An oversight in the commissioning of the North Power Station and “incorrect operating instructions” sparked an island-wide power outage last year, energy firm Belco revealed yesterday.

A Belco spokesman said the company had been “resolving warranty issues” with the contractor for the project - but declined to comment if the discussions could mean compensation for the power firm or affected customers.

Belco said in a report into the day-long outage on December 18, submitted to the Bermuda Regulatory Authority, that the trouble was caused by a loss of power to the controls of the engines at the new $110 million north power station.

The report said the control failure was caused by an unexpected tripping of output breakers on an uninterruptible power supply at the station.

It added: “There was an oversight in the commissioning of the UPS system during the construction phase and Belco was provided with incorrect operating instructions for the UPS operation and maintenance by the contractor who built the north power station.

“The loss of power to the engine control circuits served by the UPS was the result of a maintenance procedure performed by Belco.

“The procedure is considered standard and based on the redundancy of the power sources serving the UPS system, not a risk for a potential engine shutdown, however, due to the oversight in the commissioning of the UPS system and the incorrect maintenance instructions, the maintenance procedure resulted in the unexpected shutdown of the north power station engines.”

The shutdown put extra strain on the eastern power station, which became overwhelmed and caused an island-wide outage.

Belco said it had taken steps to prevent similar problems in the future, including multiple trouble shooting and test sessions with the plant contractor and UPS manufacturer.

The company added that the contractor had been able to secure a UPS configuration that ensured supply security and that an independent third party electrical contractor had overseen tests and reviews.

Belco confirmed earlier this month that a review of the outage had been submitted to the Regulatory Authority.

Wayne Caines, the president of Belco, said the company did not want to release the details behind the outage while it was “resolving warranty issues around this malfunction and resulting outage”.

Mr Caines added: “We are committed to accountability and transparency and thus have shared our key findings with the public.

“Since the incident occurred, the faulty equipment has been reconfigured to ensure another fault of this nature does not occur and impact the company’s ability to supply energy to our customers.

“Belco is committed to providing reliable and safe energy and implementing the integrated resources plan that will ensure a cleaner, more renewable energy supply to our valued customers.”