What Size Wire for a Well Pump?
Wire and breaker sizing for a Well Pump — the typical 240V circuit, plus the code details (NEC 310.16) that change the answer.
Calculations are built on the 2023 National Electrical Code (NEC) and cross-checked against the published code tables. How we verify. Last reviewed June 2026.
Copper · typical
12 AWG
On a 20A 240V circuit at 75°C terminations.
Aluminum · typical
10
Protected by a 20A breaker (NEC 240.6).
Voltage
240V
Breaker
per HP (15–30A typical)
Connection
Hardwired
GFCI
Not required
Well Pump current varies by model. The size above is the common case — always size the conductor to the unit’s nameplate rating and protect it at the labeled maximum breaker/fuse.
Well Pump Circuit Details
- Submersible well pumps are sized to the motor FLA × 125%. A ½–1½ HP 240V pump typically uses a 15–20A circuit.
- Well runs are often long — voltage drop usually governs the wire size, so check the distance, not just the amps.
- Match the pump-control-box wiring table for the specific motor.
Long run to your well pump?
Over distance, voltage drop can require a larger wire than the table above. See the 20A wire size by distance:
Size it for your exact install
Open the calculator pre-filled with 20A at 240V to add distance, material and temperature.