These 5 questions cover service equipment, panels, branch circuits, GFCI/AFCI protection and grounding. On the National Home Inspector Examination they fall under Property Inspection (70% of the exam). Try each one before you open the answer: the explanation matters more than the letter.
1. An inspector observes a 20-amp breaker protecting a circuit wired with 14 AWG copper conductors. This condition should be reported because
- 20-amp breakers require aluminum conductors
- the breaker should be a GFCI type instead
- 14 AWG may be used only for lighting circuits
- 14 AWG copper is rated 15 amps and is overfused
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Answer: D. 14 AWG copper is rated 15 amps and is overfused
14 AWG copper is the minimum branch-circuit conductor and is rated for 15 amps. Protecting it with a 20-amp breaker allows the conductor to carry more current than it can safely dissipate, creating an overheating and fire hazard. This is overfusing, a common panel defect.
Memory tip: 14 gets 15. 12 gets 20.
2. At the main service panel, the inspector finds no bonding jumper connecting the neutral bar to the enclosure. The MOST significant implication is
- a ground fault may lack a path to trip the breaker
- the panel will not accept any additional breakers
- the neutral conductors will carry excess voltage
- the panel cannot be grounded to the water pipe
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Answer: A. a ground fault may lack a path to trip the breaker
At the service equipment, the neutral must be bonded to the enclosure and the grounding system so a fault to the metal enclosure has a low-impedance path back to the source, allowing enough current to trip the overcurrent device. Without it, a faulted enclosure can remain energized.
Memory tip: Bonding gives faults a way home.
3. An older home has a main panel with no single main breaker; four large breakers at the top shut off all power. This arrangement is
- a deficiency because a single main disconnect is always required
- a deficiency because at most two disconnects are allowed
- acceptable under the historic six-handle rule
- acceptable only if the breakers are handle-tied
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Answer: C. acceptable under the historic six-handle rule
Historically, service equipment could use up to six switches or breakers (the “six-handle rule”) to disconnect all power. Newer standards require a single main disconnect for new installations, but existing six-handle panels are not defects by themselves; the inspector should describe the arrangement.
Memory tip: Six throws of the hand, historically.
4. Inside a panel, the inspector finds a conductor with white insulation re-identified with black tape and landed on a breaker. This indicates
- an improper connection that must be corrected
- a white conductor re-identified as hot, which is permitted
- a neutral conductor that has been overloaded
- a conductor from a multiwire branch circuit
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Answer: B. a white conductor re-identified as hot, which is permitted
A white or gray conductor in a cable may be used as an ungrounded (hot) conductor if it is permanently re-identified at each termination, typically with black or red tape or paint. This is common with switch loops and 240-volt circuits and is not a deficiency when properly marked.
Memory tip: White with tape = hot on purpose.
5. A home receives power through conductors that run underground from a utility transformer to the meter. The inspector should describe this as a
- service lateral
- service drop
- feeder
- branch circuit
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Answer: A. service lateral
Underground service conductors from the utility to the meter are a service lateral; overhead conductors from the pole are a service drop. Describing the service type and location is part of reporting system characteristics, and laterals cannot be inspected for most of their length.
Memory tip: Lateral is low; drop is from above.