Electrical Safety
Extension Cord
Safety
Safety
OSHA 1926.403 · OSHA 1926.405 · NYC Electrical Code §590 · Hard-Service Cords Required
Extension cords on construction sites take a beating — they're driven over, pinched in doors, pulled through sharp conduit edges, and left on wet ground. Despite this abuse, they're often the afterthought of site safety. Every misused extension cord is a potential electrocution, fire, or arc flash waiting to happen.
Selecting the Right Cord
- Hard-service cords required on construction sites: SJTOW, SOOW, or equivalent — light-duty household cords (SPT, zip cord) are prohibited
- Ampacity must match or exceed the load — check the tool's nameplate amperage and the cord jacket label
- For 100+ foot runs: use a cord one gauge heavier (e.g., 12 AWG instead of 14 AWG) to compensate for voltage drop
- Never exceed the cord's rated ampacity — undersized cords overheat, melt insulation, and start fires
Damage That Requires Immediate Retirement
- Any cut, puncture, or abrasion that exposes the conductor or inner insulation
- A missing or bent ground pin on the plug
- Damaged, cracked, or melted plug housing or connector body
- Cord that has been spliced with electrical tape — no spliced cords allowed on construction sites
- Kinking or sharp bends that have stressed the internal conductors
NYC Site Rules
- All cords must have GFCI protection at the source — verified monthly with the TEST button
- Three-to-two prong adapters ("cheater plugs") are prohibited — no exceptions
- Cords must be unplugged at end of each shift — not left energized overnight
- Label damaged cords with red tape and remove from service — do not leave for "someone else to deal with"
Discussion Questions
- Can you use a standard household extension cord (SPT) on a construction site? Why or why not?
- You have a 100-foot run to a 15-amp tool. The tool's manual says use a minimum 14 AWG cord at 100 feet. What gauge would you actually use and why?
- A cord with electrical tape over a middle section: acceptable or not? What do you do with it?
- What does SJTOW mean on an extension cord jacket, and why does the "O" matter on a construction site?
Sign-Off
Project Address
Date
Time
Foreman / Supervisor
SSM / SSC Name & License No.
Worker Attendance
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