wiring for a partially in-ground hottub

[Anonymous]

I am planning on installing the wiring for my new spa. I have read most of the postings here and would like confirmation on my understanding. The spa is going to be partially installed in the ground. The spa required 240V/50A service.

I plan on using Spa Disconnect GFCI Panel which specs 50A GFI with quick disconnect in an outside box. I am planning on installing a 50A 240V breaker in the main circuit panel. Running 4, 6 gauge wires from the panel under the house to the outside wall close to the spa (> 5 feet away from spa edge). I am planning on running the four (4) wires in 1" flex conduit from below the panel over to the outside wall. Drill through the stucco wall. Route the wires up to the spa GFCI panel. Do I need to use rigid conduit for this outside run? Is there any rules about a minimum height that the spa GFCI panel be mounted above the ground on the wall or any rules?

I plan to use plastic, gray pvc conduit pipe from the box to the spa. This would be buried 18" below the ground. Is there anything unusual about treating the bends in the pvc conduit pipe which would be different then sprinkler pvc? I assume I need to use wet grade wire. Is this required outside? Do I need to have conduit up to the spa's surface?

Did I miss anything obvious?

Thanks,
Matthew

[Wgoodrich]

Rigid conduit is required where subject to physical damage, flex is not approved for subject to physical damage. Mounting a conduit or flex on the outside surface of the house would be considered subject to physical damage.

Minimum height of disconnect is above flood elevation but not to exceed 6 feet 6 inches.

The PVC must be electrical conduit including bends. White plumbing plastic pipe is not approved for electrical installations. You may buy PVC conduit bends in 45 and 90 degree that is already preformed and ready to be glued to PVC conduit.

Yes your wires must have a W in the intials of the wire to show approved for a wet location where outside.

You may use sealtite for the last 6' into the tub for flexibility if you like.

Hope this helps

Wg

[Anonymous]

hi,

Thanks for the reply. I want to detail after re-reading the large number of spa posts. The spa has an underwater light. Also the wiring paths have changed. I will connect from the main panel (located on the side of the attached garage) and wire to an adjacent garage wall. I will trench 25' from this wall to the spa disconnect which is mounted next to the spa.

I was talking to an electrician and his understanding seemed to differ from some of the posts in the forum. One point was the need to get an separate, insulated ground wire from the main panel to the spa subpanel. He agreed you need an insulated ground (plus two hots & neutral) from the GFCI subpanel to the spa via conduit and four separate insulated wires from the GFCI subpanel via conduit to the garage wall. He said that once inside the garage, I could do away with the four separate wires and convert to a 6-3 cable with non-insulated ground. I said I don't think so. He asked my for a NEC code callout. Is he correct? It would be easier to not have to run conduit through my garage.

Secondly, I am planning on using 3, 6 gauge wires (2 hots & neutral) & 1 12 gauge (for ground). Is there any problems with using a 1" 80 gauge, gray PVC conduit? A friend will give me this. Or do I need to buy 1 1/2"?

Thanks,
Matthew

[Wgoodrich]

1" Sch 80 PVC is fine for 3 - 6 awg and grounidng wire.

See following copied section of NEC 2002 per underwater light of a hot tub.


680.43
(2) Underwater Applications. Underwater luminaires (lighting fixtures) shall comply with the provisions of 680.23 or 680.33.

680.23.F

(F) Branch-Circuit Wiring.

(1) Wiring Methods. Branch-circuit wiring on the supply side of enclosures and junction boxes connected to conduits run to wet-niche and no-niche luminaires (fixtures), and the field wiring compartments of dry-niche luminaires (fixtures), shall be installed using rigid metal conduit, intermediate metal conduit, liquidtight flexible nonmetallic conduit, or rigid nonmetallic conduit. Where installed on buildings, electrical metallic tubing shall be permitted, and where installed within buildings, electrical nonmetallic tubing or electrical metallic tubing shall be permitted.

(2) Equipment Grounding. Through-wall lighting assemblies, wet-niche, dry-niche, or no-niche luminaires (lighting fixtures) shall be connected to an insulated copper equipment grounding conductor installed with the circuit conductors. The equipment grounding conductor shall be installed without joint or splice except as permitted in (a) and (b). The equipment grounding conductor shall be sized in accordance with Table 250.122 but shall not be smaller than 12 AWG.

Hope this helps

Wg

[imported_suemarkp]

I see two issues that didn't get fully addressed. First, if you have a 50A feeder to the hot tub, you must have a #10 equipment grounding conductor in that feeder NOT #12. The three #6 and one #10 will easily fit in 1" sch80 PVC conduit.

Now whether that feeder must have an insulated -vs- covered grounding wire is confusing. All swimming pool feeders must have an insulated equipment grounding wire except for existing installations of a covered ground (like NM or UF cable). What I'm not sure of is whether hot tubs have to use these rules (it says they must comply with parts I through IV which covers about everthing). This is specified in 680.25(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 (1) existing feeders covered in 680.25(A), Exception or (2) 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."

This is in the hot tub section 680.42(C):

"Interior Wiring to Outdoor Installations. In the interior of a one family dwelling or in the interior of another building or structure associated with a one-family dwelling, any of the wiring methods recognized in Chapter 3 of this Code that contain a copper equipment grounding conductor that is insulated or enclosed within the outer sheath of the wiring method and not smaller than 12 AWG shall be permitted to be used for the connection to motor, heating, and control loads that are part of a self-contained spa or hot tub, or a packaged spa or hot tub equipment assembly. Wiring to an underwater light shall comply with 680.23 or 680.33."

But since you have a light, I don't think you can use this rule and must wire by 680.23 instead. This rule is also not clear in distinguishing between feeder and branch circuit. Since you're wiring to a separate disconnect, I would think the feeder rules apply anyway.

[Anonymous]

I am having the same issues and have read these posts. My electrician plans on installing a #6 wire with four conducters from my panel 40 feet through the attic and out of the house into conduit where it exits the house and into 220 volt 50 amp gfci. Then using the same cable #6/4 wire from GFCI 9 feet to the tub under ground in conduit. The tub does have a light. I guess when they come out to inspect I really will know for sure if this is correct.

[Wgoodrich]

If the disconnect outside of the house whether in a building or not has an overcurrent device the 680.25 would apply. FEEDER Conduit is not required for a feeder but only a branch circuit. This means after that fused disconnect then the conduit rule applies.

If the disconnect outside of the house has no overcurrent device then the entire run is a branch circuit requiring conduit the entire branch circuit run per 680.23 as a BRANCH circuit.

Definition of a feeder is any wire serving an overcurrent device.

Definition of a branch circuit is any wire installed after the LAST over current device.

680.23 is for branch circuit with underwater light.

680.25 is for feeder circuit with underwater light. Then the branch circuit would apply after that last overcurrent device.

Does this help clear things?

Wg