Daqo Transformer Passes JEC Type Tests and Seismic Qualification for Japan

50/60 Hz operation and AG5 seismic qualification address key requirements of Japan's power market

Daqo's S-2500/6.6 oil-immersed transformer, rated at 2,500 kVA and 6.6/0.69 kV, has successfully completed the full JEC-2200-2014 type test program and JIS C 60068-3-3:2021 seismic qualification. A conformity certificate has been issued by TÜV Rheinland.

Japan presents distinct requirements for power equipment. Eastern and western regions operate at different grid frequencies, while the country's seismic environment places additional demands on equipment design and reliability. Designed for both 50 Hz and 60 Hz operation, the S-2500/6.6 can be applied across Japan's different frequency regions. It has also achieved AG5 seismic qualification at 0.5g ZPA, verifying its structural integrity and electrical performance under the specified seismic conditions.

JEC-2200-2014 is a key benchmark for oil-immersed transformers in Japan, setting rigorous requirements for safety, performance and environmental adaptability. Compliance with the standard represents an important qualification for suppliers serving Japan's power and industrial sectors.

The S-2500/6.6 transformer passed all 13 type tests required under the JEC-2200-2014 test program. These included:

• Short-circuit withstand test – Category A, 3 × 500 ms per phase

• Lightning impulse test – 60 kV full wave / 65 kV chopped wave

• Temperature-rise test

• Overload test – 125% rated capacity

• Sound level measurement – ≤65 dB(A)

For customers in Japan, this independent qualification provides a credible basis for technical assessment and supplier approval, helping engineering and procurement teams evaluate the transformer with greater confidence.

Daqo develops products for global markets by engineering to local requirements from the outset. Grid conditions, technical standards and application needs are considered throughout the development process, from product design through testing and validation. This approach helps provide customers with greater assurance in project execution and long-term system reliability.

Inside Daqo's Automated Transformer Production Line