Safety requirements for the rescue device of the h

Safety requirements for elevator power failure rescue device

with the continuous progress of elevator technology, the additional functions of elevators are also changing with each passing day. Complete machine factories, component factories or relevant manufacturers in the industry have launched elevator power failure rescue devices (electric), so as to minimize the time passengers are trapped in power failure in a state of multiple ups and downs of force value as far as possible, Improve the greater sense of security that the elevator brings to passengers in daily operation. As there is no corresponding provision in the standard for elevator power failure rescue device and there is a lack of corresponding safety standard, I hereby talk about the safety requirements of elevator power failure rescue device. I hope to use this to attract jade and discuss it with you in the industry

first, the rescue device can be roughly divided into two categories according to its function:

first category: when the elevator encounters the loss of normal power supply during operation, it can make the car run to the leveling position and open the door so that passengers can safely evacuate the elevator

class II: when the elevator encounters the loss of normal power supply during operation, open the band brake through the emergency device to make the lift car level by sliding, and the professionals open the hall car door for rescue

II. Analysis of safety requirements

the first kind of situation:

from the purpose of the device, it can be seen that the function of the device is the same as that of the elevator control cabinet, except for some control functions such as floor selection. Therefore, it is more appropriate to take the relevant safety requirements of the elevator control cabinet as the reference of the safety requirements of the device. The corresponding terms mainly include the following:

1. For the control of the driving host and the power supply and control of the AC motor with static components, one of the following methods should be adopted:

1) two independent contactors should be used to cut off the motor current

when the elevator stops, if the main contact of one of the contactors is not opened, the car must be prevented from running again at the latest when the next running direction changes

2) a system composed of the following components:

a) contactors that cut off the current of each phase (pole)

at least release the contactor coil before changing the running direction every time. If the contactor is not released, prevent the elevator from running again

b) control device used to block the current flow in static elements

c) monitoring device used to check the blocking of current flow when the elevator stops each time

during normal parking, if the static element fails to effectively block the flow of current, the monitoring device shall release the contactor and prevent the elevator from running again

2. Control of brake

2.1 during normal operation, the brake shall remain released under continuous power on

2.2. To cut off the brake current, at least two independent electrical devices shall be used, whether these devices are integrated with the electrical device used to cut off the current of the elevator driving host

2.3 when the elevator stops, if the main contact of one of the contactors is not opened due to the close connection between China's extruder products and strategic new industries, the elevator should be prevented from running again at the latest when the next running direction changes

2.4. When the elevator motor may act as a generator, it should be prevented from feeding power to the electrical device that operates the brake

2.5. Disconnect the release circuit of the brake without any delay

3. The electrical safety device should still be effective during the rescue operation

both the elevator normal operation control cabinet and the rescue device can control the operation of the elevator. Therefore, the switching of the operation control function is very critical, that is, in case of power failure, the rescue device must be put into operation. When the linear relationship between load and elongation deviates, the condition that the electrical safety device is still effective must be met, and when the normal power supply is restored, the elevator normal operation control cabinet is put into operation again, It is necessary to prevent the failure of electrical safety device or brake failure and other accidents caused by the error of rescue device

3.1. According to the requirements of article 14.1.2.1.3 of GB7588, connections with different points on the electrical safety circuit are only allowed to collect information, and these connection devices should meet the requirements of safety circuit. That is, it is required that the information collection of the safety circuit of the emergency device must meet the requirements of the safety circuit. (if the method of turning the safety circuit to the device as a whole through a relay meeting the requirements of article 13.2.1.2 of GB7588 after power failure is adopted, as shown in JJ in Figure 1, according to the provisions of article 13.2.1.3 of GB7588, the measures to prevent the relevant faults of article 14.1.1.1.1 can be taken, that is: a) if one of the dynamic breaking contacts (normally closed contacts) is closed, all the dynamic making contacts are disconnected; b) If the power is 120W and one of the dynamic making contacts (normally open contacts) is closed, all the dynamic breaking contacts are disconnected. At this time, the requirements of safety circuit can be ignored)

3.2. In addition, according to the requirements of article 14.1.2.1.1 of GB7588, the electrical safety device should still directly cut off the power supply of the contactor or its relay contactor that supplies power to the driving host