Ampacity Correction factor for cable installed in cable tray

[Alexandria]

Hi,
I have a question, we are installing 3 core, 500KCMIL cable in cable tray. Cable tray is fully ventilated - ladder type. Cable is XHHW type. The ambient temp. in that particular area is 36 to 40def C, Do I need to apply temperature correction factor as per NEC table 310.15(B)(2)(a). Its a 480VAC, 3 phase system feeding to MCC.
Thanks,

 

[david luchini]

Hi,
I have a question, we are installing 3 core, 500KCMIL cable in cable tray. Cable tray is fully ventilated - ladder type. Cable is XHHW type. The ambient temp. in that particular area is 36 to 40def C, Do I need to apply temperature correction factor as per NEC table 310.15(B)(2)(a). Its a 480VAC, 3 phase system feeding to MCC.
Thanks,

Yes, I would think you need to apply ambient temperature correction factor. But, if your installation is in a dry or damp location, you could use the 90deg ampacity to apply the correction factor to.

 

[Orlyboy]

Hi,
I have a question, we are installing 3 core, 500KCMIL cable in cable tray. Cable tray is fully ventilated - ladder type. Cable is XHHW type. The ambient temp. in that particular area is 36 to 40def C, Do I need to apply temperature correction factor as per NEC table 310.15(B)(2)(a). Its a 480VAC, 3 phase system feeding to MCC.
Thanks,

I suspect you have already purchase the cable and ready to install as per your statement. Temperature correction factor consideration should be done before the cable was sized not during installation.

Yes, you should apply temperature derating factor to size the cable, also the grouping factor is a factor too.

Hope this help.

Thanks

 

[Alexandria]

I suspect you have already purchase the cable and ready to install as per your statement. Temperature correction factor consideration should be done before the cable was sized not during installation.

Yes, you should apply temperature derating factor to size the cable, also the grouping factor is a factor too.

Hope this help.

Thanks

Hi Thanks for your reply, I have considered Temperature correction factor for sizing the cable, but one of the person ask me not to consider, so want to make sure. I have not consider grouping factor, as this is a 3 core cable installed in cable tray. Thanks,

 

[kingpb]

392.22(1)(a) applies, which means single layer, and if installed with no less than 1-cable diameter between cables, than,

392.80(A)(1)(c); say's 310.15(C) temperature corrected ampacity applies.