NICET Electrical Power Testing Level I (EPT I)

Correct: According to NEC Table 110.26(A)(1), for systems operating between 151 and 600 volts to ground (which includes a 480V system, typically 277V to ground), Condition 2 applies when there are exposed live parts on one side and grounded parts on the other. Concrete, brick, or tile walls are considered grounded. For this voltage range under Condition 2, the minimum clear working space depth is 3.5 feet.

Incorrect: 3.0 feet is the requirement for Condition 1, where there are no grounded parts on the opposite side of the working space. 4.0 feet is the requirement for Condition 3, where there are exposed live parts on both sides of the working space. 2.5 feet is not a standard minimum depth for equipment operating at this voltage level under any condition in Article 110.

Takeaway: Working space depth requirements are determined by the voltage to ground and whether the opposite surface is considered a grounded or live part as defined in NEC Table 110.26(A)(1).

Correct: According to the NABCEP Code of Ethics and professional standards for inspectors, the primary obligation is to provide an accurate, independent, and honest assessment of the system. Even if an Authority Having Jurisdiction (AHJ) has previously approved an installation, the inspector is hired to provide a professional verification. If a clear violation of the National Electrical Code (NEC) or safety standards is found, it must be documented. Professional integrity requires that the inspector does not succumb to pressure to overlook safety hazards for the sake of project timelines or professional courtesy.

Incorrect: Deferring to the AHJ’s decision when a violation is clearly present fails to meet the inspector’s duty of care to the client and the public. Omitting findings from a formal report based on a verbal agreement to fix them later is a breach of transparency and professional ethics. Treating an AHJ’s oversight as a valid field modification without actual compliance or official variance documentation is a misrepresentation of the system’s safety status and a violation of the inspector’s professional mandate.

Takeaway: A PV system inspector must maintain independent professional judgment and report all safety and code violations, regardless of prior approvals by other authorities or stakeholders.

Correct: According to NEC 695.4(B)(2), the overcurrent protective device for a fire pump must be selected or set to carry indefinitely the sum of the locked-rotor current of the fire pump motor(s) and the pressure maintenance pump motor(s), plus the full-load current of the accessory equipment. This unique requirement ensures that the fire pump continues to operate under extreme conditions, prioritizing the suppression of fire over the protection of the motor itself.

Incorrect: Sizing at 125 percent of full-load current is a standard requirement for most motors under Article 430, but it is insufficient for fire pumps which must not trip under locked-rotor conditions. Coordinating the fire pump with the PV system as a primary source is incorrect because fire pumps require a highly reliable source, typically connected ahead of the service disconnecting means. Locating fire pump protection in a PV combiner box violates the requirement for fire pump sources to be independent and reliable, and it would introduce unnecessary risks of accidental shutdown.

Takeaway: Fire pump overcurrent protection is specifically designed to carry locked-rotor current indefinitely to ensure the pump operates until failure during an emergency.

Correct: According to NEC 404.4(A), switches or circuit breakers installed in wet locations must be in a weatherproof enclosure. Furthermore, for surface-mounted enclosures in damp or wet locations, there must be at least 1/4 inch (6 mm) of air space between the enclosure and the wall or other supporting surface to prevent the accumulation of moisture, unless the enclosure is specifically designed and identified for direct mounting.

Incorrect: The requirement for the maximum height of the operating handle is 6 feet 7 inches (2.0 meters) per NEC 404.8(A), not 5 feet. NEC 404.2(B) generally prohibits the switching of a grounded conductor unless the switch simultaneously disconnects all conductors of the circuit. Bonding of metal faceplates for snap switches is required by NEC 404.9(B) regardless of whether the voltage is above or below 150 volts to ground to ensure user safety from electric shock.

Takeaway: Switches in wet locations require weatherproof enclosures and a 1/4-inch air gap from the mounting surface to prevent moisture-related degradation and ensure long-term equipment integrity.

Correct: According to NEC 604.10(A)(1), manufactured wiring systems must use Type AC or Type MC cable containing copper insulated conductors not smaller than 12 AWG. Additionally, the code specifically requires an insulated copper equipment grounding conductor not smaller than 12 AWG to be part of the assembly.

Incorrect: Option B is incorrect because 12 AWG is the minimum size for general branch circuits in these systems; 14 AWG is only permitted for specific tap connections or signaling circuits. Option C is incorrect because Article 604 requires a dedicated insulated copper equipment grounding conductor rather than relying solely on the cable armor. Option D is incorrect because NEC 604.10 explicitly states that manufactured wiring systems are permitted in accessible locations, such as above suspended ceilings, to facilitate maintenance and reconfiguration.

Takeaway: Manufactured wiring systems must utilize at least 12 AWG copper conductors and include a dedicated insulated copper equipment grounding conductor within the cable assembly.

