Nec Service Grounding Chart

It is very helpful to have a separate table for selecting the.

Nec service grounding chart. For application of this section the main. A new table has been added to article 250. Table 250 102 c 1 from the 2014 nec.

Article 250 is the largest article in the nec and yet for years the article has only had the following two tables. 2017 nec study guide for grounding electrode systems this study guide was prepared by gaylord poe few things are more frustrating for an electrician than trying to figure out how the nec rules for service grounding and bonding are going to be interpreted and enforced by the local electrical inspector. Grounding and bonding table 250 66 table 250 122 part iii.

Rating or setting of automatic overcurrent device in circuit ahead of equipment conduit etc. Supply side grounded and bonding conductors are sized from table 250 102 c 1 in the 2014 nec. Size of largest ungrounded service entrance conductor awg kcmil size of grounding electrode conductor awg kcmil.

The current path shown between the supply source ground ing electrode and the grounding electrode at the service main shows that some current will flow through the earth but the. Mike holt s illustrated guide to understanding 2011 nec requirements for grounding vs. Table 250 122 for sizing equipment grounding conductors.

Table 250 66 for sizing grounding electrode conductors of alternating current systems. 58 mike holt s illustrated guide to understanding 2017 nec requirements for bonding and grounding 250 4 grounding and bonding 5 effective ground fault current path. Minimum size equipment grounding conductors for grounding raceway and equipment.

Not exceeding amperes copper awg or kcmil. Just review the table below. This table lists the minimum sizes of grounding conductors for grounding raceways and equipment.

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. Grounding electrode conductor for ac systems. Table 310 15 b 2 a ambient temperature correction factors.

In earlier codes all these conductors as well as the grounding electrode conductor were selected from table 250 66. Nfpa 70 national electrical code table 250 95. Ground wire size table.