InterNACHI Electrical Systems & Safety 4

Question 1

An arc-fault circuit interrupter (AFCI) breaker is designed to protect against which specific hazard?

Accepted Answer

Electrical arcing that can ignite nearby combustibles

Answer

AFCI breakers detect the unique electrical signature of arcing faults, which can cause fires in walls or other concealed locations.

Question 2

What is the correct term for the main disconnect switch that cuts power to the entire home's electrical system?

Accepted Answer

Main breaker

Answer

The main breaker is the primary overcurrent protection device that disconnects all power to the home's branch circuits and feeders.

Question 3

A home inspector finds knob-and-tube wiring in an attic that has been covered with insulation. Why is this a concern?

Accepted Answer

Knob-and-tube wiring requires ventilation to dissipate heat, and insulation prevents this

Answer

Knob-and-tube wiring relies on open air for heat dissipation, and burying it in insulation can cause dangerous overheating.

Question 4

What does the term 'service drop' refer to in a residential electrical inspection?

Accepted Answer

The overhead utility conductors from the pole to the weatherhead

Answer

The service drop refers to the overhead conductors supplied by the utility company that run from the utility pole to the customer's weatherhead.

Question 5

Which of the following is a common defect found with older two-prong (ungrounded) receptacles?

Accepted Answer

They have no equipment grounding conductor, offering no protection against faults

Answer

Two-prong receptacles lack the grounding conductor, meaning there is no path to safely divert fault current away from users or equipment.

(InterNACHI) International Association of Certified Home Inspectors Practice Test