Correct: According to NEC 760.136, Power-Limited Fire Alarm (PLFA) conductors are generally prohibited from being placed in the same enclosure, raceway, or cable tray as power, lighting, or Class 1 circuits. One of the primary exceptions to this rule is when the different circuits are separated by a permanent, solid, and fixed barrier that is compatible with the enclosure, ensuring that the low-voltage fire alarm signals are not compromised by the higher-voltage power circuits.

Incorrect: Identifying conductors with a red jacket or using specific cable ties does not satisfy the physical separation requirements mandated by the NEC for fire alarm circuits sharing space with power circuits. Derating is a calculation used for current-carrying capacity in power conductors but does not address the safety and interference concerns of mixing PLFA and power circuits. The physical location of a sub-panel does not remediate the code violation of improper conductor separation within a shared raceway or enclosure.

Takeaway: NEC Article 760 requires strict physical separation, typically via a fixed barrier, between power-limited fire alarm circuits and power or Class 1 circuits to maintain system integrity and safety.

Correct: According to NEC 725.136(A), Class 2 and Class 3 circuit conductors cannot be placed in any enclosure, raceway, or cable with conductors of electric light, power, or Class 1 circuits. The fact that the Class 2 wire has 600V insulation does not permit it to be mixed with power conductors in the same raceway, as the separation is required to prevent high-voltage contact with low-voltage systems in the event of insulation failure or improper handling.

Incorrect: The general rules in Article 300 regarding conductors of different systems are superseded by the specific requirements in Article 725 for Class 2 and 3 circuits. There is no NEC requirement that Class 2 circuits must be in PVC; EMT is a valid wiring method, but not when shared with power. Shielding and grounding do not waive the physical separation requirements mandated by the NEC for these circuit classes.

Takeaway: NEC Article 725 requires strict physical separation between Class 2/3 low-voltage circuits and power/Class 1 circuits to ensure system safety and integrity.

Correct: According to NFPA 70E and OSHA standards, electrical equipment such as switchgear that is likely to require examination, adjustment, or maintenance while energized must be field-marked with arc flash hazard labels. The absence of these labels means that qualified personnel cannot determine the incident energy level or the required Personal Protective Equipment (PPE) category. Consequently, the most appropriate professional action is to restrict all energized work on the affected equipment until a formal arc flash hazard analysis is conducted and the equipment is properly labeled, ensuring that any future interactions are guided by accurate risk data.

Incorrect: Focusing on thermal monitoring through infrared windows is a valid maintenance strategy for identifying loose connections but does not address the immediate safety hazard of unknown incident energy levels for personnel. Verifying grounding and bonding is critical for system stability and fault clearing, yet it does not mitigate the specific risks associated with an arc flash or provide the necessary hazard communication for workers. Adjusting circuit breaker trip settings to prevent nuisance tripping addresses operational reliability and coordination but fails to provide the safety information required to protect technicians from thermal or pressure hazards during a fault event.

Takeaway: The absence of arc flash hazard labels constitutes a critical safety failure that prevents the determination of necessary PPE, requiring a suspension of energized work until a formal hazard assessment is completed.

Correct: The Authority Having Jurisdiction (AHJ) is the legal entity responsible for enforcing the building and electrical codes within a specific area. Compliance is determined by the specific version of the NEC and any local amendments that have been officially adopted by that jurisdiction at the time the permit is issued. Even if a newer version of the NEC exists, it is not enforceable until the local government formally adopts it.

Incorrect: The most recent NFPA standards are not automatically enforceable until adopted by the local or state government. Manufacturer instructions are critical under NEC 110.3(B) but do not supersede the adopted code; they must be followed in addition to the code. Contract dates between private parties have no bearing on regulatory compliance or the legal requirements set forth by the AHJ.

Takeaway: PV system inspectors must evaluate installations based on the specific code editions and local amendments officially adopted by the AHJ at the time of permitting.

Correct: The permitting process is designed to ensure that the proposed installation complies with all safety codes, including fire setbacks, before work begins. When a discrepancy is found between the site conditions and the permit application, the applicant must provide updated documentation to the AHJ. This ensures the plan review process accounts for the actual physical constraints of the roof and maintains the integrity of the safety standards mandated by the building and fire codes.

Incorrect: Allowing the installation to proceed with only a field note is insufficient because the AHJ must verify that the revised layout still meets all code requirements before construction. Reducing the number of modules without an amended plan bypasses the formal review process and may lead to further electrical or structural inconsistencies. Signed affidavits from homeowners cannot override safety codes or legal permitting requirements established by the jurisdiction.

Takeaway: Any significant deviation from the site conditions in a permit application requires a formal plan revision and AHJ approval to ensure continued compliance with fire and building codes.