Appendix A - GSU5 Documents.pdf

GSU #5 Photos:

Photo 1: GSU#5 Bushings Photo 2: GSU#5 Bushings

Item No. (Ref

TL1650-A01 &

TL1786-A01)

Description Q'ty per

Xfmr Specification/Ratings Reference or Catalog Number Manufacturer See on Contact List

Volume I O&M Manual Tab

21, 22 Buchholz Relay & Gas Sampler 1 With Magnetic Contacts EE3-ML + RG3.3 CEDASPE CEDASPE 12 23 Rapid Pressure Rise Relay 1 900 Series 900-003-02 Qualitrol Qualitrol 10 24 Pressure Relief Device 1 10 PSI XPRD CATA Qualitrol Qualitrol 11 31 Transformer Management System (Note 1) 1 DRMCC-T3 DR Job No. 916 Dynamic Ratings Dynamic Ratings 13 35 Oil Level Indicator 1 Min - 25°C - Max TJD-0231G01H02 Taijin HHI 6 38 Breather 1 NeoBLUE Gel HS9424-084 Taijin HHI 7 51 Cooler 2 190 kW LKSAS - 1 x 190/29 GEA GEA 8 52 Oil Pump 2 460 V/60 Hz/1740 rpm R&G 100/180/125 GEA GEA 8

Mechanical Bill of Material & Componet List - Common Components

52 Oil Pump 2 460 V/60 Hz/1740 rpm R&G 100/180/125 GEA GEA 8 53 Oil Flow Indicator 2 F Type TJD-0312G03 Taijin HHI 9 60 Oil Drain Valve 1 Flanged 3" Gate Type w/Blind Flange GtVRU-B62-150P-1~3B OK Kwang OKV 16 61 Lower Filter Valve 1 Flanged 2" Globe Type w/Blind Flange GVSU-BC-150LB-1~2B OK Kwang OKV 16 62 Upper Filter Valve 1 Flanged 2" Globe Type w/Blind Flange GVSU-BC-150LB-1~2B OK Kwang OKV 16 63 Oil Drain Valve for Conservator 1 Flanged 1" Globe Type w/Blind Flange GVSU-BC-150LB-1~1B OK Kwang OKV 16 64 Sudden Pressure Relay Isolation Valve 1 Flanged 2" Gate Type GtVRU-B62-150P-1~2B OK Kwang OKV 16 65 Vacuum Pump Connection Valve 1 Flanged 3" Gate Type w/Blind Flange GtVRU-B62-150P-1~3B OK Kwang OKV 16

66, 67 Oil Return & Supply for Gas Monitor 2 Flanged 1" Ball Type (15A) BV-SS-10KR-100A OK Kwang OKV 16 71 Oil Sampling Valve 1 Flanged 15A with 1/2" NPT Adapter OSVP-BC-10K-25A OK Kwang OKV 16 -- Sampling Device (Connected to Item 71) 1 1/2" with Dust Cap SD-12 (372116-00) TJ Manufacturing TJ 16 81 Cooling System Isolation Valve 6 6" Butterfly Type HS2211-468 HHI HHI 9 84 Main Valve for Conservator 1 Flanged 3" Gate Type GtVRU-B62-150P-1~3B OK Kwang OKV 16 91 Air Vent for Cooling System 2 APB-24 Pipe Plug HS2211-840 HHI HHI 991 Air Vent for Cooling System 2 APB-24 Pipe Plug HS2211-840 HHI HHI 9 94 Cooling System Drain Valve 2 Flanged 1" Globe Type w/NPT Plug GVSU-BC-150LB-1~1B OK Kwang OKV 9

