How to use a multimeter to check for short circuits and leakage faults in your home
1. Measure short-circuit Measure short-circuit principle is relatively simple can be measured with a resistance gear, but with the sound of the kind of digital multimeter is better, hit the diode gear is best to unplug all the electrical appliances in the house, hit the switch and then find a plug to the pen inserted If there is a short circuit in the line the multimeter will be released beep .... If there is a short circuit in the line, the multimeter will release a beep sound; if the line itself is not short-circuited, then connect the appliances one by one to see if there is a short circuit in that appliance.
2. line leakage is more difficult to measure, but you can measure the resistance of the line to ground Appliance leakage, then the general zero wire or fire wire will be connected to the shell (already grounded shell) or poor insulation can be measured by the resistance file
Sometimes visual inspection can also be seen, such as some electrical appliances or wires through the environment where the more damp is possible leakage of electricity can be appropriate pad some dry things to isolate it. In addition, you can also unplug all the electrical appliances and connect them one by one, then you can find the leakage appliances.
A short circuit is a closed circuit in which the power supply is directly connected by a wire without passing through the load. Power system in operation, phase to phase or phase to ground (or neutral) between the abnormal connection (i.e. short circuit) and flow through a very large current. Under normal conditions, the resistance between phase and phase or phase and ground is very large, short circuit, its resistance is basically zero, with a multimeter to measure the resistance can be completely. This measurement, the conductive state is difficult to have the opportunity to measure, but the circuit is not on state is very good to measure the determination.
When the circuit is not closed switch, or the wire is not connected, that is, the circuit is broken somewhere. In this state of the circuit is called a broken circuit, also called open circuit. When measured with a multimeter, its basic characteristic is the resistance without resistance.
Leakage is the shell of electrical appliances and utility wires due to some reason connected to the ground and the ground between a certain potential difference. 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 with static electricity; if the long bright fixed leakage is undoubtedly.
Suspected line leakage, the possible leakage point directly to ground voltage measurement, if the voltage and AC voltage close to the leakage. You can also measure the resistance, but the operability is not as convenient as measuring the voltage.
