I plan to install a 220V appliance on one side of the kitchen. However, the 220V outlet is on the opposite wall below the counter. Can I run the electrical wire from the outlet down, and then through the floor/concrete slab to the other side? I'll have to make a groove on the slab for the wire. Any safety issue? Is this legal? (Note: Running the wire through the ceiling is not achievable.)
Type UF can be buried in the sand beneath the concrete, but any wiring must be in conduit pipe where it passes through [or touches] concrete. If you cut a groove across the surface of the concrete, you will have to make it big enough for the conduit. Armored cable is not rated for use inside concrete. A homeowner can do the work on his own residential dwelling as long as it is not a multifamily dwelling. A licensed contractor is required for everything else. I have never heard of homeowners insurance being voided [in the USA] by the property owner doing his own work.
Yes, but the wire has to have protection. The wire has to be run in RMC (Rigid Metal Conduit).
It can be done with a straight length of metal conduit, with a junction box or bend up and best to insulated or wrapped round with waterproof covering or protection.If joint is needed,the joint should be coated with a layer of waterproof e.g silicon or sealant. The wire or cable can be run into the conduit by a pre-placed draw wire or just run the cable in with extra length.The job on the concrete floor is completed and the concrete groove cut can re screeded or sealed with cement or floor finishes.
Run it in the best watertight conduit that you can find. Make it as safe as possible. Ask the guy at the home center what to use. Do it as professional as possible and hisde it as well as possible and you will not ever hear about it on an inspection. Those guys are lazy and look for obvious wiring mistakes. They don't peel apart walls or dig up concrete.
If you are going to run it through concrete use pvc pipe or rigid pipe. Emt will rot out in a few years from the moisture in the concrete.
