Kelly, For another, possibly different point of view, you might consider contacting the good folks at the NFPA, who write the NEC for their interpretation.
Regards, Kaz Gawrzyjal [email protected] -----Original Message----- From: [email protected] [mailto:[email protected]] Sent: Friday, March 10, 2000 8:12 AM To: Kelly Tsudama Cc: [email protected] Subject: Re: Correction factor for power supply cords. Kelly: The NEC is written to keep structures safe. Flexible cords used in structures are normally used in free air. If you are using a flexible cord in equipment, you need to rate its ampacity in accordance with whatever standard you are using. The NEC relies on the NRTL label and testing for the safety of equipment. If you are using a flexible cord in a high ambient I would contact the mfg for the appropriate derating. Kelly Tsudama <[email protected]> on 03/09/2000 09:33:14 PM Please respond to Kelly Tsudama <[email protected]> To: [email protected] cc: (bcc: Ed Rauch/MAIN/MC1) Subject: Correction factor for power supply cords. Hi Group I am hoping that I can get your opinions with an issue regarding the correction factor of power supply cords. For instance, in the NEC table 310-17, for single conductors in free air, there is a chart at the bottom of the table that allows you to determine how to factor in the ambient temperature. However, for a flexible power cord, the table 400-5 does not have any correction factor table. At first I thought that this is because cords always have a temperature rating marked on them, but then I recall that most (if not all) single conductors have this marking too.... Is there a need to "de-rate" a power cord's current rating based on the expected ambient temperature? If so, where in the NEC did I miss this fact? If not, why not? Thanks for your help, Kelly **************************************************************** Kelly Tsudama Cisco Systems [email protected] 408-527-0216 408-525-9150 fax 408-322-9024 pager ------------------------------------------- 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]
