Peter - Any appliance with an ac electric motor, with the exception of electric clocks (which use synchronous motors), will overheat. Whether or not this will lead to an unsafe condition will depend on the robustness of the design and the duration of the overvoltage.
Similarly, appliances with linear power supplies, like microwave ovens, the transformer may also overheat if in use at the time of the low voltage condition. I don't know what a low voltage condition will do to a magnetron, other than reduce possibly its radiation output. Most appliance fan motors are shaded-pole squirrel cage induction motors and will also overheat. The timing motors on laundry machines and automatic lawn sprinkler systems are probably also synchronous types and will not be significantly effected. Anything with a SMPS probably will be less effected than a linear, but will try to draw additional current for a fixed load condition and might get unusually warm. [I realize that my contention that most electric motors in the household are induction motors contradicts those made by others on this list during a discussion of the electric power debacle in California in summer, 2001, including the officials of the Peoples Republik of Kalifornia, when it was proposed to lower the voltage on the utility power bus to "save energy." When considering the cost of building an induction motor versus a synchronous motor, it will become clear that no engineer or capitalist worth his salt will build an appliance using a synchronous motor, unless the application calls for it.] Regards, Peter L. Tarver, PE Product Safety Manager Sanmina-SCI Homologation Services San Jose, CA [email protected] > -----Original Message----- > From: Peter Merguerian > > Dear All, > > I am interested the damaging effects on > components of electrical household > appliances as a result of overvoltages and/or > undervoltages. > > As an example, what are the types of components > that would be damaged in a > TV or personal computer from an undervoltage or > overvoltage in the electric > power line? > > Every household appliance may have different > components and I am intersted > the effects on as many appliances as possible > (refrigerator, vacuum cleaner, > TV, lawn mower, jaccuzi, electric shaver, > lighting power supplies, fans, > etc. etc.). > > > > PETER S. MERGUERIAN ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
