Common use of Insulation Coordination Clause in Contracts

Insulation Coordination. The system design parameters for substations/switchyards shall be as given below: 1. System Operating Voltage 765 kV 400 kV 765 kV 2. Maximum voltage of the system (rms) 800 kV 420 kV 800 kV 3. Rated Frequency 50 Hz 50 Hz 50 Hz 4. No. of Phases 3 3 3 5. Rated Insulation Levels i) Lightning Impulse withstand voltage for (1.2/50 micro sec.) - for Equipment other than Transformer and Reactor - for Insulator String 2100 kVp 2100 kVp 1425 kVp 1550 kVp 2100 kVp 2100 kVp ii) Switching Impulse withstand voltage (250/2500 micro sec.) dry and wet 1550 kVp 1050 kVp 1550 kVp iii) One minute power frequency dry withstand voltage (rms) 830 kV 630 kV 830 kV

Insulation Coordination. The system design parameters for substations/switchyards shall be as given below: 1. System Operating Voltage operating voltage 765 kV 400 kV 765 kV 2. Maximum voltage of the system (rms) 800 kV 420 kV 800 kV 3. Rated Frequency frequency 50 Hz 50 Hz 50 Hz 4. No. of Phases phases 3 3 3 5. Rated Insulation Levels i) Lightning Impulse withstand voltage Withstand Voltage for (1.2/50 micro sec.) - for Equipment other than Transformer and Reactor reactor - for Insulator String 2100 kVp 2100 kVp 1425 kVp 1550 kVp 2100 kVp 2100 kVp ii) Switching Impulse withstand voltage Withstand Voltage (250/2500 micro sec.) dry and wet 1550 1425 kVp 1050 kVp 1550 kVp iii) One minute power frequency dry withstand voltage (rms) 960 kV 650 kV 830 kV 630 6. Corona Extinction Voltage 508 kV 830 kV320 kV 508 kV 7. Max. radio interference voltage for frequency between 0.5 MHz and 2 MHz 2500 micro- volt at 508 kV rms 1000 micro- volt at 266 kV rms 2500 micro-volts at 508 kV rms

Insulation Coordination. The system design parameters for substations/switchyards shall be as given below: 1. System Operating Voltage 765 kV 400 kV 765 220 kV 400 kV 220 kV 2. Maximum voltage of the system (rms) 800 kV 420 kV 800 245 kV 420 kV 245 kV 3. Rated Frequency 50 Hz 50 Hz 50 Hz 50 Hz 50 Hz 4. No. of Phases 3 3 3 3 3 5. Rated Insulation Levels i) Lightning Impulse withstand voltage for (1.2/50 micro sec.) - for Equipment other than Transformer and Reactor Reactors - for Insulator String 2100 kVp 2100 kVp 1425 kVp 1550 kVp 2100 1050 kVp 2100 1050 kVp 1425 kVp 1550 kVp 1050 kVp 1050 kVp ii) Switching Impulse withstand voltage (250/2500 micro sec.) dry and wet 1550 kVp 1550kVp 1050 kVp 1550 kVp- 1050 kVp - iii) One minute power frequency dry withstand voltage 630 kV - 630 ▇▇ - 765 kV System 400 kV System 220 kV System 400 kV System 220 kV System (rms) 830 ▇▇ ▇▇) One minute power frequency dry and wet withstand voltage (rms) - - 460 kV 630 - 460 kV 830 kV6. Corona Extinction Voltage 508 kV 320 kV - 320 kV - 7. Max. radio interference voltage for frequency between 0.5 MHz and 2 MHz 2500 micro- volts at 508kV rms 1000 micro- volts at 266 kV rms 1000 micro- volts at 156 kV rms 1000 micro- volts at 266 kV rms 1000 micro- volts at 156 kV rms