MEL.L Regulatory News (MEL)

Mitsubishi Electric Reports on Improper Testing

of 72/84kV Cubicle-type Gas-insulated Switchgear

TOKYO, August 17, 2021 - Mitsubishi Electric Corporation (TOKYO: 6503) announced today that internal investigations being conducted by the company revealed on July 28 that several inspections of 72/84kV C-GIS (cubicle-type gas-insulated switchgear) manufactured at its Power Distribution Systems Center in Marugame, Kagawa Prefecture was not entirely in accordance with customer-requested standards, which required compliance with the Japan Electrotechnical Committee (JEC), the Japan Electrical Manufacturers' Association (JEM), or the International Electrotechnical Commission (IEC). There were also cases where improper statements were included in the inspection reports when inspections were conducted differently than what the standards required at the time.

Mitsubishi Electric halted shipments of the products in question as soon as the issues were discovered. Currently, only those products for which inspections are confirmed to have been conducted properly are being shipped. Electric utilities and other customers using the products in question are being notified of the situation. Regarding the safety, functionality or performance of products that have been shipped, the company has conducted tests during several stages of production such as, product development, mass production, and installation, and during each of these stages, there were no confirmation of any issues regarding the products. The company is not aware of any accident or other incident attributable to this matter. Mitsubishi Electric will be open to special inspections of the products as needed upon discussion with any customer.

An investigative committee consisting of external experts was established by Mitsubishi Electric on July 2 and the committee is currently continuing its investigations. The cause of these issues and measures to prevent any recurrence will be announced as soon as the committee issues its final report. Meanwhile, Mitsubishi Electric will publicly announce any other serious matter, including improper testing of other products that is newly uncovered through further investigations.

At present, Mitsubishi Electric has determined that there is no need to revise its consolidated earnings forecast for the current fiscal year. The company, which is working sincerely with customers and implementing necessary preventive measures, will disclose any potential impact on consolidated earnings forecast that comes to light hereafter.

Products in Question

72/84kV Cubicle-type Gas-insulated Switchgear

Models: GX-70V, HG-VA, HG-VG and HG-VG-A

Total orders: 863 (4,529 panels) shipped between 1996 and 2021

Discrepancies Identified (as of August 17, 2021)

The following conducts during routine testing prior to shipping have been uncovered:

1) Lightning Impulse Test

The lighting impulse test specified by JEC was not conducted, but a "good" result was entered in the test report.

2) Power Frequency Voltage Test

The power frequency voltage test specified by JEC-, JEM- or IEC- was not conducted, but a "good" result was entered in the test report.

3) Partial Discharge Test

The partial discharge test specified by JEC- or JEM was conducted using a different voltage-application pattern.

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About Mitsubishi Electric Corporation

With 100 years of experience in providing reliable, high-quality products, Mitsubishi Electric Corporation (TOKYO: 6503) is a recognized world leader in the manufacture, marketing and sales of electrical and electronic equipment used in information processing and communications, space development and satellite communications, consumer electronics, industrial technology, energy, transportation and building equipment. Mitsubishi Electric enriches society with technology in the spirit of its "Changes for the Better." The company recorded a revenue of 4,191.4 billion yen (U.S.$ 37.8 billion*) in the fiscal year ended March 31, 2021. For more information, please visit www.MitsubishiElectric.com

*U.S. dollar amounts are translated from yen at the rate of ¥111=U.S.$1, the approximate rate on the Tokyo Foreign Exchange Market on March 31, 2021