The 2 most practical ways to troubleshoot a circuit with a multimeter are as follows
Multimeter to measure the circuit is not through a variety of methods, relatively simple, the following two multimeter to measure whether the circuit is on the most common method, in order to more clearly and intuitively illustrate the multimeter to measure the circuit circuit circuit on and off.
First, the voltage measurement method.
First of all, the control circuit will be energised, the multimeter gear switch to AC voltage 750V, compared with the circuit schematic diagram, the multimeter a pen to keep in line 9, another pen were measured 8-7-6-5-4-3 line, in the case of the switch is not closed, the two pens with the same phase, the voltage is 0V, measuring 2-1 line, the two pens are different phases, the voltage of 380V, this is the normal state of the circuit. The normal state of the circuit, if the measurement process, which line which point of the voltage value and the circuit schematic does not match, then in most cases, the voltage value is not the right point is the point of failure!
Second, resistance measurement method.
First of all, the circuit needs to be de-energised, power test, after confirming that there is no electricity, the multimeter gear switch to the beeping gear or resistance gear, the multimeter two pens were placed in the 1 line and 9 line: under normal circumstances, respectively, press the SB1 or SB2 button, or directly, respectively, will be the two AC contactor springs manually pressed (i.e., manually so that the normally open point of the KM1 or KM2 is closed), when the 1-9 conductive! If the circuit is open, the multimeter will have the corresponding resistance value of the coil. If there is no resistance value, prove that the circuit is not, need to be measured against the circuit schematic to analyse the point by point through and through, the measurement method is similar to the voltage.
Third, the multimeter resistance measurement method and voltage measurement method is in the circuit troubleshooting in the most used two methods, can be said that each has its own benefits, each has its own convenience, the key is that you are accustomed to using which one, with your most familiar method with the help of the multimeter measurement.
