Overall design requirements for inorganic room elevator control cabinet

Before the 1990s, hydraulic elevators were highly favored by users in developed countries due to their compact structure and flexible location in machine rooms. On the basis of the advantages of hydraulic elevators, the inorganic room elevator adopts a traction drive system instead of a hydraulic transmission system, which is superior to hydraulic elevators in terms of structure, performance, and energy efficiency; Compared with regular elevators with machine rooms, inorganic room elevators save building space, reduce building costs, avoid complex building structures, and make the overall appearance of the building beautiful. Therefore, since the late 1990s, machine room elevators have rapidly developed both domestically and internationally.
In order to meet the needs of installation, maintenance, rescue operations, dynamic testing, etc., there are many differences in the control system of inorganic room elevators compared to those with machine rooms. This article only discusses the overall requirements and characteristics of the control system for non machine room elevators from the perspective of overall design and risk reduction.
1. Control cabinet structure
1.1 External dimensions
The external dimensions of the control cabinet mainly depend on its setting position, in addition to being constrained by the size of the components used. If the control cabinet is set next to the landing door, its external dimensions should be narrow in width and thin in thickness, so that its arrangement next to the landing door does not affect the movement of the landing door; If the control cabinet is installed around the driving host in the shaft, its thickness size should be relatively small to ensure a distance from the moving parts in the shaft.
1.2 Cabinet doors
If the control cabinet is set outside the shaft, the door of the control cabinet should meet the following requirements: ① The door of the control cabinet should not be equipped with a handle to prevent unrelated personnel from pulling and damaging the control cabinet; ② The lock on the control cabinet door can only be opened from the outside with a key, and the door can be closed without a key. There is an electrical safety device that complies with Article 14.1.2 of GB 7588-1995 to confirm the locking status of the door. The elevator can only operate normally when the cabinet door is closed to prevent danger caused by normal operation of the elevator when the cabinet door is open A waterproof structure is used between the door of the control cabinet and the cabinet body to prevent accidental liquid flow into the control cabinet during cleaning of the corridor, which may cause electrical faults.
If the control cabinet is installed inside the shaft, the door locking device on the control cabinet should be able to open from the outside and close the door without a key; When the open cabinet door enters the operating area of the elevator, an electrical safety device in accordance with Article 14.1.2 of GB 7588-1995 should be installed to confirm the locking status of the door. The elevator can only operate normally when the cabinet door is closed. In addition, if the open cabinet door enters the operating area of the elevator, the maintenance operation of the elevator can only be carried out when the cabinet door is closed, or the operating section of the elevator is restricted to prevent accidents caused by the collision between the open cabinet door and the operating components in the shaft.
2. Location of Control Cabinet Setting
2.1 Location
After the cancellation of the machine room for the inorganic room elevator, its control system had to be installed at an appropriate position outside or inside the shaft, and its specific position was greatly affected by the position of the driving host inside the shaft.
If the control cabinet is set next to the floor door, there should be a vertical distance (recommended at least 0.3m) between its bottom and the floor level to prevent water from entering the control cabinet during floor cleaning or accidental water leakage; The front of the control cabinet and the decorated wall form a flat surface to prevent accidental damage to the control cabinet and arouse curiosity from unrelated personnel.
2.2 Heat dissipation and dust prevention
In order to ensure the normal operation of all components inside the control cabinet, in addition to meeting electrical requirements such as anti-interference, the structure of the control cabinet should also be considered to facilitate the heat dissipation of electrical components, and attention should be paid to dust prevention while considering heat dissipation. If the control cabinet is set next to the floor door and embedded in the front wall of the shaft, and the back of the cabinet serves as the main heat dissipation surface, the rear panel should be directly connected to the shaft. If the control cabinet is installed on the shaft wall, its bottom, side, and front can serve as heat dissipation surfaces, and air convection is formed in the shaft during elevator operation, which is conducive to meeting heat dissipation requirements. However, attention should be paid to dust removal of the control cabinet during maintenance.
2.3 Easy for maintenance operations
The position of the control cabinet should be easy for workers to access for installation, debugging, maintenance, rescue, testing and other operations.
3 Maintenance work area
3.1 Work Area
Regardless of whether the control cabinet is installed inside or outside the shaft, there should be a horizontal net area in front of it with a width of at least 0.7m and a depth of 0.7m, which is the larger of the cabinet width and 0.5m. The working net height of this net area should be at least 1.8m.
3.2 Dedicated work area
When the control cabinet is located outside the shaft and unrelated personnel can access the above area, safety protection enclosures should be used to isolate the area during the operation of the control cabinet. The enclosure should be yellow in color and have warning signs similar to "Danger! Do not approach" in obvious places to protect the safety of personnel and prevent other hazards.
3.3 Maintenance Platform
When the control cabinet is installed in the shaft and requires the use of a platform for maintenance and inspection work, Article 6.4.5 of EN 81-1998/pra2:2002 specifies the platform. Therefore, the design of the platform can refer to this requirement, but it should be noted that the maintenance work area of the control cabinet should still meet the requirements of 3.1.
