Cable Insulation Class in Cable tray

[G Loh]

I thought that every cable in a cable tray needs to have the same voltage class. For example, I could have two cable in the same tray, one could be 480V and the other 15kV, as long as both cables had the same insulation voltage class (15kv in this example) the installation would be per the NEC. I'm not able to find this in the NEC. Did I dream this up or does someone know where in the NEC this requirement is stated.

Thank you for any help.

 

[Julius Right]

In my opinion, it is about Art.392.20 Cable and Conductor Installation (B) Cables Rated Over 600 Volts.
? Cables rated over 600 volts and those rated 600 volts or less installed in the same cable tray shall comply with either of the following:
(1) The cables rated over 600 volts are Type MC.
(2) The cables rated over 600 volts are separated from the cables rated 600 volts or less by a solid fixed barrier of a material compatible with the cable tray.?

 

[Julius Right]

By-the-way, in my opinion, NEC is referred to "insulation rated" and not to the voltage supplied through. Then, from NEC point of view if the cable of 15 kV rated insulation it is operated at 480 V this cable remains still 15kV rated [over 600 V].

 

[MasterTheNEC]

392.20 Cable and Conductor Installation.
(A) Multiconductor Cables Operating at 600 Volts or
Less. Multiconductor cables operating at 600 volts or less
shall be permitted to be installed in the same tray.


(B) Cables Operating at Over 600 Volts. Cables operating
at over 600 volts and those operating at 600 volts or
less installed in the same cable tray shall comply with either
of the following:
(1) The cables operating at over 600 volts are Type MC.
(2) The cables operating at over 600 volts are separated from
the cables operating at 600 volts or less by a solid fixed
barrier of a material compatible with the cable tray.

Just wanted to update to what the 2014 NEC changed.

 

[Julius Right]

Thank you MasterTheNEC. These changes are from December 2014, indeed.:ashamed1: