Design issues for main cables and branch cables
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The main cables from the cabinet room to the on-site junction box are multiple sets of 2*1.0 mm; the branch cables are all 2*1.5 mm, with no waste Do any of you have the design reference codes for this? Thank you all for your guidance.
No standard exists for this; refer to HGT20512 7.1.2. Multi-core wires can be reduced in diameter based on single-core wires. For 1.5, the strength and resistance of the wire need to be taken into account; of course, detailed calculations can be conducted to make a choice based on actual conditions
It doesn’t say that it’s based on a single core, right?
Are there any experts who can provide guidance? Thank you
As per the petrochemical regulations, specifically clause 6.1.2 of SH3019, it specifies that for non-intrinsic safety cables, the minimum value is 1.5, while for main cables it is 1. For consistency’s sake, intrinsic safety cables are also selected according to these standards. Based on experience from previous projects, this selection method meets the required performance standards. Chemical engineering specifications are relatively more lenient, but designs generally follow a factor of 1.5 or 1, unless the distances are quite close. Choosing a cable with a smaller cross-section means you need to check the voltage drop and determine whether the intrinsically safe circuit meets the requirements
In other words, for long distances, with a main cable of 1.0 and branch cables of 1.5, there is no need to worry about voltage drop; but for a main cable of 1.0 and branch cables of 1.0, does voltage drop need to be considered? Thank you for your further guidance
The distance for long-range use depends on how far it is; for ordinary low-power meters, there are no major issues within 500 meters. As for using 1.0 for the branch you mentioned, if you have experience working on previous projects or if the calculations are correct, then it can certainly be used as well, as long as it is above the minimum value required by the standards.
Come and learn* :):):):):):)
Well, it just seems exhausting to look at – so many different specifications. If mine is 1.0, provided the distance allows it.