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.
What is a ground fault?
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.
Why GFCI protection matters on construction sites
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
When ground fault protection is commonly needed on jobsites
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.
GFCI vs. Assured Grounding Program (AEGCP): what crews get wrong
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.
The 5 most common ground fault failures on construction sites
1) “Taped cord = good cord”
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.
2) GFCIs that never get tested
A GFCI can fail. Testing is quick and should be routine.
Simple habit: Test before first use each day (or during the morning check).
3) Tripping GFCIs treated as “annoying”
A GFCI that trips is telling you something:
Do not bypass it. Find the cause.
4) Temporary panels and boxes left exposed
Open covers, missing blanks, improper weather protection, and messy cable routing create predictable failures.
5) No one is assigned to inspect temporary power
If nobody owns temporary power checks, you get “everyone assumed someone else did it.”
Assign ownership. Even 5 minutes a day changes outcomes.
A simple daily ground fault protection checklist (2 minutes)
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
Quick coaching: what to say when a worker wants to bypass a GFCI
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.
Who should take what training?
You don’t need to overcomplicate it. Use training based on who touches what.
All workers (baseline)
Leads / supervisors (site control + inspection mindset)
Higher-risk tasks (servicing, troubleshooting, equipment work)
FAQ
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.
Sign up below for our weekly newsletter with helpful safety content, including weekly toolbox talks!