Hi all, I have two questions regarding cable trays.
I can size the cable tray with one of the four cases that NEC describes, but I think theres one case missing, and that is mixing cables from 1/0 up to 1000kcm.
For example, say I have 6-3/0 cables and 6-300kcm cables. I can assume that, by using the "equation":
A ? (1.1 Sd)
And making "Sd=0" (because theres no 1000kcm or bigger cables), I can use case 2.
Is that rigth? or how do you size the cable tray?
Also, NEC also states that if you bundle conductors they can be "installed in other than a single layer", so, if you dont want the ampacity increase by spacing them 2.15 times the OD, Can you place the bundled conductors without spacing and use 310.17 ampacities multiplied by 0.65?
I can size the cable tray with one of the four cases that NEC describes, but I think theres one case missing, and that is mixing cables from 1/0 up to 1000kcm.
For example, say I have 6-3/0 cables and 6-300kcm cables. I can assume that, by using the "equation":
A ? (1.1 Sd)
And making "Sd=0" (because theres no 1000kcm or bigger cables), I can use case 2.
Is that rigth? or how do you size the cable tray?
Also, NEC also states that if you bundle conductors they can be "installed in other than a single layer", so, if you dont want the ampacity increase by spacing them 2.15 times the OD, Can you place the bundled conductors without spacing and use 310.17 ampacities multiplied by 0.65?