Electrical design of elevators in public buildings and residential buildings?

The elevator room is usually located above the elevator shaft. The stairwell of an ordinary elevator can be connected or provided with openings, and the elevator machine room can also be combined. The stairwell and machine room of fire elevator should be set separately from other elevators. The electrical control equipment shall be supplied by the manufacturer in complete sets, and the power inlet, control and distribution outlet of the electrical control equipment shall be coordinated by the installation unit. The electrical design only needs to provide power for the following electrical equipment, and select circuit breakers and distribution lines.

Keywords: lighting socket wiring of elevator main switch

1, overview

The elevator room is usually located above the elevator shaft. The stairwell of an ordinary elevator can be connected or provided with openings, and the elevator machine room can also be combined. The stairwell and machine room of fire elevator should be set separately from other elevators.

The electrical control equipment shall be supplied by the manufacturer in complete sets, and the power inlet, control and distribution outlet of the electrical control equipment shall be coordinated by the installation unit. The electrical design only needs to provide power for the following electrical equipment, and select circuit breakers and distribution lines.

1) elevator main power supply;

2) Lighting and ventilation between the car, machine room and pulley;

3) Power sockets at the top and bottom of the car;

4) Power socket between the machine room and pulley;

5) elevator shaft lighting;

6) Alarm device.

The elevator controller, car lighting, car top socket and car alarm device only select the switch and the power supply line to the input end of the switch.

2. Power distribution design

2. 1 elevator load classification and power supply requirements shall conform to the importance of buildings and the requirements for elevator reliability, and conform to the provisions of the national standard Code for Design of Power Supply and Distribution Systems. Elevators in high-rise buildings and important public buildings belong to the second category, and the important one is the first category; General cargo elevators and medical elevators are three-level, and the most important thing is the second level; Multi-storey houses and ordinary public buildings have three elevators. The fire elevators of high-rise buildings shall conform to the national standard "Code for Fire Protection Design of High-rise Civil Buildings".

The power supply of ordinary elevators and fire elevators should adopt special power supply circuits respectively; The power distribution equipment of fire elevator should be clearly marked.

2.2 The power supply of the elevator should be separated from the low-voltage socket (or low-voltage distribution panel) of the transformer to form its own power supply system.

The power supply of the first-class load elevator should have two power supplies, which are sent to the last-class power distribution device and automatically switched. The circuit supplying power to the first-class load should be dedicated and should not be connected to other loads;

The power supply of the secondary load elevator should have two power supplies (or two loops), which can be sent to the last power distribution device of the two loops and automatically switched. When the low voltage side of the substation system is segmented by a single bus and the bus circuit breaker is automatically put into operation, a single circuit with reliable independent outgoing lines can be used for power supply. It can also be supplied by the emergency bus or reliable single-loop power supply of the regional double-power automatic mutual switching distribution device. ?

The power supply of the fire elevator should be sent to the last power distribution device by two power supplies (or two loops) and automatically switched.

The power supply of the three-level load elevator should be supplied by a special circuit.

2.3 Each elevator shall be equipped with a separate isolation electrical appliance and protection device, and shall be located in a place convenient for operation and maintenance in the machine room and accessible from the entrance of the machine room. If the machine room is shared by several elevators, the isolation appliances of each elevator should be easy to identify. The isolation device shall have the ability to cut off the maximum current of the elevator under normal use, but the power supply of the following equipment shall not be cut off:

1) Lighting and ventilation between cars, machine rooms and pulleys;

2) Power sockets at the top and bottom of the car;

3) Power socket between the machine room and pulley;

4) elevator shaft lighting;

5) Alarm device.

The power supply of the above lighting and ventilation devices and sockets can be obtained from the elevator main power switch, and the power supply is provided by the distribution box (cabinet) in the machine room, or the lighting power supply loop adopts led, and the lighting distribution box is set separately.

The main power switch of the elevator without machine room should be set in a place convenient for workers outside the shaft, and should have necessary safety protection.

The lighting of the hall and the indicating floor of the station is supplied by its own power supply.

The isolation appliances and short-circuit protection devices of the elevator can be set in the distribution box (cabinet) in the machine room, and circuit breakers are selected. The location of the distribution box (cabinet) should fully meet the requirements; When a large number of elevators and isolating appliances need to be installed nearby, isolating switches can be selected, short-circuit protection devices are installed in the distribution box (cabinet) in the machine room, and circuit breakers are installed in the power supply circuit of each elevator.

