Cable Tray capacity

[donaldok]

How many type TC 10-3 cables can I fit in a 24" wide ladder cable tray ?

My calculations are; 10-3 TC dia =.488in X 3.14 = 1.532" area per cable;

capacity fill of 24" wide ladder tray = 28 sq.in.

28 sq. in. / 1.532 = 18 - 10-3 Tray cables.

Is this calculation correct as the tray seems to be very empty with only 18 cables in it ?
Can I somehow install more cables ??

Thanks

 

[websparky]

Re: Cable Tray capacity

Isn't it radius x pie?
10-3 TC dia =.244in X 3.14 = .766" area per cable

 

[wirenut1980]

Re: Cable Tray capacity

Cross sectional area of a conductor is pi* radius^2

 

[petersonra]

Re: Cable Tray capacity

Originally posted by websparky:
Isn't it radius x pie?
10-3 TC dia =.244in X 3.14 = .766" area per cable

if the radius is .244 then cross sectional area is

.244*.244*PI = .187 sq inches

 

[john m. caloggero]

Re: Cable Tray capacity

Section 392.9(A)(2) provides the requirements for the number of 4/0 and smaller cables allowed in a cable tray. If the diameter is .488 inches, the area = pi x R^2 = 3.14 x .244 x .244 = .1869 sq. inches. According to Table 392.9, a 24 inch wide cable tray is allowed to have a fill of 28 sq in.
Divide 28 by .1869 = 149 cables. Remember to see section 392.11(A) for the current carrying capacity of the cables.