The first thing you need to do is get the specifications/installation instructions for the units that you are planning to install. If they say they "REQUIRE" a certain dedicated circuit, you must follow that. If they say they "RECOMMEND" a certain thing, while probably not a code requirement, you should likely follow it.

Other than that, there is an exception in the NEC for this sort of thing. It allows you to tap a 50A range circuit into not less than 20A tap circuits for wall oven and cooktops.

From Art. 210.19(3)

Exception No. 1: Conductors tapped from a 50-ampere branch circuit supplying electric ranges, wall-mounted electric ovens, and counter-mounted electric cooking units shall have an ampacity of not less than 20 amperes and shall be sufficient for the load to be served. These tap conductors include any conductors that are a part of the leads supplied with the appliance that are smaller than the branch-circuit conductors. The taps shall not be longer than necessary for servicing the appliance.

By the way, if you're planning on ever installing an induction cooktop, you might as well run two circuits. The 5 hob induction tops can easily chew up a 50A circuit on their own.

Ron, you have helped me a few times before with electrical advice.

Thanks for the reply.

So, as I understand this, I can retain the 50 amp wiring which feeds the existing stove/oven unit, and tap (in a junction box which replaces the existing 50 amp receptacle) two separate 20 amp circuits to feed each of the new cooktop and wall oven. That seems reasonable to me, as having to run separate 40 or 50 amp circuits for each did not make sense to me, although if required I would have done so.

Regarding the induction cooktop, I'm 73 years old, and I don't think that is likely at this point in my life. I am very happy with the transformation of my new kitchen as it is.

Thanks,

Ted

Ron, you have helped me a few times before with electrical advice.

Thanks for the reply.

So, as I understand this, I can retain the 50 amp wiring which feeds the existing stove/oven unit, and tap (in a junction box which replaces the existing 50 amp receptacle) two separate 20 amp circuits to feed each of the new cooktop and wall oven. That seems reasonable to me, as having to run separate 40 or 50 amp circuits for each did not make sense to me, although if required I would have done so.

Regarding the induction cooktop, I'm 73 years old, and I don't think that is likely at this point in my life. I am very happy with the transformation of my new kitchen as it is.

Thanks,

Ted

While old 3 wire circuits are grandfathered in, if you touch it to alter it, it will be required to be a new 4 wire circuit. Splitting it in a junction box to feed two appliances rather than one would seem to me to fall under the replacement bit. And replacing it, it would be the better choice to replace it with the larger wire to future proof it for choices that may require more power. You may not personally benefit from that, but any future homeowner will, and it could be a selling point that it is "induction ready". And, if you enjoy cooking, you really would benefit from switching to induction yourself. It's easier to cleanup messes on, and you can get very hot highs, easily controllable lows, and instantaneous response of one to the other, just like with a gas flame.

"shall be sufficient for the load to be served"

This usually gets you.