Cable Tray spacing 1

[fjconair]

Good day as to article 392 am I to understand that multiconductor 2001 volt and above require one cable spacing between each other, but what if their ampacity meet table 310.60.
This questioned posed due to Client comment for said applications, I am told to run these cables side by side?, see N.E.C. Article
392-80(B)(1)(b)

 

[7anoter4]

First of all –I think-art. 392.80 it is a new article in 2014 Edition.
IMO art. 392.80(B)(1)(b) permits an elevated ampacity if the cable are laid keeping one diameter clearance [310.60(c)71/72].
If you cannot keep a cable diameter clearance the permissible ampacity will be as per Table 310.60(c)75/76 [approx. 10% less].

 

[fjconair]

Good day sir your reply is correct for 2000v or less applications however I am looking for
2000v and over. You still receive a star for effort.

 

[7anoter4]

Thank you, fjconair. You are right the part B (2) it is the relevant part for type MV and MC cable (2001 V and over).
Here NEC states for single-core cable if you cannot keep the recommended distance the allowable ampacity is only 75% of the allowable in Table 310.60(C)(69) and Table 310.60(C)(70).Let’s say for 4/0 AWG MV-90 copper conductor will be 400*0.75=300 A
When keeping the indicated free air space [one cable diameter in a single layer] ampacity according to 310.60(C)(69) and Table 310.60(C)(70).For 4/0 AWG –as in above example-ampacity will be 400 A.
For triangular or square configuration keeping 2.15 times the diameter Table 310.60(C)(67) and Table 310.60(C)(68).For 4/0 2001-5000 V 335 A and for 5001-35000 V 345 A.

 

[fjconair]

let me restate my question as to article 392 am I to understand that multiconductor 2001 volt and above require one cable spacing between each other, but what if their ampacity meet table 310.60. this is all I am look for other parts of the code are clearly
called except the item.