When maintaining or inspecting machinery and equipment from inside or on the roof of a car, if any kind of loss of control or accidental movement of the car caused by maintenance or inspection may pose a personal danger to personnel, mechanical locking devices should be used to prevent the movement of the car.
4 Lighting
4.1 Lighting in the work area
Fixed electrical lighting should be installed in the control cabinet section and maintenance work area, and the illumination on the ground (or work area tread) should not be less than 200lux. A switch that can only be accessed by approved personnel should be installed at an appropriate height near the entrance of the work area to control the lighting in that area.
4.2 Lighting during power outage
In the event of a power outage in the power supply system, measures should be taken (such as setting up a dedicated backup power supply) to meet the brightness requirements, so that workers can clearly see the main power switch outside the shaft, emergency and testing operation devices, and prevent misoperation caused by insufficient light.
5 Floors
Article 6.3.1.2 of GB 7588-1995 stipulates that "the floor of the computer room should be constructed with anti slip materials.". Therefore, the floor (or tread) of the control cabinet maintenance work area, car roof, platform, and passage should be constructed with anti slip materials to prevent danger caused by staff slipping.
6 channels
The passage to the control cabinet and emergency testing operation screen of the elevator without a machine room should also meet the provisions of Article 6.2.1 of GB 7588-1995 for the passage from public roads to the machine room or pulley room. If a ladder is used, it should also comply with the provisions of Article 6.2.2 of GB 7588-1995. This is very important to raise in the design of elevator civil layout drawings.
7 Ventilation and Temperature
Regardless of whether the control cabinet is installed inside or outside the shaft, the control cabinet section should be properly ventilated and appropriately protected to minimize damage from dust, harmful gases, and moisture. To ensure the normal operation of the control system, the ambient temperature in the control cabinet section should be maintained between 5-40 ℃. The ventilation and temperature of the control cabinet section should comply with the relevant provisions of Article 6.3.5 of GB 7588-1995.
8 Main power switch
Article 13.4.1.2 of EN 81-1:1998/pra2:2002 stipulates that the main power switch should be installed inside the control cabinet outside the shaft or on the emergency and testing operation devices. If the emergency operation screen and testing operation screen are separate, they should be installed on the emergency operation screen.
If the main power switch is set inside the control cabinet or in the emergency and testing operation device, it should be set in a position that is easily accessible after the cabinet (cover) door is opened; There should be clear names and operational status markings near the main power switch; There should be warning signs inside the cabinet (cover) (such as "Do not close", "Do not supply power", etc.). When maintenance personnel disconnect the main power switch, they should hang it around the main power switch to prevent other personnel from accidentally supplying power.
9 Emergency and testing operation devices
Emergency and testing operation devices should be installed outside the shaft, and all elevator emergency operations and dynamic testing should be installed on one operation screen. Only competent personnel should be able to access the operation screen and perform operations. When the control cabinet is set outside the shaft, it can also be placed inside the control cabinet or as part of the control cabinet. If the control cabinet is set inside the shaft, the emergency and testing operation devices set outside the shaft should be covered with a cover. The cover can only be opened using a key lock, and the cover can be locked without a key. According to EN 81-1:1998/PRA2:2002, the emergency operation screen should provide the following operations or information: a) an emergency operation device that complies with Article 12.5 of GB 7588-1995 and a intercom system that complies with Article 14.2.3.5; b) Control equipment capable of conducting dynamic testing; c) Directly observing the elevator drive host or display device can provide information on the direction of car movement, the arrival of the car in the unlocking area, and the speed of the car.
10. Brake test of the driving host
The inorganic room elevator needs to undergo a single set of separate braking tests. A safer and more convenient method is to use control circuits to achieve this. For example, it can be achieved by setting a specially designed switch on the test operation screen outside the shaft, or if the control cabinet is set outside the shaft, short circuit the specified and clearly marked terminals according to the operation instructions, and then conduct a single side braking test on the driving host.
11 Tripartite calls
The control system of the inorganic room elevator should be able to achieve a tripartite communication function between the control cabinet, inside the car, and the rescue center, so that in case of elevator failure, passengers can be rescued in a timely manner, and the installation, debugging, and maintenance of the staff can be convenient and safe. In addition, from the perspective of operational safety, communication between the control cabinet and other parts can also be set up. For example, if rescue operations need to be carried out in the pit, it can be set up between the control cabinet and the pit.
12 Notes, markings, and operating instructions
The attention, marking, and operation instructions for inorganic room elevators should be carried out in accordance with the provisions of Chapter 15 of GB 7588-1995, mainly in the following aspects: ① The connection terminals of contactors, relays, fuses, and circuits in the control cabinet should be marked according to the circuit diagram; ② The operation buttons and switches on the emergency and test operation screens should be labeled with their functional names and position status; ③ Clear operating procedures should be set up inside the control cabinet or around the emergency and testing operation screens to guide staff in their operations.