Hong Kong’s largest electricity provider has apologised after a voltage dip in Sham Shui Po left some households with flickering or dimmed lights, with the under-fire utility vowing to investigate the latest in a string of such disruptions.
CLP Power said on Wednesday that its 11,000-volt power supply system in the district recorded a drop in voltage at 11.09pm the night before.
“During this period, some customers may have experienced lights dimming or flickering, while some may also have observed the circuit breaker in their electronics tripping due to the activation of protection devices,” the company said.
“CLP apologises for any inconvenience caused, and will investigate the cause of the incident.”
The disruption occurred just hours after CLP submitted to the government an investigation report which blamed external factors for a power outage that plunged more than 2,000 Wong Tai Sin households into darkness last month.
The power company said in a public statement that cable joints had “previously been interfered with”, which caused a gradual degradation in insulation and eventually led to the two sequential faults that day.
Edward Lo Wai-chau from the Hong Kong Institution of Engineers explained that “joints” referred to the connection point between two cables, as they might not be long enough to span the entire circuit they were serving.
Asked whether the damage could have been caused by previous roadworks in the area, as earlier reported by media, Lo said such incidents were not unheard of.
“This was actually quite common, but the Electricity Supply Lines (Protection) Regulation was introduced in 2000 and such cases have dropped since then,” he said on a radio show.
The regulation requires more care to be taken during roadworks to avoid damage to underground cables.
He said the question was whether third-party road workers had followed all the rules under the regulation.
CLP was likely to have found evidence of damage that was not due to regular ageing, such as joints having been chipped or bent, before it came to such a conclusion, he said.
Lo suggested authorities step up patrols and inspections, with better management of third-parties needed to prevent further failures.
CLP, which supplies Kowloon, the New Territories and most outlying islands, logged five supply disruptions in the first four months of this year, including three voltage dip incidents that left more than 200 residents trapped in lifts.
Secretary for Environment and Ecology Tse Chin-wan had summoned the company’s boss to request “fundamental improvements” to its culture and electricity supply management system in the wake of the power outage in Wong Tai Sin.
He also questioned whether CLP’s service quality was “on the decline” given the number of power disruptions in the past six months.
