OSHA 30 Construction — All Questions

What does the acronym LOTO stand for in workplace safety?

• a.Lift Over Turn Off
• b.Load On Time Out
• c.Lockout/Tagout✓
• d.Line Operator Task Order

LOTO stands for Lockout/Tagout, a procedure to control hazardous energy during servicing and maintenance. It ensures equipment is de-energized and cannot be unexpectedly started. Each authorized worker applies their own lock so the equipment stays safe until work is done.

What is the primary purpose of a lockout/tagout program?

• a.To label finished products
• b.To control hazardous energy so machines cannot start unexpectedly during service✓
• c.To track employee attendance
• d.To lock the tool room at night

The purpose of lockout/tagout is to control hazardous energy sources so that equipment cannot be energized or started while workers service or maintain it. Hazardous energy includes electrical, mechanical, hydraulic, pneumatic, thermal, and stored energy. Unexpected startup or energy release causes many serious injuries.

Under lockout/tagout, who is allowed to remove a lock from equipment?

• a.Any worker who needs the machine
• b.The first person to arrive that day
• c.Generally only the authorized worker who applied that lock✓
• d.A customer

As a rule, only the authorized employee who applied a lock may remove it. This ensures no one is still working on the equipment when it is re-energized. Special documented procedures apply if that worker is unavailable and the lock must be removed.

What does GFCI stand for and what does it protect against?

• a.Ground Fault Circuit Interrupter; it protects against electrical shock✓
• b.Gas Flow Control Instrument; it controls gas
• c.Ground Force Cable Insulator; it insulates cables
• d.General Field Control Inspector; it inspects fields

A GFCI is a Ground Fault Circuit Interrupter that protects workers from electric shock by quickly shutting off power when it detects current leaking to ground. It reacts to very small imbalances in current in a fraction of a second. GFCIs are required for many temporary power and outdoor circuits on construction sites.

On construction sites, what is one acceptable method to protect workers using temporary power from ground faults?

• a.Removing all grounding
• b.Using bare wires
• c.Using GFCI protection on receptacles or an assured equipment grounding conductor program✓
• d.Working in the rain

OSHA requires either GFCI protection on 120-volt temporary receptacles or an assured equipment grounding conductor program on construction sites. GFCIs are the more common and reliable choice. These measures protect against the shock hazards common with temporary wiring and portable tools.

What is the safest approach when working near overhead power lines?

• a.Spray them with water
• b.Touch them to test if they are live
• c.Lean ladders against them
• d.Maintain a safe clearance distance and assume all lines are energized✓

Workers should assume all overhead power lines are energized and maintain the required minimum clearance distance, which increases with voltage. Equipment such as cranes and ladders must be kept well away from lines. Contact with overhead lines is a leading cause of electrocution in construction.

What should you do before using an electrical cord or tool that appears damaged?

• a.Remove it from service and do not use it until repaired or replaced✓
• b.Use it only in dry areas
• c.Use it quickly before it fails
• d.Wrap it in cloth

A damaged cord or tool must be removed from service and not used until it is properly repaired or replaced. Frayed insulation, exposed conductors, or damaged plugs create shock and fire hazards. Inspecting cords and tools before each use is a basic electrical safety practice.

Why should the grounding prong on a three-prong plug never be removed?

• a.It is purely decorative
• b.The grounding prong provides a safe path for fault current, reducing shock risk✓
• c.It makes the plug fit better
• d.It saves electricity

The grounding prong provides a low-resistance path for fault current to flow safely to ground, reducing the risk of shock if a tool develops a fault. Removing or bending it defeats this protection. Tools with a missing ground prong should be taken out of service.

What is the correct action if a coworker is in contact with a live electrical source?

