PVIS Test Prep practice questions and answers 2026. Tap an option to test yourself — you'll see the correct answer and a plain-English explanation for every question. Free, no login.
Q21According to the NEC, what is the minimum working clearance required in front of electrical equipment operating at 250 volts?
✓ Correct answer: D. 3 feet (36 inches)
The NEC requires a minimum of 3 feet (36 inches) of working clearance in front of electrical equipment operating at 250 volts to allow safe access for installation and maintenance.
Q22When installing an inverter in a PV system, what should be the primary consideration for its location?
✓ Correct answer: C. Accessibility for service and maintenance
The primary consideration when installing an inverter is accessibility for service and maintenance. Inverters require regular inspection and possible servicing, so they must be installed in locations that allow easy access.
Q23What type of enclosure rating should be used for electrical equipment installed outdoors and exposed to rain?
✓ Correct answer: B. NEMA 3R
NEMA 3R enclosures are designed for outdoor use and provide protection against rain, sleet, snow, and external ice formation, making them appropriate for outdoor electrical equipment exposed to precipitation.
Q24According to NEC Article 690, what is required on all PV system disconnecting means?
✓ Correct answer: A. Permanent labeling identifying it as a PV system disconnect
NEC Article 690 requires that all PV system disconnecting means must be permanently marked to identify them as a PV system disconnect, allowing first responders and service personnel to quickly identify critical components.
Q25When mounting an electrical enclosure to a masonry wall, what is the most appropriate fastener to use?
✓ Correct answer: D. Concrete anchors or masonry screws
Concrete anchors or masonry screws are specifically designed to secure items to masonry walls, providing the necessary strength and stability for electrical enclosures.
Q26When installing multiple pieces of electrical equipment on a wall, what is the best approach to ensure a workmanlike appearance?
✓ Correct answer: C. Align equipment both horizontally and vertically
Aligning equipment both horizontally and vertically creates a professional, organized installation that is easier to work with and maintain while meeting the NEC requirement for a workmanlike appearance.
Q27What is the maximum height above the floor at which a disconnect switch should be installed according to NEC requirements?
✓ Correct answer: B. 6 feet 7 inches (2 meters)
The NEC specifies that disconnect switches should have their center grip of the operating handle not more than 6 feet 7 inches above the floor or working platform for accessibility.
Q28When installing a combiner box for a PV array, what is the most important factor to consider regarding its location?
✓ Correct answer: A. Minimizing the length of DC conductor runs
Placing the combiner box to minimize DC wire runs reduces voltage drop, installation costs, and potential failure points, while also helping to maximize system efficiency.
Q29What information must be included on a warning label for an AC disconnect in a PV system?
✓ Correct answer: D. Warning of multiple power sources and disconnection instructions
Warning labels on AC disconnects must identify the presence of multiple sources of power (utility and PV), and provide instructions on disconnecting all sources to completely de-energize the system.
Q30When installing electrical equipment on a roof, what is a critical consideration to maintain the roof's integrity?
✓ Correct answer: C. Proper flashing and weatherproofing of penetrations
Maintaining roof warranties and integrity requires proper flashing and weatherproofing of all roof penetrations to prevent water intrusion, which can cause structural damage and electrical hazards.
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