Guide
How to choose an extension cord safely
Choose an extension cord by indoor or outdoor rating, wire gauge, length, load, grounding, and condition rather than simply whether the plug fits.
At a glance
- Match the load
- Cord current and wattage rating must suit the connected equipment
- Use case
- Outdoor cords must be rated for outdoor use
Overview
Extension cords add resistance and can overheat when undersized, damaged, coiled under heavy load, or used beyond their rating. Longer cords generally require more attention to conductor size for high-power equipment. They should be temporary wiring, not a substitute for permanent electrical installation.
Read the cord rating
Check conductor gauge, current or wattage rating, grounding, and environmental rating. High-power heaters, tools, air conditioners, and appliances can exceed light-duty household cord capability.
Retire damaged cords
Do not use cords with cracked insulation, loose plugs, exposed conductors, melted areas, or overheating. Avoid running cords through walls, under rugs, or in places where they can be crushed or become a trip hazard.
Sources and review
MOOR's explanatory text is supported by the following source links.
- Extension Cords Fact Sheet — U.S. Consumer Product Safety Commission
- Extension Cords — Occupational Safety and Health Administration