![]() ![]() ![]() Once there, click on their link to free access to the 2020 NEC ® edition of NFPA 70. Texas Electrical Code 2020 > 2 Wiring and Protection > 250 Grounding and Bonding > 250. See the actual NEC ® text at NFPA.ORG for the complete code section. A electrode conductor, sized in accordance with 250.66 for the largest derived ungrounded conductor (s) or set of derived ungrounded. In the 2020 NEC ®, this mistake was corrected and now, a bonding jumper to other metal water piping (that does not qualify as a grounding electrode) is never required to be larger than 3/0 copper or 250 kcmil aluminum.īelow is a preview of the NEC ®. In the 2017 NEC ®, a proposal was accepted to change a code reference in 250.104(A)(1) which resulted in a bonding jumper to other metal water piping having to be sized using the same method for other items in Table 250.102(C)(1) using the 12 ½% rule (from note 2 under the table) when the largest ungrounded conductor exceeded 1100 kcmil copper or 1750 kcmil aluminum. The bonding jumper from the service to other metal water piping not meeting the criteria in 250.52(A)(1) is currently sized from NEC ® Table 250.102(C)(1) but in the 2014 NEC ®, was sized from Table 250.66 and never had to be larger than 3/0 copper or 250 kcmil aluminum. Prior to that, Table 250.66 was used to size other items including grounding electrode conductors, grounded conductors, main bonding jumpers, system bonding jumpers, supply-side bonding jumpers and bonding jumpers to other metal water piping that did not qualify as a grounding electrode. Except to ground rods which can be a 6 AWG copper. Grounding Electrode Conductor Size: 4 AWG copper conductor. Since the 2014 NEC ®, Table 250.66 has only applied to grounding electrode conductors. All other grounding electrode conductor connections, such as to the metal water pipe and to the concrete-encased electrode, will need to be sized as the 4 AWG copper required in Table 250.66. The grounding electrode conductor between the water pipe grounding electrode mentioned above and the service is sized from NEC ® Table 250.66 which never requires larger than 3/0 copper or 250 kcmil aluminum. For more information related to the NEC, please visit NFPA’s electrical solutions webpage. Code Change Summary: Revised code language on bonding metal water piping systems.Īccording to NEC ® 250.52(A)(1), metal underground water piping that is electrically continuous and in direct contact with the earth for at least 10 feet qualifies as a grounding electrode. Table 250.122 Minimum Size Equipment Grounding Conductors for Grounding Raceway and Equipment Additional information about grounding and bonding is available on our website. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |