If during the inspection of an elevator, it is found that the lead seal of the speed limiter has been removed, the positioning paint has fallen off, there is excessive oil pollution, or severe rust, the relevant parameters of the speed limiter should be retested or retested.

Safety precautions for elevator use:

(1) Be careful not to overload the elevator. When the elevator alarms, you should take the initiative to exit and wait for the next ride. Overloading the elevator is very dangerous.

(2) Do not forcefully block the elevator door. When the elevator door is about to close, do not forcefully rush into the elevator to prevent it from closing. Do not stop one foot inside and the other foot outside, as it may cause injury.

(3) Do not press the emergency button casually. The emergency button is set to deal with unexpected situations. When the elevator is running normally, do not press the emergency button, otherwise it will cause unnecessary trouble to you and others.

(4) When taking the elevator, if the elevator door is not closed and runs, it indicates that the elevator has a malfunction. Please do not take the elevator and report to the property management company or maintenance personnel at the same time.

(5) Before taking the elevator, you should first check if there are temporary signs such as "stop elevator maintenance". If available, please do not ride.

(6) When a fire occurs, it is strictly prohibited to escape by taking the elevator. Please use the staircase safety exit to escape.

(7) If there is a malfunction during elevator operation, please do not panic. You should contact the outside world by pressing the phone or alarm button and other communication methods, wait for rescue, and do not open the car door without permission to avoid accidents.

(8) After the elevator stops, passengers should pay attention to observing whether the floor and floor of the elevator car are level when entering and exiting the elevator. If they are uneven, it indicates that there is a malfunction in the elevator. Maintenance should be notified in a timely manner to ensure passenger safety.

What are the issues with elevator monitoring wiring and wireless communication

Step 1: Select the location of the video cable exiting the elevator shaft

Why is this the first step? It's like designing surveillance, you have to first know where the surveillance room is. Knowing the outlet is the key to better designing routing methods.

The ideal choice should be in the middle of the well, because at this time, the length of the accompanying video cable in the well is only about half of the depth of the well, which is the shortest and naturally introduces the least interference; But in engineering, this kind of output requirement can only be negotiated based on the situation, and actual engineering may not necessarily allow it.

In fact, this is what we often refer to as a follow-up cable and a stationary cable. Find the easiest place to exit the elevator shaft without moving the cable, and then lay it along the weak current shaft next to the elevator shaft, which can save a lot of manual wiring costs. Moreover, walking through the nearby weak current well and metal wire duct also has many benefits in shielding external interference. In the past, many people, without understanding this situation, walked out of the cable well along with other accompanying cables.

When bundling the video cable of the accompanying motion part with other accompanying cables, the designer should fully understand the structure and distribution of other accompanying cables. When bundling, the video cable should be as far away as possible from cables with high current and high frequency, and close to cables with low current and low frequency; Here, even if there is a choice of 1 centimeter, it may be worth fighting for, as the interference effect is at least inversely proportional to the square of the distance.

The metal casing of the camera, the casing of the BNC head, the outer conductor of the coaxial cable, and other video signals should be insulated from the elevator car, guide rails, etc., which requires special attention when installing the camera.

The camera power supply should preferably be centralized DC power supply, followed by the selection of elevator lighting power, and power electricity should not be used. For power supply, control and other monitoring cables, shielded cables should be selected as much as possible to prevent interference signals from leaking out.

The video cables from the elevator shaft exit to the control center should be routed through metal pipes or metal trenches to shield the cables from environmental interference along the way. Attention should be paid to the shielding in this section and the shielding inside the elevator shaft, and electrical connections should be made.

Step 2: Selection of elevator monitoring cables

The application of monitoring in elevators must consider the particularity of its continuous up and down movement. It is required to use transmission cables with high mechanical strength and tensile strength in wiring, which is different from the fixed point monitoring method of threading pipes (grooves). Generally, engineering companies attach importance to the use of high-strength cables in wiring, but the electrical characteristics of transmission cables have not been given enough attention, resulting in the widespread occurrence of elevator interference.

