comprehensive operation and maintenance contract ( comc ) of heating ventilation air conditioning ( hvac ) system , amc , amc for trane make- 07 nos . of screw chillers ( comprehensive ) , amc for trane make- 07 nos . of cooling towers ( comprehensive ) , amc for other allied high side and complete low side equipment ( comprehensive ) , operation contract for hvac system ( as per details below ) : first year , supervisor ( skilled ) , electrician ( semi-skilled ) , senior technician ( skilled ) , technician ( semi-skilled ) , operators ( semi-skilled ) , helpers ( unskilled ) , operation contract for hvac system ( as per details below ) : second year , supervisor ( skilled ) , electrician ( semi-skilled ) , senior technician ( skilled ) , technician ( semi-skilled ) , operators ( semi-skilled ) , helpers ( unskilled ) , operation contract for hvac system ( as per details below ) : third year , supervisor ( skilled ) , electrician ( semi-skilled ) , senior technician ( skilled ) , technician ( semi-skilled ) , operators ( semi-skilled ) , helpers ( unskilled )