I tend to agree with Gary that disk drives do not heft a big load change and cause flicker. I have repeatable lab test proof of this on an ITE product we make that has ten disk drives (each ranging in capacity from 9 to 50Gbytes). I have run flicker test while the box is running a program we call 'smash and hammer' which causes a lot of disk activity. This product always passes the flicker test and uses a redundant pair of hefty switch mode power supplies. On the other hand, first turn-on of this product does produce a large changing load on spinup but the test is not performed until the EUT is running normally.
Based on my experiences, I would say that these types of devices could be exempted from the test, but many times our end customers demand that these and a raft of other tests are run as a matter of routine. In my case, I can run both flicker and harmonics from the same workstation and complete the task in less than one half day. One never argues with the customer whomever they may be. Kyle Ehler [email protected] <mailto:[email protected]> Assistant Design Engineer LSI Logic Storage Systems Division 3718 N. Rock Road U.S.A. Wichita, Kansas 67226 Ph. 316 636 8657 Fax 316 636 8889 Fax 316 636 8315 -----Original Message----- From: Gary McInturff [SMTP:[email protected]] Sent: Wednesday, July 21, 1999 3:53 PM To: 'David Gelfand'; [email protected] Subject: RE: Computer classification in EN61000-3-3 IMO - Section A. List some test parameters on a variety of equipment: Photocopiers, Hairdryers or portable tools, etc and may cause voltage spikes when turned on. The test limits describe the acceptable amount of voltage drop as 3 or 4% depending( steady state and max relative voltage change). There is a time limit imposed as well, but sort of a rule of thumb if your equipment is suddenly demanding a lot of power that could cause the overhead lights to flicker (this flicker isn't always perceivable on a onsy-twosy basis) you probably need to comply to these limits. This isn't video flicker etc or switch mode power supply stuff. I don't foresee a lot of ITE equipment falling into this category. The occasionally firing of the disk drives etc shouldn't be drawing this kind of power. I have my asbestos underwear on just in case I'm wrong; somebody will let me know. Gary . -----Original Message----- From: David Gelfand [SMTP:[email protected]] Sent: Wednesday, July 21, 1999 10:27 AM To: [email protected] Subject: Re: Computer classification in EN61000-3-3 Bonjour Benoit et al, EN 61000-3-3 section 6.1 states: "Tests shall not be made on equipment which is unlikely to produce significant voltage fluctuations or flicker." How do you interpret the phrase? David. David Gelfand P.Eng Approvals Group Leader Memotec Communications Inc. Montreal Canada -----Original Message----- From: Benoit Nadeau <[email protected]> To: [email protected] <[email protected]> Date: Wednesday, July 21, 1999 12:36 PM Subject: Computer classification in EN61000-3-3 > >Bonjour de Montreal, > >After a careful reading of EN61000-3-3, we tried to identify the testing >conditions for computer devices and peripherals. Appendix A of the standard >details the conditions for various household equipments. > >In section A.11 they specify that the test condition for consumer >electronic devices is to measure only the dmax (maximum 4% of voltage >variation). > >Are computer and peripheral considered as consumer electronic device ? > >If it is the case, then we don't need a flikermeter to meet the EN61000-3-3. > >Any comments ? > > > > >-------------------------------------------------------------------------- >Benoit Nadeau, ing. M.ing. (P.Eng., M.Eng) >Gerant du Groupe Conformite (Conformity Group Manager) >Matrox <http://www.matrox.com/> >-------------------------------------------------------------------------- > >1055, boul. St-Regis >Dorval (Quebec) Canada >H9P 2T4 > >Tel : (514) 822-6000 (x2475) >FAX : (514) 822-6275 >Internet : [email protected], <mailto:[email protected]> > >--------- >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). > > > --------- 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). --------- 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). --------- 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).
