Section 30(2)(i) in The Bangalore Metro Railway (General) Rules, 2011
(i)If traction power is lost on any car bogie, the train need not be withdrawn from service, if power is lost on more than one car bogie and the reduction in speed causes delay to following trains, the passengers shall be detrained at the station and the train worked empty, otherwise, the train may remain in passenger service until it can be replaced by a serviceable train;