During the operation of the elevator, the lengths of the steel cables on the car side and counterweight side constantly change, thereby causing variations in the weight of the cables on both sides of the traction wheel. When the car is at a lower floor, most of the cable weight acts on the car side; when the car is at a higher floor, most of the weight acts on the counterweight side. This variation has little impact on the elevator's performance when the lift height is not significant, but when the lift exceeds a certain height, it severely affects the stability of the elevator operation, posing a risk to passenger safety. To address this, it is necessary to install components of a certain weight when the elevator lift height exceeds a certain threshold to balance the weight changes due to height variations, which is the elevator counterweight compensation chain. Therefore, the elevator counterweight compensation chain is defined as: a component used to connect the elevator car to the counterweight, balancing the weight of the traction cables and trailing cables, and playing a balancing role in the elevator's operation.


Currently, there are several types of compensation chains available in the market:

1. The rope compensation chain is an original type of compensation chain, suitable only for elevators with a speed of 1.75 m/s or less. Its structure involves threading sisal rope through iron chains. However, due to friction and collisions between chains during operation, it produces significant noise and causes noticeable vibrations within the car. Its only advantage is its low cost, but most elevator companies have now phased it out.

2. To reduce the noise during the operation of the rope compensation chain and to slow down the environmental corrosion on the iron chain, a PVC soft tube is wrapped around the rope compensation chain, creating a coated compensation chain. Compared to the rope compensation chain, the coated compensation chain operates with significantly less noise and a more aesthetic appearance. However, improvements are still needed in terms of flexibility and durability.

3. The full plastic compensation chain is suitable for high-speed elevators up to 6m/s, featuring a cable-like PVC structure. In use, the elevator operates with a smooth and silent performance, favored by many large elevator companies.

Once the type of balancing compensating chain is determined, the number of chains and the installation method must also be considered. Generally, first, determine the weight of the compensating chain by subtracting the weight of the trailing cable from the weight of the traction rope. Then, establish the weight per meter of the compensating chain and select from the manufacturer's variety. Professional compensating chain manufacturers typically offer flexible weight selection options. There is an allowable error range when calculating the weight per meter of the compensating chain. Within this range, there are two options: either select two compensating chains with a lighter weight per meter, or one compensating chain with a heavier weight per meter. This is primarily based on the arrangement of buffers in the elevator system. If there is one buffer below the car and one below the counterweight, or two buffers below the car and one on the counterweight side, two compensating chains are more suitable. If there are two buffers below both the car and the counterweight, then one compensating chain should be used.

The installation of elevator compensating chains varies due to the different structural types. Standard compensating chains, including rope-through and sheathed compensating chains, have a simpler structure. They are commonly used in low-height, low-speed elevators, thus requiring a simpler installation method. The two ends of the compensating chain are connected to the car bottom frame and counterweight using suspension devices. Additionally, a guide device consisting of two polyvinyl chloride wheels is set beneath the counterweight in the pit.

For the all-plastic compensation chain, due to its frequent use in high-rise, high-speed elevators, the installation process is somewhat more complex. The two ends of the compensation chain are connected to the car bottom frame and counterweight. Guide devices are installed in the pit, approximately 1 meter above the bottom of the compensation chain's bend radius. Each compensation chain has two guide devices: one mounted below the car through a bracket, and the other mounted below the counterweight through a bracket. Most compensation chain manufacturers provide matching installation accessories and tools. Only by using the correct installation tools and methods can the compensation chain ensure normal operation with the elevator.