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questions on wiring for a sauna?

sandbert | Posted in General Discussion on January 19, 2005 10:44am

You guys would know this, and probably suggest some good options too.

We had a hot tub sitting out on the patio slab.  We got rid of it and we’re replacing it with a sauna, which I’m in the process of building.  Wiring that was for the hot tub and will now supply the sauna comes up through the slab, encased in pvc conduit.  The conduit was cut off flush with the surface of the slab when the tub was set over it.  Now that wire comes up on the inside of the sauna just by the wall.  My plan is to run the wire up the wall a little (this will be under the sauna bench) through pvc conduit to an LB (is that right?) junction box.  This would give me access to the wire under the slab if for some reason I ever needed it.  From there the wire goes into the wall and up and out to the exterior where it feeds a sub-panel.  The sub-panel then supplies 240v to the sauna heater and 120v to a gfi outlet and a light.

My main question is, how do I get a good seal of the conduit coming up from the slab to the LB, to the surface of the slab where the wire come out?  So when the kids (or I) knock over the water bucket the water doesn’t run down that hole where the wire comes up.  I suppose that if I were using heavy steel conduit I could put down a floor flange and a lot of caulk and screw the conduit into that.  But the hole where the wire comes up is right up against the wall so there really isn’t room for a floor flange.  I suppose I could cut off part of the side so it would fit against the wall?  Is there a pvc alternative?

Any suggestions and comment about this or my wiring theory would be welcome.

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Replies

  1. rez | Jan 23, 2005 05:57pm | #1

    Greetings hubert,

    This post to your question will bump the thread through the 'recent discussion' listing again.

    Perhaps it will catch someones eye that can help you with advice.

    Cheers

     

  2. DanH | Jan 23, 2005 06:06pm | #2

    I'd say you should do it right. Chip out the slab around the conduit and glue on a coupling. If you don't do this then the conduit will act like a floor drain, both for water spilled inside and for rainwater seeping in from outside.

    Probably making some saw cuts near the conduit with a masonary saw would make the job easier and reduce the chance of cracking the conduit while chipping.

    You do need to protect the conduit from physical damage somehow, no matter how well attached. Probably best would be some sort of a wood box, to protect legs from burns.

  3. User avater
    Gunner | Jan 23, 2005 06:23pm | #3

    Like Dan says chip out around the pvc and do it right. I would also put the main feed coming from the house on a GFI breaker. Expensive but so are funerals.

    Who Dares Wins.

  4. User avater
    BillHartmann | Jan 23, 2005 07:21pm | #4

    "My plan is to run the wire up the wall a little (this will be under the sauna bench) through pvc conduit to an LB (is that right?) junction box"

    The LB might not be rated as a junction box. The size is too small.

    The LB is mainly a place to pull wires.

    If you want junction box you have a couple of options. Mount one just below the LB.

    Or get a pvc box and it if does not have knock holes in the right places you can drill a hole and glue in a hub.

    And ditto on chipping out around the existing stub.

    1. 4Lorn1 | Jan 24, 2005 02:44am | #5

      Good call.I think the original posters confusion is related to a misunderstanding about the roll of the conduit. As you know conduit is not primarily about keeping the water out. Their purpose is to provide mechanical protection. Any conduit underground is considered to be wet. The insulation of the conductors used have to be rated for this wet location. If the conduit keeps the water out so much the better but it is not vital. The system is designed to work with the underground conduits flooded.Condulets, LBs and such, can be used for junction boxes if they have their cubic inch or wire capacity marked, typically inside. This won't likely help him much because if connections are made up the LB needs to comply with the standard box fill requirements.It works out with a 3/4" LB and a couple of #14s made up. There just isn't much room for more. Your idea to use a box is good. If room allows he could chip out enough for a small box, he will still need to watch the fill, to be mounted partially underground. A 4" deep plastic weatherproof box looking up half out of the floor to allow for a length of Carflex to be made up as a tail to feed the sauna. Plenty of room for connections. Little chance of flowing water going into the box and easy access. Pack around the box with a bit of cement to firm it up after being glued in place. Pack the conduit coming out of the ground with duct seal to limit moisture entry. Make up with wire nuts pointing up so they drain. The silicon filled version might be a good call to limit corrosion. Ground the daylights out of everything.

      1. User avater
        SamT | Jan 24, 2005 05:02am | #6

        S'funny, when I read his post, I got the definite impressions that he had 4'-6' of cable sticking out of his underground conduit.

        He had mechanical protection covered, either thru conduit or inaccessability, all he wanted was to keep water out of his pipes. I was thinking of stuufing it with weatherseal putty.

        SamT 

        Edited 1/23/2005 9:49 pm ET by SamT

        1. sandbert | Jan 29, 2005 01:02am | #7

          Hey, I am finally getting back to you guys to thank you for the responses, sorry it took so long.  After posting the initial question last wednesday I took a couple of days off of work and started on this project, so I got into it without seeing these posts.   The idea of cutting out the concrete to expose the conduit just never occurred to me.  But as the goal was to try to eliminate water flowing in and having that conduit acting as a floor drain, I just went with a floor flange bolted to the concrete floor with a lot of caulk in and around it.  Cutting off part of the flange so that it could fit against the wall that was already framed in turned out to be easier than I had thought.  I will certainly incorporate your suggestions as to grounding, junction box and GFCI protection.

          thanks again,

          -hubert

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