Services, Grounding & BondingPregunta 45 de 120
What is the minimum length of a rod-type grounding electrode?
a.10 feet
b.6 feet
c.8 feet
d.5 feet
Explicación
Rod and pipe electrodes must be at least 8 feet long and must have at least 8 feet in contact with the soil once installed. The 10-foot value is associated with the minimum earth contact required of a metal underground water pipe electrode, and 5 or 6 feet fall short of the rod requirement.
Referencia Legal: 2023 NEC §250.52(A)(5)Practica las 120 preguntas gratis — sin registro.
Preguntas relacionadas de este tema
- Using the dwelling conductor table, what is the minimum copper conductor size for a 400-ampere single-phase dwelling service?
- A 45 kVA, three-phase transformer has a 480-volt primary. If only primary overcurrent protection is provided at 125 percent, what is the maximum standard primary device rating?
- What is the secondary full-load current of a 75 kVA transformer with a 208Y/120-volt, three-phase secondary?
- Where two rod electrodes are installed to make up the grounding electrode system, what is the minimum spacing between them?
- A single ground rod does not have to be supplemented by a second electrode if its resistance to earth does not exceed what value?
- A metal underground water pipe qualifies as a grounding electrode only if it is in direct contact with the earth for at least what length?
Última revisión: · proceso editorial
Equipo Editorial de PrepPass · Verificado con Journeyman Electrician Licensing Exam (NEC-based) · Cómo revisamos