By hvhipot 
Find the right solution when the following problems occur in the high-voltage test transformer
The structure of the high-voltage test transformer is made of laminated cold-rolled silicon steel sheets. The coil is a concentric pagoda-shaped multilayer cylinder, with the low-voltage coil inside and the high-voltage coil outside; the shell is portable, with the advantages of small size, light weight, beautiful appearance, and convenient movement.
Causes and treatment methods of floating potential of high-voltage test transformer:
Reason: The clamping channel steel, pressure nail bolts, pull plate and other parts of the transformer are sprayed with blue paint. .
Judgment method: The floating potential discharge makes a very slight “squeak, squeak” sound, which can only be heard by listening carefully. Users often mistakenly think that the high voltage or low voltage of the transformer is discharging.
Solution:
1) This discharge will not affect the normal operation of the transformer.
2) The paint can be scraped off the poorly contacted areas during power outage maintenance, so that the parts of the transformer are in good contact.
Reason: The voltage waveform of the transformer is distorted (such as resonance) and noise is generated.
Judgment method:
1) In addition to the noise of the transformer itself, the noise is also mixed with “cuckling, clucking” noise.
2) During operation, the transformer noise will suddenly become louder.
Reason: The high voltage will overexcite the test transformer, and the noise will increase and be sharp, which will directly affect the noise of the test transformer.
Judgment method: first look at the low-voltage output voltage, not the voltmeter on the low-voltage cabinet.The voltmeter only serves as an indicator and should be measured with a more accurate multimeter.
Solution: Now the 10KV voltage in cities is generally high. According to the output voltage of the low-voltage side, the tap gear should be placed in a suitable gear at this time. Under the premise of ensuring the quality of low-voltage power supply, try to adjust the high-voltage tap upwards (low-voltage) The output voltage is reduced) in order to eliminate the overexcitation phenomenon of the test transformer and reduce the noise of the test transformer at the same time.