Instrument cable specifications and models
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From the field instruments to the terminal blocks in the cabinet, there is an instrument wiring box in between, as well as branch cables. There are also main cables running from the wiring box to the cabinet. Are there any specifications regarding the selection of these instrument cables? Take the cable design for a project as an example: the branch cables use 1x2x1.5mm2 cables, while the main cables use 16x2x1.0mm2 cables. For the DO circuit branches, 1x2x2.5mm2 cables are used, and the main cables in these circuits are 12x2x2.5mm2 in size. Are there any regulatory requirements regarding the selection of these cables?
The wire diameter is related to the current-carrying capacity; for instruments, 1.0 and 1.5 mm2 are generally sufficient, with 1.5 being the more appropriate choice. Using 1.0 may result in significant voltage drops over long distances. I’ve never used 2.5 mm2 wires, and in our electrical installations we also use 1.5 mm2 wires.
Refer to HG/T 20512-2014 \"Code for Design of Instrument Piping and Wiring\"
Refer to HG/T 20512-2014 \"Code for Design of Instrument Piping and Wiring\"
What project is this of yours? Why are branch cables thicker than main cables? Is the branch cable longer? Then what’s the need for a main cable? Also, use a 2.5 cable? How far is the transmission distance for you? What a strange design……
Branch cables are generally around 40 meters long; the devices are relatively large, while the main cable is about 600 meters long.
I think there might be a problem with the design; it makes no sense for the branch cables to be thicker than the main cable