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 220 kV 765 kV 400 kV 2. Maximum voltage of the system (rms) 800 kV 420 kV 245 kV 800 kV 420 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 2100 1425 1050 2100 kVp 1425 kVp than Transformer and kVp kVp kVp Reactor - for Insulator String 2100 kVp 1550 kVp 765 kV System 400 kV System 220 KV System 765 kV System 400 kV System 2100 kVp 1550 kVp 1050 kVp ii) Switching impulse withstand voltage (250/2500 micro sec.) dry and wet 1550 kVp 1050 kVp 1550 kVp 1050 kVp iii) One-minute power frequency dry withstand voltage (rms) 830 kV 630 kV 830 kV 630 ▇▇ ▇▇) One minute power frequency dry and wet withstand voltage (rms) -- -- 460 kV -- -- 6. Corona extinction voltage 508 kV 320 kV -- 508 kV 320 kV 7. Max. radio interference voltage for frequency between 0.5 MHz and 2 MHz 2500 micro- volts at 508 kV rms 1000 micro- volts at 266 kV rms 1000 micro- volts at 156kV rms 2500 micro- volts at 508 kV rms 1000 micro- volts at 266 kV rms

Insulation Coordination. The system design parameters for substations/switchyards shall be as given below: Sl.N o. Description of parameters 765/400/220 kV Ananthapuram-II PS (AIS) 765 kV Davangere S/s Extn. 765 kV Cuddapah S/s Extn. 765 kV System 400 kV System 220 kVSystem 765 kV System 765 kV System 1. System operating voltage Operating Voltage 765 kV 400 kV 220 kV 765 kV 400 765 kV 2. Maximum voltage of the system (rms) 800 kV 420 kV 245 kV 800 kV 420 800 kV 3. Rated frequency Frequency 50 Hz 50 Hz 50 Hz 50 Hz 50 Hz 4. No. of phases Phases 3 3 3 3 3 5. Rated Insulation levelsLevels i) Lightning Impulse withstand voltage Withstand Voltage for (1.2/50 micro sec.) - for Equipment Other 2100 1425 1050 2100 kVp 1425 kVp other than Transformer and kVp kVp kVp Reactor - for Insulator String 2100 kVp 2100 kVp 1425 kVp 1550 kVp 1050 kVp 1050 kVp 2100 kVp 2100 kVp 2100 kVp 2100 kVp Sl.N o. Description of parameters 765/400/220 kV Ananthapuram-II PS (AIS) 765 kV Davangere S/s Extn. 765 kV Cuddapah S/s Extn. 765 kV System 400 kV System 220 KV kVSystem 765 kV System 765 kV System 400 kV System 2100 kVp 1550 kVp 1050 kVp ii) Switching impulse withstand voltage Impulse Withstand Voltage (250/2500 micro sec.) dry and wet 1550 kVp 1050 kVp -- 1550 kVp 1050 1425 kVp iii) One-minute power frequency dry withstand voltage (rms) 830 kV 630 kV 830 kV 630 ▇▇ ▇▇) One minute power frequency dry and wet withstand voltage (rms) -- -- 460 kV -- -- 6. Corona extinction voltage 508 kV 320 kV -- 508 kV 320 kV 7. Max. radio interference voltage for frequency between 0.5 MHz and 2 MHz 2500 micro- volts at 508 kV rms 1000 micro- volts at 266 kV rms 1000 micro- volts at 156kV rms 2500 micro- volts at 508 kV rms 1000 micro- volts at 266 kV rms