Transformer sounds are divided into normal and abnormal sounds. The normal sound is the "hum sound" emitted by the transformer excitation, which varies with the load; when the transformer has an abnormal sound, it should be analyzed first to determine whether the sound is inside or outside the transformer.

1. The sound comes from the inside, and the possible parts are:

If the iron core is not tightly clamped, there will be "dingdong" and "huhu" sounds;

If the iron core is not grounded, there will be a slight discharge "cracking" sound;

Bad switch contacts will produce "squeak" and "crack" sounds, and the sound will become louder as the load increases;

When the surface of the casing is greasy, there will be a "hissing" sound.

2. The sound is external, and the possible parts are:

Overload operation, it will make a heavy "humming" sound;

The voltage is too high, and the sound of the transformer is loud and sharp;

When the transformer is running with a phase loss, the sound of the transformer is sharper than usual;

When magnetic resonance occurs in the grid system, the transformer will emit noise with uneven thickness;

When the low-voltage side is short-circuited or grounded, the transformer will make a loud "boom" sound.