Electrician Jobsite English & Troubleshooting
Lockout/Tagout Meaning & LOTO English Vocabulary
Learn 10 lockout/tagout English terms covering roles, energy sources, isolating devices, stored energy, verification, and re-energization.
Page highlights
- Learn the English terms for ten lockout/tagout steps, from identifying energy sources and applying locks to verifying zero energy.
- Learn 10 core jobsite terms, examples, and safe usage boundaries.
- Take the free assessment, then practice this guide.
What does lockout/tagout (LOTO) mean?
Lockout/tagout (LOTO) is hazardous-energy control language. Lockout refers to securing an energy-isolating device; tagout identifies a warning system. A tag is not a physical lock. Their permitted use and supporting controls depend on the applicable rules and workplace procedure.
In Chinese-language searches you may also see 鎖牌 or 上鎖掛牌. In workplace English, use the full term lockout/tagout and name the actual control. Do not assume a regional shorthand establishes an equivalent procedure.
- Authorized employee: carries out the assigned energy-control work within their training and authorization.
- Affected employee: uses the equipment or works in the affected area; this role does not itself authorize lockout work.
- US scope matters: 1910.147 addresses hazardous-energy control in servicing and maintenance; electrical exposure within Subpart S is addressed by provisions including 1910.333.
Introduction
LOTO vocabulary describes a formal control system, not a personal sequence invented from memory. Learn the words so you can understand the employer procedure, ask precise questions, and recognize when a required step or role is missing.
Does OFF mean safe to touch?
Switching off is an action; proving dead is a verification. A lock prevents re-energization, while testing establishes the present state.
- Isolator · disconnects energy
- Lock and tag · prevent operation
- Record · identifies owner and scope
Learning outcomes
- Distinguish people, devices, energy sources, and process states.
- Avoid treating a stop control as an isolating device.
- Use sequence language without presenting this page as a workplace procedure.
authorized employee
In OSHA LOTO terminology, a person who locks or tags out equipment to perform covered servicing or maintenance.
Example: Only the authorized employee applies the energy-control steps assigned by the procedure.
Usage boundary: Role definitions differ across employers and jurisdictions.
affected employee
In OSHA terminology, a person whose job requires operating or using affected equipment, or working in the relevant area, but who is not performing the lockout role for that task.
Example: Affected employees must be notified according to the energy-control program.
Usage boundary: Do not assume affected means permitted to apply or remove another person's lock.
energy source
A source of electrical, mechanical, hydraulic, pneumatic, chemical, thermal, gravitational, or other energy.
Example: The job brief identifies electrical, pneumatic, and stored mechanical energy sources.
Usage boundary: Disconnecting one source may leave other hazardous energy present.
energy-isolating device
A mechanical device that physically prevents the transmission or release of energy within the applicable procedure.
Example: The push button stops the machine, but it is not the specified energy-isolating device.
Usage boundary: Control-circuit devices are not automatically energy-isolating devices.
lockout device
A device that holds an energy-isolating device in a safe or off position according to the energy-control program.
Example: Check that the lockout device is compatible with the isolating device and the procedure.
Usage boundary: Do not use an improvised lock or attachment method.
tagout device
A prominent warning device applied under a defined tagout system to indicate that equipment must not be operated.
Example: The tag identifies the controlled equipment and the responsible person under the program.
Usage boundary: A tag is a warning and does not physically restrain a device like a lock.
stored or residual energy
Energy remaining in capacitors, pressure systems, springs, elevated parts, rotating equipment, heat, or other sources after primary isolation.
Example: The procedure includes controlling stored pressure and checking for residual electrical energy.
Usage boundary: Zero motion does not prove zero stored energy.
zero-energy state
A term used in some programs for a condition in which hazardous energy has been isolated, controlled, and verified under the applicable procedure.
Example: Do not declare a zero-energy state until every required source and verification step is complete.
Usage boundary: Use the exact definition and wording in your workplace program.
verify isolation
To confirm through the program's required checks that the energy-control measures are effective.
Example: The authorized person must verify isolation before covered work begins.
Usage boundary: Verification method and responsibility come from the applicable procedure.
re-energize / restore energy
To return energy to equipment after the release process, checks, device removal, and notifications required by the program.
Example: Do not re-energize until the release-from-lockout process is authorized and complete.
Usage boundary: Removing another person's lock is governed by strict procedures, not convenience.
Role and state check
A machine is stopped, a warning tag is visible, and an operator says, “It is locked out.” You do not know who applied the controls or whether stored energy was addressed.
Ask questions that separate visible clues from confirmed program status.
I can see the machine is stopped and a tag is present, but I cannot confirm the lockout status. Who is the authorized person, which energy-isolating devices are controlled, how was stored energy addressed, and has isolation been verified under the program?
Is pressing an emergency stop the same as lockout?
No. A stop control may stop operation but is not automatically an energy-isolating device or a completed energy-control process.
Can a tag replace a lock?
Only under the specific legal and program conditions that apply. A tag warns; a lock physically restrains. Never make the substitution informally.
Is this page a LOTO procedure?
No. It is vocabulary training. Use your employer's written energy-control procedure, training, authorization, and applicable regulation.
References
- OSHA — Control of Hazardous Energy (Lockout/Tagout): United States
- OSHA Lockout/Tagout Tutorial — Definitions: United States
- OSHA 29 CFR 1910.333 — Selection and use of work practices: United States
- WorkSafeBC — De-energization and lockout: Canada
- Safe Work Australia — Managing electrical risks in the workplace: Australia
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