Wire size
Wire size for 200 amps
A 200 amp circuit needs 3/0 AWG copper at the 75 degree C column of NEC Table 310.16, or a larger aluminium conductor. If the terminations are only rated 60 degrees C, which is common on equipment at 100 amps or less, you need a larger conductor copper instead.
Conductor size for 200 amps
NEC 110.14(C) limits you to the lowest-rated termination in the circuit, which on most equipment at 100 amps or less is 60 °C. Check the breaker and the device before using the 75 °C column.
| Material | 60 °C | 75 °C | 90 °C |
|---|---|---|---|
| Copper | – | 3/0 | 3/0 |
| Aluminium | – | – | 4/0 |
| One-way run | Drop | Percent | Within 3% |
|---|---|---|---|
| 50 ft | 1.5 V | 0.6% | Yes |
| 100 ft | 3.1 V | 1.3% | Yes |
| 150 ft | 4.6 V | 1.9% | Yes |
| 200 ft | 6.2 V | 2.6% | Yes |
What runs on a 200 amp circuit
Standard modern dwelling service, large subpanels and shop services.
The thing to watch on this circuit
Two hundred amp services are commonly run in 2/0 copper or 4/0 aluminium. Service entrance conductors may use NEC 310.12 dwelling ratios, which permit smaller conductors than Table 310.16 alone.
Common questions
What size wire do I need for 200 amps?
- A 200 amp circuit needs 3/0 AWG copper at the 75 degree C column of NEC Table 310.16, or a larger aluminium conductor. If the terminations are only rated 60 degrees C, which is common on equipment at 100 amps or less, you need a larger conductor copper instead.
What breaker goes with a 200 amp circuit?
- A 200 amp breaker. The conductor is sized to the breaker, not the other way round, and NEC 240.4 requires the overcurrent device to protect the conductor.
How far can I run 200 amps before voltage drop matters?
- On 3/0 AWG copper at 240 volts, voltage drop reaches 0.6 percent at 50 feet and 2.6 percent at 200 feet. The NEC recommends staying under 3 percent on a branch circuit in the informational note to 210.19(A)(1), which is advice rather than a requirement, so this conductor stays inside 3 percent for all of these distances.
Can I use aluminium wire for a 200 amp circuit?
- Table 310.16 does not list an aluminium conductor small enough for this circuit, so use copper.
What is a 200 amp circuit usually for?
- Standard modern dwelling service, large subpanels and shop services.
Conductor sizes are computed from NEC Table 310.16 with the 240.4(D) small-conductor cap applied. Table 310.16 assumes not more than three current-carrying conductors at 30 °C ambient; correct for ambient (310.15(B)(1)) and conductor count (310.15(C)(1)) before use, and verify against the code edition your jurisdiction has adopted.