Due to the fact that the elevator room is a nearly enclosed and narrow space, and there are many cables such as control, lighting, and fans in the elevator room, it increases the difficulty of wiring video cables. Based on actual analysis, the selection of cables in elevator monitoring should follow the following principles.

1. Satisfying tensile strength: Half of the elevator cables are used for extension, and high-rise elevators can reach up to 100 meters. The weight of a 100 meter cable is nearly 100 kilograms, so the cable must have sufficient tensile strength. There are now self-supporting flat composite elevator monitoring cables on the market. This type of cable combines video coaxial cables, power lines, data lines, and steel strands to form a flat ribbon cable. This way, the tension of the entire cable is borne by the steel strands, and the tensile strength is very good. It will not break the signal cable due to gravity during elevator operation.

2. Good electrical parameters: During the movement of the cable up and down with the elevator, there will be a section in the middle that will bend and deform due to gravity, causing changes in the electrical parameters of the cable such as impedance and distributed capacitance. When cables with poor quality are subjected to force deformation, large parameter changes can cause impedance mismatch, increased video attenuation, and signal reflection, which can lead to a decrease in video signal signal-to-noise ratio and video interference. Therefore, it is advisable to choose video cables with good shielding and thick wire diameter to prevent interference signals from invading. Practice has proven that sywv's coaxial cables are superior to syv, and multi-layer shielding is superior to single-layer shielding.

Step 3: Tips for Elevator Wiring

In elevator monitoring wiring, the method of bundling with other cables is mostly used. However, due to the leakage of AC signals in other cables through transmission cables, when video cables are tied parallel to them for a long distance, they are equivalent to a pair of "antennas". This interference signal will be coupled into the video signal, resulting in video interference.

So in the wiring, try to shorten the parallel bundling length between the video cable and other cables as much as possible. If conditions permit, the video cable can be fixed from the middle point of the elevator shaft and led back to the main control room from other channels (cable shafts), which can avoid coupling interference of AC sound radiation. For projects with conditions, shielded wires can be used for the control and lighting cables used in elevators to reduce external radiation and avoid video interference.

Step 4: How to avoid elevator interference and solutions

The main sources of interference in elevator video include: the traction motor of the elevator, and the AC type is more severe than the DC type; Elevators have greater interference during startup, acceleration, and integral (other) deceleration leveling compared to straight and uniform speed operation; The high-frequency interference radiated by using frequency converters to regulate elevators is greater than that of thyristors and variable line/phase voltages; The interference of elevator radiation in the process specification is relatively small. Solving elevator interference should mainly start from the following points.

(1) Choosing video cables with low attenuation coefficient, good shielding performance, and high tensile strength can improve their anti-interference ability, reduce video attenuation, and prevent interference signals from invading the video cable shielding layer.

(2) Reasonable wiring: Reasonable wiring can effectively prevent interference signals from being "coupled" through cables, minimize parallel bundling distance with other cables, keep video cables away from interference sources, and thus "avoid" interference.

(3) Use a clean power source to prevent power interference. It is best to use centralized power supply in the computer room to avoid power interference. Interference from the power source entering the video signal is also the most difficult interference problem to solve. If it is impossible to determine where the interference signal is introduced into the system, first determine whether it is power interference. Find a battery and directly power the camera. If the interference is eliminated, it proves to be power interference. If it cannot be eliminated, it proves to be intrusion interference in the transmission cable.

Analysis and troubleshooting of common faults in elevators

1、 The power supply to the grid is normal, and there are no fast or slow trains in the elevator.

Main reasons:

(1) The fuse melt of the main circuit or control circuit burns out;

(2) The voltage relay is damaged, and the contact of the safety protection switch in other circuits is poor or damaged;

(3) The wiring from the control cabinet terminal to the motor terminal is not properly connected;

(4) Various protective switch actions have not been restored.

Exclusion method:

(1) Check whether the fuse melt of the main circuit and control circuit is blown, installed, and clamped in place. Eliminate the fault based on the inspection results.

