Ground Wire Size for a 200 Amp Panel
Free online tool • 2026 NEC Compliant
A 200-amp electrical service panel requires two different grounding conductors, each sized differently. The Grounding Electrode Conductor (GEC) connects the panel to ground rods or the water pipe and is sized by Table 250.66. The Equipment Grounding Conductor (EGC) that runs in feeders is sized by Table 250.122. Use the calculator to determine the correct size for each conductor type.
Select the rating of the circuit breaker or fuse protecting this branch circuit or feeder.
Minimum Required Size
NEC Table 250.122copper · Equipment Grounding Conductor (EGC)
NEC Table 250.122 Reference Table (Copper)
| OCD Rating | Min Copper Size |
|---|---|
| 15 A | 14 AWG |
| 20 A | 12 AWG |
| 30 A | 10 AWG |
| 40 A | 10 AWG |
| 60 A | 10 AWG |
| 100 A | 8 AWG |
| 200 A | 6 AWG |
| 300 A | 4 AWG |
| 400 A | 3 AWG |
| 500 A | 2 AWG |
| 600 A | 1 AWG |
| 800 A | 1/0 AWG |
| 1000 A | 2/0 AWG |
| 1200 A | 3/0 AWG |
| 1600 A | 4/0 AWG |
| 2000 A | 250 kcmil |
NEC Reference: The EGC runs with the branch circuit or feeder. For a 20 A overcurrent device, use minimum 12 AWG copper wire.
How to Use This Calculator
Select GEC or EGC mode
GEC for service-to-earth, EGC for panel-to-sub-panel feeder.
For GEC: select service size
Choose your service entrance conductor size (typically 2/0 AWG Cu for 200A service).
For EGC: select 200A OCD
Select 200A from the overcurrent device dropdown.
Choose conductor material
Select copper or aluminum.
Frequently Asked Questions
What size GEC do I need for a 200 amp panel?
For a 200A panel with typical 2/0 AWG copper service entrance conductors, NEC Table 250.66 requires a minimum 4 AWG copper GEC (or 2 AWG aluminum). If the service uses 4/0 AWG or larger, the GEC requirement increases to 2 AWG copper.
What size EGC wire for a 200 amp sub-panel?
Per NEC Table 250.122, the EGC for a 200A overcurrent device is minimum 6 AWG copper or 4 AWG aluminum.
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