DRAKENSBERG PUMPED STORAGE SCHEME 29 June 2015

2 Unit 1-3 Generator Stator refurbishment (Tender: PS(DPS)2015/DJ/01) Clarification Meeting 29 June 2015

Overview 3 Background Scope of work Interfaces Technical (requirements)

Background 4 The generators at DPSS were originally installed in the early eighties, with Units 1, 2 and 3 commissioned during 1981 and Unit 4 in early Due to core defects and a partial core failure, Unit 4 was refurbished in 2001 and again in 2014 (due to subsequent damage from a stator earth fault). Units 1-3 are now already past their approximate life expectancy of 30 years and have been showing signs of aging with evidence of insulation deterioration, core looseness and discoloration of some lamination packets indicating local overheating. Overhang vibration is also present on Units 1-3, leading to further deterioration of the machine.

5 Scope of work The scope encompasses the Design, manufacture, factory acceptance testing, transport and installation of stator core and stator windings, including a renewed cooling system and all components required to refurbish units 1-3 generators.

Interfaces 6 Generator Cooling System Existing stator frame 380VAC Unit Board Interface (for generator cooling fans) C&I Interface (for generator condition monitoring) Generator Protection Interface (for main machine tripping)

Interfaces key data (Cont.) 7 INTERFACE SYSTEMPARAMETERRATINGS Cooling Generator CW Supply flow rate125l/s CW System Design Pressure10 Bar CW System Maximum Pressure12 Bar CW System Inlet Temperature30°C Unit Boards Fans Operating Voltage380VAC Fans MCC Control Voltage220VAC Control System Operating Voltage24VDC Temperature Monitoring TypePt100 Air and CW Flow Monitoring Type4-20mA

Technical requirements 09 January The following gate keepers shall be enforced: 1) The Tenderer shall have at least 20 years’ experience in manufacturing and installing large hydro/pumped storage generator-motors. The Tenderer’s nominated sub- suppliers shall also have 20 years’ experience in manufacturing and supply of their particular scope of supply. The tenderer shall have supplied large generator-motors to major international utilities, outside of their country of origin 2) Tenderer must have successfully installed and commissioned at least 5 (five) generators of similar type of at least 150 MVA over the last 10 years having achieved the ratings and efficiencies specified in the Schedules. 3) The Tenderer offer meets the minimum power output requirement.

Technical returnables 9 Completed Schedule B with any deviations clearly listed Information on Company history and list of previous projects and scope of supply. List of installations including capacity per unit. List of power utility customers including installed capacity and Letters of recommendation from at least two key clients. Schedule of Proposed Subcontractors/ Sub-consultants Duration of partnership with main contractor and Duration of experience in manufacturing relevant G/M components. List of proposed manufacturing facilities and locations. CVs of Proposed Key Persons Quality Method Statements SHE Method Statements and Related Documents

Technical returnables (Cont.) 10 Detailed project schedule from contract award to implementation, including detailing of site implementation activities Preliminary assembly drawings of concept designs – assembled stator and major parts (including, but not limited to Core, cooling system, cooler data, winding) Sample QCP for similar scope of supply. Proposed instrumentation layout and relevant drawings. Relevant technical information/ brochures Portfolio of training provided

Thank you Questions??