Selecting the right gauge wire for an outdoor outlet is important for safety and performance. The gauge of wire determines how much electric current it can carry and the correct gauge prevents overheating and electrical fires. This guide will walk you through the key factors to consider when choosing what gauge wire to use for your outdoor outlet.
Introduction
Outdoor outlets are convenient for powering lawn tools, holiday lights, irrigation systems and more. But the wiring needs to be robust enough to handle environmental factors like rain, snow and temperature extremes. Choosing the right gauge wire prevents electrical issues down the road.
Generally, larger gauge numbers indicate thinner wires, while smaller gauge numbers are thicker wires. Thicker wires can carry more current. When selecting your wire gauge, consider the following factors:
Electrical Load
How much power will your outdoor outlet need to supply? Are you just plugging in a couple of landscape lights? Running power tools for home improvement projects? Connecting a hot tub or irrigation system? The wiring must be robust enough to handle the amps required, without overheating.
Wire Run Length
The longer the wire run from your electrical panel to the outlet, the thicker the gauge you’ll need. Longer wire lengths cause voltage drop, so thicker wires help compensate.
Number of Outlets
If you’re wiring multiple outdoor outlets, go with a thicker gauge. More outlets pull more power along the length.
Budget
Thicker gauge wires cost more than thin wires. Factor your budget into the decision when choosing between two possible gauges.
Recommended Gauges
Here are the commonly recommended wire gauges for standard 120V outdoor outlets:
Up to 50 Feet
For wire runs up to 50 feet from the electrical panel, 12 AWG is usually sufficient for most outdoor outlet needs. This will cover moderate power requirements.
50 to 100 Feet
For wire runs between 50 to 100 feet, 10 AWG wire is better suited for the longer distances.
Over 100 Feet
For very long wire runs over 100 feet from the panel, 8 AWG is the recommended gauge to handle the voltage drop.
High Power Devices
For outlets powering high draw equipment like multiple tools, hot tubs, pumps, heaters, etc., go one gauge thicker than the run length requires. For example use 10 AWG for a 50 foot run instead of 12 AWG.
Multiple Outlets
When wiring more than one outlet, increase the gauge if the total length for all outlets will be over 50 feet. For example, for two outlets at 75 feet total run length, use 10 AWG instead of 12 AWG.
Ground Wire
The ground wire should always match the gauge of the hot and neutral current carrying wires.
Other Considerations
- Use only copper wiring for outdoor outlets, not aluminum. Copper stands up to weather and soil better.
- Use exterior rated wiring with water-resistant outer sheathing. Regular indoor Romex will deteriorate outside.
- Use wiring approved for direct burial if not running through conduit.
- Use GFCI protected outlets for health and safety, especially near wet areas.
- Consider tamper-resistant outlets if small children may be around.
- A dedicated circuit just for outdoor outlets is ideal, shared only with other exterior wiring.
- Always shut off the circuit breaker before doing any work.
Conclusion
Choosing the proper gauge wire for outdoor outlets comes down to the run length, number of outlets, amp rating of devices used, and your budget. With some planning, you can determine the ideal wire thickness for your specific needs. Proper outdoor wiring will provide years of safely powering your exterior activities and enhancements. Just be sure to shut off the power and take all safety precautions when installing electrical wiring.