101 Rubber Cell Type Conservator 1 3380 Liter RB270-HDD Hansoltech HHI 5 103 Conservator Vacuum Valves 2 Flanged 1" Gate Type GtVRU-B62-150P-1~1B OK Kwang OKV 16 104 Conservator Air Vent Valves 1 Flanged 1" Gate Type w/Blind Flange GtVRU-B62-150P-1~1B OK Kwang OKV 16 201 Hydrogen & Water Monitor 1 Calisto Calisto Morgan Schaffer Morgan Schaffer 15 207 Winding Temperature Indicator 1 0 - 150°C AKM35401-15X-6.0 Qualitrol Qualitrol 14

Note 1: The Transformer Management System (TMS) includes Bushing Health Monitor System, Abient Temperature Probe and other components. Refer to the Dynamic Ratings Drawings at the end of Tab 13 and the various manuals and data brochures found under Tab 13 for complete details on the overall DRMCC System

Item No. (Ref

TL1650-A01)

Description Q'ty per

Xfmr Specification/Ratings Reference or Catalog Number Manufacturer See on Contact List

Volume II O&M Manual Tab

1 HV Bushings (Note 2) 3 Type "O Plus C", 138 kV, 800A T138Z0800AA ABB - Alamo ABB - Alamo 3 2 HV Neutral Bushing 1 Type "O Plus C", 34.5 kV, 1200A T034W0412UT ABB - Alamo ABB - Alamo 4 3 LV Bushings 3 Type T, 25 kV, 6000A T025V0600WG ABB - Alamo ABB - Alamo 5

131 Core & Clamp Ground Bushings 2 Bulk Type, 7.2 kV, 200A TBA07021S HHI HHI 6 -- SFRA Shipping Bushings 7 Bulk Type, 1.2 kV, 200A TBA01022G HHI HHI 6 9 No Load Tap Changer 1 Type PVB PVB02-3-2X630-06050ME HHI HHI 7

43 Hand Drive for NLTC 1 Type ZR-03 ZR-03 HHI HHI 7 10 HV Surge Arrester 3 Type VN 76 kV MCOV VN219576 5001 Ohio Brass/Hubbel Hubbel 9

Mechanical Bill of Material & Componet List - 115 kV Transformers

10 HV Surge Arrester 3 Type VN, 76 kV MCOV VN219576-5001 Ohio Brass/Hubbel Hubbel 9

Note 2:

Item No. (Ref

TL1650-A01)

Description Q'ty per

Xfmr Specification/Ratings Reference or Catalog Number Manufacturer See on Contact List

Volume II O&M Manual Tab

1 HV Bushings (Note 2) TBD 2 HV Neutral Bushing TBD 3 LV Bushings TBD

ABB has revised the style number for the former Type AB Condenser Bushing. They are now identified as "O Plus C" and provided a new style number. Tab 3 contains the ABB Announcement informing customers of the change in style numbers. Drawings are included in the manual that shows the new style number (T138Z0800AA) and the old style number (IZUA138012-AAASEEABB).

Mechanical Bill of Material & Componet List - 230 kV Transformers

3 LV Bushings TBD 131 Core & Clamp Ground Bushings TBD -- SFRA Shipping Bushings TBD 9 No Load Tap Changer TBD

43 Hand Drive for NLTC TBD 10 HV Surge Arrester TBD

Serial Number 20082153TLC004-001

Core and core clamp grounding bushings.

Core and core clamp grounding bushings.

145 146

I HV SIDEI

I LV SIDEI

I LV SIDEI

~ 080926 ~ 081124 ~ 090224 p J. K. LEE p J, K. LEE p G. C. LEE

REVISED BY COMMENTS REVISED BY COMMENTS

c AIDED ITEM. 205 c c

080926

081124 ITEM. 12 AND 144

090224

H. P. KIM H. P. KIM Y. S. LEE

D 080926 D 081124 D 090224 s S. D. HAN s S, D. HAN s S. D. HAN N N N

24 91

~ 090430 p G. C. LEE

REVISED TAP CHANGER TYPE

c ITEM. 9

090430

Y. S. LEE

D 090430 s S. D. HAN N

GANTRY CRANE

CLEARANCE LINE

~ ADDED FIBER OPTIC SENSOR p <ITEM. 206> c MOVED HV BUSHING POSITION D s N

09J713

G. C. LEE

09J713

Y. S, LEE

09J713 S, D. H~N

( r:

