InterNACHI Electrical Systems and Safety 4 — Questions and Answers
Question 1: What is the maximum height above the floor at which a standard wall-mounted electrical outlet may be installed per general accessibility guidelines?
- 18 inches
- 36 inches
- 48 inches
- No maximum is specified in the NEC (Correct answer)
Correct answer: No maximum is specified in the NEC
The NEC does not specify a maximum height for receptacle installation, though accessibility guidelines (ADA) recommend no higher than 48 inches.
Question 2: An inspector observes a service entrance cable with damaged outer insulation at the weatherhead. What is the primary concern?
- Water intrusion causing corrosion inside the meter base (Correct answer)
- Reduced amperage capacity of the service
- The utility company will disconnect service automatically
- Damaged insulation affects only aesthetics
Correct answer: Water intrusion causing corrosion inside the meter base
Damaged service entrance cable insulation allows moisture to enter the cable and meter base, causing corrosion and potential arcing failures.
Question 3: Which of the following is the correct InterNACHI-recommended finding when a home inspector observes a 60-amp main disconnect in a home with central air conditioning and electric range?
- 60-amp service is adequate for any modern home
- The service capacity appears insufficient for the electrical loads present and evaluation by an electrician is recommended (Correct answer)
- This only needs reporting if the panel is over 40 years old
- 60-amp service is acceptable if no additions have been made
Correct answer: The service capacity appears insufficient for the electrical loads present and evaluation by an electrician is recommended
Modern homes with central AC and electric cooking typically require 150–200 amp service; 60-amp service is likely undersized and warrants an electrician's evaluation.
Question 4: A home inspector finds Federal Pacific Electric (FPE) Stab-Lok panel in a home. What should the report state?
- FPE panels are recalled and must be replaced immediately
- FPE Stab-Lok panels have documented reliability concerns and evaluation by a licensed electrician is recommended (Correct answer)
- FPE panels are acceptable if breakers do not trip during inspection
- No action needed if the panel is less than 30 years old
Correct answer: FPE Stab-Lok panels have documented reliability concerns and evaluation by a licensed electrician is recommended
FPE Stab-Lok panels have a documented history of breaker failures and fire risk; inspectors should recommend evaluation but cannot require replacement.
Question 5: What does it mean when an electrical panel has its neutral and ground buses bonded together in a sub-panel?
- This is a code-compliant practice in all panels
- This is a defect that creates a parallel neutral path and shock hazard (Correct answer)
- Bonding is only required in the main panel and permitted in sub-panels
- This indicates the sub-panel has an improper main breaker
Correct answer: This is a defect that creates a parallel neutral path and shock hazard
In sub-panels, the neutral and ground buses must be separated because bonding them creates a parallel return path that can energize ground wires.
Question 6: What type of electrical hazard is indicated by scorch marks or discoloration around an outlet or switch cover plate?
- Overloaded neutral conductor
- Evidence of arcing or overheating at that device (Correct answer)
- Normal aging of plastic outlet covers
- Indication of reversed polarity only
Correct answer: Evidence of arcing or overheating at that device
Scorch marks or discoloration around electrical devices indicate past or ongoing arcing or heat buildup, which is a serious fire hazard.
Question 7: According to InterNACHI standards, what is an inspector's responsibility when they cannot access an electrical panel due to stored items blocking it?
- Move the items and inspect the panel
- Skip the panel and note no deficiencies were observed
- Report the panel as inaccessible and recommend evaluation (Correct answer)
- Assume the panel is code-compliant if the home passed prior inspections
Correct answer: Report the panel as inaccessible and recommend evaluation
When a panel cannot be accessed, the inspector must report it as inaccessible and recommend that it be evaluated when access is available.
InterNACHI Electrical Systems and Safety 4
What is the maximum height above the floor at which a standard wall-mounted electrical outlet may be installed per general accessibility guidelines?