You posted this before but said you had the manufacturer coming.
What exactly is the problem?
What is it you are trying to do?
What supply do you have?
OK, thanks for that.
There should be a plate on the appliance that gives a figure of how many watts or Kwatts it uses.
Can you post this please?
What are the colours of the wires you are using and what is it wired into?
Is it wired into a plug or an outlet in the wall?
The more detail you can give me on this the better.
Take off the plate on the rear of the oven.
It should be marked to identify the terminals.
Slacken the screw, put the wire under and around the screw, tighten it again.
Do this for all three wires then put the cover back on.
Switch on and set the clock.
You should be up and running with the oven.
Hope this helps
Let me know how it goes or if you need more help.
Thank you for the payment and the feedback, it is appreciated.
You weren't being thick, far better to double check and be correct than get it wrong.
Good luck with the appliance.