2.4 main switch selection

The feed switch of elevator power supply equipment should adopt low-voltage circuit breaker. The rated current of low-voltage circuit breaker should be determined according to the continuous load current and starting current of traction motor. The load-time characteristic of overcurrent protection device should match the load-time characteristic curve of equipment.

2.5 The power supply circuit of lighting, ventilation device and socket should be divided into at least two power supply circuits according to the location and working characteristics of the equipment, and isolation appliances and protection devices should be set respectively:

1) Power supply circuit and protection circuit breaker of car electrical equipment (lighting, ventilation, socket and alarm device) (since there are multiple elevator drive hosts in the machine room, each car should be equipped with one), and the circuit breaker should be set beside the corresponding main switch.

2) Power supply circuit and protective circuit breaker of electrical equipment (lighting, ventilation and sockets) in machine room, shaft and pit. The circuit breaker shall be located in the machine room near the entrance.

Generally, the lighting is powered by 220V AC voltage, and the power supply circuit of well lighting should adopt single PE wire, and the exposed conductive part of well lighting should be reliably grounded. When the well lighting needs to be powered by safe voltage, special power supply lines and protective circuit breakers shall be provided. The low-voltage side of the lighting transformer should be equipped with isolation devices and protection devices, and the exposed conductive parts are strictly prohibited to be directly grounded or grounded in other ways.

General sockets are "2P+PE type 250V". When the socket needs to be powered by safe voltage, a special power supply circuit and protective circuit breaker should be set, and the low-voltage side of the transformer should be provided with isolating appliances and protective devices. The exposed conductive part is strictly forbidden to be directly grounded or grounded by other means. There should be obvious differences between power outlets with different voltages, and there should be no possibility of interchange and the danger of mistake.

3. Setting and control of electric lighting, ventilation devices and sockets

3. 1 elevator shaft lighting

The enclosed elevator shaft should be equipped with permanent electric lighting, which can illuminate the elevator shaft even if all doors are closed during maintenance and repair. Within 0.5m of the highest point and lowest point of the shaft, lamps shall be installed respectively, with a maximum interval of 7m in the middle, and the illumination shall be not less than 50lx. Control switches shall be installed in the machine room and the pit respectively. The lamps installed in the shaft should have protective measures and certain waterproof ability, which should at least reach IP2 1.

3.2 Lighting and power socket of elevator machine room

The computer room shall be equipped with fixed electrical lighting, and the ground illumination shall be no less than 200lx. A switch should be set at an appropriate height near the entrance (or entrances) of the computer room to control the lighting of the computer room when entering. One or more power sockets shall be set in the computer room.

3.3 Lighting and power socket between pulleys

Permanent electric lighting with sufficient brightness shall be provided between pulleys. A switch should be set at an appropriate height near the entrance of the room to control the lighting in the room when entering. One or more power sockets shall be arranged between pulleys.

3.4 Automotive Lighting and Power Sockets

The car should be equipped with permanent electric lighting, the illumination on the control device should be not less than 50lx, and the illumination on the car floor should be not less than 50lx. If the lighting is incandescent, at least two bulbs should be connected in parallel.

There should be an emergency power supply, which can be charged automatically. When the power supply in normal lighting is interrupted, at least 1W bulb can be powered1h. When there is a power failure in normal lighting, the lighting power supply should be switched on automatically. One or more power sockets shall be provided at the top of the car.

3.5 pit socket

0.5m away from the bottom of the pit shall be provided with a power socket. The socket should have protective measures and certain waterproof ability, which should at least reach IP2 1.

3.6 Lighting of ground station

Near the landing door, the natural or artificial lighting of the landing station should not be less than 50lx on the ground, so that when the user opens the landing door and enters the car, even if the lighting in the car fails, he can clearly see the front of it.

4, line laying

4. 1 cable selection

When selecting the elevator power supply conductor, it should be determined according to the nameplate current of the motor and its corresponding working system. The continuous working current of the conductor should not be less than the calculated current. When the line is long, the voltage loss should also be checked (the fluctuation range of DC elevator power supply voltage should not be greater than 3%, and AC elevator is 5%).

