NABCEP - Certified North American Board of Certified Energy Practitioners Specialist Workplace Safety and OSHA Questions and Answers — Questions and Answers
Question 1: According to OSHA standard 1926 Subpart M, personal fall arrest systems or guardrails are required when solar installers are working on a low-slope roof with an unprotected side or edge that is how many feet or more above a lower level?
- 4 feet
- 6 feet (Correct answer)
- 8 feet
- 10 feet
Correct answer: 6 feet
OSHA's standard for construction, 29 CFR 1926.501(b)(1), mandates that fall protection (such as a personal fall arrest system, safety net, or guardrail system) must be used when employees are on a walking/working surface with an unprotected side or edge that is 6 feet or more above a lower level.
Question 2: A solar technician is preparing to perform maintenance on a grid-tied string inverter. According to OSHA's Lockout/Tagout (LOTO) standard (29 CFR 1910.147), which of the following is a critical first step in the LOTO procedure?
- Verify the system is de-energized with a multimeter.
- Apply a personal lock and tag to the AC disconnect.
- Notify all affected employees of the impending shutdown. (Correct answer)
- Immediately open the DC disconnect to isolate the array.
Correct answer: Notify all affected employees of the impending shutdown.
The OSHA Lockout/Tagout standard requires that before equipment is shut down, the authorized employee must notify all affected employees that a LOTO procedure is about to begin. This ensures everyone in the area is aware of the service and does not attempt to re-energize the equipment. While all other steps are part of the process, notification is the initial preparatory step.
Question 3: Within OSHA's Hierarchy of Controls, which of the following is considered the LEAST effective method for protecting workers from hazards and should be relied upon only after other controls have been implemented?
- Engineering Controls (e.g., installing guardrails)
- Administrative Controls (e.g., safety training)
- Substitution (e.g., using a less hazardous chemical)
- Personal Protective Equipment (PPE) (e.g., wearing a hard hat) (Correct answer)
Correct answer: Personal Protective Equipment (PPE) (e.g., wearing a hard hat)
The OSHA Hierarchy of Controls ranks hazard control methods from most to least effective. Personal Protective Equipment (PPE) is at the bottom of the hierarchy, meaning it is the last line of defense. The most effective controls are Elimination and Substitution, followed by Engineering Controls, then Administrative Controls, and finally PPE.
Question 4: An installer is using a portable extension ladder to access a flat commercial roof for a site survey. To comply with OSHA standard 1926.1053, the side rails of the ladder must extend at least how far above the upper landing surface?
- 1 foot
- 2 feet
- 3 feet (Correct answer)
- 4 feet
Correct answer: 3 feet
OSHA standard 29 CFR 1926.1053(b)(1) explicitly states that when a portable ladder is used for access to an upper landing surface, the ladder's side rails must extend at least 3 feet (0.9 m) above that surface to provide a secure handhold for employees mounting and dismounting the ladder.
Question 5: An installer is working on a rooftop PV array where the inverter and all disconnects have been shut off. However, the conductors between the modules are still exposed to sunlight. According to OSHA's electrical safety principles, how must these conductors be treated?
- As de-energized, because the system is disconnected.
- As low-voltage and safe to handle without gloves.
- As energized, until tested and proven to be de-energized. (Correct answer)
- As safe, as long as the equipment grounding conductor is attached.
Correct answer: As energized, until tested and proven to be de-energized.
A fundamental principle of electrical safety under OSHA (e.g., 1910.333 and 1926.960) is to treat all electrical circuits as energized until they are tested and verified to be de-energized. PV source circuits are energized by sunlight, even when disconnected from the inverter, and pose a significant shock hazard. A qualified person must use proper test equipment to verify a zero-energy state before direct contact.
Question 6: What is the primary purpose of conducting a Job Safety Analysis (JSA), also known as a Job Hazard Analysis (JHA), before beginning a PV installation task?
- To assign blame after an accident occurs.
- To fulfill a client's contractual requirement.
- To proactively identify and control task-specific hazards. (Correct answer)
- To document the total number of hours worked on a project.
Correct answer: To proactively identify and control task-specific hazards.
The primary purpose of a Job Safety Analysis (JSA) is to proactively identify potential hazards associated with each step of a job and determine the safest way to perform the work. By breaking down a task, identifying risks, and establishing control measures, a JSA helps prevent accidents before they happen.
