Ground faults are one of the most common electrical hazards on construction sites, and one of the most preventable.
If you have temporary power, wet conditions, rough handling of cords, or portable tools, you have the ingredients for shock incidents. Most of the time, the hazard is not obvious until someone gets hurt or a GFCI starts tripping.
This guide explains ground faults in plain language, where jobsites usually fail, and the simple checks that reduce risk fast.
A ground fault happens when electricity leaks out of the intended circuit and finds an unintended path to ground. Sometimes through metal, water, or a person.
Common causes on construction sites:
Damaged insulation on cords and tools
Moisture in connections, boxes, or equipment
Improper grounding/bonding (especially on temporary setups)
Wear and tear from foot traffic, pinch points, sharp edges, and lifts
A key point crews need to understand: A tool can “still work” and still be unsafe.
Ground faults don’t always stop the tool; they create a shock hazard.
A GFCI (Ground Fault Circuit Interrupter) monitors current going out and coming back. If it detects leakage (meaning current is escaping the intended path), it shuts off power extremely fast.
On construction sites, that speed matters because:
Conditions change by the hour (water, mud, metal surfaces)
Cords get moved constantly
Temporary power is exposed to damage
Non-electricians use electrical equipment all day
Field rule: If you’re using temporary power or portable tools, ground fault protection should be part of the setup, not an optional add-on.
If you want a focused refresher your crew will actually remember, assign Ground Fault Protection for Construction
These are the scenarios where ground faults show up again and again:
Working outdoors or on unfinished structures
Working in wet/damp areas (basements, slabs, washdown zones, rain)
Running extension cords across traffic routes
Using portable power tools or temporary lighting
Using generators or temporary distribution boxes
Operating around metal frameworks, rebar, scaffolding, or conductive surfaces
If any of those describe your day, you should assume your site needs strong ground fault controls.
Some sites rely on GFCI protection. Some use an Assured Equipment Grounding Conductor Program (AEGCP) as an alternative.
The problem is not the idea, it’s the execution.
AEGCP only works when it is disciplined. That means:
Daily visual inspections
Regular continuity testing
Clear tagging and removal from service
Documentation that is actually maintained
Where it fails most often:
“We do inspections,” but there’s no record
Testing doesn’t happen on schedule
Damaged cords get “set aside” instead of being removed
Nobody owns the program
If your site is not rock-solid on process and documentation, GFCI is usually the safer, simpler control.
Tape is not a repair. Splices, cuts, and missing ground pins are all reasons to remove a cord immediately.
Rule: If you wouldn’t put your own hands on it in the rain, it doesn’t belong on the site.
A GFCI can fail. Testing is quick and should be routine.
Simple habit: Test before first use each day (or during the morning check).
A GFCI that trips is telling you something:
moisture in a plug/connector
damaged cord
faulty tool
miswired equipment
overloaded setup
Do not bypass it. Find the cause.
Open covers, missing blanks, improper weather protection, and messy cable routing create predictable failures.
If nobody owns temporary power checks, you get “everyone assumed someone else did it.”
Assign ownership. Even 5 minutes a day changes outcomes.
Use this as a quick walk-through before work starts:
Cords & Tools
No cuts, splices, tape repairs, missing ground pins
Cords routed away from pinch points, sharp edges, and traffic lanes
Connections kept out of puddles/wet surfaces
GFCI Protection
GFCI present where required (especially temporary power/portable tools)
GFCI tested (test/reset)
No bypasses, adapters, or “temporary” workarounds
Temporary Power Setup
Panels closed, labeled, protected from impact and weather
No open knockouts or exposed live parts
Cords not daisy-chained through power bars or improvised splitters
Stop-Work Trigger
If a cord is damaged, a GFCI trips repeatedly, or water is present near power — stop and fix before continuing.
Use this line: “If it’s tripping, it’s protecting you from something real. We fix the cause, we don’t defeat the control.”
That one sentence sets the expectation clearly without turning it into a debate.
You don’t need to overcomplicate it. Use training based on who touches what.
Do GFCIs eliminate the risk completely?
No — they reduce severity and duration of exposure. You still need inspections, proper routing, and removal of damaged equipment.
Why does a GFCI trip more in wet weather?
Moisture can create leakage paths and reduce insulation resistance. Wet conditions turn small defects into real hazards.
Is a cord okay if it “still works”?
No. Electrical damage often doesn’t stop a tool from running — it just increases the chance the current uses you as the path.
If you want to reduce electrical incidents without slowing the job down, start with the right training for your crews and leads.
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