Long Distance Wire Runs
Long electrical wire runs present unique challenges due to voltage drop. As distance increases, wire resistance causes voltage loss that can affect equipment performance and efficiency.
Why Long Runs Are Different
Distance directly impacts wire sizing requirements:
- Voltage drop increases with wire length
- Longer runs require larger wire gauges
- Cost increases significantly for long runs
- Planning is critical for efficiency
Calculating for Long Runs
Always calculate voltage drop for runs exceeding 50 feet:
- Use the voltage drop formula: VD = 2 × I × R × L
- Keep drop under 3% for branch circuits
- Keep total drop under 5% including feeder
Wire Size Adjustments
Upsize wire gauge to compensate for long distances.
Distance Guidelines
Under 50 ft: Standard sizing. 50-100 ft: May need 1 gauge larger. 100-150 ft: Likely need 1-2 gauges larger. Over 150 ft: Calculate carefully.
Common Long Run Applications
These applications often require long wire runs:
- Detached garages and workshops
- Well pumps and irrigation systems
- Outdoor lighting and landscape lighting
- Barn and outbuilding power
Cost Considerations
Balance wire cost against efficiency losses from voltage drop.
Important
Never sacrifice safety for cost savings. Undersized wire on long runs wastes energy and can damage equipment.
Conclusion
Long distance wire runs require careful planning and proper sizing. Always calculate voltage drop and upsize wire as needed to ensure efficient, code-compliant installations.
Use our Voltage Drop Calculator to determine correct wire size for any distance.