Transformer Resistance Testing

How to operate the DC resistance tester:

1.Power supply

There are two kinds of power supply supplied by DC resistance tester: AC220V/DC12V. In the case of strong electromagnetic interference, it is advisable to use the DC power test, which has a stable numerical value and strong anti-interference ability.

2. The join method of the test line

Connect the I +, V +, V -, I- terminals of the instrument to the subjects. This way can eliminate the influence of contact resistance and wire resistance on measurement.

3. Measurement

After connecting the test line, the power switch is closed, and the power indicator light is on. Press the "Start Stop" button, at this time the table header will display "E0000". According to the size of the measured value, choose the resistance gear range, and press the switch, at this time the gear indicator light is on. And the stable value of the four and a half LCD displays is the measured resistance value, please pay attention to the unit of the selected range（mΩ/Ω/kΩ）when reading the value. What's more, when measuring a large inductive test such as a power transformer, it is best to short-circuit the other coil which is no need to measure and outside the test loop in order to avoid electromagnetic interference.

4. Discharge

The total power supply can be turned off directly after the test is complete.  If in the perceptual test, shutting off the power should not be immediately after the removal of the operation. It should let the instrument has a continuous discharge process. Generally, discharge should be at least 20 seconds, otherwise the electric inductance will endanger the safety of the person.