CHST Electrical Safety and LOTO 4 — Questions and Answers
Question 1: Under OSHA 29 CFR 1910.147, which condition allows an employer to use an alternative to traditional lockout when equipment design does not allow for lockout?
- Verbal authorization from the supervisor
- A written tagout program with additional safety measures (Correct answer)
- A safety observer stationed at the equipment
- Posting warning signs within 6 feet of the energy source
Correct answer: A written tagout program with additional safety measures
When equipment cannot be locked out, OSHA allows tagout if the employer demonstrates equivalent protection through additional safety measures documented in a written program.
Question 2: A construction worker discovers a frayed extension cord on a jobsite. What is the most appropriate immediate action?
- Wrap the damaged area with electrical tape and continue use
- Remove the cord from service and tag it out of service (Correct answer)
- Reduce the load on the cord by unplugging one tool
- Notify OSHA before taking any action
Correct answer: Remove the cord from service and tag it out of service
Damaged extension cords must be immediately removed from service and tagged to prevent use until repaired or replaced.
Question 3: What is the minimum approach distance for unqualified workers near overhead power lines energized at 50 kV or less on a construction site?
- 3 feet
- 6 feet
- 10 feet (Correct answer)
- 15 feet
Correct answer: 10 feet
OSHA 29 CFR 1926.416 requires unqualified workers to maintain at least 10 feet from overhead power lines energized at 50 kV or less.
Question 4: During a group lockout procedure, each authorized employee must:
- Share one group lockout device managed by the lead worker
- Apply their own personal lock to the group lockout hasp (Correct answer)
- Verbally confirm to the supervisor they are clear of the equipment
- Sign a group sign-off sheet maintained by the safety officer
Correct answer: Apply their own personal lock to the group lockout hasp
In group LOTO, each authorized employee applies their own personal lock to a hasp so no one can restore energy until all workers have removed their locks.
Question 5: Which class of fire extinguisher is specifically rated for energized electrical equipment fires?
- Class A
- Class B
- Class C (Correct answer)
- Class D
Correct answer: Class C
Class C extinguishers use non-conductive agents and are rated for fires involving energized electrical equipment.
Question 6: A CHST is reviewing a LOTO procedure for a conveyor system with multiple energy sources. What must the procedure specifically address for each energy source?
- The cost of the lockout hardware
- The type and magnitude of energy, and steps to isolate and control it (Correct answer)
- The names of all authorized employees who may perform lockout
- The date when the procedure was last revised
Correct answer: The type and magnitude of energy, and steps to isolate and control it
OSHA requires LOTO procedures to document the type and magnitude of each energy source and the specific steps to isolate and control each one.
Question 7: What does the acronym 'GFCI' stand for, and what is its primary function on construction sites?
- Ground Fault Circuit Interrupter; protects against overcurrent that can cause fires
- Ground Fault Circuit Interrupter; protects workers from electrocution by detecting leakage current (Correct answer)
- General Fault Current Indicator; monitors voltage fluctuations in temporary wiring
- Ground Frequency Current Isolator; separates construction circuits from utility power
Correct answer: Ground Fault Circuit Interrupter; protects workers from electrocution by detecting leakage current
A Ground Fault Circuit Interrupter detects small leakage currents to ground and trips within milliseconds to prevent electrocution.
CHST Electrical Safety and LOTO 4
Under OSHA 29 CFR 1910.147, which condition allows an employer to use an alternative to traditional lockout when equipment design does not allow for lockout?