Mixed Deck — All CEI Topics Flashcards

When should an electrical inspector call for a re-inspection after a failed inspection?

Answer: After all cited violations have been corrected and the contractor has notified the inspection office

A re-inspection is appropriate only after the contractor has corrected all cited deficiencies and formally notified the inspection office that the work is ready.

What is the purpose of a combiner box in a large PV array installation?

Answer: Combine multiple PV source circuits into a single PV output circuit

A combiner box aggregates the output of multiple PV source circuits (strings) into a single PV output circuit, typically including fuses or breakers for each string.

During a residential inspection, the inspector notices that a bathroom has a receptacle outlet within 6 feet of the sink but it is not GFCI-protected. The homeowner claims it was installed before GFCI requirements existed. What is the correct inspection action?

Answer: Require GFCI protection as existing installations in bathrooms must comply when altered or re-inspected under current code adoption

When electrical work is performed or a permit is issued, jurisdictions typically require bringing affected areas into compliance with current GFCI requirements per NEC 406.4(D).

What is the main goal of electrical safety regulations?

Answer: Protect against hazards and accidents

The main goal of electrical safety regulations is to protect individuals and property from the inherent hazards associated with electricity, such as electric shock, electrocution, fires, and explosions. These regulations establish minimum standards for the design, installation, maintenance, and operation of electrical systems. By enforcing these rules, they aim to minimize risks and prevent accidents, ensuring a safe environment for everyone.

Which conductor in a feeder must be identified by white or gray insulation, or three continuous white stripes for sizes 6 AWG and smaller per NEC 200.6?

Answer: Grounded (neutral) conductor

NEC 200.6 requires grounded conductors (neutral) 6 AWG and smaller to be identified by continuous white or gray insulation, or three continuous white stripes.

NEC 705.12(B) sets a limit on the size of a back-fed breaker relative to the panel's busbar rating. What is the '120% rule'?

Answer: The sum of the main breaker and the back-fed supply breaker cannot exceed 120% of the busbar rating

The 120% rule states that the sum of the main breaker ampere rating plus the back-fed breaker ampere rating must not exceed 120% of the panel's busbar ampere rating.

What is a Zone 0 hazardous location characterized by?

Answer: Flammable gases present continuously or for long periods

Zone 0 is the most hazardous zone where flammable concentrations exist continuously or for long periods during normal operation.

A contractor submits plans stamped by a licensed engineer showing a 3-phase 208V panel fed from a 480/277V system without a transformer on the drawings. What should the reviewer do?

Answer: Request clarification or correction to show the step-down transformer

The reviewer must ensure the drawings are complete and internally consistent; a missing transformer feeding a 208V panel from a 480V source is a critical omission.

An inspector is reviewing a generator transfer switch installation. Which condition is a code violation that must be corrected?

Answer: A transfer switch that allows the neutral to float (non-switched neutral on a grounded generator)

When a generator is a separately derived system (with a switched neutral), NEC 250.30 requires the neutral to be switched at the transfer switch to prevent parallel neutral paths and shock hazards.

Which insulation type is rated for use in wet locations and has a 90°C temperature rating?

Answer: Type THWN-2

Type THWN-2 is rated for wet locations with a 90°C temperature rating, making it suitable for conduit in damp or wet environments.

According to NFPA 70E, what is the primary purpose of an Energized Electrical Work Permit?

Answer: To document justification and safety procedures for working on energized equipment

NFPA 70E requires an Energized Electrical Work Permit to document why energized work is necessary and the safety procedures to be followed.

What is the most effective way to measure success in plan review & permit processing within CEI professional practice?

Answer: Use a combination of quantitative metrics, qualitative assessments, and stakeholder feedback aligned with defined objectives

Effective measurement combines multiple data sources — quantitative metrics, qualitative assessments, and stakeholder feedback — all aligned with clearly defined objectives for a comprehensive evaluation.

When inspecting a CT (current transformer) metering installation, why are instrument transformers used?

Answer: To reduce high current to a manageable level for meter measurement

CT metering uses current transformers to step down high currents to a standard 5A secondary rating, allowing revenue-grade meters to measure large loads accurately.

What is the minimum clearance required by the NEC between the top of a service entrance conductor and a window that opens?

Answer: 3 feet

NEC 230.9(A) requires service conductors to be at least 3 feet from windows that open.

What does NEC 230.82 specify regarding equipment connected on the supply side of the service disconnecting means?

Answer: Listed surge protective devices and meters are permitted supply-side

NEC 230.82 lists equipment permitted to be connected on the supply side of the service disconnecting means, including meters and surge protective devices meeting certain criteria.

How should CEI professionals handle confidential information related to grounding & bonding requirements?

Answer: Follow established protocols for data protection, access control, and disclosure in accordance with applicable regulations

Confidential information must be handled according to established protocols, regulatory requirements, and professional ethics standards, including proper access control and disclosure procedures.

When inspecting a grid-tied PV system, which device is required to disconnect the system from the utility grid during a power outage?

Answer: Anti-islanding protection relay

Anti-islanding protection is required by IEEE 1547 to prevent a PV inverter from energizing a de-energized utility line, protecting utility workers.

Which NEC article primarily covers Class I, Zone 0, Zone 1, and Zone 2 hazardous locations?

Answer: Article 505

Article 505 covers Class I, Zone 0, 1, and 2 locations using the IEC zone system as an alternative to the Division system in Article 501.

Which document establishes the minimum qualifications and safety training requirements that a 'qualified person' must meet before working on electrical equipment under OSHA standards?

Answer: OSHA 29 CFR 1910.332 training requirements in conjunction with 1910.331–1910.335

OSHA 29 CFR 1910.332 specifies the safety training requirements that define what a 'qualified person' must know, as part of the electrical safety standards in 1910.331–1910.335.

Which type of fitting is required when a grounding electrode conductor passes through a knockout in a metal enclosure?

Answer: A fitting listed for grounding electrode conductor use

Per NEC 250.64(B), grounding electrode conductors must be protected from physical damage, and fittings must be listed for the purpose when entering metal enclosures.