2.3 Electrical Systems

The Service

The inspection follows power from the utility inward. The service drop (overhead) or service lateral (underground) brings power to the meter and main panel. On overhead services the inspector checks the weatherhead, the drip loop, conductor clearance over the roof and grade, and that the mast is secure. The service size — the ampacity of the main disconnect and conductors — is read at the main breaker; common residential sizes are 100, 150, and 200 amps. An undersized service (e.g., 60-amp in a modern home) or evidence the panel is overloaded is reported.

The inspector identifies the main disconnect (the single means to shut off all power) and notes the panel manufacturer. A few legacy panel brands — notably Federal Pacific Electric (FPE) Stab-Lok and Zinsco — are widely reported as having breakers that may fail to trip, and the inspector recommends evaluation even when nothing else is visibly wrong.

The Main Panel & Breakers

With the dead-front cover removed, the inspector evaluates overcurrent protection and connections:

Double-tapping — two wires under a single breaker designed for one — is among the most common findings. Bonding and grounding must be correct: in the main panel the neutral (grounded) and ground (grounding) conductors are bonded together to the enclosure; in a subpanel they must be separated — neutrals isolated on an insulated bus, equipment grounds bonded to the can, and any main-bonding jumper removed. The system must connect to a grounding electrode (ground rod/Ufer/water pipe). Reversed or missing bonding is a shock hazard.

Branch Wiring, GFCI & AFCI

Branch wiring is typically copper. Two legacy systems are reported hazards: single-strand aluminum branch wiring (mid-1960s–70s), which expands, oxidizes, and loosens at connections — a fire risk requiring special connectors (e.g., COPALUM or listed AlumiConn) — and knob-and-tube wiring, an early ungrounded method that fails when buried in insulation or modified. Inspectors note overheating, missing junction-box covers, and improper splices.

GFCI (Ground-Fault Circuit Interrupter) protection shuts off power when current leaks to ground, protecting against shock. It is required at kitchens (counter receptacles), bathrooms, garages, exteriors, basements, crawlspaces, laundry, and within 6 feet of a sink. AFCI (Arc-Fault Circuit Interrupter) protection detects dangerous arcing to prevent fires and now covers most living-area branch circuits — bedrooms, living rooms, dining rooms, hallways, kitchens, and similar.

The inspector tests representative GFCI/AFCI devices, reports missing protection at required locations, and notes reversed polarity, open grounds, and ungrounded three-prong receptacles.

Conductor Sizing & Overcurrent Matching

A recurring exam theme is matching breaker size to wire gauge, because overcurrent protection only works when the breaker trips before the wire overheats. The standard residential pairings are:

A 20-amp breaker protecting 14-gauge wire is a classic defect: the wire can overheat at 16–20 amps without ever tripping the breaker — a fire hazard. The inspector also reports aluminum conductors on the wrong terminations and breakers that don't match the panel brand (mixing breakers not listed for that panel).

Devices, Safety & Reporting

At receptacles and fixtures the inspector tests for reversed polarity (hot and neutral swapped), open grounds, open neutrals, and bootleg grounds (a jumper faking a ground). Other reported safety items include missing cover plates, exposed splices outside a junction box, extension cords used as permanent wiring, and overheated or scorched devices. Around water, the inspector confirms GFCI function with the test button and an external tester. Smoke and carbon-monoxide alarm presence is noted where within scope.

Throughout, the electrical inspection stays within the visual, representative-sample standard: the inspector does not dismantle fixtures, trace every circuit, or perform load calculations. When findings exceed that standard — aluminum branch wiring, knob-and-tube, an obsolete panel brand, or pervasive amateur wiring — the correct report language is to identify the hazard and recommend evaluation and correction by a licensed electrician, the same specialist-referral discipline applied across building systems.

A useful summary of the highest-priority electrical safety findings the exam expects a candidate to recognize on sight: double-tapped breakers, oversized breakers on undersized wire, missing or reversed bonding, open grounds, exposed live splices, an obsolete or hazard-prone panel brand, aluminum branch wiring, knob-and-tube, and missing GFCI/AFCI protection at required locations. Each is a shock or fire hazard, and each is reported with the recommendation that a qualified electrician evaluate and correct it before the property changes hands.