A residential geothermal heat pump system has a total of 4 ground loops, each with a length of 100 ft. The loops are buried at a depth of 6 ft. What is the minimum size of the ground loop conductor required, according to Article 490.21(B) of the 2026 NEC?
- A10 AWG
- 8 AWG
- C6 AWG
- D4 AWG
Exam tip
Always check the manufacturer's specifications for ground loop conductor requirements.
Why B is correct
Article 490.21(B) requires that the ground loop conductor size be calculated based on the loop length and burial depth. The standard size for a loop with these specifications is 8 AWG.