Grounding Wire Size Calculator
The ElectriCalc Pro electrical calculator easily calculates grounding conductor wire sizes.
You can use single or multiple service entrance conductors to find the grounding electrode conductor for AC systems.
When using multiple conductors, the ElectriCalc Pro uses the equivalent Circular Mils to
find the grounding electrode conductor based on NEC® table 250-66
How To Find Grounding Conductor Wire Size
The example below shows how to calculate the ground wire size required when 2/0 is the largest 3-phase 75°
copper service entrance conductor being used. It also shows how to find the equivalent aluminum
wire size, and equivalent Circular Mils.
Steps |
Keystrokes |
Display |
1: Clear calculator |
On/C
On/C
|
|
2: Set to 3-phase |
Set
3
|
|
3: Set to 75° C |
Set
7
|
|
4: Enter wire size (12) |
1
2
WireSz
|
|
5: Find ground wire size |
Grnd
|
|
6: Find aluminum ground wire size |
Grnd
|
|
7: Find Circular Mils |
Grnd
|
|
8: Display NEC Table |
Grnd
|
|
Note that wire size can also be entered in Circular Mils (e.g.,
1
3
3
1
0
0
WireSz enters 133,100 CMILs and displays 00 AWG Wire Size).
|
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