68 Power conductors
The formula
The following formula may be used to calculate the minimum wire size in
Circular Mils (CM) required to connect any two points knowing current,
distance and the desired drop for a specific cable:
CM=
11.1x
Ix D/V
where:
CM = wire size required in Circular Mils
I = current in amps (use the maximum expected)
D = distance in feet
V = Allowable voltage drop.
Typical wire values
The following are typical values for circular mils and nominal maximum
current for some of the more common wire sizes.
Table 20
Wire characteristics
Wire gauge Circhlils A max
441,750 90
6
26,250 65
816,510 50
10
10,380 35
12
6,530 25
Note: Maximum amperage is affected by many factors induding temperature
and insulation. Consult a wire handbook for precise tables.
Power engineering 553-3001-l 52
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