No matter what series of system mechanisms we choose for the switch, we need to follow our standard time for installation, testing, and opening. For example, the inherent opening and use time of the switch is closely related to the speed of the switch socket, which directly affects its opening and closing performance.
If the opening and closing time of the switch socket is too long, the speed will naturally decrease, and the arcing time will increase, leading to the loss of opening and closing of the switch; If the switch is closed for a long time, the closing speed will naturally decrease, and the electric force will increase, leading to the failure of the switch to close. If the time difference between the three phases is too large, it will cause the line and transformer to be switched on and off in full phase, resulting in operation overvoltage that endangers insulation. Therefore, the inherent opening and closing time, three-phase synchronization, and other time parameters are clearly specified in the technical conditions of each J1 dog, and are mandatory test items for each switch before leaving the factory.
Therefore, the time parameter of the limit switch is also a crucial mechanical characteristic. Switch socket time reference measuring instruments and methods:
(1) Electric stopwatch measurement: Using an electric stopwatch can measure time intervals greater than 0.0IS, and for quick fuses and wall switches of 35kV and below, the opening and closing times can be measured using an electric stopwatch. Different durations can be displayed with light bulbs (each break is connected in series with a low-voltage light bulb), and then the distance difference is measured.
(2) Ray oscilloscope measurement; For measurements that require an accurate time parameter of 0.00ISs, an electric stopwatch cannot be used. Generally, a light oscilloscope is used to record and measure the opening and closing time of the switch and the time difference between different phases of the three phases. The time parameters of fast fuses with voltage levels of 110KV and above are generally measured using a light oscilloscope. The closing time, opening time, and three-phase closing asynchrony and opening asynchrony time difference of the switch can be measured from the one-time opening and closing of the switch socket.
Stroke and overtravel measurement of switch sockets:
The measurement of the total travel, overtravel (the travel of the moving contact when the moving and stationary contacts first come into contact with the switch closing position), and the distance between the moving and stationary contacts when they are separated is usually done by selecting a reference point on the stationary contact and measuring it with a steel ruler. When measuring overtravel, a light bulb or multimeter can be used to assist in determining the just closing point. The above parameter measurements are based on the test data after passing the switch operation test. As the switch has already passed the operation test before leaving the factory, users do not need to conduct all operation tests during installation and testing.