Test method for AC capacitors(I)

1.Multimeter detection method

    For fixed capacitors above 0. 01 μ F. The R × 1k block of the multimeter can be used to directly test whether the capacitor has charging process and whether there is internal short circuit or leakage, and the capacity of the capacitor can be estimated according to the amplitude of the pointer swinging to the right. In the test operation, first touch the two pins of the capacitor with a two-meter pen, then change the pen to touch again. If the capacitance is good, the multimeter pointer will swing to the right, and then quickly return to the infinite position to the left. The larger the capacitance, the greater the swing of the pointer. If the meter pen touches the two pins of the capacitor, the multimeter pointer does not swing to the right, indicating that the capacity of the capacitance is less than 0.01 μ F or has disappeared. In the measurement, if the pointer swinging to the right can not return to the infinite position to the left, indicating that the capacitance leakage or breakdown.

2. Simple detection method for fuses 

    The fuse (rated current in of its fuse is determined by the following formula: 0. 8 / C / A, where C is the capacitance of the capacitor) and the capacitor to be tested is connected in series to a 220V AC power supply. If the fuse of the fuse explodes, the internal circuit of the capacitor has been short-circuited. If the fuse of the fuse does not break, after a few seconds of charging, cut off the power supply, with a screwdriver with insulation to the capacitor of the two short circuit discharge, sparks show that the capacitor is good. Conversely, the capacitance of the capacitor has become smaller or has been opened. This method should be repeated several times in order to get the correct conclusion.