Instrument cable core cross-sectional area requirements:
1. The cross-sectional area of ​​the wire of the instrument signal cable should meet the requirements of the measurement and control circuit for the line impedance, and the mechanical strength of the cable during construction. The minimum core cross-sectional area should not be less than 0.5mm2.
2. In the case of explosion hazardous area 2 or non-explosion-proof area, the core cross-sectional area of ​​the two-core or three-core instrument signal cable radiating in the bridge or protection tube should be 1.0mm2-1.5mm2, thermocouple compensation wire. Should choose 1.0mm2-2.5mm2. The multi-core cable used for the main cable can be reduced to 0.75mm2-1.5mm2 under the condition that the line resistance is satisfied.
3. The core cross-sectional area of ​​the grounding wire shall comply with the relevant provisions of the current national standard "Code for Design of Power Engineering Cables" GB 50217 and "Code for Design of Explosive Hazardous Environmental Power Equipment" GB 50058.