How to use a multimeter to measure short-circuit, circuit breakers, leakage
How to check for short circuits and short circuits
Confirm that the circuit should be in a de-energised state before detection, and it is strictly prohibited to operate with electricity, especially high voltage. If you are using a pointer multimeter, you only need to hit it to the R × 10 gear, digital multimeter will have a buzzer put, you can directly use the buzzer gear, or also use the resistance gear.
Pay attention to the pen insertion method, the black pen inserted into the COM jack, the red pen inserted in the measurement voltage resistance jack. The multimeter pen on the two ends to be measured, the pointer multimeter pen does not move, on behalf of the resistance value of infinity, that is, the circuit-breaking state. Digital multimeter disconnected state for the buzzer file does not sound, or with the resistance file digital display is 1.
If the pointer multimeter needle full bias, digital multimeter drop sound, or the resistance value shows zero or very small, it shows that in the short-circuit state.
Leakage is the leakage of current due to insulation damage or other reasons. Appliance shell and utility wires due to some reason connected to the ground and the ground between a certain potential difference will produce leakage.
Electrical appliances charged measurement: digital multimeter or pointer multimeter measurement, playing to 250V AC voltage gear, pay attention to the location of the red and black pens to distinguish. Measurement of suspected leakage of electrical appliances metal shell, a pen connected to the shell of the appliance, another pen ground (or tap).
Pointer or digital display voltage is higher than between 30-50V, switch to AC 50V gear, if the power supply is confirmed to be higher than 30 volts of leakage, lower than 30 volts is normal, and then the zero, fire power supply plug line to the right measurement once can be determined.
You can also use an electric meter pen, the best way to detect leakage is to use an electric pen to contact the charged body, if the neon bubble light immediately went out, proving that the charged body is static electricity, if the long bright fixed leakage undoubtedly.
