Electrical — FAQ
What gauge extension cord do contractors need?
Most contractor tools require 12-gauge cords to safely deliver 15 amps without voltage drop. Circular saws, compressors, and hammer drills pull high startup current that thinner cords can't handle. For light-duty work like charging batteries, 14-gauge suffices.
What does SJTW mean on extension cords?
SJTW stands for Service Junior Thermoplastic Water-resistant. This designation means the cord handles hard use, resists moisture, and suits outdoor applications. It's the minimum rating OSHA accepts for construction sites. Always verify the jacket is marked SJTW, not just SJT.
Are lighted ends worth the extra cost?
Absolutely. Lighted connectors provide instant power verification without testing tools. On busy jobsites, visual confirmation prevents accidental disconnects and speeds troubleshooting when breakers trip. The tiny LED draws negligible power but saves hours of frustration.
Can I connect multiple extension cords together?
OSHA prohibits connecting multiple cords on construction sites due to voltage drop and connection failure risks. Each connection adds resistance and potential failure points. Instead, carry appropriate lengths or use a single longer cord. If you must connect, keep total length under 100 feet and use same-gauge cords.
How do I store extension cords for maximum lifespan?
Coil cords in large loops (3-foot diameter) to prevent kinking. Store indoors or in weatherproof boxes to protect connectors from moisture. Hang rather than pile to prevent weight compression. Inspect monthly for cuts, especially near connectors. Replace immediately if copper shows through jacket.
What's the difference between UL and ETL listing?
Both indicate compliance with OSHA safety standards. UL (Underwriters Laboratories) and ETL (Intertek) test to the same NEC requirements. ETL is often faster and less expensive for manufacturers, potentially saving contractors money. Both listings are legally equivalent and OSHA-accepted.
