Lockout/Tagout and Establishing an Electrically Safe Work Condition
The Safety section (18% of the trade exam) is grounded in Cal/OSHA Title 8 and NFPA 70E. Rule #1 of the trade: the safest circuit to work on is a de-energized, verified-dead one.
1. What LOTO is
Lockout/Tagout controls hazardous energy so equipment cannot be unexpectedly energized or started while someone is servicing it. In California it's governed by Cal/OSHA Title 8 §3314 (control of hazardous energy for cleaning, repairing, servicing).
2. The core LOTO rules
- Each authorized worker applies their OWN personal lock (group jobs = every worker's lock on).
- Only the worker who applied a lock removes it (per the documented procedure).
- After locking/tagging out, verify a zero-energy state — test that the equipment can't operate and verify absence of voltage before touching anything.
- A tag alone (tagout) is only a warning — it does not physically prevent operation, so it's less protective than a lock. Lock when you can.