Safety, Tools, and Job Site Practices
What this domain covers
Safety, Tools, and Job Site Practices tests safe execution: OSHA construction rules, NFPA 70E electrical safety, ladder and fall protection, lockout/tagout, tool use, fiber and battery hazards, and housekeeping. The exam expects field judgment, not slogans.
Core rules
- Treat every circuit as energized until you have tested it with a proven meter. Use lockout/tagout: identify the source, open the disconnect, lock it, tag it, and verify absence of voltage at the point of work.
- On construction sites, OSHA requires ground-fault circuit interrupter protection for temporary receptacles, and fall protection is generally required at 6 ft or more. Use the right ladder: extend it 3 ft above the landing, set it at a 4:1 angle, and maintain three points of contact.
- NFPA 70E establishes arc-flash and shock risk assessment. For low-voltage work, the hazard is not zero: power supplies, PoE, batteries, and backfeed from control circuits can all expose a worker to unexpected voltage.
- Fiber work has specific hazards: laser light can damage the eye, and bare fiber shards can penetrate skin. Never look into a fiber end; use a fiber inspection scope; dispose of shards in a labeled container.
- Cable pulling can injure hands, shoulders, and backs. Use gloves, proper pulling tension, lubricant, and a second person; do not pull over sharp edges or through unsupported ceilings.
- Housekeeping is a safety control. Keep walkways clear, secure ceiling tiles, support cable reels, and store lithium batteries and chemicals according to the manufacturer's instructions.
Worked example
A technician is asked to add a device to a 120 V control panel. The breaker is labeled spare, but the panel is still fed from a lighting circuit. The correct procedure is to identify the source, open and lock the disconnect, tag it, test the conductors with a known-good meter, and only then work. If the panel cannot be de-energized, the technician needs an energized-work permit, appropriate PPE, and a risk assessment under NFPA 70E. The reasoning is that labels can be wrong, and low voltage does not describe the 120 V feed to the power supply.
Traps that cost marks
Trusting a breaker label; working alone on energized equipment; using a ladder's top step; skipping GFCI on temporary power; looking into a fiber connector; and leaving cable debris in a walkway.