Belco have blamed Sunday night's Island-wide power cut on a rare fault in the copper busbars at their Serpentine Road headquarter's switchboard.

An inquest into what went wrong is now underway and the company will be talking to the UK manufacturer of the busbars, which are conductors that concentrate the plant's electrical power for distribution.

Belco spokesman Robin Sidders said sparks were flying when engineers opened up the metal safety casing around the bars but denied there was an explosion.

The fault, at 8.34 p.m. on Sunday night, had a knock-on effect as the bars feed into the Belmont and Flatts substations which send power west and east.

Mrs. Sidders said: "When this fault occurred, power was lost simultaneously from the Belmont substation to the western end of the Island and from the Flatts substation to the eastern end of the Island.'' She said power was also lost in other areas such as Paget and Devonshire as a protective measure for the network.

Belco engineers then scrambled around trying to find the fault.

But Mrs. Sidders explained that the fault in the busbars was difficult to detect.

Mrs. Sidders said: "This type of fault is rare and has never occurred on this type of switching equipment at Belco.

"As the busbars are metal enclosed it can also be difficult to detect a busbar fault.'' Asked what Belco could do to ensure the fault did not happen again, Mrs.

Sidders said: "It's not something that has happened before. We can't say it won't happen again but it is not likely to happen again.

"It's difficult to say what precautions will be taken. We will be talking with the UK manufacturer.

"During any power outage, Belco follows a restoration process which begins with ascertaining the problem, isolating the equipment which has the fault to prevent any further loss of power and then restoration of power in phases.

"In this instance, the fault was determined after a careful process of elimination, which included checking the engines, the transmission equipment at the substations and on the main plant.'' "It was found that the copper bars, known as busbars, had developed a fault.

"As part of our plant design, there is an identical set of back-up, or reserve busbars. Once it was determined that a busbar fault had occurred, they were closely inspected and then the four generators affected were physically switched to the back-up busbars.

"The rest of Belco's system was then stabilised and the process of restoring power began at 9.21 p.m.'' She said one-third of customers were restored to power by 11.30 p.m. By 1 a.m., half of all customers who lost power had power restored. Power was fully restored by 3.57 this morning.

"As a result of the fault, however, there was also some knock-on outages and dimming of lights experienced, primarily in Paget and Hamilton Parish, but they were quickly restored this morning by our work crews.'' Engineers have started to strip the busbar equipment to pinpoint the exact cause of the fault, said Mrs. Sidders.

"We are hopeful the cause will be determined as quickly as possible.

"As with any power outage, we apologise to our customers for the inconvenience, especially as this occurred on the evening of Mother's Day.

"We appreciate their cooperation and patience as we worked to restore power as quickly and safely as possible.'' Sunday's power cut also hit phone lines across the Island on Sunday night.

A BTC spokeswoman said: "Due to the Belco power outage we lost power to four of our outside plants.

"BTC had to bring in generators to restore power at our Harrington Sound East plant at Shark Hole, which left residents in the area without a phone service for two hours.

"South Hill in Paget saw power out for an hour.

"The telephone service was disrupted for two hours, 20 minutes for residents serviced by our George's Bay Road in Sandys facility and the outage at our Store Hill in Smith's plant left residents without power for one-and-a-half hours.''