• a.Do nothing and wait
• b.Grab them immediately with bare hands
• c.De-energize the source or use a non-conductive object to separate them, then call for help✓
• d.Pour water on them

You should never touch a person who is in contact with a live electrical source with bare hands, because the current can pass to you. First de-energize the source if possible, or use a non-conductive object to separate the person from the source, then call for emergency help. Attempting a bare-hand rescue can create a second victim.

What is the role of PPE when selected as part of electrical safety?

• a.To make workers look uniform
• b.To protect the worker as a last line of defense when hazards cannot be otherwise removed✓
• c.To increase productivity
• d.To replace training

PPE, such as insulating gloves and arc-rated clothing, protects the worker as the last line of defense when electrical hazards cannot be eliminated or controlled by other means. It must be rated for the voltage and hazard involved. PPE supplements, but never replaces, de-energizing and safe work practices.

What is an arc flash?

• a.A warning label
• b.A type of light bulb
• c.A sudden release of energy from an electrical arc that can cause severe burns✓
• d.A camera flash

An arc flash is a rapid release of energy caused by an electrical arc, producing intense heat, light, and pressure that can cause severe burns and other injuries. Proper arc-rated PPE and safe work distances reduce the danger. De-energizing equipment before work is the best protection.

Which PPE is specifically designed to protect against electrical shock when handling energized conductors?

• a.Cotton work gloves
• b.Rated insulating rubber gloves✓
• c.Leather gloves alone
• d.No gloves needed

Rated insulating rubber gloves, often worn with leather protectors, are designed to protect against electrical shock when working on or near energized conductors. They must be voltage-rated for the task and tested regularly. Ordinary work gloves offer no shock protection.

Why is it dangerous to use electrical equipment in wet or damp conditions?

• a.It makes tools quieter
• b.Water insulates the worker
• c.It has no effect
• d.Water improves conductivity and greatly increases shock risk✓

Water is a conductor and dramatically lowers the body's resistance, increasing the severity of an electric shock. Wet conditions make ground faults far more likely to injure a worker. GFCI protection and keeping connections dry are essential in these environments.

What is the first step in a typical lockout/tagout procedure?

• a.Prepare for shutdown by identifying energy sources and notifying affected employees✓
• b.Start the machine
• c.Leave the area
• d.Remove all guards

The first step of lockout/tagout is preparation: identifying all energy sources and notifying affected employees of the planned shutdown. The equipment is then shut down, isolated, locked and tagged, and any stored energy released. Finally, the isolation is verified before work begins.

After applying locks and tags, what critical step verifies the equipment is safe?

• a.Skip verification to save time
• b.Attempt to start the equipment to confirm it will not operate (verify zero energy)✓
• c.Paint the machine
• d.Assume it is off

After isolating and locking out energy, workers must verify a zero-energy state, often by attempting to start the equipment to confirm it will not operate. Test instruments are used to confirm electrical circuits are de-energized. Skipping verification is a common and dangerous mistake.

What does 'stored energy' refer to in lockout/tagout?

• a.Solar panels
• b.Backup generators
• c.Residual energy such as in capacitors, springs, hydraulics, or elevated parts that must be released or restrained✓
• d.Energy in batteries only

Stored energy is residual or potential energy that remains after the main source is disconnected, such as in capacitors, compressed springs, pressurized hydraulics, or raised machine parts. This energy must be released, blocked, or restrained before servicing. Overlooking stored energy can cause unexpected and dangerous movement.

What should unqualified workers do around exposed energized electrical parts?

• a.Stand as close as possible
• b.Stay outside the limited approach boundary unless qualified and protected✓
• c.There is no concern
• d.Touch them to test

Unqualified workers must stay outside the established approach boundaries around exposed energized parts. Only qualified persons with proper training and PPE may approach closer under controlled conditions. Maintaining distance prevents accidental contact and arc-flash exposure.

Why must extension cords used in construction be rated for hard or extra-hard usage?

