Home built in '04 with separate in-cabinet microwave and oven. I'm the process of replacing the microwave and the new one comes with a 20a plug, whereas the old one (and the oven) were hardwired inside the same junction box being fed by a single 30a breaker.
Something tells me converting the new microwave plug to hardwire isn't the best idea and that my only real solution is to have a new 20a line run.
Would love to hear your thoughts, TIA.
You are correct in thinking converting a microwave plug to hardwire isn't the best idea. You can reuse the existing branch wiring and just add a 20A receptacle.
There are some very special code rules in running a 30A or larger 120V circuit, so I would avoid reusing the 30A breaker if at all possible.
You can usually find nameplate information inside the microwave door, it should give you some electrical information such as the wattage input, or amperage requirement. Something like 1550 watts or 12.9 amps. If you are lucky it might give you an MOCP (maximum over current protection) that would be you breaker size you should install to maintain the warranty.
If it doesn't have an MOCP and your nameplate is less than 2000 watts or 16 amps. Then it would be wise to install a 20A breaker.
I am assuming that this circuit is only feeding the microwave, and I am also assuming the branch wiring is a #12 or greater.
Hope this helps. Good luck.
