Determining voltage for 1960s GE-J-720 wall oven install

Hi I recently bought a 1960 GE J-720
It’s a wall mount oven called an “Automatic Oven”

It has 3 lead wires, red black and white.
They appear to be 12GA.

I want to wire the oven up and test it before building it into my kitchen.
What I’m trying to determine is:

  1. Should I wire this up as 220V? I assume yes, but just want to confirm.

  2. What lead wire is which? it has red, white and black.

  3. How does one typically ground the oven?

I’ve been unable to find any manual for the 60’s GE wall mount ovens online, if anyone has one that would be very helpful answering most/all of these questions.
Thanks!

Its 220 to 240. This pic. should help.

Thanks ThatGuy!

You are welcome!

Ok, one last question!
The leads for the oven are run inside flex conduit to a junction box at the end.
On the top of the junction box there is a sticker that reads in bold red letters:

“ELECTRICIAN NOTE - the unit frame must be grounded in conformance with local codes see installation instructions. The frame of this unit is not grounded to neutral.”

So, after looking at the 3-wire diagram you sent ThatGuy, is this label suggesting that I should anchor the “grounding strap” at the neutral connection to the inside of the junction box? Since the junction box leads to the flex conduit which connects to the frame of the oven I assume that would essentially ground the frame? Or is there some other way people usually do this?

Thanks again!

I’d check and see if you have continuity from the oven to neutral. If you do, you should be OK.

If you have 4 wires, then go ahead and ground the oven. Inside your breaker box, ground and neural are connected. Fun fact.