• a.To conduct more electricity
• b.To withstand the rough conditions of a job site without insulation damage✓
• c.To look professional
• d.To reduce cost

Construction extension cords must be rated for hard or extra-hard usage so their insulation can withstand abrasion, moisture, and rough handling on a job site. Cords rated only for household use damage easily and create shock and fire hazards. The rating is marked on the cord jacket.

What is the danger of overloading an electrical circuit or extension cord?

• a.Faster tool operation
• b.There is no danger
• c.Overheating that can cause fires and equipment damage✓
• d.It saves money

Overloading a circuit or cord draws more current than it is rated for, causing it to overheat and potentially start a fire or damage equipment. Cords should be sized for the load and length of the run. Daisy-chaining cords and power strips increases this risk.

Which of the following best describes a 'qualified person' for electrical work?

• a.Anyone wearing gloves
• b.A person trained and knowledgeable in electrical equipment operation and the hazards involved✓
• c.A new apprentice on day one
• d.A visitor to the site

A qualified person is trained and knowledgeable in the construction and operation of electrical equipment and installations and in recognizing and avoiding the associated hazards. Only qualified persons may perform certain energized electrical tasks. Proper training and demonstrated skill define this designation.

A Class A ground-fault circuit interrupter (GFCI) is designed to trip when it senses leakage current of approximately what level?

• a.Only when the circuit breaker also senses a dangerous overload downstream
• b.About 5 milliamperes (in the 4-6 mA range)✓
• c.At least 20 amperes flowing to the equipment
• d.Roughly 120 volts measured between the hot and neutral conductors

A Class A GFCI trips when leakage to ground reaches about 5 mA (the 4-6 mA range), well below the level that causes serious harm. Under 29 CFR 1926.404(b)(1), GFCI protection is a required means of protecting workers on temporary construction receptacles. It responds far faster and to far smaller currents than an ordinary circuit breaker.

Under an assured equipment grounding conductor program, how often must equipment grounding conductors be tested at a minimum?

• a.Only one time, when the equipment is first purchased from the manufacturer
• b.Once every calendar year regardless of how the equipment is handled on site
• c.Only after an employee reports receiving a noticeable electric shock
• d.At least every three months✓

Under 29 CFR 1926.404(b)(1)(iii), the assured equipment grounding conductor program requires testing before first use, after repairs, after any incident suspected of causing damage, and at intervals not exceeding three months. A designated competent person implements the program. Tested equipment is identified so workers know it was checked.

On a construction site, GFCI protection is generally required for which receptacles supplying temporary power?

• a.Only receptacles located inside a fully enclosed and heated office trailer
• b.Only receptacles rated above 480 volts serving fixed machinery
• c.120-volt, single-phase 15-, 20-, and 30-ampere receptacles not part of the permanent wiring✓
• d.Only the permanent building receptacles that the utility company has energized

29 CFR 1926.404(b)(1)(ii) requires GFCI protection for all 120-volt, single-phase 15-, 20-, and 30-ampere receptacles that are not part of the permanent wiring. This covers the temporary receptacles and portable tools common on job sites. The alternative is a full assured equipment grounding conductor program.

Which subpart of 29 CFR Part 1926 primarily covers electrical safety requirements for construction?

• a.Subpart CC, which addresses cranes and derricks used in construction
• b.Subpart P, which addresses excavations, trenching, and soil classification
• c.Subpart M, which is dedicated entirely to fall protection systems
• d.Subpart K✓

Subpart K (29 CFR 1926.400 through 1926.449) contains the electrical safety requirements for construction. It covers installation safety, safety-related work practices, safety-related maintenance, and safety requirements for special equipment. Subparts M, P, and CC address other hazards entirely.

For equipment operating near overhead power lines rated up to 50 kV, what is the minimum required clearance?

