Dear Mr. Histor (Electrical)(OP)15 Jan 23 12:20 "....We have a 230V motor space heater power cable and a shielded thermistor cable to enter into motor terminal box in one cable entry...."
I am of the opinion:
(a) it is fine, if the shielded thermistor cable is rate for >230V say 400V.
(b) otherwise, they shall be in separate metallic or PVC conduits.
(c) A single metallic duct with metallic partition separating the two circuits are also acceptable.
Che Kuan Yau (Singapore)
Histor: Please check with your corporate specifications AND with your local authority having jurisdiction (national electric code). You might find that you require spatial distance and/or physical barriers separating "data" level signals (< 25 V) from low voltage (25 - 480 V) and both of those from higher voltage levels. You may also find that there is a requirement to separate "power" cables from "instrument" cables, regardless of voltage level.
Converting energy to motion for more than half a century