19.2 Lockout/Tagout & Safe Work Practices

Safety Items Beyond the Clearance Table

Not every Arkansas Prov Safety stem is a 110.26 depth lookup. The outline’s 3 Safety questions also probe whether you understand how electricians keep equipment from being re-energized while someone is in the circuit. That skill set is lockout/tagout (LOTO) and related safe work practices.

The NEC is primarily an installation Code. Detailed LOTO program duties live in OSHA 1910.147 (control of hazardous energy) and in electrical safety work practices such as NFPA 70E. On a Journeyman licensing exam, you still need the principles: isolate, lock, tag, try, and do not remove another worker’s lock. Pair those principles with NEC rules you can open in the book — disconnecting means, working space kept clear, and guarding of live parts.

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What LOTO Is Trying to Prevent

Hazardous energy in electrical work is not only shock from contact with energized conductors. It includes unexpected re-energization while a worker has conductors exposed, tools on terminals, or body parts in equipment. Classic failure modes:

• Someone else flips a breaker back on because it was only turned off
• A temporary jumper or control circuit re-feeds the equipment
• Stored energy (capacitors, springs, elevated loads) remains after the supply is opened
• Multiple energy sources feed the same equipment and only one was opened

LOTO is the controlled process that makes “it should be off” into “it is secured off and verified.”

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Core LOTO Sequence (Exam-Level)

Teach this as a story, not a slogan:

1. Prepare / notify. Identify all energy sources that can feed the equipment. Notify affected employees that the equipment will be shut down and locked out.
2. Shut down. Use the normal stopping procedure so the equipment is in a controlled off state before isolation.
3. Isolate. Open the disconnecting means that removes electrical supply — and isolate other energy types (pneumatic, hydraulic, mechanical) if present.
4. Lock and tag. Apply a lock that prevents operation of the disconnect. Attach a tag that identifies the worker and warns against re-energizing.
5. Release / control stored energy. Discharge capacitors, block elevated parts, vent pressure — whatever the equipment can still store.
6. Verify zero energy (try-out). Attempt to restart with normal controls, check for voltage with an appropriately rated tester, confirm the circuit is dead, then return controls to off. Verification is what separates real LOTO from wishful thinking.
7. Perform the work.
8. Remove LOTO and restore. Only after tools, workers, and guards are clear — and typically only the person who applied a lock removes that lock, following the employer’s procedure.

Exam trap: “Breaker is off” ≠ LOTO. Without a lock (when lockable), a tag identifying the worker, isolation of all sources, and verification, the control is incomplete.

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Individual Locks, Group Locks, and Tags

One worker, one lock

Each authorized employee places their own lock. That way the equipment cannot be re-energized until that person removes their lock. Borrowing one shared lock for an entire crew defeats the personal-protection idea.

Group lockout

When several workers are on the same equipment, use a multi-lock hasp, lockbox, or equivalent group procedure so every worker’s lock is on the isolation point (or on the group device that controls the primary lock). The last lock off is the signal that the equipment can be restored — not a verbal “I think everyone is clear.”

Tags vs locks

• A lock physically prevents the disconnect from being closed.
• A tag communicates “do not operate” and identifies responsibility.

When a disconnecting means is capable of being locked, safe practice and OSHA energy-control rules expect a lock (with tag as required by the program). Tagout-only is a weaker control used only under limited conditions defined by the employer’s program when locking is not feasible — not the default for a lockable breaker handle. On Prov-style questions, prefer the answer that locks the isolating device and verifies zero energy.

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Safe Work Practice Hierarchy

Electrical safe work practice programs (NFPA 70E-style thinking) rank controls:

1. Eliminate the hazard — de-energize, lock out, verify dead, then work.
2. If energized work is justified — only for testing, troubleshooting, or where de-energizing creates a greater hazard or is infeasible under the employer’s rules; use an energized work permit process where required, establish approach boundaries, and wear PPE matched to the hazard.
3. Administrative controls and PPE support the above — they do not replace isolation when isolation is required.

For Journeyman exam purposes: the preferred answer is almost always de-energize and verify unless the stem explicitly describes live testing that cannot be done dead.

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NEC Companions You Can Look Up

LOTO principles are not printed as “OSHA 1910.147” inside the NEC, but several Code rules support the same safety outcome:

If a stem asks which practice is safest before replacing a starter, choose isolation + lock + verify over “stand on a rubber mat and work hot.”

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Common Exam Scenarios

Scenario A — Single disconnect, one electrician. Open the correctly identified disconnect, apply personal lock and tag, release stored energy, verify absence of voltage, then work. Remove lock only when finished and clear.

Scenario B — Two electricians, one panel. Both locks on a hasp (or group procedure). Either worker leaving early removes only their lock; the remaining lock still prevents re-energization.

Scenario C — Multiple sources. Equipment fed from a normal source and a generator / UPS / control power transformer may require more than one isolation point. Incomplete isolation is incomplete LOTO.

Scenario D — Someone else’s lock. Do not cut or remove another employee’s lock except under a documented emergency/absent-employee procedure supervised by the employer. Exam answers that casually “cut the lock to finish the job” are wrong.

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Jobsite Habits That Show Up as Stems

• Do not use the working space as storage while “the power is locked out anyway.”
• Do not rely on a typed note taped to a breaker without a lock when the breaker can accept a lockout device.
• Do not assume the upstream feeder breaker is the only source — check prints, labels, and try-out.
• Use an adequately rated voltage tester and prove the tester on a known live source before and after checking the circuit (live-dead-live discipline).

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How This Maps to Arkansas’s 3 Safety Items

With only three Safety questions, Prov will not run a full OSHA auditor quiz. Expect compact stems:

• Best practice before working on a circuit → de-energize, lock, tag, verify
• Why each worker needs a personal lock → prevents re-energization until that worker is clear
• Tag without lock on a lockable disconnect → inadequate when locking is possible
• Interaction with 110.26 → clear space still required for safe access during LOTO work

Study LOTO as decision rules, then use your tabbed 110.26 for clearance companions.

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Timed Open-Book Tips for §19.2

• You may not find “lockout/tagout” as a NEC article title — answer from safe-work principles plus any disconnect/working-space section the stem points to.
• If the stem names a motor disconnect “within sight,” open the relevant 430 disconnect rule and apply LOTO principles to that disconnect.
• Prefer answers that include verification / try-out, not merely “turn off the breaker.”
• Never pick an option that allows removing a coworker’s lock for convenience.