(2) Check if the voltage relay is damaged; Check whether the voltage relay is engaged and whether the wiring of the voltage relay coil is connected; Check if the voltage relay operates normally. Eliminate the fault based on the inspection results.

(3) Check if the wiring terminals of the control cabinet are properly connected; Check whether the wiring of the motor junction box is in place and clamped; Eliminate intentional behavior based on inspection results.

(4) Check if the current, overload, weak magnetic field, voltage, and various component contacts or actions of the safety circuit of the elevator are abnormal, and troubleshoot according to the inspection results.

2、 The elevator goes down normally, but there are no express trains going up.

Main reasons:

(1) The wiring of the first and second limit switches for upward movement is not solid, and the switch contacts are poor or damaged.

(2) The up control contactor or relay is not engaged or damaged.

(3) Loose or detached control circuit wiring.

Exclusion method:

(1) Connect the wiring of the limit switch contacts firmly, replace the limit switch contacts, and replace the limit switch.

(2) Connect the wiring of the relay coil of the down control contactor firmly and replace the contactor relay.

(3) Connect the loose or detached wiring of the control circuit properly

3、 The elevator car does not stop at the level position.

Main reasons:

(1) The contact between the reed contacts of the upper and lower level sensors is poor, the relative position and size of the magnetic barrier or sensor do not meet the standard requirements, and the sensor wiring is poor.

(2) The upper and lower leveling sensors are damaged.

(3) The control circuit has malfunctioned.

(4) The up and down direction contactors do not reset.

Exclusion method:

(1) Connect the contacts of the reed switch, adjust the sensor, and adjust the size of the magnetic barrier or sensor.

(2) Replace the leveling sensor

(3) Eliminate faults in the control circuit.

(4) Adjust the up and down direction contactors.

4、 The elevator car runs to the selected floor without changing speed.

Main reasons:

(1) The wiring of the selected floor speed sensor is poor or damaged.

(2) The position and size of the speed sensor and sensing plate do not meet the standard requirements.

(3) There is a malfunction in the control circuit.

(4) The quick contactor does not reset.

Exclusion method:

(1) Replace the sensor or connect the sensor wiring properly.

(2) Adjust the position and size of the sensor and sensor board to meet the standards.

(3) Check the control circuit and eliminate any faults in the control circuit.

(4) Adjust the quick contactor.

5、 The elevator has a slow train but not a fast train.

Main reasons:

(1) Poor or damaged contact of the hall door electric lock switch of the car door or a certain floor door.

(2) The up and down operation control relays and quick contactors are damaged.

(3) There is a malfunction in the control circuit.

Exclusion method:

(1) Adjust and repair the electric lock contacts of the floor door and car door, or replace the contacts.

(2) Replace the up and down control relays or contactors.

(3) Check the control circuit and eliminate any faults in the control circuit.

6、 The elevator car suddenly changes speed and stops before reaching the speed change point.

Main reasons:

(1) The door opener collides with the roller of the floor lock.

(2) Improper adjustment of the door lock on the knife level.

Exclusion method:

(1) Adjust the door opener or door lock roller.

(2) Adjust the door opener or floor lock.

7、 The accuracy error of the elevator car leveling is too large.

Main reasons:

(1) The elevator car is overloaded.

(2) The brake is not fully opened or adjusted improperly.

(3) The position and size of the leveling sensor and the magnetic barrier have changed.

(4) Improper adjustment of braking torque.

Exclusion method:

(1) Overloading operation is strictly prohibited.

(2) Adjust the brake to ensure that its clearance meets the standard requirements.

(3) Adjust the position and size of the leveling sensor and magnetic barrier.

(4) Adjust the braking torque.

8、 There is abnormal noise and vibration inside the elevator car during operation.

Main reasons:

(1) The guide shoe bearings are severely worn.

(2) The guide shoe lining is severely worn.

(3) There is a collision between the sensor and the magnetic barrier.

(4) Poor lubrication of the reverse pulley, guide pulley bearings, and shaft sleeves.

(5) Poor lubrication of the guide rail.

