Power has now been restored to approximately 3,000 ESB customers who were left without power this morning in the Fingal region of Dublin.
A spokesman for the company said power went out at about 2.30am because of a fault in a transformer in a Swords substation.
The spokesman said the fault was not related to the industrial dispute at the State electricity company where some 1,200 ESB technicians began strike action at 8am.