Don, In my company we have been looking at inrush issues for our power conversion products. There are two reasons,
1) Customers really dislike those nuisance trips of the circuit breaker. They may only occur once in 10 or 100 times the product is turned on, but it causes problems. These trips are usually caused by rapidly filling up of a bulk capacitance or when a customer uses a GFCI and there is an inrush through fairly large "Y" caps on the EMI filter. This is usually exacerbated when the power is turned on, at or near the top of the line frequency sine wave. The GFCI problem is usually not an issue with products that have a full time EMI filter (i.e. inline before the power switch.). 2) The second is kind of new, as of January 1st, 2001 The European Community is mandating compliance with the EN61000-3-2 Harmonics & EN61000-3-3 Voltage Fluctuation and Flicker, both for equipment with up to 16 Amps per phase. If you look at the requirements of EN61000-3-3, you will see that inrush may in fact cause a voltage fluctuation that is out of compliance. There are other standards under consideration for equipment with line current greater than 16 Amps per phase. In my mind, the way to control inrush is with inductance or with one of the various soft-start circuits that are often used. -doug ================================= Douglas E. Powell Regulatory Compliance Engineer Advanced Energy Industries, Inc. 1625 Sharp Point Dr. Ft. Collins, Co 80525 mailto:[email protected] http:\\www.advanced-energy.com\ ================================= -----Original Message----- From: [email protected] [mailto:[email protected]] Sent: Thursday, June 01, 2000 7:03 AM To: [email protected] Subject: Looking for Inrush Current Standard I am looking for a standard or standards (IEC, EN or similar) which contain inrush current requirements for power supplies. The standard might require the inrush to be: <20A for 50 us<t<1.5ms, <10A for 1.5ms<t<500ms, 0.6A for t>500ms. Do any good standards exist on inrush current? Thanks, Don MacArthur ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: [email protected] Michael Garretson: [email protected] For policy questions, send mail to: Richard Nute: [email protected] ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: [email protected] Michael Garretson: [email protected] For policy questions, send mail to: Richard Nute: [email protected]
