I took out an old oven and replaced it with a new gas one so now I have a spare 220 line that I don’t need anymore. It backs up to the garage and I’m Wondering if there is anything useful I could use it for other than just capping it off and putting it in an access panel for the future.
It depends. If it's a 4-wire connection (hot-hot-neutral-ground) you are good to go.
If is a 3-wire connection (hot-hot-neutral and no equipment safety ground), you have two choices (or not):
- If the neutral wire is a bare wire, you can permanently recharacterize it as a ground wire, and use the two "hots" to drive a 240V-only load (but not a 120/240 load like a dryer). You move the ground wire from the neutral bar to the ground bar. (in a main panel they may be the same bar). This option is not available if the neutral is white or gray.
- You can convert it to a 4-wire connection by retrofitting a ground wire. Fortunately the ground wire need only be #10 and can follow any viable route back to the panel, any other #10 ground or conduit, or the grounding electrode system.
With that matter taken care of, you can redirect/retask it to another purpose so long as all splices are made in junction boxes which are accessible.
If it is already a 4-wire connection, or if you are making it a 4-wire connection, leave things in a state where you can convert it back to service for an electric range. Some jurisdictions require you provision this service, and easy convertibility meets the requirement.
A spare 40 amp that is acceptable from the garage can be used for all kinds of things , welders, compressors or an electric vehicle charger to name a few items. I might also suggest that it be left in place, not often but a couple of times I have been asked to install electric ovens where Gas was in use and have found that the home originally had electric wiring (some folks don't like gas if you sell the home. years ago it was easy to find convection ovens that were electric but not until more recently were gas conveaction ovens available (being the second reason).
I had what I presumed was a 220 plug installed in an out-room on the house I bought (was labeled "kiln" on the main box). Not long after, we had to replace the A/C and they put a new condenser on that side and I told them to use that 220 line (we eventually removed the wall). Saved them some time and me some money.
Import an electric kettle from Europe and put a 220V plug on it. Then you can marvel at this great invention that we've been using here since the middle of the 20th century.