Electric Dryer Circuit: Complete Wiring Guide
Bill of materials
Electric dryers use a 30A/240V circuit with 10 AWG copper and NEMA 14-30R receptacle. NEC 2023 added GFCI protection for laundry areas, so new dryer circuits now require a GFCI breaker.
Standard electric dryers use a 30A 240V circuit with a NEMA 14-30R receptacle (4-prong). NEC 2023 requires GFCI protection for laundry circuits per 210.8(A)(10). Use 10/3 NM-B (Romex) for short runs or 10 AWG THHN in conduit.
30A dryer circuit (standard)
| Component | Specification | NEC basis |
|---|---|---|
| Wire (copper) | 10 AWG THHN | Table 310.16, 110.14(C) |
| Wire (aluminum alt.) | 8 AWG THHN | Table 310.16, 110.14(C) |
| Breaker | 30A double-pole | 240.4 |
| Voltage | 240V single-phase | |
| Conduit (EMT) | 1/2" EMT | Chapter 9 Table 4 |
| GFCI | Required (GFCI breaker or device) | 210.8(A)(10) |
| Max distance (3% VD) | 120 ft at 240V copper | 210.19(A) Note 4 |
Installation notes
This project requires GFCI protection per NEC 210.8(A)(10). The simplest approach is a GFCI breaker at the panel, which protects the entire circuit. For 240V circuits, use a 2-pole GFCI breaker sized to match the circuit. GFCI breakers cost $40-80 depending on amperage.
For the wire run, you have two options: NM-B cable (Romex) for interior runs through framing, or individual THHN conductors in conduit for exposed runs, outdoor installations, or runs through unfinished spaces. NM-B is faster to install but cannot be used outdoors or in conduit. For conduit, use EMT (metallic) or PVC Schedule 40.
Run length matters: every foot of wire adds voltage drop, reducing power to your equipment. The table below shows the exact voltage drop at common distances. If your run exceeds the 3% threshold, upsize one gauge.
Voltage drop by distance
Percentage voltage drop at common run lengths. NEC recommends 3% maximum for branch circuits and 5% for combined feeder plus branch.
| Distance | 10 AWG Co | 8 AWG Al | 8 AWG Co |
|---|---|---|---|
| 25 ft | 0.6% | 0.6% | 0.4% |
| 50 ft | 1.2% | 1.3% | 0.8% |
| 75 ft | 1.9% | 1.9% | 1.2% |
| 100 ft | 2.5% | 2.6% | 1.6% |
| 150 ft | 3.7% | 3.8% | 2.3% |
| 200 ft | 5.0% | 5.1% | 3.1% |
Common products for 10 AWG Copper circuits
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Related wire data
Detailed ampacity: 10 AWG copper, 8 AWG aluminum. Wire size lookup: 30A circuit. Calculators: voltage drop · panel load calculator.
Frequently asked questions
What wire size do I need for electric dryer circuit?
Use 10 AWG copper or 8 AWG aluminum on a 30A breaker at 240V. This is based on NEC 2023 Table 310.16 ampacity with 110.14(C) termination limits. The equipment nameplate or installation manual sets the minimum circuit ampacity and maximum breaker; follow it where it differs.
Does electric dryer circuit require GFCI?
Yes. GFCI protection is required per NEC 210.8(A)(10).
NEC 2023 references verified February 2026