(6) The door knife collides with the roller of the floor lock, or collides with the floor sill of the floor door.

(7) The accompanying cable scraper guide bracket.

(8) Poor tension adjustment of traction steel wire rope.

(9) Compensation chain rubbing against the guiding device or pit floor.

Exclusion method:

(1) Replace the guide shoe bearings.

(2) Replace the guide shoe lining.

(3) Adjust the position and size of the sensor and magnetic barrier.

(4) Lubricating the reverse pulley and guide wheel bearings.

(5) Lubricating the guide rail.

(6) Adjust the gap between the door blade and the floor lock roller, and between the door blade and the floor door pit.

(7) Adjust or rebind the cables.

(8) Adjust the tension of the traction wire rope.

(9) Lift the compensation chain or adjust the guiding device.

9、 The elevator cannot start running after selecting the floor memory and closing the door.

Main reasons:

(1) Poor or damaged contact of the electric interlocking switch of the car door.

(2) The brake holding brake failed to release.

(3) Power supply voltage too low

(4) Power supply phase failure.

Exclusion method:

(1) Repair or replace the interlocking switch of the elevator door.

(2) Adjust the brake to release it.

(3) Wait until the power supply voltage is normal before putting it into operation.

(4) Repair phase failure.

10、 Difficulty in starting the elevator or significant decrease in operating speed.

Main reasons:

(1) The power supply voltage is too low or the phase is broken.

(2) Poor lubrication of motor rolling bearings.

(3) Poor lubrication of the traction machine reducer.

(4) The brake is not released.

Exclusion method:

(1) Check and repair.

(2) Add oil, clean, and replace lubricating oil.

(3) Add oil or replace lubricating oil.

(4) Adjust the brake.

11、 During the process of opening and closing the door, the door leaf shakes and experiences jamming.

Main reasons:

(1) There is a foreign object blocking the pedal groove.

(2) The eccentric wheel of the suspension door roller is loose, and the gap with the upper sill is too large or too small.

(3) The connecting bolts between the hanging door roller and the door leaf are loose or the roller is severely worn.

(4) The roller slide of the hanging door is deformed or the door panel is deformed.

Exclusion method:

(1) Clean the foreign objects inside the pedal groove.

(2) Repair and adjust.

(3) Adjust or replace the suspension door roller.

(4) Repair the sliding door panel.

12、 The impact sound during the opening and closing process of the DC door machine is too loud.

Main reasons:

(1) Improper adjustment of the opening and closing limit resistors.

(2) Improper adjustment of the speed limit resistor for opening and closing doors, or poor contact of the adjustment ring.

Exclusion method:

(1) Adjust the position of the limit resistor.

(2) Adjust the position of the resistance ring or adjust the contact pressure of the resistance ring.

13、 The elevator cannot open the door when it reaches the level position.

Main reasons:

(1) The fuse of the switch door circuit has melted.

(2) Poor or damaged contact of the limit switch contacts for opening and closing doors.

(3) Poor contact, detachment or damage of the sensor plug for early door opening.

(4) The door opening relay is damaged or its control circuit is faulty.

(5) The transmission belt of the door opener is detached or broken.

Exclusion method:

(1) Replace the melt of the fuse.

(2) Replace or repair the limit switch.

(3) Replace or repair the sensor plug.

(4) Replace the circuit breaker and repair control circuit faults.

(5) Adjust or replace the door opener belt.

14、 Pressing the door close button does not automatically close the door.

Main reasons:

(1) The fuse of the switch door circuit has melted.

(2) The door closing relay is damaged or its control circuit is faulty.

(3) The contact of the first limit switch for closing the door is poor or damaged.

(4) The safety touchpad is not reset or the switch is damaged.

(5) The photoelectric protection device is faulty.

Exclusion method:

(1) Replace the fuse melt.

(2) Replace the relay or check for circuit faults and repair them.

(3) Replace the limit switch.

(4) Adjust the safety touchpad or replace the safety touchpad switch.

(5) Repair or replace the door photoelectric protection device.