Quality Control
We understand that enterprise’s reputation basically relies on outstanding product quality and in-time effective services. Our whole operation system is strictly controlled and managed under stringent guidelines,to ensuring the quality of products in all stages. Each plant has its own testing lab, all products must meet the comprehensive inspection standards. All in all, product quality stand on the 1st place, so we can earn the trust from our customers.
We have obtained certifications from international authoritative organizations such as UL, cUL, CSA, CE, IEEE as well as test reports from SGS, CESI, etc.
Main Quality Control
YAWEI promise each one of our delivered transformers has passed the most strictly test and we remained 0 fault rate record for more than 10 years so far, our oil immersed power transformer is designed in accordance with IEC, ANSI and other major international standards.
Electromagnetic Wire Quality Control
The manufacturing of electromagnetic wires requires high-quality copper or aluminum wires. During the manufacturing process, it is important to control the tension, wire diameter, insulation layer thickness, and uniformity of the winding. The completed electromagnetic coil needs to perform final testing, including insulation resistance, withstand voltage testing, and short-circuit testing, to ensure that it can withstand the electrical stress in real work situation.
Insulation Wrapping Check
Check whether the surface of the paper wrapped wire is smooth, free of damage, oil stains, and creases. The insulation layer should be uniform and undamaged. Check whether the winding is uniform, the number of winding layers and winding method meet the process requirements. The conductor of the paper wrapped wire is continuous and free of breakage.
Oil Tank Quality Control
Check the dimensions, out surface of the oil tank, the welding point to ensure the manufacturing process meet the requirements. What’s more, the leakage test for every oil tank and oil conservator under a certain pressure and a certain period must be done before sandblasting and painting. During leakage test, we can check the sealing quality and improve accordingly.
Iron Core Test
The core laminations should be neat, we will test whether there are short circuits or insulation damage between laminations, and conduct the test of the magnetic flux density, magnetization strength, and iron loss parameters of the core, and evaluate the insulation status of the core and whether there is partial discharge situation inside through partial discharge testing.
Accessory Check
QC staff shall check the accessories of the power transformer, whether they installed correctly and accordingly, such as pressure relief device, gas relay, tapping changer, high voltage bushings and low voltage bushings, thermometers.
Distribution Transformer Test
By measuring no-load loss and load loss, evaluate the efficiency and temperature rise of the transformer to ensure its thermal stability during operation. Evaluate the performance of insulation oil and materials by testing leakage current and dielectric loss factor. Conduct AC withstand voltage tests on the transformer to test its insulation strength and ensure that there will be no breakdown or flashover under high voltage,etc.
High Voltage Transformer Test
High voltage testing is an important step in verifying the insulation performance of electrical transformers, ensuring the safety and reliability under high voltage conditions. Measure the voltage ratio of each tap of the transformer to ensure it meets the design requirements, simulate transient overvoltage caused by lightning strikes, and test the transformer’s impulse withstand capability,etc.
Ultra High Voltage Test
For higher voltage up to 500KV, we have a special testing hall to perform the professional test including lightning impulse test, power frequency withstand voltage test, load loss and impedance voltage measurement.