>> MANUFACTURING

The switchgear works hosts sophisticated world class facilities for design, manufacture, and testing of its products.

The Switch gear complex is located in a large 1,32,500 sq. ft plot at Ambad in Nashik.

The Complex comprises of four manufacturing divisions:

The Instrument Transformer and Bushings Division

• Current Transformers(CTs) with potential ranging from 24kV to 420kV
• Inductive Voltage Transformers) PTs/IVTs in voltages ranging from 24kV to 245kV
• Capacitor Voltage Transformers (CVTs). With voltages ranging from 72.5kV to 420kV
• Coupling Capacitors (CCs) in voltages ranging from 72.5kV to 420kV
• Grading Capacitors for Multibreak EHV Circuit Breakers up to 420kV
• Condenser Bushings/Transformer Bushings For Air To Oil Application in voltages ranging from 72.5kV to 420kV

Vacuum Circuit Breaker Division

• 12 / 15 kV Medium Voltage Indoor Vacuum Circuit Breaker and Switchboards
• 12 / 36 kV Outdoor Vacuum Circuit Breaker
• 12 kV Outdoor Pole Mounted Capacitor Switches
• 36 kV to 72.5 kV On Load Tap Changers

SF6 Gas Circuit Breaker Division

• 24 kV to 420 kV SF6 outdoor SF6 Gas Circuit Breakers
• 3.3 kV to 36kV indoor SF6 gas circuit breakers and metal clad Switchboards

Zinc Oxide Lightning Arrester Division

• Distribution class LA up to 36 kV
• Substation class LA up to 420 kV

Vacuum Interrupter Division is located at Aurangabad & manufactures

• Complete range of Vacuum Interrupters right from 1 kV to 52kV class
• Polycrete products
• Power quality products

Initiatives for maintaining world class standards include

• Just In Time Principles for handling material requirements.
• Thrust on packing of the final product in a manner that will ensure that customers receive the same in proper conditions.
• Continuous efforts to increase employee involvement by training, and participation by way of the Kaizen principle.
• Small Group Involvement

Infrastructure at the Transformers & Bushings Division

• Microprocessor Controlled Capacitor Element Winding Machines
• Microprocessor Controlled Wide Band Winding Machines for Condenser Bushings.
• Toroidal Winding Machines for Current Transformers.
• Autoclaves for Drying & Impregnation of Paper Insulation of the Products.
• Pulse MIG Welding Machines & TIG Welding Machines. Oil Degassing & Filtration Plant.
• Many special purpose machines for applications such as Preforming of the Insulation.

Testing Facilities in the EHV Lab

• Testing of equipment up to 500kV.
  Dimension Of EHV Lab
• Main Hall : - 20M x 20M x 18M (internal clear dimensions )

Special Constructional Features of EHV Lab

• Electromagnetic Shielding for accurate measurements of partial discharge and radio interference voltage.
• Earthing Systems for full wave and chopped lightning impulse measurements.
• Floor Suitable for air cushion load movement.

Major Test Equipment at the EHV Laboratory

• 750 kVAC Test Transformer(ASEA , Made in Sweden)
• 800 kV, 1000 PF Coupling capacitor(Micafil, Made in Switzerland)
• 400 kV Standard Voltage Transformer(MWB , Made in Germany)
• 600 kV 49.96 PF Standard Capacitor(Micafil , Made in Switzerland)
• Balanced Partial Discharge Meter(Baur , Made in USA)
• Schering Bridge For Capacitance,
• TanDelta & Accuracy Measurement (Tettex , Made in Switzerland)
• Current Transformer Accuracy Bridge (Olman , Made in Canada)
• Standard Current Comparator (Tettex , Made in Switzerland)
• Motor Generator Test Set For Testing Of IVTs (CGL, Made in India)
• Planned Major Addition Impulse Test System

Infrastructure available at Vacuum Circuit Breaker Division

• CNC Turret Punch Press 50 ton, COMA
• 505050(AMADA)
• Press Brake 80
• TPress Brake 150
• TPower Presses 63
• T & 16 TCNC Turret Punch Press 50 ton
• COMA 505050 Press Brake 80
• TCopy Punch Press
• Plate Straightening machine

Testing Facilities (Mechanical Testing)

