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)