We sincerely apologize for the inconvenience caused to our customers yesterday.
On 9 April at around 8:00 am, the building in which one of our three switching centres is located, suffered a total power failure disrupting the power supply to the entire building. Our switching centre’s standby battery system immediately substituted the failed power source and there was no disruption to service. Our backup generator then commenced operation, successfully taking over from the standby battery system.
At approximately 10:35am a component in the starter circuit board of the backup generator broke down unexpectedly, causing the generator to stop operating. This also caused a huge surge of electrical current that triggered circuit breakers to disconnect the cellular switching system from the standby battery system. The resulting power outage disrupted cellular service in several areas in Hong Kong and selected MTR stations in Kowloon.
Emergency restoration and recovery procedures started immediately and service was restored progressively from 12:15pm onwards. Aside from a small number of selected services, voice and mobile internet services were largely back to normal at 1:00pm. From 2:30pm onwards, all SMS services had returned to normal. The Company’s two remaining switching centres operated as normal during this incident.
The Company carries out inspections and tests of all power generation facilities regularly. The backup generator which caused the outage successfully passed recent inspections and tests on February 22nd. The Company will submit an incident report to the Office of the Communications Authority and will re-evaluate its procedures for informing the public and its customers
We will thoroughly investigate both the reasons for the building’s power outage and the failure of our power backup systems in order to ascertain the root cause. We are determined to learn from these findings and make improvements to prevent similar incidents in future.