Hi Dan, We use UL 1450 Motor Operated Air Compressors, and here is the definition of constant temperatures:
46.1.11 With reference to those tests that are to be continued until constant temperatures are attained, thermal equilibrium is considered to exist when three successive readings taken at intervals of 10 percent of the previously elapsed duration of the test, but not less than 5-minute intervals, indicate no change. Ray -----Original Message----- From: Joshua Wiseman [mailto:[email protected]] Sent: Wednesday, June 28, 2000 2:39 PM To: 'Dan Mitchell'; [email protected] Subject: RE: UL1950/UL2601 Thermals 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:[email protected] <mailto:[email protected]> ] Sent: Wednesday, June 28, 2000 8:32 AM To: [email protected] 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: [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]