• a.10 feet✓
• b.About 42 inches, the same height used for a standard guardrail
• c.There is no set clearance as long as a spotter watches the load
• d.3 feet, the same clearance kept in front of an electrical panel

OSHA requires a minimum clearance of 10 feet for lines rated up to 50 kV, per 29 CFR 1926.1408 and 1926.600. For higher voltages the clearance increases by 4 inches for every additional 10 kV. All overhead lines should be treated as energized.

When equipment must work near overhead lines rated above 50 kV, how is the required clearance adjusted?

• a.It is reduced by half whenever a qualified signal person is present
• b.It increases 4 inches for every additional 10 kV above 50 kV✓
• c.It only matters when the humidity is high enough to cause arcing
• d.It stays fixed at 10 feet regardless of how high the line voltage climbs

Per 29 CFR 1926.1408, for lines over 50 kV the minimum clearance is 10 feet plus 4 inches for each 10 kV over 50 kV (or use the table/other options in the standard). Higher voltage can arc across greater distances. Utilities should be contacted to de-energize or insulate lines where feasible.

What is the primary function of lockout/tagout of electrical circuits under 29 CFR 1926.417?

• a.To label finished electrical assemblies before they are shipped to the customer
• b.To prevent circuits from being energized while workers install or repair them✓
• c.To keep an accurate written record of every employee's daily work hours
• d.To physically lock the tool crib and material storage areas overnight

29 CFR 1926.417 requires that controls and equipment be rendered inoperative and tagged, and circuits deenergized and locked or tagged, before work begins. This prevents inadvertent energizing while employees work on the circuit. It protects against electrocution and arc-flash injuries during installation and maintenance.

How does a tag differ from a lock in controlling hazardous electrical energy?

• a.A tag may be removed by anyone, while a lock must stay on the equipment forever
• b.A tag is a warning device only, while a lock physically prevents operation✓
• c.A tag physically blocks the switch, while a lock is only a written reminder
• d.There is no difference because both provide the same physical restraint of energy

A tag is a warning device that alerts workers not to operate a control, but it provides no physical restraint, as noted under 29 CFR 1926.417 and general lockout principles. A lock physically prevents the energy-isolating device from being moved. Where only tags are used, added means of protection are needed.

Under temporary wiring rules, lamps used for general illumination must be:

• a.Protected from breakage by a guard✓
• b.Rated for at least 480 volts even when used on a standard 120-volt circuit
• c.Wired directly to the utility service without any overcurrent protection installed
• d.Left completely uncovered so they provide the maximum possible light output

29 CFR 1926.405(a)(2)(ii)(E) requires that temporary lamps for general illumination be protected from accidental contact or breakage by a suitable guard. A broken bulb can expose live parts and create shock and ignition hazards. Metal-shell, paper-lined lampholders are prohibited.

Which practice with flexible extension cords is prohibited on construction sites?

• a.Choosing a cord marked for hard or extra-hard service in the field
• b.Keeping cords up off wet ground and away from sharp metal edges
• c.Fastening them with staples or running them through pinch points such as doorways✓
• d.Inspecting the cord jacket and plug for damage before each use of the tool

Under 29 CFR 1926.405(a)(2)(ii)(J) and 1926.416(e), flexible cords may not be run through doorways, windows, or holes that could pinch them, nor fastened with staples or hung in ways that damage the insulation. Damaged insulation creates shock and fire hazards. Cords may not be used as a substitute for fixed wiring.

What working clearance does OSHA generally require in front of energized electrical panels rated 600 volts or less?

• a.No clearance at all, so materials may be stacked against the panel to save room
• b.At least 3 feet of clear working space✓
• c.Exactly 10 feet, matching the clearance kept from overhead power lines
• d.Only enough room for the panel door to open a few inches

29 CFR 1926.403(i) requires sufficient access and working space around electric equipment, generally at least 3 feet of depth for equipment 600 volts or less. Blocking a panel delays emergency shutoff and increases arc-flash exposure. The space must be kept clear and not used for storage.

