Leakage is because the insulation layer of the wire is damaged and the electrical shell of the equipment between the electrical connection between the relationship, which caused the current in the wire "leakage" out, such as the motor shell and three-phase electricity any phase contact may cause leakage; there is also the shell of household appliances and utility wires in the firewire between the electrical connection due to some reason. Electrical connection, so that the metal casing of household appliances and the fire wire between a certain potential difference between such phenomena also become leakage. The occurrence of leakage will produce a relatively large danger, very easy to cause the operation of the machine personnel electrocution accident, in this area we will often use leakage protector to protect the circuit.

1, resistance method to detect leakage faults
Resistance method to detect leakage faults first disconnect the power supply of the electrical equipment, we can use the pointer multimeter RX10K gear if the digital multimeter gear can be played on the 200M gear, with a multimeter pen contact with the firewire (phase) of the circuit, and then use another pen to contact with the metal casing of the equipment, under normal circumstances, the multimeter's pointer should show the value of the resistance to infinity, if the pointer has a deflection, then it means that the electrical equipment is not leakage. If the needle has a deflection, it means that the metal casing of the electrical equipment and the power supply between the insulation strength is not enough, so it is a leakage of electricity.