Dear Members, Does anyone know the reason FCC exempts devices listed under FCC §15.103(d) as quoted below? “(d) A digital device utilized exclusively in an appliance, e.g., microwave over, dishwasher, clothes dryer, air conditioner (central or window), etc.” FCC KDB 772105 clarify the exempted household appliances: “Exempt household appliances are electrical machines intended for household tasks that assist persons in washing and drying clothes, household cleaning, cooking, or food preparation; or is equipment that is directly involved in conditioning the supply of household water and air (heating, cooling and humidifying) in a residence. This includes appliances such as a vacuum cleaner, washing machine, dishwasher, clothes dryer, air conditioner (central or window), etc. This exemption is limited to basic housekeeping appliances and is not intended to apply to all home-use products that may contain digital logic.” I wonder (and would like to learn from members) if the exemption is due to the discontinous disturbance as stated in the EN 55014-1 (CISPR 14-1), the emission requirements for household appliances in the EU. I list several paragraphs excerpted from CISPR 14-1: 2005 for reference: “Switching operations in thermostatically controlled appliances, automatic programme controlled machines and other electrically controlled or operated appliances generate discontinuous disturbance. The subjective effect of discontinuous disturbance varies with repetition rate and amplitude in audio and video presentation. Therefore distinction is made between various kinds of discontinuous disturbance. “(CISPR 14-1 Clause 4.2)
“The limits for discontinuous disturbance depend mainly on the character of the disturbance and on the click rate N ...” (CISPR 14-1 Clause 4.2.1) “For discontinuous disturbance, the click limit Lq is attained by increasing the relevant limit L (as given in 4.1.1) with: 44 dB for N<0.2, or 20 lg (30/N) dB for 0.2≤N<30 “ Thank you very much for your time and look forward to your comments. Best regards, Grace Lin - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at http://product-compliance.oc.ieee.org/ Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <emcp...@radiusnorth.net> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org> David Heald <dhe...@gmail.com>
