CHST Electrical Safety and LOTO 5 — Questions and Answers
Question 1: When must a LOTO periodic inspection be performed, and what must it include?
- Every 5 years; a review of the written procedure only
- At least annually; a review of the procedure with each authorized employee (Correct answer)
- Every 6 months; retraining all affected employees on energy control
- Before every lockout; verification that locks are functioning properly
Correct answer: At least annually; a review of the procedure with each authorized employee
OSHA 29 CFR 1910.147(c)(6) requires LOTO procedures to be inspected at least annually and reviewed with each authorized employee who uses the procedure.
Question 2: A construction electrician is working on a 480V motor control center. After locking out the breaker, what is the next critical step before touching conductors?
- Notify the building owner that power is off
- Test for absence of voltage using an appropriate voltage tester (Correct answer)
- Wait 30 minutes for residual current to dissipate
- Apply insulating blankets over the breaker panel
Correct answer: Test for absence of voltage using an appropriate voltage tester
After lockout, workers must verify zero energy state by testing with a voltmeter or tick tracer rated for the voltage before touching any conductors.
Question 3: Which type of stored energy must be addressed during LOTO on a hydraulic press in addition to electrical lockout?
- Chemical energy stored in hydraulic fluid additives
- Pneumatic, hydraulic, gravitational, and spring (mechanical) energies (Correct answer)
- Thermal energy from motor heat only
- Electrical energy in the hydraulic pump motor only
Correct answer: Pneumatic, hydraulic, gravitational, and spring (mechanical) energies
LOTO must address all forms of hazardous energy including electrical, pneumatic, hydraulic, gravitational, thermal, and mechanical (spring) energy.
Question 4: On a construction site, temporary wiring must be protected by GFCIs or an assured equipment grounding conductor program (AEGCP). Under the AEGCP, how frequently must receptacles be tested?
- Daily before each use
- Before first use, after repairs, and at 3-month intervals (Correct answer)
- Weekly on Mondays before work begins
- Only when a worker receives a shock
Correct answer: Before first use, after repairs, and at 3-month intervals
OSHA 1926.404(b)(1)(iii) requires AEGCP receptacles to be tested before first use, after repairs, and at 3-month intervals.
Question 5: What is the purpose of a 'try-out' (or test) step after applying lockout to a machine?
- To confirm the lock is properly seated on the hasp
- To verify the machine cannot be started before work begins (Correct answer)
- To check that all affected employees have been notified
- To test the emergency stop button operation
Correct answer: To verify the machine cannot be started before work begins
The try-out step verifies the energy isolation was successful by attempting to start or operate the equipment before performing maintenance.
Question 6: A new subcontractor arrives on site and will work near but not on equipment that is under lockout. What category does this worker fall under per OSHA 1910.147?
- Authorized employee
- Affected employee
- Other employee (Correct answer)
- Qualified electrical worker
Correct answer: Other employee
Workers who are not involved in servicing the equipment and not required to operate it are classified as 'other employees' and must be trained on the purpose and prohibition of LOTO.
Question 7: Which OSHA standard specifically governs electrical safety requirements for construction, including grounding and wiring design?
- 29 CFR 1910.303
- 29 CFR 1926.400 through 1926.449 (Correct answer)
- 29 CFR 1910.147
- 29 CFR 1926.50
Correct answer: 29 CFR 1926.400 through 1926.449
Subpart K of 29 CFR 1926 (sections 1926.400–1926.449) covers electrical safety standards specifically for the construction industry.
CHST Electrical Safety and LOTO 5
When must a LOTO periodic inspection be performed, and what must it include?