Well Pump Electrical Requirements

Voltage Requirements

Common Voltages

Why 230V Is Standard

• Lower current = smaller wire needed
• Less voltage drop over distance
• More efficient for motors
• Standard in residential panels

Voltage Tolerance

• Pumps accept ±10% of rated voltage
• 230V pump: 207V to 253V acceptable
• Below minimum: motor overheats
• Above maximum: insulation damage

Check Nameplate

• Always verify pump voltage rating
• Match to your electrical service
• Don't guess—damage results

Breaker Sizing

General Guidelines

These are guidelines. Always use manufacturer specifications.

Sizing Method

• Find motor Full Load Amps (FLA) on nameplate
• Multiply FLA × 1.25 for wire sizing
• Breaker per NEC Article 430
• Consult electrician for exact sizing

Double-Pole Breaker

• 230V requires double-pole breaker
• Both hot legs protected
• Common handle tie

Wire Sizing

Distance Matters

• Wire must reach pump + length in well
• Long runs need larger wire
• Voltage drop increases with distance
• Too much drop = motor damage

Wire Size Chart (230V)

Check manufacturer wire chart for your specific pump.

Submersible Wire Types

• UF-B: Underground feeder (to well)
• Submersible cable: Inside well (water-resistant)
• Splice at wellhead properly

Voltage Drop

• Max 5% drop is standard
• Calculate using motor FLA and distance
• Use online calculator or chart
• When in doubt, go one size larger

Code Requirements

NEC Articles

• Article 430: Motors
• Article 680: Swimming pools/spas (if applicable)
• Local codes may be stricter

Common Requirements

• Dedicated circuit for pump
• Disconnect within sight of pump
• Ground wire required
• Motor protection (may be required)

Permit Requirements

• Many areas require electrical permit
• Licensed electrician may be required
• Inspection before covering

Grounding

• Equipment ground to panel
• Grounding electrode at well (may be required)
• Critical for safety

We service all major pump brands including Franklin Electric, Grundfos, Goulds (Xylem), and Sta-Rite (Pentair). Our trucks carry common parts and components for same-day repairs.

Frequently Asked Questions

What voltage do well pumps use?

Most residential: 230V. Small pumps under 1/2 HP may be 115V. Check your pump nameplate.

What size breaker do I need for a well pump?

Typically 15-30A depending on HP. 1 HP pump usually 20A breaker. Use manufacturer specs and motor FLA.

Why does my pump keep tripping the breaker?

Could be: undersized breaker, bad pump motor, voltage issues, wiring problem. Have it diagnosed—don't just upsize breaker.

Can I use extension cord for well pump?

No—pumps need dedicated, properly sized circuit. Extension cords cause voltage drop and fire risk.

What happens if wire is too small?

Voltage drop, motor overheating, shortened pump life, potential fire hazard. Always use correct size.