Date:20.02.
2025
Rev.04
CUSTOMER : HP POWER TRANSMISSION PACKAGE-1 LTD
CONTRACTOR NAME : - MEGHA ENGINEERING & INFRASTRUCTURES LIMITED (MEIL)
MANUFACTURER :- TESLA TRANSFORMERS (GLOBAL) PRIVATE LIMITED
Sr. No. Particulars Unit Parameters
1 Service & Application Outdoor
2 Type Distribution Transformer
3 Location Ground mounted
4 Transformer complies to IS: 1180 / IS: 2026
5 Type of Cooling ONAN
6 Type of Oil Mineral oil, IS:335 (Latest)
7 Rated kVA KVA 200
Rated Voltage of H.V.( Volts) / Current
8 Volts & Amp 33KV / 3.5 Amps.
(Amps)
Rated voltage of L.V.(Volts) / Current
9 Volts & Amp 0.433KV / 266.67 Amps.
(Amps)
10 Frequency Hz 50 HZ
11 Number of phases 3 Phase
12 Vector Symbol Dyn11
13 System Voltage variation ±10%
14 System Frequency variation ±5%
15 Combined Voltage & Frequency variation ±10%
16 Continuous over voltage rating % 112%
17 Maximum Ambient Temperature °C 95°C
Maximum Hot spot Ambient Temperature 50°C
17.1 °C
(Ambient Temperature 50° C)
Max. Temperature rise of oil over ambient °C 45°C
18 Temperature
Max.Temperature rise of winding over °C 50°C
19 ambient temperature
Maximum flux density at normal voltage & Tesla ≤1.60 Tesla & ≤1.70 Tesla
20 frequency and at 10% over voltage
21 Maximum current density in winding
HV A/Sq.mm 2.4 A / mm² (Max.)
LV A/Sq.mm 2.4 A / mm² (Max.)
22 Tapings
(+)5 %to (-)5 % in steps of 2.5% on
a. Voltage range
HV side of transformer. (OCTC)
b. No. of positions 4 Step,5 Position
c. Step Voltage V 825 V
Date:20.02.2025
Rev.04
Audible sound level at rated voltage and
23 As Per NEMA TR-1
frequency in dB as per NEMA standards
24 Core materials and Grade CRGO - M4/M-3/M-OH / HIB or better
Winding Details
1 Winding Material Electrolytic Copper
2 Connections
a. H.V. Winding Delta
b. L.V. Winding Star
Neutral will be provided in cable box
c. Neutral brought out from tank
and extra neutral top on cable box
Losses and Performance
Maximum No Load losses at normal ratio,
1 300 W
without positive toelrance
Maximum Load losses at 75Deg.C & at
2 1680 W
normal ratio, without positive toelrance
a) Total load losses at 50% load at rated
3 W 720 Watt (as per IS 1180)
frequency
b) Total load losses at 100% load at rated
W 2257 Watt (as per IS 1180)
frequency
4 Percentage Impedance at Normal tap % 4.5%± IS Tolerance
5 No Load Current Approx % 5.33 Amp.(2% of full load current)
6 Regulation at full load at u.p.f % 0.4596%
7 Efficiency
a. 100% Full Load % 99.55
b. 75% Full Load % 99.61
c. 50% Full Load % 99.64
8 Maximum efficiency % 99.64
9 Load at which Max.efficiency occurs kVA KVA 56.46% Load
Constructional details
1 Details of Bushing rating & Type
a. HV 52 kV / 630 Amps. Porcelain
b. LV 1.1 kV / 630 Amps. Porcelain
2 Type of Construction Stacked , core type construction
3 Insulation between laminations CRGO Silicon steel grade
4 Type of joint between core limb and yoke Mitrered Joint
5 Type of Winding
a.HV Winding Cross Over
b.LV Winding Spiral
Insulation of conductors
a.HV Winding turn Insulation Uniform insulation (DPC)
Date:20.02.2025
Rev.04
b.LV Winding turn Insulation Uniform insulation (DPC)
c.Between HV and LV Winding 20 mm Radial
d.Between LV Winding and core 06 mm Radial
Electric Clearance
Phase to Phase 530 for HV in Air
Phase to Earth 480 for HV in Air
Test Voltages
1 Impulse (1.2 / 50 micro second wave)
withstand voltage 95 KVrms
a. H.V Winding 250 KVp
( Basic insulation impulase level ) KVp
b. L.V Winding KVp N.A.
c. HV Neutral KVp N.A.
d. LV Neutral KVp N.A.
2 One minute power Frequency
withstand voltage
a. H.V Winding KVrms 95 KVrms
b. L.V Winding KVrms 3 KVrms
Details of Tank and Material
1 Minimum Thickness of side plates mm 4
2 Minimum Thickness of bottom plates mm 6
3 Minimum Thickness of cover plates mm 6
Minimum Thickness of radiator (pipes or
4 mm 1.2 mm / 4.05 mm
sheets)
Weight and Dimensions (Approx.)
1 Net untanking weight
(Core and windings with clamps ) 1380kg
2 Volume of insulating oil L 1000ltr/ 820kg
3 Tank and fittings 1020kg
4 Total Weight of Transformer 3220kg
Overall dimension of transformer ( L x W x
5 mm 2020 x 1760 x 2850
H)
Parts to be detached for transport
Painting
1 Surface preparation Painting prcedure : As per IS:1180
2 Paint type Epoxy
3 Shade RAL: 7032
4 Thickness for Tank Microns 100
5 Thickness for Radiators Microns 90
Current transformer
Date:20.02.2025
Rev.04
HV side Phase /
1 N.A.
Neutral current transformer
a. Ratio N.A.
b. Class / Burden N.A.
2 LV side Phase / Neutral current transformer LV Phase CT
a. Ratio 270/1.75A
b. Class / Burden CL-5, 10VA
Tests
1 Dynamic SC details
Short circuit thermal capacity shall be
* ok accepted
31.5KA/3sec.
Kindly submit thernal withstand calculation
* ok acttached
(short circuit capability)
