Three Phase Transformer DC Winding Resistance Tester 20A Wide 0-25kΩ Range Yn Y

For power systems, the transformer is the core equipment, so the long-term, reliable operation of a transformer is related to the stability and reliability of the whole system.

The DC resistance of a transformer is a mandatory test item for semi-finished products and finished products during manufacture, factory testing, installation, hand-over testing and preventive testing by power departments. It can effectively discover manufacturing defects such as the material selection, welding, loose connection points, missing strands and broken wires of transformer coils, as well as hidden risks existing after operation. To meet the need for rapid measurement of transformer DC resistance, the XHZ1320AX was developed by our company using its own technical advantages. This instrument is a new-generation rapid tester integrating the magnetic-assist method for testing, three-phase testing (Yn, Y and ∆) and demagnetization functions, and is an ideal device for measuring the DC resistance of large power transformers. The screen adopts a true-color, large-size, high-resolution LCD, with touch and jog-dial operation for convenient on-site use. It has a Chinese menu prompt function, is simple and intuitive to operate, completes all DC resistance test items with one-time wiring, and offers fast test speed, high accuracy and a wide range.

The XHZ1320AX is positioned as a coil winding quality and three-phase unbalance verification instrument for the manufacture, hand-over and preventive testing of large power transformers. It is engineered for transformer manufacturers performing semi-finished and finished-product winding DC resistance testing on the production line, for power departments conducting hand-over tests and preventive tests on installed transformers, for installation and commissioning teams that must record, print and archive winding resistance data on site, and for testing personnel who need a single instrument to cover Yn, Y and ∆ connected windings with automatic three-phase unbalance ratio calculation. Unlike the other instruments in the same category, which focus on oil testing, insulation testing, ratio testing or pre-energization demagnetization, this instrument is dedicated to measuring and recording the DC resistance of transformer windings and to verifying the three-phase unbalance ratio across the full measurement range.

Check that you have received the following items in the complete set:

Yn-type, Y-type and ∆-type windings can all be tested using the three-phase measurement method, and the three-phase unbalance ratio is calculated automatically. As a new-generation rapid tester integrating magnetic-assist testing, three-phase testing and demagnetization, it is an ideal device for measuring the DC resistance of large power transformers.

The maximum output current of the test power supply is 20A and the test range is 0–25kΩ, meeting the test requirements of the vast majority of transformers. Single-phase ranges go from 0.5mΩ–1Ω at the 20A range up to 500Ω–25kΩ at the <1mA range; three-phase ranges go from 0.5mΩ–0.8Ω at 10A+10A up to 2.0Ω–80Ω at 0.1A+0.1A.

During the test, the resistance change rate within 5S, 15S and 30S can be calculated automatically, which assists test personnel in judging the stability of the test data and prevents misreading of data.

The instrument has multiple protection functions such as back-EMF protection, wire-break protection and power-off protection. It is equipped with a thermal printer, stores 200 data records on board, and supports USB flash drive mass storage.

Connect the yellow, green, red and black clamps of the high-voltage test leads (longer) to the A, B, C and O bushings of the high-voltage side of the device under test, and the clamps of the low-voltage test leads (shorter) to the a, b, c and o bushings of the low-voltage side (leave the black clamp floating if there is no neutral O/o bushing). After the terminals are connected to the device under test, turn on the power switch; once initialization is complete the instrument enters the main menu screen, and the 7-inch capacitive touch screen plus one-key jog dial make operation convenient.