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-   -   I'd like to install Warm Wire to an Existing circuit (https://www.askmehelpdesk.com/showthread.php?t=500087)

  • Aug 20, 2010, 11:49 AM
    kcsmith1958
    I'd like to install Warm Wire to an Existing circuit
    Here's the deal, so before you tell me that it HAS to be a dedicated circuit, please read on...

    We're changing the kitchen flooring from vinyl tiles to ceramic. We'd like to install some Warm Wire - to cover @ 100 square feet - here's the detail on the Warm Wire directly from the SunTouch website

    100 sq ft area
    470 total wire needed (@ 2.5" OC)
    Amp draw = 10.0
    Resistance = 9-12 ohms

    I've got existing 20 Amp circuits in the kitchen - one with the refrigerator (6.5 Amps) and one other plug (2 outlets) - that's it on that circuit. A frig is not "continuous" power, and the Warm Wire wouldn't be continuous power either.

    Can I make this work?

    Ideas, thoughts, etc. - Thanks!

    Kendal
  • Aug 20, 2010, 12:11 PM
    KISS

    OK, I won't. But I will tell you that space heating loads must be sized at 1.25 their rating. So the 10 A becomes 12.5A and 6.5+12.5 = 19A leaveing no wiggle room for even the motor on the fridge to start.

    The heating load should be a 15 A circuit. 12.5A sized up to nearest breaker.
  • Aug 20, 2010, 12:28 PM
    kcsmith1958

    Oooo - oh bummer. I thought I might be able to get by with neither of them being a continuous power appliance.

    I don't think I have any room to add a breaker. I can check to see if any of the wiring will support upgrading from 20 Amp to 30 Amp - requires 10 gauge wire correct?

    Kendal
  • Aug 20, 2010, 12:59 PM
    Stratmando

    #12 is fine, you may be able to use one of these, do you have conduit or a way to get to the Panel?
    piggyback breaker - Google Product Search
  • Aug 20, 2010, 01:19 PM
    kcsmith1958

    I can get to the breaker panel no problem - no conduit, all the wires are in/thru the floor joists - so with one of these dudes, I can fit two breakers in the space of one?. running new wires, I assume?

    Kendal
  • Aug 20, 2010, 01:49 PM
    KISS

    Yep. You can buy twins in 15/15, 15/20 and 20/20 Amp.
  • Aug 20, 2010, 01:55 PM
    kcsmith1958

    After a bit of research, I think I'll have to go into the sub-panel that's already installed. The main panel is all 1/2" breakers, it's a GE main panel - from what I've read, there are no such animals as piggyback 1/2" breakers in any amperage.

    But, the sub panel does have a couple open 15 amp 1" breakers in it that I can get to.

    With the Warm Wire install I've got coming up - 10 Amp draw - sized to 12.5 A from the previous post - I could tap one of those 15 A breakers with the piggyback breaker, run new 14 gauge wire to the Warm Wire thermostat and I'll be all set - Yes? Or do I have to go to one of the 20s and use the 12 gauge wire?

    Kendal
  • Aug 20, 2010, 02:00 PM
    KISS

    15 A, 14 AWG is fine.
  • Aug 20, 2010, 02:02 PM
    tkrussell
    The heat circuit needs to be all #12 copper wire on a 20 amp breaker.
  • Aug 20, 2010, 02:13 PM
    KISS

    tk:

    Why? The circuit draws 10 Amps?

    100 sq ft area
    470 total wire needed (@ 2.5" OC)
    Amp draw = 10.0
    Resistance = 9-12 ohms
  • Aug 20, 2010, 02:25 PM
    kcsmith1958

    There is one 20 Amp breaker in the sub panel that I can get to and install a 20/20 piggyback.

    Sounds like as long as I can get the wire run from the wall upstairs in the kitchen to the basement and across the 40' run to get to the sub-panel / breaker box, I'm all set.

    Got any tips on running that 12 gauge wire down through the floor and into the furnace area where it will come out? Oh yeah, the kitchen is completely wallpapered, I will have the baseboards off to install the tile floor. And I won't have much room in the basement where the wire will be - then it has to make a 90 degree turn and make the 35' run across the width of the basement to the panel.

    I'm going to guess that I should have it make the really long run first and pull it over into the furnace area (unfinished) and go up into the kitchen that way - as the 12 gauge wire won't be easy to work with on that long run across... Yes?

    BTW - thanks for all the help on this, you guys are awesome.

    Kendal
  • Aug 20, 2010, 03:23 PM
    Stratmando

    Romex should not be too bad.
    If the Kitchen has conduits to the panel, I would fish through there.
    When I need additional wire ran in an existing conduit, I attach my new wires to one of the old wires, and attach another wire of the one I am removing.
    Ground should already be run.
  • Aug 20, 2010, 04:16 PM
    KISS

    Yep, big steerable, 4' or longer, drill bits. Available at Home Depot. Steering wheel is separate. They also contain an eye for fishing a pull wire back.
  • Aug 21, 2010, 03:04 AM
    tkrussell
    Kiss, I had a dumb moment, and I doubled up. I realized it once I hit the send button.

    Your right, and I was wrong.

    #14 on a 15 amp CB is fine.

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