4.2 Wiring Selection

According to different purposes, wires, hard cables and soft cables can be used for wiring, and there should be different protection methods and laying methods:

1) If the conductor is laid in a conduit (or trunking) made of metal or plastic or protected in an equivalent way, it can be used for all lines except the power supply circuit of the elevator driving host;

2) Hard cables can only be laid on the shaft (or the wall of the machine room) or installed in conduits, trunking or similar devices;

3) Ordinary flexible cables can only be used in conduits, trunking or protective devices that can ensure the same protection.

4.3 The power supply line supplying power to the elevator shall not be laid in the elevator shaft. In addition to the elevator dedicated lines, other lines shall not be laid along the elevator shaft. Wiring in the machine room shall be protected by wire conduits or trunking, and the wire conduits or trunking shall be flame retardant. Cables and wires laid in the hoistway, if laid openly, should be flame-retardant and moisture-proof. If they are non-flame-retardant, they should be protected by conduits or trunking made of flame-retardant materials.

4.4 Waterproof measures should be taken for the power and control cables and wires of the fire elevator (such as setting a gradient of 4 ~ 5 cm at the elevator door).

5, disaster prevention alarm device

5. 1 The fire elevator can also be used as an ordinary elevator at ordinary times. A special fire switch and a priority call switch are added at the waiting place near the landing door on the evacuation floor for firefighters to use in case of fire. After confirming the fire, the fire control room should also be able to control all elevators to stop at the evacuation floor and receive their feedback signals. After the car arrives at the evacuation floor, it should be guaranteed to recall the car first, so that it can run without the call of the corresponding landing. After the car arrives at the designated floor, it stays there, and the car door is opened until a new instruction is issued in the car.

5.2 In order to enable passengers to effectively seek help from outside the car when necessary, an alarm device which is easy for passengers to identify and touch should be installed in the car. The equipment shall use alarm bells, intercom system, external telephone or similar equipment. Organizations in buildings should be able to respond to emergency calls in a timely and effective manner. When the alarm device needs local power supply, it should have an emergency power supply that can automatically charge. In the case of normal power interruption, at least 1h power can be provided for the alarm device. When the normal power supply fails, the emergency power supply should be automatically connected. The emergency power supply of alarm device can be used together with the emergency power supply of lighting.

5.3 For super high-rise buildings and high-rise public buildings, elevator operation status indicator panels shall be set in the disaster prevention control center.

5.4 When the elevator travel is more than 30m, an emergency power intercom system or similar device shall be set between the car and the elevator machine room.

5.5 The fire elevator car should be equipped with a dedicated fixed telephone for fire fighting, and a closed-circuit monitoring camera can be set as required.

6, lightning protection equipotential connection

Lightning protection equipotential connection measures should be taken for buildings with lightning protection structures of Class II exceeding 45m and Class III exceeding 60m, and the bottom and top of elevator guide rail should be connected with lightning protection devices (lightning arrester, down conductor, grounding device and other connecting conductors, etc.). ) respectively.

7. Indirect contact protection of electrical equipment in elevator machine room, shaft and car.

7. 1 The zero line and grounding line of the low-voltage distribution system should always be separated.

7.2 Equipotential bonding measures should be taken for the metal part of the whole elevator device. Grounding branch lines shall be connected to the terminals of grounding trunk lines respectively, and shall not be connected to each other before grounding.

Equipotential junction boxes are set in each pit and each machine room and connected with lightning protection devices. The junction box is separately connected to the equipotential connection terminal board with a grounding wire, which is convenient for inspection and maintenance. Copper conductor shall be used, and the conductor section shall not be less than 6mm. When it is also used as lightning protection equipotential bonding, copper conductor should be adopted, and the cross section of the conductor should not be less than 16mm 2.

When the automobile grounding wire adopts cable core wires, there shall be no less than two wires, and copper core wires shall be adopted, and the cross section of each core wire shall not be less than 2.5mm 2.

7.3 Grounding devices are used for potential connection, protective grounding and grounding of elevator control computer working grounding in buildings.

8. Refer to the figure

According to the specific conditions of the project, under the premise of meeting the national standards, there can be many combinations in the design, and the distribution lines can also be increased or decreased appropriately.

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