bdm5066
Member
- Location
- Pittsburgh, PA
My application involves 10 sets of 3 single-conductor, 500kcmil, 5kV cable in a 36” cable tray. These cables have a diameter of 1.26”. Each triplexed set of cables has a #1/0 ground with an OD of .48”.
NEC 392.22(C) states the following:
I take this to mean that we sum the diameters of all of our cables (10 x 3 x 1.26 + 10 x .48 = 42.6”). Therefore we’re over the 36” limit.
However, one my colleagues disagrees. His interpretation is that you total the diameters of only the bottom layer when you have triplexed, single conductor cables. In other words, only the blue lines in the below sketch would be counted.
Point being, what's your interpretation of the above issue?
NEC 392.22(C) states the following:
The sum of the diameters of single-conductor and multi-conductor cables shall not exceed the cable tray width, and the cables shall be installed in a single layer. Where single conductor cables are triplexed, quadruplexed, or bound together in circuit groups, the sum of the diameters of the single conductors shall not exceed the cable tray width, and these groups shall be installed in a single layer arrangement.
I take this to mean that we sum the diameters of all of our cables (10 x 3 x 1.26 + 10 x .48 = 42.6”). Therefore we’re over the 36” limit.
However, one my colleagues disagrees. His interpretation is that you total the diameters of only the bottom layer when you have triplexed, single conductor cables. In other words, only the blue lines in the below sketch would be counted.
Point being, what's your interpretation of the above issue?