Method of multimeter to find fault of electrical control circuit
Two most practical methods for troubleshooting circuit faults with multimeter
First, the voltage measurement method.
Firstly, the control loop is electrified, and the gear switch of the multimeter is set to the AC voltage of 750V V. According to the circuit schematic diagram, one probe of the multimeter is kept at line 9, and the other probe is used to measure line 8-7-6-5-4-3 respectively. When the switch is not closed, the two probes are in the same phase and the voltage is 0 V. When measuring line 2-1, the two probes are out of phase and the voltage is 380V V.
Second, resistance measurement method.
First of all, it is necessary to cut off the circuit, check the electricity, and after confirming that there is no electricity, set the gear switch of the multimeter to the buzzer gear or the resistance gear, and place the two probes of the multimeter at line 1 and line 9 respectively: under normal circumstances, press the SB1 or SB2 button respectively, or directly press the two AC contactor springs manually (that is, manually close the normally open point of KM1 or KM2). At this time, 1-9 is on, the circuit is on, and the multimeter will have. If there is no resistance value, it proves that the circuit is impassable, and it is necessary to measure and analyze the on-off point by point against the circuit schematic diagram. The measurement method is similar to that of voltage.
Third, the resistance measurement method and voltage measurement method of multimeter are the two most commonly used methods in circuit troubleshooting. It can be said that each has its own advantages and conveniences. The key is which one you are used to, and use the multimeter to measure with the method you are most familiar with.
Method of multimeter to find fault of electrical control circuit
Generally, there are voltage method and resistance method to find line faults. Voltage method is to detect the fault point by measuring voltage, and resistance method is to find the fault by measuring resistance. Each of them has its own advantages. If you are not familiar with the line, we recommend the resistance method to judge the fault, which is relatively safe.
