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Swimming pool, hot tub, etc. wiring methods

Mr. Inspector

SAWHORSE
Joined
Nov 28, 2009
Messages
4,030
Location
Poconos/eastern PA
LFNMC is listed in the the 2015, 2018 and 1021 IRC table as an wiring method for swimming pools, hot tubs and other areas related to open water. There is nothing about what LFNMC is in any IRC or the NEC. What is it? Some people suggested that there is no such thing or it is a mistake. It's not an acceptable wiring method for swimming pools, hot tubs, etc. in the NEC. The IRC and the NEC don't seem to agree on these wiring methods for an Corrosive Environment at swimming pools , hot tub, etc. even though the IRC is suppose to be made from the NEC.
Does anyone know what's going on here?
 
LFNMC does not exist in the NEC and the IRC electrical section is from the NEC. It has to be a typo. There is no definition of LFNMC in the IRC and it is not listed as one of the wiring methods in the IRC.

The only half-assed plausible answer is that they mean both LFNC and LFMC.
 
LFNMC does not exist in the NEC and the IRC electrical section is from the NEC. It has to be a typo. There is no definition of LFNMC in the IRC and it is not listed as one of the wiring methods in the IRC.

The only half-assed plausible answer is that they mean both LFNC and LFMC.
According with 2018 IRC it would not be NFMC because it is already has it's own column in the table. But nether LFMC or LFNC is not listed as an allowable wiring method in the IRC per table E3801.2 Allowable Wiring Methods or in table 3801.4 Allowable Applications for Wiring Methods.

So LFNMC (if there is such a thing) , LFNC or LFMC can't be used at all for one and two family dwellings?
 
2020 NEC
ARTICLE 680
Swimming Pools, Fountains, and Similar Installations

680.11 Underground Wiring. Underground wiring shall comply with 680.11 (A) through (C).

(A) Underground Wiring. Underground wiring within 1.5 m (5 ft) horizontally from the inside wall of the pool shall be permitted. The following wiring methods shall be considered suitable for the conditions in these locations:

1. Rigid metal conduit
2. Intermediate metal conduit
3. Rigid polyvinyl chloride conduit
4. Reinforced thermosetting resin conduit
5. Jacketed Type MC cable that is listed for burial use
6. Liquidtight flexible nonmetallic conduit listed for direct burial use
7. Liquidtight flexible metal conduit listed for direct burial use

(B) Wiring Under Pools. Underground wiring shall not be permitted under the pool unless this wiring is necessary to supply pool equipment permitted by this article.

(C) Minimum Cover Requirements. Minimum cover depths shall be as given in Table 300.5.

680.14 Wiring Methods in Corrosive Environment. Wiring methods in a corrosive environment shall be listed and identi- fied for use in such areas. Rigid metal conduit, intermediate metal conduit, rigid polyvinyl chloride conduit, and reinforced thermosetting resin conduit shall be considered to be resistant to the corrosive environment.

680.21 Motors.
(A) Wiring Methods. The wiring to a pool motor shall comply with 680.21(A) (1) unless modified for specific circumstances by (A) (2) or (A) (3).
(1) General. Wiring methods installed in a corrosive environ- ment shall comply with 680.14 or shall be Type MC cable listed for that location. Wiring methods installed in these locations 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, the wiring methods of branch circuits shall comply with the general requirements in Chapter 3.
(2) Flexible Connections. Where necessary to employ flexible connections at or adjacent to the motor, liquidtight flexible metal or liquidtight flexible nonmetallic conduit with listed fittings shall be permitted.
 
According with 2018 IRC it would not be NFMC because it is already has it's own column in the table. But nether LFMC or LFNC is not listed as an allowable wiring method in the IRC per table E3801.2 Allowable Wiring Methods or in table 3801.4 Allowable Applications for Wiring Methods.

So LFNMC (if there is such a thing) , LFNC or LFMC can't be used at all for one and two family dwellings?
Not sure what NFMC is.
This morning I spoke with the ICC and reported the typo. It is probably suppose to be LFNC since there is another column for LFMC.

This is why there should be no electrical section in the IRC and simply refer to the NFPA 70 just like Florida does. It opens the doors for typos and confustion
 
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