Last night’s power cut was caused by a faulty cable at the Par-la-Ville substation.

The outage plunged some Hamilton businesses into darkness for the second time in five days, prompting further complaints about electricity supplier Belco.

This afternoon a Belco spokesman said that supplies were cut to customers on Queen Street and the Bermudiana Arcade for more than 90 minutes at around 5.30pm because of a fault to a high voltage cable which may have become “stressed” as a result of last Thursday’s outage.

“New equipment was required after a transformer fault caused an outage in Hamilton on Thursday, 26 June,” the spokesman said.

“The transformer fault may also have contributed to last night’s outage, which affected businesses on Queen Street, in and near the Bermudiana Arcade. Last night’s outage was caused by a fault on a high voltage cable in the Par-la-Ville Substation. Belco energy delivery investigators report that the HV cable may have been stressed by the transformer fault, although an inspection of substation equipment immediately after the 26 June outage did not indicate damage. Energy delivery continues to investigate the Par-la-Ville substation equipment faults, while also inspecting equipment in Belco’s other Hamilton substations.

“Investigators emphasised that neither heat nor load on the electricity system were factors in the recent outages; yesterday’s peak system load was only 94.3 megawatts and the 2014 peak load to date is 100.5 megawatts, well below normal summertime peak loads and reflecting relatively moderate air temperatures to date.

“A new transformer, which was installed in the Par-la-Ville Substation on Sunday, will be fully commissioned by the end of this week. Crews have been working long hours to complete the complex job as quickly as possible.

“Belco apologises for the inconvenience and assures customers that every effort is being made to ensure that the electricity system is safe, secure and reliable.”