Calculate Wire Size Needed

Calculate Wire Size Needed

“Voltage Drop Index” method:

 

Amps x Distance (one way)  /  Voltage x Percent Loss = VDI

 

Voltage Drop Index Gauge
VDI Gauge
1 = # 16
2 = # 14
3 = # 12
5 = # 10
8 = # 8
12 = # 6
20 = # 4
34 = # 2
49 = # 1/0
62 = # 2/0
78 = #3/0
99 =# 4/0

 

For example, 

10 Amps Current
100 Feet one-way distance
24 Volt system
2% Loss

Calculate,

10 x 100   = 20.83
24 x 2

Use #4 Wire