This dry type test transformers have the characteristics of light weight, small volume, beautiful appearance, stable performance, easy to use and carry, especially suitable for field operation. It is a new type of AC / DC dual-purpose high-voltage test transformer. This series of generators are suitable for power system and various power users to test the insulation performance of various electrical equipment, DC high voltage and small current of various voltage systems or devices of electrical products.

The input voltage of the dry type transformer is 200V / 400V. By changing the input voltage according to the principle of electromagnetic induction, the output high voltage can be continuously adjusted from zero voltage to rated maximum value.

In the test of DC withstand voltage and leakage current, as long as the high voltage silicon stack is mounted on the high voltage output terminal, the input voltage can be changed, and the DC high voltage output with different values can be obtained.

The specific working principle of this kind of products is shown in figure (1). When it is used for cascade use, its wiring is shown in. figure (2)

GYD: test transformer

JS: time relay

TY: self coupling voltage regulator

FM: alarm

LJ: over current relay

D1, D2, D3: indicator light

C: AC contactor

RD: fuse

K: Main power switch

K1: time relay power switch

AK: voltage regulator return to zero limit switch

AQ: Start button

CL: high voltage silicon stack

AT: stop button

A: Output ammeter

KV: output voltmeter

Operation method

1. Before the test, the shell " " end of the high-voltage test transformer and the grounding end " " of the power control box must be well grounded, otherwise the safety of personnel and equipment will be endangered.

2. Be familiar with the electrical principle and wiring diagram of high voltage test transformer and power control box before operation. If the DC withstand voltage and leakage test are checked, the high-voltage watt or micro ampere meter can be rotated at the high-voltage end of the high-voltage test transformer.

3. After the preparation is completed and the circuit is checked to be correct, the main power switch can be turned on, and the red switch indicator light is also on. If it doesn't work, return the handle of voltage regulator to zero in counter clockwise direction, and the indicator light on the red stop button will be on, otherwise the start button will refuse to close.

4. Press the start button, and the green button indicator light is on. At this time, rotate the handle of the voltage regulator clockwise at the speed of 1.5-2 kV per second and the high voltage will raise gradually. Pay high attention to the indication of the voltmeter and the condition of the test object until the required test high voltage is adjusted.

5. To test the withstand voltage test time of the product, pull out the timer for the required time, and then press the timing and alarm switch, that is, test the product withstand voltage within the specified time, and then give an alarm to inform that if the tested product is broken down, the over-current relay will trip automatically. At this time, the reading value of the voltmeter is the value of the breakdown voltage of the product.

6. If it is necessary to protect the tested product from breakdown, first connect the protective ball gap continuously at the high voltage side, and adjust the discharge voltage of the protection ball to about 1.15 times of the test voltage.