Regarding UL1950, IEC950, etc. I can't find proof either. Although I have been told by several agencies the same thing 1 degree C over 15 minutes. I too am curious to see this in writing.
Josh -----Original Message----- From: Dan Mitchell [mailto:dan_mitch...@condordc.com] Sent: Wednesday, June 28, 2000 8:32 AM To: emc-p...@ieee.org Subject: UL1950/UL2601 Thermals In UL2601 Clause 42.3.3) Duty Cycle - for Equipment for Continuous operation it lists 2 ways to conclude the test a) temperature of the windings stabilize and do not increase by more than 2 deg. C in 1 hr, or b) 2.5 hr, which ever is shorter. UL1950 only states that; "for continuous operation, until steady conditions are established". I haven't been able to establish what is meant by "Steady Conditions". I was told once by a rep. of a large safety company that it meant "no more than a 1 deg. C rise in 15 minute period". However, since I can't find this written in the standard, I am a bit skeptical. If anybody has a good definition of "Steady Conditions" and can point it out to me in UL1950 or in the PAGs, I would appreciate it. Daniel W. Mitchell Product Safety Engineer Condor DC Power Supplies, Inc. P: (805) 486-4565 x323 F: (805) 483-4307 ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson: pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