• Tensile Testing M/C - Capacity 20 T
• Spring Testing M/C - Capacity 500 kg
• Hardness Tester
• Conductivity Tester

Testing Facilities (Electrical Testing)

• Primary injection test set up to 1000A
• AC Power Frequency high voltage test set 0-5 kV and
• 0-100 kV Millivolt Drop test set 0-200A
• DC Circuit Breaker Analyzer

Infrastructure available at the SF6 Gas Circuit Breaker Division

• CNC plant covering CNC machining centers
• CNC lathes, having high level of process capabilities operated by qualified engineers,
• Amada Turret punch press for sheet metal precision.
• Fabrication process of high quality standards implemented by means of:
  1) Use of Superior quality of sheet metal
  2) Adherence to Component accuracy
  3) Checklist control of finish and dimensions
  4) Use of appropriate tools, jigs, fixtures
  5) Painting and plating process meeting the world-class requirement of surface finish
• Surface coating of the metallic components to withstand all weather conditions.

The sheet metal parts are shot-blasted, zinc sprayed, primer coated with epoxy-polyurethane primer and are finish painted with the polyurethane paint. Customer needs and latest developments in process technology dictate the review and validation of process technology to meet International Quality standards.

The Central R& D & knowledgeable consultants power the search for better and efficient means of manufacturing and process control.

The plating facilities are equipped with ultra modern plants for plating processes like silver plating, copper plating, hard anodizing and hard chrome plating, zinc cobalt black passivisation .The manufacturing plant is built to ensure that the products are manufactured and assembled in minimum dust level by providing RCC building, megaoxy flooring and air pressurization system in Pole Unit assembly area.

Testing Facilities

• 520 kV Test Transformer
• Computerization of breaker testing to monitor required quality characteristics(Visual:SF61)
• Precise and accurate Gas Leak detection system demonstrating required reliability of the product(visual SF62)
• Pull testing machine for pre-testing & pre-qualification of insulating pull rods.
• Calibration lab to control accuracy of measuring and test equipment.

Infrastructure available at the Lightning Arresters Division

• Spray Drier 70 T Hydraulic Press Tunnel Furnaces Double Sided
• 4 way Lapping Machine

Assembly area Testing facilities

• 300 kV High voltage test transformer
• Partial Discharge Test Setup
• 600 kV Impulse Generator
• Accelerated Aging Test Setup for ZnO elements
• Automated element test line. Measuring Devices

Infrastructure at the Vacuum Interrupter Division

Conventional manufacturing of vacuum interrupters involved the individual evacuation and pinching of the tube. This system has been phased out and up graded to batch evacuation. The process of Non Pinch Vacuum Interrupters involves three technologies

• Powder Metallurgy
• Metalizing of High Alumina Ceramics
• Vacuum Brazing

Centralized Facilities at Switchgear Complex

The support infrastructure consists of Sophisticated tool room with following machines

• Newall vertical jig boring machine
• Deckel milling machines
• Surface grinding machines
• Cylindrical grinder
• Other lathes, milling, drilling and cutting machines

Plating & Painting Plants

• Phosphating plant
• Microprocessor based Pre - treatment plant
• Zinc plating
• Silver plating
• Tin plating
• Hard chrome
• Hard anodizing
• Conveyorised automatic Powder coating plant
• Painting - Electrostatic painting system

The state of art Information technology set up comprises of

• The division effectively utilizes all modules of SAP.
• The Computer Aided Design (CAD) Center equipped with advanced computing techniques for analysis of design features and developmental work.

Test Facilities

• The EHV laboratory test facilities are utilized for Type tests/ Special tests and for routine tests by Instrument Transformer and Bushing division CGL's R&D center at Kanjurmarg-Mumbai is recognized by Department of Science & Technology, Government of India.

Facilities available at the Laboratory include:

• 2.6 MV, 200 kWh Impulse Generator with associated measuring and recording equipment
• 300 kV Impulse Generator with measuring / recording equipment
• Short circuit testing laboratory - up to 50 kA for 0.2 sec Measurement and Calibration laboratory
• Mechanical test laboratory
• Chemical test laboratory with Gas Chromatography
• Partial discharge measuring facilities
• Noise level and Harmonic analysis facilities
• Temperature rise test facilities