Portable electric tools that are double-insulated are permitted to be used without a grounding prong because:

• a.They automatically shut off before any fault current can ever reach the housing
• b.Their design provides two independent layers of insulation between live parts and the user✓
• c.Double insulation means the tool can safely be submerged in water while running
• d.The manufacturer removed the grounding prong to make the tool lighter to carry

Double-insulated tools, recognized under 29 CFR 1926.302 and 1926.404(f), use two independent insulation layers so a single failure will not energize the housing, allowing them to omit the grounding conductor. They are marked with a square-within-a-square symbol. They still must be kept dry and inspected before use.

How does a GFCI differ in purpose from an ordinary circuit breaker?

• a.A GFCI is only for direct current, while a breaker is only for alternating current
• b.A GFCI protects people from shock; a breaker protects wiring from overload✓
• c.They serve the identical purpose and can always be used interchangeably in a circuit
• d.A GFCI protects the wiring from overheating, while a breaker protects people from shock

A GFCI senses small ground-fault currents that can injure a person and trips in a fraction of a second, while a circuit breaker or fuse protects conductors from overcurrent and short circuits. The two devices address different hazards, so both are needed. GFCI use on construction sites is required by 29 CFR 1926.404(b)(1).

Around exposed energized parts, which employees are permitted to work on or near them?

• a.Any worker who has read the safety data sheet for the electrical equipment
• b.New apprentices on their first day, as long as a coworker watches them closely
• c.Any employee on the crew who happens to be wearing leather work gloves that day
• d.Only qualified persons trained to recognize and avoid the hazards✓

Under 29 CFR 1926.416 and the definitions in 1926.449, only qualified persons trained in the construction and operation of the equipment and in recognizing and avoiding electrical hazards may work on or near exposed energized parts. Unqualified persons must stay outside the approach boundaries. De-energizing is preferred whenever feasible.

In a battery-charging area for construction equipment, what specific atmospheric hazard must be controlled?

• a.The release of an inert gas that has no ignition potential whatsoever
• b.An excess of oxygen that makes ordinary tools too heavy to lift safely
• c.Accumulation of flammable hydrogen gas released during charging✓
• d.A buildup of harmless water vapor that only fogs up workers' safety glasses

Charging lead-acid batteries releases hydrogen, a highly flammable gas, so 29 CFR 1926.441 requires adequate ventilation and prohibits open flames and smoking in charging areas. Facilities for flushing eyes and neutralizing acid spills must also be provided. Hydrogen can explode if allowed to accumulate near an ignition source.

Before servicing equipment that contains capacitors, what precaution addresses stored electrical energy?

• a.Paint the capacitors a bright color so workers can see them more easily
• b.Work quickly so that any remaining charge does not have time to cause a shock
• c.Discharge the capacitors and verify zero energy before contact✓
• d.Assume the capacitors are safe because the main disconnect has been switched off

Capacitors can retain a dangerous charge after power is removed, so lockout/tagout procedures under 29 CFR 1926.417 require releasing or restraining stored energy and verifying a zero-energy state before work. Verification is done with a properly rated test instrument. Overlooking stored energy causes unexpected shocks.

Approximately what level of electric current passing through the body can cause a 'freezing' or inability to let go?

• a.Around 10 milliamperes✓
• b.Only currents above 240 volts, because voltage alone determines muscle control
• c.Any current at all, even a fraction of a microampere, causes muscle freezing
• d.Around 500 amperes, roughly the output of a large welding machine

At roughly 10 mA, muscular contraction can prevent a person from releasing an energized conductor, prolonging exposure. Currents near 100 mA through the chest can cause ventricular fibrillation. These physiological effects are why 29 CFR 1926.404(b)(1) mandates GFCI protection to limit shock current and duration.

Why should a metal or aluminum ladder never be used for electrical work near energized parts?

