# Electrical Safety Vocabulary for Apprentices > Learn 10 electrical safety terms in English with Chinese explanations, jobsite examples, stop points, and US, Australian, and Canadian sources. Canonical: https://elect-learn.org/en/guides/electrical-safety-vocabulary/ Language: en JSON: https://elect-learn.org/en/guides/electrical-safety-vocabulary/index.json Page updated: 2026-10-23 Maintained by: Elect Learn (https://elect-learn.org) Review status: No independent professional review is recorded. Cited sources do not imply review or endorsement by those organizations. Review policy: https://elect-learn.org/en/methodology/ Learning reference only: electrical codes, permits, inspection bodies, and licensing rules differ by region. This course is not a substitute for local code, licensed training, permits, or authority requirements. Before any hands-on work, de-energize, verify absence of voltage, and follow local regulators/AHJ and employer procedures. ## What tool indicates if a system is de-energized? An appropriately rated voltage-testing instrument is used as part of a qualified person's verification procedure. A switch in the OFF position, a dark indicator or a continuity beep is not sufficient evidence of a de-energized system. For US electrical work within its scope, OSHA 1910.333(b)(2)(iv) requires verification at the circuit elements and equipment parts to which workers will be exposed, including possible backfeed or induced voltage. Learn the terminology here; actual verification follows local rules, equipment instructions and an employer's procedure. - [OSHA 1910.333 — verification of deenergized condition]() - [OSHA interpretation — an indicator light is not deenergization test equipment]() - [Multimeter symbols, modes and readings]() - [Lockout/tagout language and roles]() ## Introduction Safety language must be precise because a vague sentence can hide an unverified condition. Learn to distinguish energized from de-energized, isolated from switched off, and observed from proven. ## 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 - Use electrical-state words without overstating certainty. - Recognize terms that trigger a stop or escalation. - Separate general principles from local legal requirements. ## energized Connected to an energy source or containing electrical or other stored energy. Example: Treat the conductors as energized until the required safe condition is established. Usage boundary: Equipment can contain more than one energy source. ## de-energized Disconnected from relevant energy sources, with the required controls and verification applied for the task. Example: The motor is stopped, but it has not yet been established as de-energized. Usage boundary: Stopped or switched off does not automatically mean de-energized. ## exposed live part An energized conductive part that is not suitably guarded or insulated against contact for the situation. Example: The missing cover leaves an exposed live part, so the area must be controlled. Usage boundary: Do not approach merely to get a better look. ## shock hazard A condition in which contact or approach can expose a person to harmful electric current. Example: Water beside damaged electrical equipment creates a potential shock hazard. Usage boundary: Keep clear and use the approved reporting and isolation process. ## arc flash A dangerous release of energy caused by an electric arc, potentially producing intense heat, light, pressure, and debris. Example: The task requires an arc-flash risk assessment under the applicable program. Usage boundary: Do not simulate faults or open equipment to create a learning demonstration. ## personal protective equipment (PPE) Equipment worn or used to reduce exposure to identified hazards when selected, rated, maintained, and used correctly. Example: Confirm the required PPE before entering the controlled work area. Usage boundary: PPE does not replace de-energizing when de-energizing is required. ## approach boundary A defined limit used by an applicable safety system to control approach to an electrical hazard. Example: Do not cross the marked boundary without the required authorization and controls. Usage boundary: Boundary names and distances are jurisdiction- and program-specific. ## lockout/tagout (LOTO) A formal energy-control process using defined devices, roles, steps, and verification to prevent unexpected energization or energy release. Example: The task cannot start until the required lockout/tagout procedure is complete. Usage boundary: Follow the employer procedure and applicable law; do not invent a personal shortcut. ## stored energy Energy that remains or can be released after a normal power source is disconnected. Example: The capacitor and spring mechanism may contain stored energy. Usage boundary: Electrical, mechanical, pneumatic, hydraulic, thermal, and gravitational energy may all matter. ## permit to work A formal document or system used in some workplaces to authorize and control specified work under defined conditions. Example: The permit to work lists the task boundary, controls, responsible people, and validity period. Usage boundary: A permit does not replace the actual controls, competence, or verification. ## Certainty ladder drill A machine has stopped and the local stop button is pressed. No isolation or verification has been completed. Describe only what is known and state what remains incomplete. The machine is stopped and the stop control is active. I cannot confirm it is de-energized. The required isolation, lockout/tagout, stored-energy control, and verification steps are still incomplete. ## Does off mean de-energized? No. Off may describe a control or operating state. De-energized is a safety state established through the required energy-control and verification process. ## Are safety terms identical in every country? No. General concepts overlap, but legal definitions, roles, equipment, distances, and required procedures differ. Use the applicable local source. ## Can an apprentice verify a de-energized condition? That depends on the task, training, supervision, employer program, and jurisdiction. Do not assume authorization from job title alone. ## References - [OSHA 29 CFR 1910.333 — Selection and use of work practices](): United States - [OSHA — Control of Hazardous Energy (Lockout/Tagout)](): United States - [Safe Work Australia — Managing electrical risks in the workplace](): Australia - [CCOHS — Electrical Safety: Basic Information](): Canada - [WorkSafeBC — De-energization and lockout](): Canada ## Related guides - [Lockout/Tagout Meaning & LOTO English Vocabulary]() - [Electrician Jobsite English Phrases: Listen & Practice]() - [Electrical Troubleshooting Terms: Meaning & Examples]()