in the EPWT-20S ?

General Information:
The DC resistance of the transformer is a must-test item for the semi-finished product, finished product factory test, installation, handover test and preventive test of the power sector in the transformer manufacturing. Defects and hidden dangers after operation. EPWT-20S three-channel DC winding resistance tester integrates three-phase simultaneous test, magnetization function, and demagnetization function, realizes three-phase simultaneous power-on, independent current sampling, voltage sampling, and simultaneously measures and displays three-phase resistance and three-phase resistance The function of unbalance rate greatly shortens the test time of the DC resistance of the transformer, and solves the problem that the DC resistance test of each tap winding of the power transformer takes a long time.


-The instrument can choose the output current value (the maximum output current value is 20A), which is suitable for measuring the inductive DC resistance of transformers and transformers.

-For large transformers whose five-column core and low-voltage windings are connected in a delta, the instrument can use the method of high and low-voltage series excitation for testing.

-The instrument is equipped with three-phase measurement function, in order to complete the three-phase direct resistance measurement in one connection of the star-connected winding, and automatically calculate the three-phase unbalance rate, which greatly saves the measurement time and improves the work efficiency. The phase-by-phase test function can also be used to perform phase-by-phase tests on transformers with YN and D(Y) connections until the test is completed.

-With perfect protection circuit and sound discharge alarm, discharge indication is clear, reducing misoperation.

-The instrument adopts a 7-inch color touch screen, an English operation interface, and the test data can be displayed in real time.

-With RS232 communication interface, with the control software of the upper computer, the test data can be transmitted to the background.

-With a USB interface, the test data can be transferred to a U disk.

-The instrument has a built-in calendar clock, which can store, recall and print 100 groups of test data.

-The parameter setting is more perfect, and you can set the test winding, tap position, test phase, test product temperature, converted temperature, etc. of the transformer.

-The instrument adopts an industrial plastic case, which is easy to carry and prolongs its service life.

Technical Specifications:

Measuring Current

Three-phase test: 10A+10A, 5A+5A, 1A+1A

Single-phase test: 20A, 10A, 5A, 1A, 200mA

Measuring Range

Three-phase test:

10A+10A: 1mΩ~0.5Ω

5A+5A: 2mΩ~1Ω

1A+1A: 10mΩ~5Ω

Single-phase test:

20A: 0.5mΩ~1Ω

10A: 1mΩ~2Ω

5A: 2mΩ~4Ω

1A: 10mΩ~20Ω

200mA: 100mΩ~100Ω

Measuring Accuracy

±(0.2%+2 digits)

Min. Resolution


Power Supply

AC220V±10%, 50Hz±1Hz

Working temperature


Ambient humidity

≤80% RH, no condensation


428mm* 350mm* 230mm (L*W*H)

Tester weight

10.2 kg