Insulation voltage tester characteristics
1. Four display Windows simultaneously display high and low voltage voltage, current and withstand time, as well as multiple status indicators.
2. Test results can be viewed and printed, with automatic/manual printing.
3. Human-machine dialogue full keyboard operation mode, intelligent whole process of work, optional automatic mode and manual mode.
4. Real-time display of high voltage, high voltage current, low voltage current, time and withstand voltage results, intuitive display.
5. Perfect over voltage, over current protection, arbitrary set output voltage, high voltage current upper limit, low voltage current upper limit and timing time.
6. With zero back detection function, zero back to determine before the test, safe and reliable.
8. Approaching voltage regulation algorithm, automatically withstand voltage timing after reaching the set voltage, and automatically reduce voltage back to zero after the end of timing.
9. When the set high voltage current or low voltage current is exceeded, the voltage output will be cut off automatically, and the voltage will be reduced to zero, and sound and light alarm will occur.
Hardware and software anti-interference design, a variety of anti-interference means to adapt to the harsh electromagnetic environment.
11. Automatic error diagnosis, easy to find and solve problems.
12. Wireless remote control function, remote communication, door interlocking alarm light alarm bell, external voltage divider calibration interface, etc.
Principle of instrument testing
Compared with the main insulation of transformer, that is, the insulation between winding and winding and between winding and iron core, transformer has another important insulation performance index -- longitudinal insulation. Longitudinal insulation is refers to the transformer winding with different potential difference and insulation between the different parts, mainly including winding turn-to-turn, interlayer and insulation between the period of performance, and the national standard and the international electrotechnical commission (IEC) standards specified in the "induced overvoltage withstand test" is a dedicated to one of the transformer longitudinal insulation performance of the test method.
The longitudinal insulation of the transformer mainly depends on the insulating medium in the windings -- the insulating paint of the enameled wire itself, transformer oil, insulating paper, impregnated paint and insulating glue, etc. (different types of transformers may contain one or more of the insulating media); Vertical insulation dielectric is difficult to ensure 100% purity, inevitably mixed with solid impurities, bubbles or water, etc., the production process will also be damaged to varying degrees; Transformer is working at the highest field strength on the defect, long-term load operation temperature and lower dielectric breakdown voltage, caused by partial discharge, dielectric absorption power applied alternating electric field by dielectric loss will increase significantly, lead to serious, dielectric heating medium conductivity increases, the parts of a large current will generate heat, The temperature of the dielectric will continue to rise, and the rise in temperature will in turn increase the conductivity of the dielectric. Such a long-term vicious cycle will eventually lead to the thermal breakdown of the dielectric and the destruction of the entire transformer. This fault is manifested in the characteristics of the transformer is the no-load current and no-load power consumption significantly increased, and the winding has scorching, arc, vibration and noise and other undesirable phenomena. So it is very necessary to detect whether the transformer contains longitudinal insulation defect by induction withstand voltage test.
