How to Measure Inductance with a Multimeter?
Detection of color coded inductors
Place the multimeter in the R × 1 position, and connect the red and black probes to either lead of the color code inductor. At this point, the pointer should swing to the right. According to the measured resistance value, it can be distinguished into the following three situations:
The resistance value of the tested color code inductor is zero, indicating an internal short-circuit fault. The magnitude of the DC resistance of the tested color code inductor is directly related to the diameter of the enameled wire used to wrap the inductor coil and the number of turns wound. As long as the resistance value can be measured, it can be considered that the tested color code inductor is normal.
2. Inspection of Zhongzhou Transformer
A? Set the multimeter to R × 1 and check the on/off status of each winding one by one according to the pin arrangement of the medium cycle transformer, in order to determine if it is normal. B? Testing insulation performance
Place the multimeter in the R × 10k range and perform the following state tests:
(1) The resistance value between the primary winding and the secondary winding;
(2) The resistance value between the primary winding and the casing;
(3) The resistance value between the secondary winding and the casing.
The above test results can be divided into three situations:
(1) The resistance value is infinite: normal;
(2) Zero resistance: There is a short-circuit fault;
(3) Resistance less than infinity but greater than zero: there is a leakage fault.
3. Testing of power transformers
A? Check for any obvious abnormalities by observing the appearance of the transformer. Whether the coil leads are broken, desoldered, whether there are burnt marks on the insulation material, whether the iron core fastening screws are loose, whether the silicon steel sheets are corroded, whether the winding coils are exposed, etc.
B? Insulation test. Measure the resistance values between the iron core and the primary, between the primary and each secondary, between the iron core and each secondary, between the electrostatic shielding layer and the secondary winding, and between each winding of the secondary using a multimeter R × 10k. The multimeter pointer should all point to infinity and remain stationary. Otherwise, it indicates poor insulation performance of the transformer.
