Gasboy 9120K Series Installation - Manual (Page 18)

Wiring Conduit
Page 14 MDE-4567C 9120K and 9820K Series AST Pumps Installation and Operation Manual · September 2008
Conduit Size Charts
To determine conduit size needed, use the THHN/THWN Wire Areas chart (first chart) to find
the area for each wire gauge. Add up all wire areas. Use the Areas of Trade Size Conduit chart
(second chart) to select the smallest number in the 25% fill area (based on NEC 501-1) that
comes closest without exceeding the total wire area.
THHN/THWN Wire Areas
Gauge
Diameter Area (square units)
Inches Millimeters Inches Millimeters
18 0.090 2.29 0.007 4.1
16 0.104 2.64 0.009 5.5
14 0.118 2.95 0.011 6.8
12 0.135 3.43 0.014 9.2
10 0.169 4.29 0.022 14.5
8 0.216 5.49 0.037 23.7
6 0.259 6.60 0.053 34.2
4 0.331 8.41 0.086 55.5
3 0.359 9.14 0.102 65.6
2 0.394 10.01 0.122 78.7
1063A 0.417 10.59 0.137 88.4
Areas of Trade-Size Conduit
Trade Size
Internal Diameter Area (square units) Fill Area (square units) 25% Fill
Inches Millimeters Inches Millimeters Inches Millimeters
1/2 0.629 16 0.303 196 0.076 49
3/4 0.826 21 0.532 343 0.133 86
1 1.063 27 0.862 556 0.215 139
1-1/4 1.378 35 1.50 968 0.375 242
1-1/2 1.614 41 2.04 1314 0.509 329
2 2.087 53 3.36 2165 0.839 541