Why DC Winding Resistance Testing of Transformers is Needed?

DC winding resistance testing is considered an essential winding troubleshooting method, revealing problems such as loose windings, winding deformations, local winding defects or incorrect connections, which are considered a fault category as they cause a large number of transformer failures each year. Winding resistance testing can also reveal problems with the transformer tap changers, on-load tap changers (OLTCs) and/or de-energized tap changers (DETCs) - the main and, according to some statistics, the most prominent component category for failure in transformers.

JYR-20S adopts third-generation constant current source technology, with a maximum output current of 20A, a range of 0Ω to 20kΩ, and an output voltage of up to 24V. It features a built-in channel conversion matrix. JYR20Svarious tests on power transformers can be performed without rewiring. The instrument can complete three-phase simultaneous tests, phase-by-phase tests, magnetic assistance tests, and single-phase DC winding resistance tests.

JYR-20S Mian Feature Function:

1. Testing lines are connected to the transformer in one trial, without resetting testing line during testing process.
2. Adopting simultaneous testing of three phases when Yn type is tested, high-voltage YN three-phase simultaneous measurement compensation method (including O-phase resistance),and calculate balance rate of resistance of three phases automatically.

3. Under Yn/D(Y)type can be tested phase by phase, and calculate balance rate of resistance of three phases automatically, it solves the problem that the leading wire resistance of neutral point can not be measured.

4. Apply automatic magnetic assist for testing low voltage when testing large capacity YnD11 transformer (with magnetic assist box inside).

5. Auxiliary to judge the data stability, automatically calculate the percentage of 5", 15" or 30" resistance deviation, and accurately judge the authenticity of the test data

6. Large screen display, humanized operation, printing with USB and 485 communication interface.

7. Protection function from misconnection 380V power, power off and back EMF, discharging indication is clear.

Other Functions of JYR-20S:

1.JYR-20S with temperature conversion function. Select the test material (copper/aluminum) and input the temperature (optional special wireless temperature probe to collect the test temperature directly),then automatically convert to the resistance at the set standard temperature for easy comparison with historical data.

2.100 sets of test data can be stored;With USB interface to import data into the USB drive;With the built-in Bluetooth communication module to interact with PC and other computer data or connect to a micro-Bluetooth printer to print data reports.

3.The "Test/Stop" mechanical button with shortcuts and automatic shutdown function if no operating in 5 minutes.

4.Built-in rechargeable lithium battery, a single charge can complete a hundred of transformer tests.Fully balanced battery charging technology effectively extends battery life.

5.With high-brightness color touch LCD display, touch menu operation is fast and clear.

6.With discharge sound alarm, overheat alarm and other perfect protection circuit. Clear instructions to reduce mishandling.

Technology Specification:

Deployment	JYR-10S	JYR-20S
Output current	Auto、 10A、 3A、 1A、 300m A、 100mA 、 30mA、 10mA	Auto、 20A 、 3A、 1A、 300m A、 100mA 、 30mA、 10mA
Test range	0~20kΩ
Accuracy	For 10S: 0.2%±0.4μΩ For 20S: 0.2%±0.2μΩ
Minimum resolution	0.1μΩ
Power supply in operation	AC220V±10%, 50Hz±1Hz(can be customized)
Temperature in operation	-20~40℃
Relative humidity	≤80%RH, No forming dew
Volume	Length 420mm  Width 320mm  Height 200mm
Net weight	13.8 kg

CALIBRATION CERTIFICATE:

All KRI tests will adopt international express to reach any corner of the world as fast as 72 hours