is the bus duct have derating factor ?????
 

is there is derating factor for the bus duct like cables or no
and what standard code menti**ed that ?>>
thnx

[CENTER][SIZE=6][COLOR=Red][B]al salamo alykom
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[B]yes dear [/B] : [SIZE=4]there is [URL="http://www.ieees.com/url.php?ref=http://www.ieees.com/showthread.php?t=2120"] derating [/URL] [URL="http://www.ieees.com/url.php?ref=http://www.ieees.com/showthread.php?t=2120"] factor [/URL] for the bus [URL="http://www.ieees.com/url.php?ref=http://www.ieees.com/showthread.php?t=2120"] duct [/URL] like cables

[/SIZE][SIZE=2]bus duct are capable of carrying full rated current c**tinuously in ambient c**diti** of 95% relative humidity and maximum temperature of 50 0C without exceeding 55 0C temperature rise. When installed in higher ambient temperature, the busduct current rating shall be derated according to factors related to the ambient temperature mainly.
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[U]bus duct is treated as the folowing[/U]
[SIZE=1][COLOR=#000000][LIST][*] [SIZE=2]Higher efficiency in power transmissi** / distributi**. [/SIZE][*] [SIZE=2]Lower cost of installati**. [/SIZE][*] [SIZE=2]Easier maintenance. [/SIZE][*] [SIZE=2]**** compact and suitable for tight plant room space. [/SIZE][*] [SIZE=2]Higher reliability. [/SIZE][*] [SIZE=2]L**ger life span. [/SIZE][*] [SIZE=2]Higher flexibility for future expansi**. [/SIZE][*] [SIZE=2]Extremely high short circuit current ratings. (100kA for 3 sec**ds) [/SIZE][*] [SIZE=2]Extrmely flexible in installati**.[/SIZE][/LIST][B][SIZE=4]****over it is limited use in egypt[/SIZE][/B]
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TAHIYATI[/SIZE][/B][/COLOR]
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شكررررررررررررا

thnx so much for ur help but can u tell me what will be the factors if the ambient temp is above 55 c