Wire Size GuideNEC 2023 · 2026 · Updated Apr 2026

What wire size for a 175 amp circuit?

Q: What is the minimum wire size for a 175 amp circuit?

The minimum wire size is 2/0 AWG copper or 4/0 AWG aluminum per NEC 2023 Table 310.16 with 110.14(C) termination limits applied. For long runs, you may need to upsize to account for voltage drop. See the max distance table above.

Q: Can I use aluminum wire for a 175 amp circuit?

Yes. 4/0 AWG aluminum handles 175A. Aluminum requires anti-oxidant compound and AL-rated terminals (marked AL/CU on the device). It costs roughly 40-60% less than copper but requires a larger gauge for equivalent ampacity. See the 2/0 AWG copper vs aluminum comparison.

Q: How far can I run 2/0 AWG wire on a 175 amp circuit?

At 240V, 2/0 AWG copper can run approximately 212 feet before exceeding the 3% voltage drop recommendation. For longer distances, upsize to the next gauge. Use the voltage drop calculator for your exact scenario.

Q: What breaker size for a 175 amp circuit?

Use a 175A breaker. The breaker must match the circuit rating, not the wire ampacity. For continuous loads (like EV chargers), the breaker must be rated at 125% of the load per NEC 210.19(A)(1).

For a 175A circuit on a 175A breaker: Use 2/0 AWG copper (175A capacity) or 4/0 AWG aluminum (180A capacity). Common applications: large subpanels and feeders where 150A is insufficient but 200A is oversized.

Copper2/0 AWG

Aluminum4/0 AWG

Breaker175A

Voltage240V

All valid wire sizes for a 175 amp circuit

A 175 amp feeder bridges the gap between 150A and 200A service sizes. The minimum wire is 2/0 AWG copper or 4/0 AWG aluminum. This size is common for large detached buildings and commercial feeders.

175A is a standard breaker size per NEC 240.6(A). At this amperage, aluminum feeders provide significant cost savings: 4/0 aluminum costs roughly 40% of equivalent copper. Verify voltage drop on runs over 75 feet.

Any gauge with ampacity equal to or greater than 175A per NEC 2023 Table 310.16, after 110.14(C) termination limits are applied. Smaller gauge number means thicker wire, higher cost, but lower voltage drop.

Gauge	Material	Capacity	Max distance (3% drop)	Conduit
2/0 AWG (minimum)	Copper	175A	212 ft	1-1/2" EMT
3/0 AWG	Copper	200A	267 ft	2" EMT
4/0 AWG	Copper	230A	337 ft	2" EMT
4/0 AWG (minimum)	Aluminum	180A	205 ft	2" EMT
1/0 AWG (310.15(B)(7))	Copper	175A	168 ft	1-1/2" EMT
3/0 AWG (310.15(B)(7))	Aluminum	175A	163 ft	1-1/2" EMT

Maximum wire run distance

One-way distance in feet before voltage drop exceeds 3%, per NEC Chapter 9 Table 8 resistance values. If your run is longer than these distances, upsize one gauge.

Gauge	Material	120V	208V	240V	480V
2/0 AWG	Copper	106 ft	184 ft	212 ft	422 ft
3/0 AWG	Copper	134 ft	232 ft	267 ft	535 ft
4/0 AWG	Copper	169 ft	294 ft	337 ft	681 ft
4/0 AWG	Aluminum	102 ft	178 ft	205 ft	410 ft
1/0 AWG	Copper	84 ft	146 ft	168 ft	337 ft
3/0 AWG	Aluminum	81 ft	141 ft	163 ft	326 ft

Common 175A circuit projects

175A subpanel
large detached building
commercial feeder

Frequently asked questions

What is the minimum wire size for a 175 amp circuit?

The minimum wire size is 2/0 AWG copper or 4/0 AWG aluminum per NEC 2023 Table 310.16 with 110.14(C) termination limits applied. For long runs, you may need to upsize to account for voltage drop. See the max distance table above.

Can I use aluminum wire for a 175 amp circuit?

Yes. 4/0 AWG aluminum handles 175A. Aluminum requires anti-oxidant compound and AL-rated terminals (marked AL/CU on the device). It costs roughly 40-60% less than copper but requires a larger gauge for equivalent ampacity. See the 2/0 AWG copper vs aluminum comparison.

How far can I run 2/0 AWG wire on a 175 amp circuit?

At 240V, 2/0 AWG copper can run approximately 212 feet before exceeding the 3% voltage drop recommendation. For longer distances, upsize to the next gauge. Use the voltage drop calculator for your exact scenario.

What breaker size for a 175 amp circuit?

Use a 175A breaker. The breaker must match the circuit rating, not the wire ampacity. For continuous loads (like EV chargers), the breaker must be rated at 125% of the load per NEC 210.19(A)(1).

Do I need GFCI on a 175 amp circuit?

GFCI requirements depend on location, not amperage. NEC 2023 requires GFCI in kitchens, bathrooms, garages, outdoors, basements, laundry areas, and near sinks. Check the GFCI requirements by room for your specific installation.

Common products for 2/0 AWG Copper circuits

🧵Wire2/0 AWG copperCheck prices on Amazon (paid link) ⚡200A SubpanelFor 2/0 AWG feeder circuitsCheck prices on Amazon (paid link) 📏Conduit1-1/2" EMT for 2/0 AWGCheck prices on Amazon (paid link)

As an Amazon Associate we earn from qualifying purchases.

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Important: For reference only. Not a substitute for a licensed electrician. Electrical work can cause serious injury, death, fire, or property damage if performed incorrectly. Always hire a licensed electrician for electrical work, especially for service upgrades, panel work, and 240V circuits. Values are derived from NFPA 70 (NEC) for educational purposes. Always verify against your locally adopted NEC edition and amendments - local jurisdictions may enforce stricter requirements. WireRef provides reference information only and is not responsible for work performed based on this content. NEC® is a registered trademark of the National Fire Protection Association. Free NEC access via NFPA · OSHA Electrical Safety · Terms of use.

NEC 2023 references verified April 2026