Use resistance method to detect motor forward and reverse control circuit

The motor forward and reverse control circuit has many connectors, so after new installation or repair, the circuit may be messed up and errors may occur. Using the resistance method for detection can avoid accidents. The circuit is as shown in the figure. Set the multimeter to R×100Ω. Under normal circumstances, the resistance values ​​between each point of the control loop are as shown in the table below. If the wiring is wrongly connected and the resistance value is inconsistent with the value listed in the above table, the test run must not be powered on. The resistance value (1300Ω) listed in the above table is the coil resistance value of the CJ10-10 AC contactor, and the rated working voltage of the coil is 380V. If the rated voltage is 220V, or other models, you need to use a multimeter to actually measure the resistance of the coil, and then test it with the above method.