Hello -

I've been reading the postings here and in other locations to help me ensure that I install underground electrical wiring for a spa in a safe and up-to-code manner. I have a few questions to confirm my understanding. I live in California. Thanks, in advance, for your responses.

1) 50 amp branch line will be 4 wire #6 THHN starting from the sub-panel breaker in my garage to an externally mounted box with 50 amp GFCI breaker to the spa. OK?

2) The run from the sub-panel to the external breaker box will be encased in flexible liquidtight non-metallic conduit (Carlon Carflex or similar). That's about 50'. OK?

3) The run from the external breaker box to the spa will be in schedule 40 UL listed (grey) conduit buried 18" under grade with a warning tape 12" under grade. That's about 50'. OK?

4) Does the PVC conduit require any special support or can I just lay it into the 18" trench and then cover with dirt 6" at a time and compact each layer?

5) Should I drill weep holes in the PVC conduit even if the conduit is fully sealed along its entire length?

6) At the external breaker box end, can the PVC conduit emerge from the soil and terminate at the breaker box without any additional protection (such as metal conduit)?

7) The spa is a hard-wired type. At the spa end, the PVC conduit will emerge vertically from the edge of the concrete pad and terminate in a double-gang PVC box 6" above the concrete pad. I am not planning on providing additional mounting for the PVC box. OK?

8) From the PVC box, the wire run will exit in flexible liquidtight non-metallic conduit (Carlon Carflex or similar) and enter the spa skirt/cabinet. The flexible conduit run will be approximately 2 feet. The run will terminate at the spa's internal power terminals. OK?

Thanks again for your help.

Mark

My answers follow in bold

1) 50 amp branch line will be 4 wire #6 THHN starting from the sub-panel breaker in my garage to an externally mounted box with 50 amp GFCI breaker to the spa. OK?
OK but only need 3-#6 and 1#10 green THWN to use as an equipment ground. And be sure any wire that is in aconduit outdoors or underground is rated THWN, for wet locations, most THHN is dual rated, but be sure to check

2) The run from the sub-panel to the external breaker box will be encased in flexible liquidtight non-metallic conduit (Carlon Carflex or similar). That's
About 50'. OK?
OK

3) The run from the external breaker box to the spa will be in schedule 40 UL listed (grey) conduit buried 18" under grade with a warning tape 12" under grade. That's about 50'. OK?

Perfect

4) Does the PVC conduit require any special support or can I just lay it into the 18" trench and then cover with dirt 6" at a time and compact each layer?
No special support, just don't let any rocks get near the pipe.


5) Should I drill weep holes in the PVC conduit even if the conduit is fully sealed along its entire length?
Yes, but only need at one end that is the lowest end where water will collect.

6) At the external breaker box end, can the PVC conduit emerge from the soil and terminate at the breaker box without any additional protection (such as metal conduit)? Yes , unless this is a location that something can damage the conduit, but Sch 40 is usually fine and can take a decent beating

7) The spa is a hard-wired type. At the spa end, the PVC conduit will emerge vertically from the edge of the concrete pad and terminate in a double-gang PVC box 6" above the concrete pad. I am not planning on providing additional mounting for the PVC box. OK? Many local codes require conduit risers in concrete to not be PVC and to be GRC rigid steel conduit, with the right fittings you can change over to steel conduit below and rise with steel coming thru the concrete.PVC with no extra support can break off too easily when rising up out of concrete.

8) From the PVC box, the wire run will exit in flexible liquidtight non-metallic conduit (Carlon Carflex or similar) and enter the spa skirt/cabinet. The flexible conduit run will be approximately 2 feet. The run will terminate at the spa's internal power terminals. OK?
Sounds fine

There needs to be a service disconnect or an emergency shutoff no closer than 5 feet away form the tub, and no more than 50 and within site of the tub. There also needs to be a120 volt GFI convenience outlet no closer than 5 feet and no farther than 10 feet away from the tub.

Otherwise sounds like you good to go.

My answers follow in bold

There needs to be a service disconnect or an emergency shutoff no closer than 5 feet away form the tub, and no more than 50 and within site of the tub. There also needs to be a120 volt GFI convenience outlet no closer than 5 feet and no farther than 10 feet away from the tub.



Thanks very much for the quick response... I appreciate it! Just one follow-up...

I've looked into this requirement and have seen conflicting information on whether I need to install the convenience outlet at all. The NEC is clear on the disconnecting requirement, but when I went to my local city building department to research my plans, I was told that a hard wired spa did not require an outlet near the spa. However, I have not yet gone back yet to get the plans approved.

Do you know the rationale behind requiring a convenience outlet? I surmise it is to make it inconvenient for someone to provide a general purpose outlet in the same location that a plug-in spa's power outlet is located. So if my spa is hard-wired, that would seem to not apply.

The only reason I'm questioning this is I'd rather not go to the trouble of installing a 120V branch circuit that I expect to never use unless it's absolutely required by code.

Thanks,
Mark

The reason is to insure there is an outlet for a radio, etc. and no extension cords will be necessary.Also for repair tools to service the unit.

I was off on the dimensions, no closer than 10 feet and no farther than 20 feet for an outdoor pool, that may help you.

NEC 680.42 Outdoor tub installations refer to Part 1 & 2 of 680, see 680.22(3)
Of the 2005 NEC, (http://www.nfpa.org/aboutthecodes/AboutTheCodes.asp?DocNum=70) makes no mention of cord or hardwired pool/tub.

However, this is why local code should always be checked, each AHJ can modify the code as they see fit.

Thanks very much, tkrussell. You've been a big help!