Licensed Electrical Inspector (LEI) G Class Theory flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Ohm's Law

Current equals voltage divided by resistance (I = E/R). Used to solve for unknown circuit values in series and parallel networks.

Power Formula

Power in watts equals voltage times current (P = E × I). For resistive loads it can also be written as I²R or E²/R.

Parallel Circuit Rule

Voltage is the same across all branches, while total current is the sum of branch currents. Total resistance is always less than the smallest branch resistance.

Three-Phase Power

Balanced three-phase power equals 1.732 times line voltage times line current times power factor. Used for motors and large distribution equipment.

Voltage Drop Formula

Single-phase voltage drop equals two times resistivity constant times current times length divided by circular mils. Three-phase uses 1.732 instead of two.

Conductor Ampacity Correction

Ampacity is reduced for high ambient temperature and for more than three current-carrying conductors in a raceway. Final ampacity governs overcurrent sizing.

Box Fill Calculation

Each conductor, clamp, device yoke, and grounding conductor counts toward box volume. Total volume must not exceed the box's marked capacity.

Bend Limit Between Boxes

No more than 360 degrees of bends is permitted between pull points. This protects insulation during conductor pulling.

NM-B Cable Restrictions

Nonmetallic sheathed cable is limited to dry locations and protected from physical damage. It is prohibited in wet locations and hazardous areas.

Equipment Grounding Conductor

A low-impedance path that carries fault current back to the source so the overcurrent device opens quickly. It does not carry normal load current.

Service Neutral Bonding

The grounded conductor is bonded to the enclosure and grounding electrode only at the service. Downstream panels keep neutral and ground separate.

Ground-Fault Circuit Interrupter

A device that compares current on the hot and neutral conductors and trips when leakage to ground is detected, protecting people from shock.

Selective Coordination

Arranging overcurrent devices so the one nearest a fault opens first. This limits outage scope and preserves upstream service continuity.

Interrupting Rating

The maximum fault current a device can safely interrupt. It must equal or exceed the available fault current at its installation point.

Permit Requirement

A permit is generally required before installing or altering electrical wiring. Exempt minor repairs must still comply with the adopted code.

Rough-In Inspection

An inspection performed after wiring and boxes are installed but before concealment. It verifies methods, support, and box fill before walls close.

Final Inspection

The last inspection, performed after devices, fixtures, and labeling are complete. Passing it allows issuance of a certificate of occupancy.

Stop-Work Order

An order halting work that proceeds without a permit or in an unsafe manner. Work resumes only after the issue is corrected.

Plan Review Scope

Review checks load calculations, service size, conductor and overcurrent ratings, grounding design, and compliance with the adopted code edition.

Deficiency Notice Content

A written notice citing the specific code section, describing the observed condition, and stating the corrective action required.

Insulation Resistance Test

A test applying elevated DC voltage to measure insulation integrity. Low readings indicate moisture, damage, or contamination in the wiring.

Receptacle Tester

A plug-in device that indicates wiring conditions such as open grounds, reversed polarity, and open neutrals. Some models also test GFCI and AFCI function.

Lockout Tagout

A procedure that isolates energy sources, applies locks and tags, and verifies absence of voltage before work begins on de-energized equipment.

Arc Flash Boundary

The distance at which incident energy equals the threshold for second-degree burns. Inside it, arc-rated PPE is required.

Limited Approach Boundary

A distance from exposed energized parts that unqualified persons may not cross. Qualified persons may cross with proper risk assessment and PPE.

Hierarchy of Controls

Controls ranked from most to least effective: elimination, substitution, engineering controls, administrative controls, and personal protective equipment.

Hazardous Location Classification

Locations are classified by class for the material, division or zone for frequency, and group for the specific substance. Equipment must match.

Rapid Shutdown

A photovoltaic system requirement that reduces conductor voltage near the array to a safe level for firefighters within a specified time.

Equipotential Bonding Pools

Pool and spa requirements bond metal parts, water, and equipment together to equalize voltage and reduce shock risk in wet areas.

Conflict of Interest

A situation where an inspector's financial or personal interest could influence enforcement. It must be disclosed and avoided.

Inspector Authority Limit

An inspector may enforce only adopted code provisions and lawful orders. Personal preference cannot be the basis for a correction.

Inspection Record Retention

Inspection reports, corrections, and re-inspection results are retained per the jurisdiction's schedule and serve as evidence of due diligence.