{"id":8397,"date":"2013-09-16T21:56:58","date_gmt":"2013-09-16T21:56:58","guid":{"rendered":"http:\/\/iaeimagazine.org\/2014\/05\/16\/sole-connections\/"},"modified":"2014-06-04T22:43:52","modified_gmt":"2014-06-04T22:43:52","slug":"sole-connections","status":"publish","type":"post","link":"https:\/\/iaeimagazine.org\/columns\/focus-on-the-code\/sole-connections\/","title":{"rendered":"Sole Connections"},"content":{"rendered":"

Question:<\/span>
\nAt 250.66(A) and (B), the Code<\/span> refers to a “sole connection to\u00a0the grounding electrode.\u201d Please explain\u00a0what sole connection means; and is the term sole connection<\/span> defined\u00a0anywhere in the NEC<\/span>? PM<\/p>\n

 <\/p>\n

Answer:<\/span>
\nThe words “sole\u201d or “solely\u201d appear\u00a0many times throughout the NEC, <\/span>but are not defined in Article 100 or in\u00a0the “.2\u201d sections of individual chapters. The dictionary defines it as an\u00a0adjective that means “only\u201d; in this situation it is the only connection to the\u00a0grounding electrode system. \u00a0Synonyms that show up under a word search are: only, solitary, single, individual, singular,\u00a0lone, one and only, and exclusive.<\/p>\n

This term sole\u00a0connection<\/span> is referring to the only connection to the actual grounding\u00a0electrode itself, and not necessarily a sole or single ground rod. Using the\u00a0ground rod scenario as an example, if the singular grounding electrode in\u00a0question consists of two ground rods (one rod supplementing the other), the\u00a0grounding electrode conductor and the bonding jumper to the second ground rod
\nwould be considered the sole connection to this grounding electrode system.<\/p>\n

The sole connection\u00a0clarification was made crystal clear by action taken by code-making panel 5 for
\nthe 2014 NEC<\/span>. The revised language at 250.66(A) and (B) is an attempt to\u00a0clarify the sole connection sizing provisions for grounding electrode\u00a0conductors to rod, pipe, plate, and concrete-encased electrodes. The plural\u00a0language added at 250.66(A) and (B) makes it clear that the sole connection\u00a0provisions are still relevant, even if more than one of these types of\u00a0electrodes are installed or are present at a building or structure. As an\u00a0example, let\u2019s say a single ground rod was installed to supplement a metal\u00a0underground water piping system that qualified as a grounding electrode [3.0 m\u00a0(10 ft) or more in contact with the earth]. The ungrounded service-entrance
\nconductors involved are sized at 4\/0 AWG copper, which would require a 2 AWG\u00a0copper grounding electrode conductor. Installing a 2 AWG copper grounding\u00a0electrode conductor from the service disconnecting means to the metal water\u00a0piping system would be in order. Section 250.66(A) would permit a 6 AWG copper\u00a0grounding electrode conductor from the service disconnecting means to the\u00a0ground rod, or a 6 AWG copper grounding electrode conductor from the metal\u00a0water piping system to the ground rod, as this 6 AWG copper grounding electrode\u00a0conductor would be the sole connection to the ground rod. However, using this\u00a0same scenario, with the two ground rods involved connected together with a\u00a0bonding jumper [as required in 250.53(A)(2)], has caused some confusion as to\u00a0whether or not the connection to the first ground rod is now the sole\u00a0connection, since both a grounding electrode conductor and a bonding jumper are\u00a0now connected to this first ground rod. The plural language and revised text at\u00a0both 250.66(A) and (B) should make it clear that the Code<\/span> considers\u00a0these two ground rods to be one electrode as far as the sole connection sizing\u00a0provisions are concerned, and 6 AWG copper conductor could be used at both
\nground rods.<\/p>\n

This revision\u00a0should clarify that if a grounding electrode conductor is installed to multiple\u00a0concrete-encased electrodes connected together with a bonding jumper(s), the\u00a0maximum size grounding electrode conductor to the first concrete-encased\u00a0electrode or any bonding jumper(s) between the multiple concrete-encased\u00a0electrodes is not required to be larger than a 4 AWG copper conductor.<\/p>\n

\u2014 L. Keith
\nLofland<\/p>\n

IAEI Director of
\nEducation<\/p>\n","protected":false},"excerpt":{"rendered":"

Question: At 250.66(A) and (B), the Code refers to a “sole connection to\u00a0the grounding electrode.\u201d Please explain\u00a0what sole connection means; and is the term sole connection defined\u00a0anywhere in the NEC? PM   Answer: The words “sole\u201d or “solely\u201d appear\u00a0many times throughout the NEC, but are not defined in Article 100 or in\u00a0the “.2\u201d sections of […]<\/p>\n","protected":false},"author":39,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[22,270],"tags":[407],"class_list":{"0":"post-8397","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-focus-on-the-code","7":"category-septemberoctober-2013","8":"tag-focus-on-the-code"},"_links":{"self":[{"href":"https:\/\/iaeimagazine.org\/wp-json\/wp\/v2\/posts\/8397","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/iaeimagazine.org\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/iaeimagazine.org\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/iaeimagazine.org\/wp-json\/wp\/v2\/users\/39"}],"replies":[{"embeddable":true,"href":"https:\/\/iaeimagazine.org\/wp-json\/wp\/v2\/comments?post=8397"}],"version-history":[{"count":0,"href":"https:\/\/iaeimagazine.org\/wp-json\/wp\/v2\/posts\/8397\/revisions"}],"wp:attachment":[{"href":"https:\/\/iaeimagazine.org\/wp-json\/wp\/v2\/media?parent=8397"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/iaeimagazine.org\/wp-json\/wp\/v2\/categories?post=8397"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/iaeimagazine.org\/wp-json\/wp\/v2\/tags?post=8397"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}