Supplement."