~ FZ- • A ~i''' '"'''""'"' 7XI9 STRAND PLASTIC COATED, GALVANIZED STEEL 0 f'.-- METHOD OF ATTACHING•

CLAMPED CLOSED LODPEND

(STEEL ROUND BAR1 SS40Q)

PIN

( If

• B

V<sTEEL ROUND 3AR• SS400>

TANK COVER

= DETAIL 'B'

DETAIL OF FALL PROTECTION AND RAILC ITEM. I44)

POCKET

(STEEL GAS PIPE• SGPJ

C 4) DO. 4HJLES

FOR PIN

27 75

'' 5I . 4-,5/ '"'' .

·:VB" 4- B" < 4x6) ~0. 688 8.0 .

0.5 5. 25 o. 5 ru

"' M

"' ru

B. 0 LES

718' 718'

\ C 24) 9/I6' HO

L. V BUSHING TOP TERMINAL

ADDED RTD POCKET ~

(ITEM. 99, 140)

CENTER LINE

22. 969 61. 22t0.4

\ UPPER

o. 47

MOUNTING BRACKET

EART-j TERMIN ~

EARTH \

CABLE

1-CDf<E CLAMP L. V/T, V I. P. B MOUNTING FLANGE DETAIL

DETAIL OF CORE & CLAMP GROUNDI~G DEVICE( ITEM. 132)

~ 091103 p G. C. LEE

GROUNDING PAR ITEM. 13D

C MAT' L• STAINLESS STEEU

GANTRY CRANE

p

091107

G. C. LEE

.n ltl

I5')

DETAIL OF HO EARTHING DEVICE

C ITEM. I37)

CENTER LINE

92. 0 108. 0

76. 4 76. 4

I HV SIDEI

~ 091121 p G. c. L0 E

AMBIENT TEMPERATURE c c ADDED WINDING TEMPERATURE INDICA

091103 AS EUILT

091l07 C ITEM. 207) 091121 MOVED H. V C~BLE HOLDER

Y. S, LEE Y. S. LEE Y. S, LeE

C ITEM. 205)

D 091103 D 091l07 D 091121 s S, J, HAN s S. D. HAN s S, D. H~N N N N

' 41

NO.

I.

2.

3.

9.

10.

II.

I2.

21.

22.

23.

24.

31.

35.

38.

41.

43.

51.

52.

53.

60.

61.

62.

63.

64.

65.

66.

67.

71.

Bl.

84.

91.

94.

96.

97.

9B.

99.

101.

103.

104.

106.

107, 108.

109.

110.

Ill.

112.

113.

114.

115.

116.

117.

liB.

131.

132.

134.

137.

140.

144.

145.

146.

190.

191.

200.

201.

202.

203.

204.

205.

206.

207.

DESCRIPTIONS

H. V BUSHING

H. V. N BUSHING

LV BUSHING

NO-LOAD TAP CHANGER<NLTC>

H. V SURGE ARRESTER WITH SUB-BASE

SURGE COUNTER FDR H. V ARRSTER

CABLE HOLDER FOR H. V

BUCHHOLZ RELAY

GAS RELEASE DEVICE FOR BUCHHOLZ RELAY

SUDDEN PRESSURE RELAY

PRESSURE RELIEF DEVICE FOR MAIN BODY

SPECIFICATIONS

ABB/IZUAI3BOI2-AAASEEABB

ABB/034W0412UT

ABB/025V0600WG

PBV02-3-2X630-06050ME

HCOV 76kVCVN219576-5001) 24-5121

SEE DETAIL

EE3-ML/CEDASPE

RG-3. 3

QUALITROL/900-003-02

QUAL ITROL/XPRD

<OIL PIPE WITH SCREEN)

