Nec Section 250

250 52 gives the requirements for grounding electrodes.

Nec section 250. Article 250 covers the grounding requirements for providing a path to the earth to reduce overvoltage from lightning and the bonding requirements for a low impedance fault current path back to the source of the electrical supply to facilitate the oper ation of overcurrent protection devices in the event of a ground fault. Section 250 32 a requires a grounding electrode system in accordance with part iii of article 250. Nec article 250 sections 250 1 through 250 4 the purpose of the national electrical code is the practical safeguarding of persons and property from hazards arising from the use of electricity 90 1 a.

They are all installed underground. Grounding and bonding table 250 66 table 250 122 part iii. The previous 2011 code language in 250 122 b required that any time an ungrounded conductor of a circuit was increased in size for any reason.

Ieee 142 gives a thorough theoretical treatise of it. Article 250 covers the grounding requirements for providing a path to the earth to reduce overvoltage from lightning and the bonding requirements for a low impedance fault current path back to the source of the electrical supply to facilitate the opera tion of overcurrent devices in the event of a ground fault. In the 2014 nec there were only two items.

Section 250 52 b describes all of the items and materials that cannot be used as a grounding electrode. The conductor used to make this connection is the grounding electrode conductor. Nec section 250 24 c is a requirement to connect the equipment grounding conductors the service equipment enclosures and where the system is grounded the grounded service conductor to a grounding electrode.

250 58 instructs us to use the same electrode for grounding conductor enclosures and equipment in or on that same building. Grounding electrode system utility transformer service conductor service disconnect feeder branch circuit sub panel main bonding jumper 250 102 c grounding electrode conductor 250 66 grounding electrodes 250 50 bonding of devices 250 134 t250 122. The requirements are located in part iii of national electrical code nec article 250 specifically 250 32.

There is one thing that all grounding electrodes have in common. The code language describing the metal frame of a building or structure as a grounding electrode has been removed and replaced. The equipment grounding conductor of the circuit was also to be increased in size the same proportional amount.