Electrical Systems Inspection Flashcards
7 cards from real CMI practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Electrical Systems Inspection flashcards as text
Why do home inspectors flag Federal Pacific Electric (FPE) Stab-Lok panels during inspections?
Answer: Their breakers have been documented to fail to trip under overload conditions, creating a fire risk
FPE Stab-Lok breakers have been documented to fail to trip when overloaded, leaving circuits unprotected and posing a significant fire hazard.
What is the primary inspection concern when 15-amp branch circuits in a home are wired with single-strand aluminum instead of copper?
Answer: Aluminum connections can loosen over time and overheat at devices and terminations not listed for aluminum conductors
Aluminum expands and contracts more than copper with temperature changes, causing connections to loosen at terminals not rated for aluminum, leading to overheating and fire risk.
When inspecting the service entrance cable at the exterior of a home, which combination of items should the inspector evaluate?
Answer: Weatherhead height, drip loop presence, clearance from windows and doors, and proper sealing at the entry point
A complete service entrance inspection checks weatherhead height above grade, a drip loop to prevent water ingress, NEC-required clearances from openings, and a sealed penetration through the structure.
A home inspector finds 14 AWG wiring (15-amp capacity) protected by a 30-amp circuit breaker. What deficiency is present?
Answer: Over-fusing: the breaker rating far exceeds the wire's safe ampacity, creating a fire hazard
Over-fusing occurs when overcurrent protection (the breaker) is rated higher than the wire it protects, allowing the wire to overheat and ignite before the breaker trips.
Per NEC 110.26(A)(1), what minimum depth of clear working space is required in front of a residential electrical panel (0–150V to ground)?
Answer: 36 inches
NEC 110.26(A)(1) requires at least 36 inches of clear working depth in front of electrical equipment operating at 0–150V to ground to allow safe access for electricians.
Under which circumstances should a home inspector recommend immediate further evaluation of a residential electrical panel by a licensed electrician?
Answer: When the inspector observes double-tapping, improper breaker sizing, evidence of overheating, or other unsafe conditions
Defects such as double-tapped breakers, mismatched wire/breaker sizes, and signs of overheating indicate active safety hazards that require prompt professional correction.
What is 'backstabbing' when referring to electrical receptacles and switches, and why is it a concern?
Answer: Inserting conductors into the push-in release-hole terminals rather than using the screw terminals, which can cause loose, arcing connections
Push-in (stab-in) terminals on the back of devices can loosen over time, leading to high-resistance connections, overheating, and arcing that may cause fires or outlet failure.