How to use a multimeter to measure leakage, short circuit, zero firewire and difference

I. Measurement of leakage

Turn the multimeter to 2M (megohm) and measure the ground resistance between the line and the ground wire normal value is infinity, but below 0.5M (megohm), there is leakage. The same is true when measuring the resistance to ground between the neutral and ground wires.1oz vs 2oz Copper？

Second, the measurement of short-circuit

Turn the multimeter to the buzzer and use the red and black pens of the multimeter to measure the fire and zero wires respectively. Buzzer beeps or multimeter indicator lights up, that is, between the fire wire and the zero line is connected, this phenomenon is usually referred to as "short-circuit".

Measurement of broken circuit

You can also use the multimeter buzzer to measure. For example, the red stylus and black stylus connected to both ends of the wire. If there is a beep, it means that there is no break in the wire. Conversely, if there is no beep, the wire has a break. Knowing the principle, we can also measure many electrical products, such as household wall switches, sockets, household kettles, rice cookers and so on. , helping us to quickly determine the cause of failure.

IV. Measurement of battery power

Measurement of 1.5 volts (V) of the battery, we will rotate the multimeter to the automatic milliampere file (mA) - 1.5 volts (V) of the gear current measurement, if the measured current is 30 to 40 milliampere (mA), indicating that the enterprise power to compare with the adequate. If it can't be lower than 30 milliamps (mA), it means that China's batteries are not enough to make use of the power demand, and need to be replaced by a battery.

How to distinguish between fire wire, zero wire and ground wire

We hit the multimeter to an AC voltage range (~ V) of 750 volts and put a black stylus around our hand four to five times and hang it in the air. The other stylus is used to test each of the three wires. The high voltage value is the fire wire, the low voltage value is the zero wire, and the low voltage value is the ground wire.

How to judge the quality of the motor

Set the multimeter to 2000 ohms (ω), and measure the three terminals (AB, AC, BC) of the motor with the red and black pens of the multimeter respectively. When the resistance value is the same, the motor winding is normal.

Seven, how to judge a motor insulation performance is good or bad

Multimeter turned to 2000 ohms (ω), in turn, the red pen (A, B, C) connected to the motor terminals, pcblink how to test pcb board with a multimeterthe black pen connected to the motor shell, the value of infinity, the motor has no leakage phenomenon.