CPI Electrical Bonding & GFCI Requirements 2 — Questions and Answers
Question 1: What is the minimum size copper conductor required for equipotential bonding of a swimming pool structure per NEC Article 680?
- #8 AWG solid copper (Correct answer)
- #10 AWG stranded copper
- #12 AWG solid copper
- #6 AWG stranded copper
Correct answer: #8 AWG solid copper
NEC 680.26 requires a solid #8 AWG copper conductor for the equipotential bonding grid of swimming pools.
Question 2: A pool inspector finds a metal pool ladder that is not connected to the equipotential bonding grid. Which hazard does this primarily create?
- Voltage gradient between the ladder and pool water (Correct answer)
- Overloading of the GFCI breaker
- Corrosion of the ladder from galvanic action
- Increased resistance in the pool pump motor
Correct answer: Voltage gradient between the ladder and pool water
An unbonded metal ladder can develop a voltage potential difference relative to the water, creating a shock hazard for swimmers.
Question 3: Under NEC 680.22(A), GFCI protection is required for all 120V receptacles located within how many feet of the inside wall of a swimming pool?
- 20 feet (Correct answer)
- 10 feet
- 15 feet
- 6 feet
Correct answer: 20 feet
NEC 680.22(A) requires GFCI protection for all 120V, 15A and 20A receptacles within 20 feet of the pool's inside wall.
Question 4: Which of the following pool components is NOT required to be included in the equipotential bonding grid?
- Pool heater plastic PVC piping (Correct answer)
- Metal pool light housing
- Diving board support structure
- Underwater lighting conduit
Correct answer: Pool heater plastic PVC piping
Non-conductive plastic/PVC piping does not conduct electricity and therefore does not need to be bonded.
Question 5: A GFCI device trips at what maximum ground fault current level to protect people from electrocution?
- 5 milliamps (Correct answer)
- 15 milliamps
- 20 milliamps
- 1 milliamp
Correct answer: 5 milliamps
Standard personnel protection GFCIs are designed to trip at 4–6 milliamps (typically rated at 5 mA) to interrupt potentially lethal ground faults.
Question 6: When inspecting a spa, a CPI inspector finds the GFCI breaker trips immediately when the spa is turned on. The most likely cause is:
- A ground fault in the heater or pump motor wiring (Correct answer)
- A blown fuse in the main panel
- Incorrect bonding conductor size
- Loose connection at the equipotential bonding lug
Correct answer: A ground fault in the heater or pump motor wiring
Immediate GFCI tripping upon energizing the equipment indicates current is leaking to ground, most commonly from damaged wiring in the heater or pump.
Question 7: Per NEC 680.26, the equipotential bonding grid must include all metal within the pool structure and all metal within how many inches of the pool water?
- 5 feet (60 inches) (Correct answer)
- 3 feet (36 inches)
- 18 inches
- 24 inches
Correct answer: 5 feet (60 inches)
NEC 680.26 requires bonding of all metal parts within 5 feet of the pool water's edge that are accessible to pool users.
CPI Electrical Bonding & GFCI Requirements 2
What is the minimum size copper conductor required for equipotential bonding of a swimming pool structure per NEC Article 680?