CBI Electrical Systems Inspection 2

Question 1

What is proper grounding and why is it essential in electrical systems?

Accepted Answer

Connecting electrical systems to earth ground to provide a safe path for fault currents and prevent shock hazards

Answer

Grounding provides a low-resistance path for fault currents to flow to earth, allowing overcurrent devices (breakers/fuses) to trip quickly during a ground fault, preventing electrical shock and fire.

Question 2

What is the difference between a 15-amp and 20-amp circuit?

Accepted Answer

A 20-amp circuit uses 12-gauge wire and handles higher loads; a 15-amp circuit uses 14-gauge wire for lighter loads

Answer

20-amp circuits require larger 12 AWG wire and are used for kitchen, bathroom, and garage outlets. 15-amp circuits use 14 AWG wire for general-purpose outlets and lighting in most rooms.

Question 3

What is the purpose of a main electrical panel inspection?

Accepted Answer

To verify proper installation, correct breaker sizing, appropriate wire connections, grounding, and safe clearances

Answer

Panel inspections verify proper bus connections, correct breaker-to-wire sizing, secure connections, bonding and grounding, working clearances (30 inches front, 36 inches wide), labeling, and absence of double-tapped breakers.

Question 4

What is a tamper-resistant receptacle and where is it required?

Accepted Answer

A receptacle with internal shutters that prevent insertion of foreign objects, required in all new residential construction

Answer

Tamper-resistant receptacles (TR) have spring-loaded shutters that only open when equal pressure is applied to both slots simultaneously (like a plug), preventing children from inserting objects. Required in all 15A and 20A residential outlets.

Question 5

What wire types are approved for residential branch circuit wiring?

Accepted Answer

NM cable (Romex) for dry locations and UF cable for underground/wet locations in most residential applications

Answer

NM (non-metallic sheathed) cable is the most common residential wiring for dry interior locations. UF cable is rated for direct burial. MC (metal-clad) cable is required in some jurisdictions and commercial applications.

CBI - Certified Building Inspector Practice Test

CBI - Certified Building Inspector Practice Test

CBI Electrical Systems Inspection 2