e -01/UJVNL/EE (M&G)/KPS/2025-26
Rated Short Time Withstand Current for 3
25 sec – Asymmetrical 1.55 times of 25 KArms
26 Trip Relay Hand Reset Mechanical
27 Hooter Hooter for alarm and tripping
28 Annunciators 4 Window for OTI, WTI, Bucz, OC/EF
Current Transformer
29 Rated voltage 12 KV
30 Impulse withstand voltage 75 KVP
31 Primary winding 28KV rms
32 Secondary winding 3KV rms
33 Frequency 50Hz
34 Rated continuous thermal current 120% of rated primary current
35 Short time thermal rating and its duration 25KA for 3 sec.
36 Rated output 15VA 15VA
37 Class of accuracy 1
38 Type Resin Casted
39 ALF 5P20
40 Standard IS:2705
41 Potential Transformer As Per Design & Standards
42 Other Design Aspects As per Site Requirements
Equipment- 6.6KV/415V, 500kVA Transformer
1 HV Voltage 6.6kV
2 LV Voltage 415V
3 HV Current As per design
4 LV Current As per design
5 Vector Group DYN11
6 Cooling Type ONAN
7 Protections Involved OTI, WTI, BUCZ
8 Tap Steps 5% (+/-)
9 Highest System Voltage 6.8 KV
10 HV Side Termination CABLE BOX
11 LV Side Termination CABLE BOX
12 Percentage Impedance 4.50%
13 Confirming Standard IS 2026
14 Frequency Variations 3% (+/-)
15 Standard Frequency 50Hz
16 Pressure Release Mechanism PRV Valve
17 Other Design Aspects As per Site Requirements
Equipment- 6.6/11KV, 500kVA Transformer
1 HV Voltage 11kV
2 LV Voltage 6.6kV
3 HV Current As per design
4 LV Current As per design
5 Vector Group DYN11
6 Cooling Type ONAN
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e -01/UJVNL/EE (M&G)/KPS/2025-26
7 Protections Involved OTI, WTI, BUCZ
8 Tap Steps 5% (+/-)
9 Highest System Voltage 12KV
10 HV Side Termination CABLE BOX
11 LV Side Termination CABLE BOX
12 Percentage Impedance 4.50%
13 Confirming Standard IS 2026
14 Frequency Variations 3% (+/-)
15 Standard Frequency 50Hz
16 Pressure Release Mechanism PRV Valve
17 Other Design Aspects As per Site Requirements
Equipment-11 KV Lightening Arrester
1 Standards applicable IS 15086 Part 5, IEC 60099 Part 5
2 Arrestor Voltage Rating 9 kV rms
3 Discharge Class Station Low (SL) as per IEC60099-4
4 Type of Construction Gapless Polymeric
5 Connection Phase to Earth
6 Maximum Continuous Operating voltage 8 kV
7 Nominal Discharge Current 10 kAp
8 Energy Discharge capacity (kJ/kV) > 4.5 at Ur (minimum)
9 Reference current 5 mA peak
10 Rated Frequency 50 Hz
11 Application / Installation Outdoor
12 System voltage & Design Ambient Temperature
13 a) Nominal Voltage 11 Kv
14 b) Highest Voltage 12 kV
15 c) Design Ambient Temperature 50°C
16 Type of System Earthing Solidly Grounded
17 Thermal stability As per IEC 60099-4
18 Withstand test voltages value of LA to be protected
19 a) One Minute Power frequency 28 kV
20 b) Lightning Impulse 75 kV
21 Nominal Discharge 10 kA Heavy duty
22 Nominal Creepage Distance (mm) 31 mm / kV
23 Type of mounting Vertical / Pedestal Mounting
24 Temperature rise As per IEC 60099-4
Equipment- 6.6kV VCB Panel
1 Rated Voltage 6.6kV
2 Rated Current 1250A
3 Breaking Current 25kA
4 Rated short circuit making current (peak) 62.5KA
5 Maximum break time 3 cycles
6 First – pole – to clear factor 1.5
7 Rated Auxiliary supply for spring charge
motor, lamp & heater circuit. 230V A.C
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