• a.Metal ladders are simply too heavy for most workers to carry to the work area
• b.Aluminum ladders rust quickly and therefore become structurally unsafe outdoors
• c.The reflective surface of a metal ladder can distract nearby crane operators
• d.Its conductive rails can carry current and electrocute the user✓

29 CFR 1926.1053(b)(12) prohibits using ladders with conductive side rails where the worker or ladder could contact energized parts. A nonconductive fiberglass ladder is used instead. A metal ladder can provide a direct path for fault current through the worker to ground.

When verifying that a circuit is de-energized before work, a qualified worker should:

• a.Touch the conductor briefly with a bare finger to feel whether it is warm
• b.Assume the circuit is dead if the overhead lights in the room are turned off
• c.Use a properly rated tester and confirm the tester works before and after✓
• d.Rely on the position of the wall switch alone without any instrument test

Safe verification requires a test instrument rated for the voltage, and the tester should be checked on a known live source before and after use (the 'test the tester' step). This confirms a true zero-energy state before contact, consistent with 29 CFR 1926.417 lockout/tagout verification. Never rely on switch position or indicator lights alone.

In a group lockout situation where several workers service the same equipment, how is worker protection ensured?

• a.The first worker to arrive locks it and the last worker to leave removes it for all
• b.Each authorized worker applies his or her own personal lock✓
• c.One supervisor applies a single lock that covers every worker on the entire crew
• d.Locks are unnecessary as long as a warning tag is hung on the main disconnect

In group lockout, each authorized employee places a personal lock on the energy-isolating device (often using a group lockbox), so the equipment cannot be re-energized until every worker removes his or her own lock. This follows the hazardous-energy control principles applied under 29 CFR 1926.417. It guarantees no one is still exposed when power is restored.

What is the primary danger of an arc blast, as distinct from the thermal burn of an arc flash?

• a.A pressure wave that can throw workers and rupture eardrums✓
• b.A buildup of harmless condensation on nearby electrical enclosure surfaces
• c.A slow release of odorless gas that gradually reduces the oxygen in the room
• d.A mild static discharge that only causes a tingling sensation in the fingertips

An arc blast produces a high-pressure wave and molten-metal shrapnel that can knock workers down, cause concussive injuries, and rupture eardrums, in addition to the intense heat of the arc flash. De-energizing before work is the best protection, and arc-rated PPE is used when energized work is unavoidable. These hazards are addressed under 29 CFR 1926.416 and consensus standard NFPA 70E.

According to OSHA's preferred approach, when may work be performed on energized electrical equipment?

• a.Only when de-energizing is infeasible or introduces greater hazards✓
• b.Any time the worker feels personally comfortable working on live circuits
• c.Only during daylight hours, regardless of whether the circuit can be shut off
• d.Whenever de-energizing the equipment would slow the project's schedule at all

The safest practice, reflected in 29 CFR 1926.416 and NFPA 70E, is to de-energize equipment before work; energized work is justified only when de-energizing is infeasible or would create a greater hazard. Even then, only qualified persons with proper PPE and an energized-work permit may proceed. Schedule convenience is not an acceptable justification.

Before digging or trenching, what step protects workers and equipment from buried electrical lines?

• a.Have underground utilities located and marked (call 811)✓
• b.Assume no lines exist unless the property owner specifically warns you
• c.Begin digging immediately and stop only if a spark is actually seen
• d.Dig a shallow test hole with a metal bar to feel for any hidden cables

Contacting the one-call service (811) to have utilities located and marked before excavation helps prevent striking energized underground lines, a serious electrocution and explosion hazard. This supports the excavation requirements of Subpart P and the electrical protections of Subpart K. Hand-digging is used to expose lines near the marks.

Splices and repairs in a flexible cord on a construction site must:

• a.Be wrapped in ordinary cloth tape and returned to service right away
• b.Be made only by the newest apprentice as part of on-the-job training
• c.Be left exposed so inspectors can easily see where the repair was made
• d.Retain the original insulation and strain-relief qualities✓

29 CFR 1926.405(g)(2)(iii) allows repair of hard-service cords only if the splice retains the insulation, outer sheath, and mechanical strength of the original, typically by molded or vulcanized methods. Ordinary tape does not qualify. Otherwise the cord must be replaced.

