1. INTRODUCTION
ECONOMICAL AND TECHNOLOGY ...................
FEASIBLE VOLTAGE IS 11-37KV
MOST CONVENIENT UTILIZATION…………………………
VOLTAGES ARE 240/415 V
INDUSTRIAL MOTERS MAY BE RUN AT
3.3, 6.6, or 11 KV
It is impossible to transmit directly, even
over modest distances
.
2. STEP UP AND STEP DOWN OF VOLTAGE
LEVELS IS ACCOMPLISHED BY MEANS
OF ELECTROMAGNETIC DEVICES
CALLED
4. PRINCIPLE OF TRANSFORMER
• A T/F IS A STATIC DEVICE
• CONSISTS OF TWO OR MORE
STATIONARY ELECTRIC CIRCUITS
• COMMON MAGNETIC CIRCUIT
OF TRANSFERRING ELECTRICAL
ENERGY BETWEEN THEM
• ENERGY TRANSFER TAKES PLACE
WITHOUT CHANGE ITS
FREQUENCEY.
5. COMPANY’S PRODUCTS
• DISTRIBUTION TRANSFORMER
MANUFACTURING AND REPAIRING
• CURRENT TRANSFORMERS
• POTENTIAL TRANSFORMERS
• AUTO TRANSFORMERS
8. WINDING SECTION
Coil preparation as per the specification according to
the design
One of the specification for a 100 kVA transformer
(Aluminum wire)
11. LT CABELS AND FUSES FOR
DISTRIBUTION TRANSFORMER
Sr No T/F IN
KVA
FULL LOAD
CURRENT
11 KV HT
FULL LOAD
CURRENT
0.43 KV LT
CAPABLE
CURRENT
CAPACITY
AMP.
FUSE
WIRE
S.W.G
11KV HT
FUSE
WIRE
S.W.G
0.43KV LT
1. 25 1.31 34.8 16/25 51 38 21
2. 50 2.62 69.6 50 117 33 18
3. 63 3.30 88.0 70 130 33 2X18
4. 100 5.25 139.1 95/120 180 32 17X2
5. 200 10.50 278.2 240 375 25 15X2
6. 500 26.25 695.6 2X500 2X400 19 -------
12. TESTS OF TRANSFORMERS
• INSULATION RESISTANCE TEST
• TRANSFORMER TURNS RATIO TESTER
• INSULATING OIL TESTER
• OPEN CIRCUIT TEST
• SHORT CIRCUIT TEST
• DVDF TEST (Double voltage Double frequency
test)
13. INSULATION RESISTANCE TEST
Nominal Equipment
Voltage (Vac)
Min Test
Voltage (Vdc)
Min Insulation
Resistance
(MΩ)
250 500 25
600 1,000 100
1,000 1,000 100
2,500 1,000 500
5,000 2,500 1,000
8,000 2,500 2,000
15,000 2,500 5,000
25,000 5,000 20,000
34,500 and above 15,000 100,000
14. TRANSFORMER TURNS
RATIO TESTER
• Specifications:
• Display : LCD
• Power supply : 220V±10%, AC 50 Hz
• Measurement ratio : 1:10000
• Measuring groups : 1-12 point
• Accuracy : PT and TRANSFORMER
0.1% rdg+0.01% FS for Ratio range of 1-1000
0.2% rdg+0.02% FS for Ratio range of 100-10000
• CT
0.2% rdg+0.02% FS for Ratio range of 1-1000
0.5% rdg+0.05% FS for Ratio range of 100-10000
• Test voltage : H.T.: 80V AC max; L.T.: 5V AC max.
• Use environment : < 40º C. < 85% R.H.
• Accessories : Test leads 8 meters long
• Dimensions : 43x 32 x 21.5 cm (TRM 101)
• Weight : 8 kg. (TRM 101)
15. INSULATING OIL TESTER : OTS-E series
CHARACTERISTICS UNIT RESULT REQUIRED VALUES
BREAKDOWN VOLTAGE(with 2.5 mm gap)
KV
>145KV 50 KV min
72.5-145 40 KV min
<72.2 KV 30 KV min
SPECIFIC RESISTANCES at 90 ‘C OHM
WATER CONTENT ppm 145 KV & above 25 ppm max
<145 KV 35 ppm max
DIELECTRIC DISSIPATION FACTOR at 90 C ---- 145 KV & above 0.2 max
<145 KV 1.0 max
INTERFACIAL TENSION at 27 C N/m 0.18 min
NEUTRALIZATION VALUE mgKOH 0.5 max
FLASH POINT C 125 min
SLUDGE ---- NON- DETECTABLE
16. Open circuit test Is to used to find out the core or fixed losses
Short circuit test
This test is used to find out the full load copper losses of the transformers
17. DVDF test (Double voltage Double
frequency test)
• This test checks the inter-turn insulation.
• For a 11KV/433V transformer,866 Volts are applied at the 433V winding with the
help of a Generator for 1 minute. This induces 22KV on 11KV side. The frequency
of the 866V supply is also increased to 100HZ.
Technical Specification:
• Capacity : As per customer's requirement.
• Input to motor : 415 V three phase, 50 Hz.
• Out put voltage : 100 to 900 V AC.
• Out put frequency : 2 X Input Frequency or 3 X input frequency (as specified)
19. NAME PLATE OF COMPANEY
ON TRANSFROMERS
• HINDUSTAN TRANSFORMER PVT. LTD.
• TEMP. RISE OIL = 50 C
• TEMP. RISE WINDING = 55 C
• VOLTAGE AT HV = 11000 V , LV = 433 V
• LINE AMPS HV = 10.49 A , LV = 266 A
• PHASE HV = 3 LV =3
• TYPE OF COLLING = ONAL
• Hz = 50
• KVA = 200
• WEIGHT IF OIL = 850 Kg
