Endeavour Energy has warned&nbsp;up to 1700 electricity customers in Blaxland, East Blaxland, Glenbrook and Mount Riverview to prepare for possible loss of power this afternoon [Thursday] in order for crews to repair&nbsp;a substation cable damaged in a fire on Wednesday. Customers may be without power from&nbsp;2pm for up to eight hours. “Endeavour Energy is doing all it can to limit the length of any interruption and hopes to restore power to the majority of customers by early this evening,” said a spokeswoman. “Endeavour Energy is taking steps to minimise the number of customers that may be interrupted as the load increases this afternoon by providing extra network capacity. “Endeavour Energy apologises to customers for the inconvenience and thanks them for their assistance and understanding as crews complete repairs ahead of&nbsp;tomorrow’s&nbsp;forecast extreme temperatures. “Endeavour Energy is also asking electricity customers in the Lower Blue Mountains to help limit electricity usage today by turning off pool pumps and limiting the use of air conditioners, where possible.” Customers can check updates about local power supplies by:&nbsp;calling&nbsp;131 003&nbsp;and entering their postcode; entering their suburb into the power outage application via its website&nbsp;www.endeavourenergy.com.au; downloading the&nbsp;Endeavour Energy outage app&nbsp;to their smart phone via iTunes or the Google App Store.