1. What is a transformer?

A transformer is a commonly used device in a power system. It can convert electrical energy at a certain voltage level into electrical energy at another voltage level. The transformer is composed of iron core, winding and shell. Among them, the iron core is an important part to introduce the magnetoelectric coupling effect into the transformer, and the winding is to input or output electric energy in the form of a conductive coil. Therefore, when a transformer fails, we usually need to detect whether there is a problem with the winding and iron core of the transformer.

Second, the method of using a multimeter to detect whether the transformer is good or bad

1. Detection of transformer short circuit

When there is a short circuit in the winding, the detection method is as follows:

① Adjust the current gear of the multimeter to a small value, and connect the electrodes of the multimeter according to the two ends of the transformer winding. If the current shows close to zero, there is no short circuit in the transformer.

② If the detected current value is the upper limit of the normal value, it indicates that there is a short circuit problem in the transformer. At this time, the fault point should be found in time for repair.

2. Detection of transformer open circuit

When there is an open circuit in the winding of the transformer, the detection method is as follows:

① Adjust the resistance gear of the multimeter to a small value, and connect the electrodes according to the two ends of the transformer winding. If the resistance value is normal, then there is no open circuit problem in the transformer.

② If the resistance value is infinite, it indicates that there is an open circuit problem in the transformer and needs to be repaired.

3. Detect poor contact of transformer winding

When there is poor contact between the windings or between the windings and the core, the detection method is as follows:

① Adjust the resistance gear of the multimeter to a small value, and connect the electrodes between the transformer winding and the transformer core. If the resistance value is normal, it indicates good contact.

②If the resistance value is too large, it indicates poor contact. You can gently move the winding or iron core with your hands to observe whether there is any change. If there is an obvious change, it indicates that the contact problem is minor. Otherwise, serious poor contact faults need to be repaired.

To sum up, the above is the method of using a multimeter to detect whether the transformer is good or bad. If you encounter a transformer fault, you can detect it according to the above method, and repair and replace it in time to ensure the normal operation of the power system.