Width = (i - 1) * s + i * 2* d + 12"

Depth = 36" + 2 * d

Here:

i is the number of MV cables in the trench,

s is the distance between the MV cables in the trench, in inches;

d is the cable diameter in inches;

12 inches is the distance from the beginning of the trench to the first cable.

Width = (i - 1) * s + i * 2* d + 6"

Depth = 36" + d

Here:

i is the number of DC Feeder cables in the trench,

s is the distance between the DC Feeder cables in the trench, in inches;

d is the cable diameter in inches;

6" is the distance from the beginning of the trench to the first cable.

Width = (i - 1) * s + i * 3* d + 3"

Depth = 24" + d

Here:

i is the number of AC Feeder cables in the trench,

s is the distance between the AC Feeder cables in the trench, in inches;

d is the cable diameter in inches;

3" is the distance from the beginning of the trench to the first cable.

Width = (i - 1) * s + i * g/2* d + 3"

Depth = 30" + 2 * d

Here:

i is the number of whip cables in the trench,

s is the distance between the whip cables in the trench, in inches;

g is the number of whips in the group, equal to 8;

d is the cable diameter in inches;

3" is the distance from the beginning of the trench to the first cable.

Width = Width Whip Trenches + Width Feeder Trenches

Depth = 30" + 2 * d

Here:

d is the cable diameter in inches.