680.25(1) Feeders.
Code Change Summary: Revisions were made to the requirements for feeders serving pool equipment.
Several of the wiring methods previously found in 680.25 were removed and replaced with references to 680.14 where they now reside. As well, the requirements for feeders were greatly simplified.
Under the 2014 NEC®, the rules for a feeder serving swimming pool loads were very restrictive, especially when dealing with existing panelboards supplied by an existing feeder. Imagine bidding the electrical installation for a new swimming pool at an existing dwelling where a service disconnect outside supplied an interior panelboard by an SE cable feeder with a bare equipment grounding conductor. Even if there was plenty of room in the existing interior panel to add the new swimming pool loads, it was not allowed to be done because the existing SE cable feeder to the panelboard did not have an insulated equipment grounding conductor. In such a case, the existing SE cable feeder would need to be replaced with a wiring method containing an insulated equipment grounding conductor.
In the 2017 NEC®, the rules have changed and make much more sense. For an existing panelboard located in an area not considered to be corrosive, the existing SE cable feeder mentioned above with an uninsulated equipment grounding conductor can remain. If the new pool loads have wiring that passes through a corrosive environment as defined in 680.14(A), they must be in a wiring method that complies with 680.14(B) and have an insulated equipment grounding conductor.
Below is a preview of the NEC®. See the actual NEC® text at NFPA.ORG for the complete code section. Once there, click on their link to free access to the 2017 NEC® edition of NFPA 70.
2014 Code Language (according to Errata 70-14-2 on the NFPA website: http://www.nfpa.org/Assets/files/AboutTheCodes/70/Errata70-14-2.pdf)
680.25 Feeders. These provisions shall apply to any feeder on the supply side of panelboards supplying branch circuits for pool equipment covered in Part II of this article and on the load side of the service equipment or the source of a separately derived system.
(A) Wiring Methods.
(1) Feeders. Feeders shall be installed in rigid metal conduit or intermediate metal conduit. The following wiring methods shall be permitted if not subject to physical damage:
(1) Liquidtight flexible nonmetallic conduit.
(2) Rigid polyvinyl chloride conduit.
(3) Reinforced thermosetting resin conduit.
(4) Electrical metallic tubing where installed on or within a building.
(5) Electrical nonmetallic tubing where installed within a building.
(6) Type MC cable where installed within a building and if not subject to corrosive environment.
(2) Aluminum Conduit. Aluminum conduit shall not be permitted in the pool area where subject to corrosion.
(B) Grounding. An equipment grounding conductor shall be installed with the feeder conductors between the grounding terminal of the pool equipment panelboard and the grounding terminal of the applicable service equipment or source of a separately derived system. For other than feeders to separate buildings that do not utilize an insulated equipment grounding conductor in accordance with 680.25(B)(2), this equipment grounding conductor shall be insulated.
2017 Code Language:
680.25 Feeders. These provisions shall apply to any feeder on the supply side of panelboards supplying branch circuits for pool equipment covered in Part II of this article and on the load side of the service equipment or the source of a separately derived system.
(A) Feeders. Where feeders are installed in corrosive environments as described in 680.14, the wiring method of that portion of the feeder shall be as required in 680.14(B) or shall be liquidtight flexible nonmetallic conduit. Wiring methods installed in corrosive environments as described in 680.14 shall contain an insulated copper equipment grounding conductor sized in accordance with Table 250.122, but not smaller than 12 AWG.
Where installed in noncorrosive environments, feeders shall comply with the general requirements in Chapter 3.
(B) Aluminum Conduit. Aluminum conduit shall not be permitted in the pool area where subject to corrosion.