Randall, First, the standard is IEC (or EN) 61000-3-2, not -3. Article 5 defines Class D products as those "Equipment having an input current with a "special wave shape" as defined in figure 1 and an active input power, P<= 600 W, measured under the test conditions given in the relevant clause of annex C."
Question #1 - does your product produce a wave shape that meets this requirement? If yes, your product is Class D. If no, your product is Class A. Question #2 - What Class are you? If Class A, you must test as there is no relaxation based on power draw (assuming you draw less than 1 kW). If Class D, what is the active input power? If greater than 75 watts, test. If less than or equal to 75 watts, relax and ignore the whole thing. The definition of Class D doesn't address the active input power level. Only the limits for Class D address this issue. Ghery S. Pettit Intel Corporation -----Original Message----- From: Flinders, Randall [mailto:[email protected]] Sent: Tuesday, January 18, 2000 10:12 AM To: 'emc-pstc' Subject: Harmonics Testing Greetings EMC Professionals! I have a quick question regarding Harmonics testing to EN61000-3-3. We have an ITE product with a switching power supply. The product uses about 38 watts input power. According to the standard, which scenario applies? Scenario #1 The unit does not need to be tested, because it falls below the Class D Input power range of 75(50)W to 600W. Section 7.4 of the standard states that "...No limits apply for equipment with an active input power up to and including 75W...." Scenario #2 Since the unit does not use more than 75W (or more than 50W for that matter), the unit then defaults to the Class A requirements and therefor must meet the less stringent Class A limits. Section 5 of EN61000-3-3 states: " Class A: Balanced 3-phase equipment AND ALL OTHER EQUIPMENT, except that stated [in Classes B-D]..." So I guess my question is this: when an ITE product with a switching power supply uses less than 50W (75w), does it become an exempt Class D Device, or doe sit become a Class A device? Your insights would be appreciated..... Regards, Randy Flinders Chairman Orange County Chapter IEEE EMC Society [email protected] (714) 513-8012 (714) 513-8265 Fax Note: The opinions expressed herein are personal and in no way represent the position of the IEEE, The EMC Society, or my employer. --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators).
