How to Measure the Current Size of the Dial Switch
Release time：2019-07-25 Clicks： Click
How to measure the current of the switch, we will give you detailed details here.
The advantages of this measuring method are intuitive and convenient. The disadvantage is that the current passing through the switch is very small, and the oxide film on the contact surface can not be destroyed, which results in large recognition error. Therefore, this method is not recommended in the measurement of the circuit resistance of the switching switch.
Indirect measurement by voltage drop method (volt-ampere method):
Voltage drop method is the DC current through the switch socket. The voltage drop (mV) between the inlet and outlet terminals of the switch socket is measured by a millivoltmeter. Then the main circuit resistance of the switch socket is calculated by Ohm's law.
Measuring circuit with transformer and silicon rectifier. At the same time, the voltage drop method is recommended to measure the main circuit resistance of the switch socket because the current passing through the test is large enough to destroy the metal oxide film on the contact surface, reduce the measurement error, and the measured value is more accurate. Therefore, the voltage drop method is recommended to measure the main circuit of the switch socket.
The cumbersome calculation of the switching switch shows that if the attenuation time constant on the switching socket circuit is set at 45ms, and the phase A and B circuits are connected simultaneously, when the DC component in phase A and B reaches o.866, the phase a delay MS input, then the DC component in phase B (assuming that it happens to be a side phase) can reach 112%. If the decay time constant in the switching socket system is increased to 60 ms, the maximum DC component in the six-phase (three-phase) system will reach l15%. In the "split" test, the DC component at the instant of contact separation is related to the duration of short circuit, that is, the opening time of circuit breaker and the action time of relay protection.