CHST CHST - Construction Health and Safety Technician Electrical Safety and LOTO Questions and Answers 2 — Questions and Answers
Question 1: Under OSHA's lockout/tagout standard (29 CFR 1910.147), which of the following is required before servicing equipment that has multiple energy sources?
- Only the primary energy source must be locked out
- All energy sources must be identified and each one individually locked out (Correct answer)
- A single lock on the main disconnect is sufficient
- Tagout alone is acceptable for all energy sources
Correct answer: All energy sources must be identified and each one individually locked out
OSHA requires that all energy sources, including electrical, hydraulic, pneumatic, and stored energy, be identified and individually locked out before servicing.
Question 2: What is the minimum approach distance for an unqualified worker near exposed energized parts operating at 50 kV on a construction site per OSHA 1926 Subpart K?
- 5 feet
- 10 feet (Correct answer)
- 15 feet
- 20 feet
Correct answer: 10 feet
OSHA 1926.416 requires unqualified workers to maintain at least 10 feet from exposed energized conductors or parts rated up to 50 kV.
Question 3: During a lockout/tagout procedure, who is authorized to remove a lock placed by another worker?
- The site superintendent
- Any qualified electrician on the crew
- Only the worker who applied the lock, with limited exceptions under employer procedures (Correct answer)
- The general contractor's safety manager
Correct answer: Only the worker who applied the lock, with limited exceptions under employer procedures
OSHA requires that only the employee who applied the lock may remove it, except under specific documented employer procedures when that worker is unavailable.
Question 4: A CHST observes a worker using a portable electric tool on a construction site without a GFCI. Which OSHA standard is being violated?
- 29 CFR 1926.404(b)(1) (Correct answer)
- 29 CFR 1910.333(a)
- 29 CFR 1926.502(d)
- 29 CFR 1910.147(c)(1)
Correct answer: 29 CFR 1926.404(b)(1)
OSHA 1926.404(b)(1) requires ground-fault circuit interrupter protection or an assured equipment grounding conductor program for temporary wiring on construction sites.
Question 5: What does the term 'zero energy state' mean in the context of lockout/tagout?
- The equipment is running at its lowest power setting
- All stored and residual energy has been relieved, disconnected, or restrained so the equipment cannot operate (Correct answer)
- The circuit breaker is in the off position but not locked
- The equipment has been unplugged but capacitors may still hold a charge
Correct answer: All stored and residual energy has been relieved, disconnected, or restrained so the equipment cannot operate
Zero energy state means all forms of hazardous energy have been controlled so the equipment cannot unexpectedly start or release energy during servicing.
Question 6: Which color is OSHA-recommended for danger tags used in a tagout procedure?
- Yellow
- Orange
- Red (Correct answer)
- Blue
Correct answer: Red
OSHA specifies that danger tags used for tagout must be red and must warn against hazardous conditions if the equipment is energized.
CHST CHST - Construction Health and Safety Technician Electrical Safety and LOTO Questions and Answers 2
Under OSHA's lockout/tagout standard (29 CFR 1910.147), which of the following is required before servicing equipment that has multiple energy sources?