The dry-type test transformer is a special step-up device dedicated to the AC withstand voltage test of electrical equipment. Because its insulating material is made of epoxy resin, it is called the dry-type, and because it is the same as the capacity. Compared with oil-immersed test transformers with the same power cord, they are lighter in weight, smaller in size, beautiful in appearance, and stable in performance. Therefore, they have become the first-choice withstand voltage equipment for power systems and power users to test the insulation performance of various electrical equipment on site.

1. Matters needing attention in the test of dry-type test transformer

(1) Before the test, the shell "〨" of the high-voltage dry-type test transformer and the ground terminal "〨" of the power control box must be well grounded, otherwise the safety of people and equipment will be endangered.

(2) Before operation, you must be familiar with the electrical principle and wiring diagram of the high-voltage test transformer and the power control box. If it is to carry out DC withstand voltage and leakage test, the high-voltage silicon stack (high-voltage rectifier diode) or DC digital micro-ammeter can be screwed on the high-voltage end of the high-voltage dry-type test transformer first.

(3) After the preparation is completed, after checking the power supply and wiring, you can turn on the main power switch. At this time, the red switch indicator light is also on. If it does not light up, the regulator handle should be returned to the zero position in the counterclockwise direction, and the indicator light on the red stop button is on, otherwise the start button refuses to cooperate.

(4) Press the start button, the green button indicator light is on, then rotate the handle of the voltage regulator evenly and slowly at a clockwise speed of 1.5-2 kV per second, the high voltage gradually rises and pay close attention to the indication of the voltmeter and the test product Circumstances, until the required test high pressure is adjusted.

(5) According to the test time of the product to be subjected to the withstand voltage test, pull the timer for the required timing and then press the timing and alarm switch, that is, test the product withstand voltage within the specified time, and then give an alarm. When the product is broken down, the overcurrent relay automatically trips. At this time, the reading of the voltmeter is the value of the breakdown voltage of the product.

(6) If you need to protect the tested product from breakdown, you can first connect the discharge protection ball gap to the high voltage side to adjust the discharge voltage of the protection ball to about 1.15 times the test voltage.