Heat Treatment Oven (with separate control cabinet)

[Dr.Al]

I have another question. My thermocouple has a nice braided steel shielded cable. But it is longer than necessary. Should I cut that cable then use the cut off piece inside the control box from the jack to the controller. Guessing the conductors in that nice cable are special also.

I'm most definitely not an expert, but I think that would be okay to use inside the control box. Just make sure you maintain the polarity (i.e. use the same wire as + on inside and outside) as the two wires will be different materials to each other.