Laying of instrument cables
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Is it better to use a direct pull method for laying instrument cables, or to use multi-core cables with junction boxes on site for distribution? Which approach is superior? Does the distance between the cables have a significant impact?
The direct pulling method has high costs; its advantage is that it eliminates the fault point represented by the distribution box, while its disadvantage is that no spare cables can be reserved
That is, direct wiring is used for mature processes, while branched wiring is used for new processes or those with significant changes
What kind of logic is this! The cost of direct connection should be lower. Firstly, the material cost is lower for direct connection, as there is no need for junction boxes or cable protection; however, the labor cost is slightly higher for direct connection. Overall, the cost of direct connection is likely to be slightly less than that of using junction boxes. From a usage perspective, the transition using a junction box is better than direct pulling, mainly because it provides spare cables, which facilitates adding new ones in the future or replacing them in case of cable damage. The choice of method depends on the cable installation distance; in my opinion, when it exceeds 200 meters, a junction box should be used for connection, while for distances under 200 meters, a direct connection is sufficient.
The new device uses a 32-core cable that goes into one junction box; surely 16 two-core flame-retardant cables would be cheaper than one 32-core flame-retardant cable. The labor costs will also be much higher.
This post was last edited by hfrs on 2018-7-4 at 10:40. Hehe, the price of copper determines the price of cables; I can assure you that when the amount of copper used is the same, there is no difference in price!
In my opinion, whether to use direct wiring or a junction box depends mainly on the number of connection points required on site; if only one connection point is needed, then direct wiring is definitely the better option. If there are too many points with the same path, it must be a junction box. Excessive distance between wires can lead to losses; if the distance is too large, it may be advisable to add signal amplifiers in between
Perhaps wiring the box in that way is more convenient
I learned something new – I had assumed that sleeves would increase costs significantly.
Centralized instruments use junction boxes, while those that are distributed are connected directly.