Insulation resistance tester is by using a voltage excitation device under test or network, using ohm's law to measure resistance, insulation resistance change big, could herald a potential failure, so we when doing the test, to regular calibration of megger, to ensure that the instrument itself did not change over time.
Insulation resistance tester can be used to measure the resistance of various insulation materials and transformers, motors, cables, electrical equipment and other insulation resistance, the next with xiaobian together to see some of its common problems.
1. What does the output short-circuit current represent
Long cables, motors and transformers with many windings belong to capacitive loads. When measuring the resistance of such objects, the output short-circuit current can reflect the internal resistance of the output high voltage source in the megohm meter.
2. Why use the "G" end of the meter to measure higher resistance
The "G" end of the instrument (shielding terminal) is used to eliminate the influence of humidity and dirt in the test environment on the measurement results. When measuring high resistance values, if the results are not stable, consider using the G-terminal to eliminate errors.
3, in addition to the resistance value, why also measure the absorption ratio, polarization index
In the insulation test, the insulation resistance value at a certain moment can not fully reflect the advantages and disadvantages of the insulation performance of the test product. On the one hand, because of the insulating material with the same performance, the insulation resistance is small when the volume is large, and the insulation resistance is large when the volume is small. On the other hand, there are charge absorption ratio (DAR) and polarization (PI) processes in insulating materials with high voltage.
4. Why can it produce higher DC high voltage
According to the PRINCIPLE of DC conversion, the insulation resistance tester powered by several batteries is processed by the boost circuit, and the lower supply voltage will be raised to the higher output DC voltage, resulting in high voltage but small output power.
Wuhan Xinshengneng is a professional insulation resistance equipment manufacturer, not only produces all kinds of power testing equipment, and professional technical team to provide all kinds of test technical services, more products more models to choose from, welcome to call 0312-3188565 details!
