Scribd
Upload
68 views5 pages

Technical Specs for HVPNL CTs

The document provides technical specifications for current transformers (CTs) for use in Haryana Vidhyut Prasaran Nigam Ltd. It includes 17 items specifying parameters like voltage and current ratings, insulation levels, creepage distances, and temperature rise limits for CTs at voltage levels of 245kV, 145kV, 72.5kV, 36kV and 12kV. Ratios, earthing method, thermal rating and ratio taps are also specified.

Uploaded by

Saber Abdelaal
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as DOC, PDF, TXT or read online on Scribd
68 views5 pages

Technical Specs for HVPNL CTs

The document provides technical specifications for current transformers (CTs) for use in Haryana Vidhyut Prasaran Nigam Ltd. It includes 17 items specifying parameters like voltage and current ratings, insulation levels, creepage distances, and temperature rise limits for CTs at voltage levels of 245kV, 145kV, 72.5kV, 36kV and 12kV. Ratios, earthing method, thermal rating and ratio taps are also specified.

Uploaded by

Saber Abdelaal
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as DOC, PDF, TXT or read online on Scribd
You are on page 1/ 5

HARYANA VIDYUT PRASARAN NIGAM

LTD.

TECHNICAL SPECIFICATION

FOR

245kV, 145kV, 72.5kV & 36kV


T/F, LINE, T/F INCOMER, CAP. CT &
NEUTRAL CTs & 12kV NCTs

CT-1
PRINCIPAL PARAMETERS:

The current transformers covered in this specification shall meet the technical
requirements listed hereunder.

CT-2
PRINCIPAL TECHNICAL PARAMETERS:

Sr. Item 245kV 145kV 72.5kV 36kV 12kV


No.
1. Type of C.T./ installation.
single phase, single phase, oil filled, Hermetically sealed, outdoor type.
dead tank, oil
filled,
hermetically
sealed, outdoor
type.
2. Type of Mounting Steel Structures
3. Suitable for system 50 Hz
Frequency
4. Highest system Voltage 245 145 72.5 36 12
(KV rms)
5. Minimum Neutral CT 33 15 15 15 8.66
Insulating Voltage
6. Current Ratio A/A
a. Line 1200-800-400/ 600-300-150/ 600-300-150/ 300-150/5 -
1-1-1-1-1 1-1-1 1-1-1
b. Transformer 300-150/0.577- 150-100-75/ 200-150/ 200-100/ 0.577- -
1-1-1-1 0.577-1-1 0.577-1-1 5,
100-50/5-5
c. Transformer Incomer - 500-250/ 1000-500/ 600-400-300 -
0.577-1-1-1 0.577-1-1-1 /0.577-5-5-1-1
d. Capacitor CT - - 150/1 150/5 -
e. NCT 300-150/1 150-100-75/1 200-150/1, 600-400-300/5, 1200-900/5,
1000-500/1 100-50/5 300-150/5
7. Method of Earthing the Solidly Earthed
System
8. Rated Continuous Thermal 125% for all taps
current
9. Ratio taps The tapings shall be only on secondary winding.
10. Acceptable limit of As per IS:2705 or equivalent IEC
temperature rise above the
specified ambient
temperature for
continuous operation at
rated current.
11. Acceptance partial As per IS:11322-1985 or equivalent IEC
discharge level at 1.1
times the rated
voltage.
12. 1.2/50 microsecond lightning impulse withstand voltage (kVp)
a. CTs 1050 650 325 170 -
b. NCTs 170 95 95 95 75
13. 1 minute dry & wet power frequency withstand Voltage primary (kV rms)
a. CTs 460 275 140 70 -
b. NCTs 70 38 38 38 28

CT-3
Sr. Item 245kV 145kV 72.5kV 36kV 12kV
No.
14. Power frequency over 3
voltage withstand
requirement for secondary
winding  (kV rms) (for 1
minute)
15. Min. creepage distance of porcelain housing (mm)
a. CTs 6125 3625 1815 900 -
b. NCTs 900 440 440 440 250
16. Rated short time withstand 40 31.5 31.5 16 18.4
current (kArms) for 1
Second.
17. Rated Dynamic withstand 100 78.75 78.75 40 46
current (kAp)
18. Maximum Creepage 4.0
Factor

CT-4
CT-5

You might also like