* Zambia lost 345 MW due to faults
* Zesco asks CEC to cut back by 90 MW
LUSAKA Feb 28 (Reuters) - Zambia's Copperbelt Energy Power Corp (CEC) has asked mining companies to ration electricity due to faults at two of the country's power stations, its spokeswoman said on Thursday.
CEC buys electricity in bulk from state-owned Zesco Ltd, which it in turn supplies mines in Africa's top copper producer.
CEC spokeswoman Chama Nsabika-Kalima told Reuters Zesco had requested Zambia's largest supplier of power to the mines to cut 90 MW during the morning and evening peak periods.
"We have in turn requested our customers to contribute to the required reduction in demand to help sustain the system during this period," Nsabika-Kalima said.
Zesco said in a statement on Thursday it had lost 345 MW of power after a fault at the Kafue Gorge Power Station last week and another at Kariba North Bank Power Station on Monday this week.
"Repair works for both units are underway to ensure all machines are on full generation capacity and power supply is stabilised," it said.
Mining firms supplied with power by Copperbelt Energy include Konkola Copper Mines owned by London-listed Vedanta Resources and Mopani Copper Mines owned by Glencore of Switzerland.