Why is even a 120-volt circuit potentially fatal to a worker?

• a.It cannot actually harm anyone because 120 volts is considered a low voltage
• b.It is dangerous solely because of the noise the circuit makes when it faults
• c.It can drive enough current through the body to stop the heart✓
• d.It only causes harm if the worker is also touching a much higher-voltage line

Fatalities occur at 120 volts because the current that flows depends on body resistance, which drops sharply when skin is wet, and as little as about 100 mA through the chest can cause fatal ventricular fibrillation. Low voltage is not the same as low hazard. This is why 29 CFR 1926.404(b)(1) requires GFCI protection on ordinary 120-volt receptacles.

If a mobile crane or aerial lift contacts an overhead power line, what should the operator generally do?

• a.Reach out and push the line away from the machine with a bare hand
• b.Climb out and walk normally back to the site office to report the contact
• c.Immediately step down to the ground while still holding the metal handrail
• d.Stay in the cab if possible and warn others to keep clear✓

If contact occurs and the equipment remains energized, the safest action is usually to stay in the cab, because stepping off can create a path for current through the body. If forced to exit due to fire, the operator should jump clear without touching the machine and ground at once, then shuffle away. These practices support 29 CFR 1926.1408 power-line safety.

What is the function of bonding metal parts of an electrical installation?

• a.To give the installation a uniform color for easier visual inspection
• b.To insulate each metal part completely from every other metal part nearby
• c.To connect them so there is no dangerous voltage difference between them✓
• d.To make the metal parts heavier so they resist vibration from equipment

Bonding connects metal parts so they are at the same electrical potential, preventing a dangerous voltage difference that could shock a worker who bridges two parts. It works together with grounding to provide a safe fault-current path. These grounding and bonding requirements appear in 29 CFR 1926.404(f).

Replacing a blown fuse with one of a higher amperage rating is dangerous because it:

• a.Changes the color of the indicator light on the electrical panel
• b.Voids the tool warranty but presents no real safety concern at all
• c.Makes the connected tools run noticeably slower than they should
• d.Defeats the overcurrent protection and can allow wiring to overheat✓

Overcurrent devices such as fuses and breakers are sized to protect the conductors; installing a higher-rated fuse allows excessive current that can overheat wiring and start a fire, contrary to 29 CFR 1926.404(e). Overcurrent protection must match the circuit design. Never bypass or upsize protective devices.

Disconnecting means and circuit breakers on a construction site must be:

• a.Located at least 25 feet from any receptacle used for portable tools
• b.Legibly marked to show their purpose unless obvious from location✓
• c.Painted the same color as the surrounding wall to avoid distraction
• d.Left completely unlabeled so that only electricians can identify them

29 CFR 1926.403(f) requires that each disconnecting means and overcurrent device be legibly marked to indicate its purpose unless located and arranged so the purpose is evident. Clear marking lets workers quickly shut off the correct circuit in an emergency. Unmarked panels delay a safe shutdown.

When a GFCI on a construction receptacle trips repeatedly ('nuisance tripping'), the correct response is to:

• a.Investigate and correct the fault rather than bypass the GFCI✓
• b.Remove or jumper out the GFCI so the tool can keep running without interruption
• c.Ignore it entirely because repeated tripping is a normal and harmless event
• d.Replace the GFCI with a higher-amperage fuse to stop the interruptions

Repeated tripping usually signals a real ground fault in the tool, cord, or wiring and must be investigated and corrected, never bypassed. Defeating GFCI protection removes a life-saving safeguard required by 29 CFR 1926.404(b)(1). The faulty equipment should be removed from service until repaired.