CHST CHST - Construction Health and Safety Technician Electrical Safety and LOTO Questions and Answers 3 — Questions and Answers
Question 1: Under OSHA's LOTO standard (29 CFR 1910.147), what must an employer do before employees perform LOTO procedures for the first time?
- Notify OSHA in writing
- Train employees and certify the training (Correct answer)
- Post lockout procedures on a public bulletin board
- Install permanent warning signs on all equipment
Correct answer: Train employees and certify the training
OSHA requires employers to train each authorized and affected employee and certify that training has been accomplished.
Question 2: Which type of energy is specifically addressed by the term 'stored energy' in LOTO procedures?
- Electrical energy in live circuits
- Residual energy such as capacitors, springs, or pressurized fluids (Correct answer)
- Energy from active power generation
- Heat energy from external sources
Correct answer: Residual energy such as capacitors, springs, or pressurized fluids
Stored (residual) energy includes capacitor charge, compressed springs, pressurized hydraulics/pneumatics, and gravity potential that remain after the primary energy source is isolated.
Question 3: A construction worker needs to work inside an electrical panel. After de-energizing and locking out, which test confirms zero energy state?
- Visual inspection of the breaker position
- Testing with an appropriate voltage-rated meter or tester on all conductors (Correct answer)
- Checking that indicator lights are off
- Asking the electrician-in-charge if power is off
Correct answer: Testing with an appropriate voltage-rated meter or tester on all conductors
OSHA requires verification of zero energy state by testing with appropriate test equipment rated for the voltage on all conductors before work begins.
Question 4: What is the minimum approach distance for unqualified workers near exposed energized parts operating at 50–300 volts under OSHA 1910.333?
- Any distance, as long as PPE is worn
- Avoid contact — no specific distance required for low voltage (Correct answer)
- 3 feet 6 inches
- 10 feet
Correct answer: Avoid contact — no specific distance required for low voltage
For voltages up to 300V, unqualified workers must avoid contact but OSHA does not specify a minimum numeric distance; qualified workers' approach distances apply.
Question 5: Which of the following correctly describes a 'tagout' device under 29 CFR 1910.147?
- A locking device that physically prevents energy release
- A prominent warning device that cannot be removed without deliberate action (Correct answer)
- An electronic monitoring system that alerts workers to energy presence
- A color-coded sign installed by the safety manager only
Correct answer: A prominent warning device that cannot be removed without deliberate action
A tagout device is a prominent warning tag that can only be removed by the authorized employee who installed it and that indicates the energy-isolating device shall not be operated.
Question 6: On a multi-employer construction site, two subcontractors need to work simultaneously on the same locked-out machine. What LOTO method must be used?
- The general contractor applies a single lock for all workers
- Each authorized employee applies their own personal lock using a hasp (Correct answer)
- The equipment owner applies one lock and verbally notifies all workers
- A tagout-only system with each worker's name on the tag
Correct answer: Each authorized employee applies their own personal lock using a hasp
A hasp (multi-lock device) allows each authorized employee to attach their own personal lock, ensuring equipment cannot be re-energized until every worker removes their lock.
Question 7: According to NFPA 70E, what is the primary purpose of an Energized Electrical Work Permit?
- To satisfy OSHA recordkeeping requirements for electrical incidents
- To document justification, risk assessment, and safety measures when work on energized equipment cannot be avoided (Correct answer)
- To replace LOTO procedures for low-voltage systems
- To authorize unqualified workers to perform electrical tasks under supervision
Correct answer: To document justification, risk assessment, and safety measures when work on energized equipment cannot be avoided
An Energized Electrical Work Permit formally documents why de-energizing is not feasible, the hazard analysis, required PPE, and approval chain before energized work begins.
CHST CHST - Construction Health and Safety Technician Electrical Safety and LOTO Questions and Answers 3
Under OSHA's LOTO standard (29 CFR 1910.147), what must an employer do before employees perform LOTO procedures for the first time?