Are there any requirements for the cross-sectional area of the ground wire?

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For the grounding conductors in factories, aside from flat iron and round steel, the most common types are yellow-green colored grounding wires, or yellow-green colored copper-clad steel wires. So, are there any requirements regarding the cross-sectional area of grounding wires depending on their intended use? It’s unlikely that a 2.5 mm2 grounding wire would be sufficient for grounding the casing of high-voltage motors. Is there anyone who is familiar with this topic and can provide some insights? Minimum requirements: For lightning protection grounding conductors, the cross-sectional area of flat steel should be no less than 50 mm2, and the diameter of round steel should be no less than 8 mm; if it is a yellow-green colored grounding wire, its cross-sectional area should be no less than 2.5 mm2 (according to standard GB50065 – 16 mm2 for wires without mechanical protection, and a higher value for those with mechanical protection). For anti-static grounding conductors, the cross-sectional area of flat steel should be no less than 50 mm2, and the diameter of round steel should be no less than 8 mm; copper-core grounding wires require a cross-sectional area of at least 16 mm2 (as specified in SH3097 for fixed equipment). For protective grounding, if the cross-sectional area of the phase wire is 16 mm2 or less, it should be the same as that of the phase wire; if it is between 16 and 35 mm2, it should also be 16 mm2; if the phase wire’s cross-sectional area is greater than 35 mm2, then the protective grounding conductor’s cross-sectional area should be half of that of the phase wire (per GB50650). Is this understanding correct? If a small motor uses a cable with a 4 mm2 phase wire, then using a 2.5 mm2 grounding wire for the motor’s casing might violate the standards. But since I’m already using a 5-core cable with a grounding wire inside the junction box, does the casing of the equipment also need to meet these requirements?