This picture taken on April 6, 2023 shows illuminated neon signs in Hong Kong. (PHOTO / AFP)

HONG KONG – Hongkong Electric Company Ltd should correct the “inadequacies” reflected in its report to prevent any repeat of the power outage that hit various areas of Hong Kong Island in April, Secretary for Environment and Ecology Tse Chin-wan said Wednesday.

Answering a query at the Legislative Council, Tse said the Electrical and Mechanical Services Department was still conducting its investigation on the incident but HEC’s own investigation report reflected “inadequacies” in the management of circuit diagrams. 

The power outage that happened at 12:45 am on April 19 left residents in various areas of Hong Kong Island without electricity for up to over 40 minutes

“While the investigation by the (EMSD) is still underway, HEC's report has reflected HEC's inadequacies in the management of the drawings,” Tse said.  

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“In this regard, HEC is obliged for immediately formulating improvement measures on different aspects, including establishing guidelines on updating detailed transmission schematic drawings, single-line diagrams and circuit diagrams of energy management systems, as well as their respective methods of use and limitations, in order to prevent reoccurrence of similar incidents,” he added.

The power outage that happened at 12:45 am on April 19 left residents in various areas of Hong Kong Island without electricity for up to over 40 minutes.

In his question to Tse, LegCo member Chan Hok-fung noted that it had been reported that the incident was related to the failure to update the circuit diagrams of the Cyberport 275-kV Switching Station’s Energy Management System in a timely manner.

“HEC indicated that the relevant drawings with specific uses were updated after the completion of the power network enhancement project at the Cyberport Substation in 2009. HEC explained that as the spare cable circuits were not used in the daily operation of the power network, the updates were not included in all drawings,” Tse said. 

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According data Tse submitted to the LegCo, the number of power interruptions that affected more than 100 HEC customers has gone down from 35 incidents in 2019 to 32 in 2020, 25 in 2021, and 23 last year.