Johannesburg - Residents of Mamelodi, east of Pretoria, risk spending Christmas without electricity after a substation was damaged, the City of Tshwane said on Wednesday."In the early hours of this morning [Wednesday], our electricity control room received a trip signal from the Mamelodi substation,” said spokesperson Selby Bokaba in a statement.“Our technicians found the substation badly damaged, with cables, switch gears and other components stolen by unknown persons.”"Our technical team is currently on-site to find switching alternatives in order to restore service to the residents. Due to the extent of the damage, repair work is estimated to take up to 48 hours."Affected areas were Mamelodi West C1 to C5, B1 to B3, and A1 to A5, Sunvalley, Denneboom, and Kinsley Hostel.He said it was unfortunate that residents had to suffer as a result of criminal activities."We urge our customers to become vigilant and report suspicious activities around the substations."Eskom said the power grid was stable and no power cuts were expected over Christmas."The risk is low and this will continue up to the second week of the new year. We do not anticipate any load shedding," said spokesperson Khulu Phasiwe.Eskom has called on customers to switch off all electrical appliances before they go on holiday.