If the difficulty level of laying out cables in an ordinary security project is rated at 7.5 points, then the difficulty level of properly fixing and bundling the elevator monitoring cables is definitely above 9.0. How to handle the cables in the elevator during the project is very important, as the way of cable fixation and bundling directly affects the lifespan of the cables.

For such a complex environment as an elevator, how are the monitoring cables fixed and bundled?

Fixing of cables

1、Fixed expansion bolt；

2、Wrap the steel rope around the expansion bolt once.；

3、And fasten a lock to the steel rope.；

4、Adjust the two steel ropes to achieve balanced force distribution；

5、Tighten the nut on the expansion bolt;

6、Add another lock on top of the already fastened one (wind the steel rope head several times and then lock it)

The method of tying up

Key points for bundling: Use three tie straps to form a three-link knot. The two side rings should be tied to the elevator data cable and the elevator monitoring cable respectively. The diameter of the middle buffer ring should be controlled at 1-1.5 centimeters. The ring on the data cable should be slightly tighter to avoid shifting, while the ring on the monitoring cable should be looser so that it can slide when under force. Diagram:

1、First, make the cable ties for the elevator data cables，

2、Add an intermediate buffer ring，

3、Then make the cable ties for the monitoring cables into loops，

4、Adjust each ring buckle to the desired tightness (note: adjust the lanyard connector to the inner side of the cable)。

The spacing between the bundles was determined based on observations of the environmental conditions of the elevator shaft, analysis of the materials of the elevator data cables and monitoring cables, as well as discussions among many netizens on the Internet. It was considered that the spacing between the bundles should be 50-80 centimeters. Firstly, it should not be too dense or too sparse: too dense would cause a large pulling force between the two different material cables, while too sparse would result in a larger separation distance between the two cables when the elevator moves. Secondly, the ends should be sparse and the middle should be dense: in the first one-third of the cable segments at both ends of the monitoring cable, the spacing between the bundles should be slightly sparse, while the middle one-third of the cable segments should be slightly dense. This is because when the elevator is on the top or bottom floors or when it is parked for a long time, the first one-third segments of the two cables will have a larger misalignment, but the swing amplitude will not be too large. When the elevator is running in the middle floors, the swing amplitude of the middle one-third segment of the cable will be larger but the misalignment will be smaller. Due to the high frequency of the elevator's movement between the lower floors or the long time it stays parked, special attention should be paid to the spacing of the first one-third segment. Comparison diagram of the three states of the elevator:

Some clarifications:

1．There are still areas for improvement in the plan. The plastic ties should be replaced with single-core metal wires with a diameter of around 1.5mm. This is because, first, after the plastic ties age and become brittle, they may break, causing the bundled cables to separate and creating safety hazards; second, the forming performance of single-core metal wires is better than that of plastic ties, which is conducive to making the bundling rings for monitoring harnesses (not too tight or too loose, and the cables can slide within the ring), and even if the outer layer of plastic coating ages and becomes brittle, the single-core metal wires will not break.　　

2．The laying of the monitoring cables should be carried out in two ways: Firstly, ensure that the entire roll of cable is laid and bundled smoothly without any twisting or knotting; Secondly, fix the elevator car end first, then lay and bundle the cable from bottom to top, until reaching the fixed point in the middle of the elevator shaft.　　

3．The fixing method for one end of the elevator car: Since expansion screws cannot be used on the elevator car, the steel rope for suspending the monitoring cable should be hung on the round and smooth metal crossbeam at the bottom of the car; or holes can be drilled on the vertical steel plate at the bottom of the car, and ordinary metal screws can be used as the suspension points for the monitoring cable instead.　　

4．When fixing the monitoring cable at both ends, since the smallest specification of the lock is 4mm, while the steel wire inside the monitoring cable is about 2mm, the lock often has difficulty locking the steel wire tightly. In this case, there are two methods: one is to wrap the steel wire 2 to 3 times around the lock opening before locking; the other is to find a section of steel wire or steel wire with a diameter of 4mm of appropriate length and lock it together with the lock. The latter method is preferable. There are three points to note: first, it is best to use copper wire. If using telephone wire, it must be of a larger aluminum diameter, and a single strand can be used. Second, the middle ring must not be too small, otherwise the buffering effect will not be obvious. Third, the middle is tight and the two ends are loose, this must be done.