Transmission Exhibition will open. Let us learn about breaks.

Through studying the standard and summarizing the experience in practice, the writer thinks that the following problems should be paid attention to when checking the control circuit of brake coil.

(1) Carefully consulting the electrical schematic diagram and wiring diagram, and carefully analyzing the number of electrical devices in the control circuit and their mutual independence. For example, in Figure 2, we can find that XC, SC and YXC are independent and interrelated.

(2) Checking the control circuit of the brake to confirm whether more than two electrical devices are used to cut off the brake current.

(3) Analysis of the independence between the electrical devices that cut off the current of the brake. After determining the number of electrical devices to cut off the brake current not less than two, the independence between the electrical devices should be further analyzed.

(4) After completing the examination of the electrical schematic diagram, on-site inspection can be carried out. Generally, the following steps can be taken.

First of all, checking whether the equipment and drawings are consistent. After confirming the equipment and drawings are consistent, checking the remaining problems in the drawings audit, such as the number and type of electrical devices.

The elevator is electrified, the car is placed at the middle level station, and the elevator door is closed.

When the elevator is running, the maintenance personnel in the machine room hold down a contactor that has been sucked in to cut off the brake current.

Elevator flat parking. At this point, the contactor under test should be in a closed state under the artificial external force, which can simulate the state of electric shock adhesion. The elevator should not be operated when the inside repair personnel chooses the original floor.

In the above-mentioned tests, it should be assigned to guard next to the main power supply, in case of accidents should be immediately cut off the elevator.

In the above test, when the elevator running direction changes, the elevator can not run, it can be determined that the brake electrical control system meets the requirements of the standard, confirming that the test conclusion is qualified.