Motor  drive  is  supplied  from  a  three-phase  power  converter  has  conversion efficiency  of  90  %  when operating  at  rated load.  On  the  other  hand, when  the motor  operates  at  rated  load,  it  delivered  net  output  power  of  45  kW.  The motor  electrical  and  mechanical  losses  are 1125  W  and  1200W  respectively. Calculate  the  efficiency  of  the  system  from  supply  utility  to    motor  shaft.