TRANSFORMER MANAGEMENT SYSTEM DYNAMIC RATING T3-7300

OIL LEVEL INDICATOR FOR MAIN CONSERVATOR TJD-0231/TAIJIN

BREATHER FOR MAIN CONSERVATOR 5KG<TOII5>1TAIJIN

LOCAL CONTROL PANEL L SEPARATE TERMINAL BOX TLI650-L01

HAND DRIVE UNIT ZR-03

UNIT COOLER GEA/ LKSAS-1 X 190/29

OIL PUMP GEA/5011401100

OIL FLOW INDICATOR TAIJIN/TJD-0312

OIL DRAIN VALVE GATE TYPE 3'<NPT THREAD PLUG)

LOWER FILTERING VALVE GLOGE TYPE 2'<NPT THREAD PLUG>

UPPER FILTERING VALVE GLOBE TYPE 2'<NPT THREAD PLUG)

OIL DRAIN VALVE FOR MAIN CONSERVATOR GLOBE TYPE I'<NPT THREAD PLUG>

ISOLATING VALVE FOR SUDDEN PRESSURE RELAY GATE TYPE 2'

VACUUM PUMP CONNECTION VALVE GATE TYPE 3'

OIL RETURN VALVE FOR GAS MONITOR BALL TYPE 1/2' STAINLESS VALVE

OIL SUPPLY VALVE FOR GAS MONITOR BALL TYPE 1/2' STAINLESS VALVE

OIL SAMPLING VALVE BALL TYPE WITH 1/2 NPT ADAPTER

CONNECTION VALVE FOR COOLER AND PUMP BUTTERFLY TYPE 6'

CONNECTION VALVE FOR MAIN CONSERVATOR GATE TYPE 3'

AIR VENT FOR OIL COOLER APB-24 TYPE

OIL DRAIN VALVE FOR COOLER GLOBE TYPE I'<NPT THREAD PLUG>

PROVISION SENSOR POCKET FOR 0, T, I< FUTURE> -

PROVISION SENSOR POCKET FOR W. T. I< FUTURE> -

POCKET FOR SPARE -

RTD POCKET FOR DYNAMIC RATING AKM 44666

MAIN CONSERVATOR RB270/HANSOL

VACUUM CONNECTION VALVE FOR CONSERVATOR GATE TYPE I'

VALVE FOR AIR VENT OF CONSERVATOR 1'

LIFTING LUG FOR COMPLETE TRANSFORMER -

LIFTING EYE FOR ACTIVE PART WITH TANK COVER -

LIFTING EYE FOR CONSERVATOR -

PULLING EYE -

JACK PAD -

HAND HOLE FOR LV BUSHING DIA 19. 7'

HAND HOLE FOR BUSHING DIA 15, 7'

MAN HOLE FOR TOP DIA 24'

INSPECTION HOLE FOR TANK BOTTOM DIA 4'

MAN HOLE FOR CONSERVATOR DIA 15. 7'

INSPECTION HOLE FOR SIDE DIA 15, 7'

SKID BASE FOR c R TLI650-A52

STEEL SUPPORTING BASE<REMOVABLE> TLI650-A52

GROUNDING PAD FOR MAIN BODY NEMA 2HOLES TYPE<TLI650-A52)

CORE AND CLAMP GROUNDING DEVICE TBA07021S+PROTECTOR

AIR/GAS VENTING PIPE LINE 1' STEEL PIPE

H. V. N GROUNDING CONNECTION BUS BAR + INSULATOR

AMBIENT TEMPERATURE SENSOR -

FALL PROTECTION AND RAIL SEE DETAIL

WIRING CONDUIT ROUTE SEE DWG

WIRING JUNCTION BOX SEE DWG

IMPACT RECORDER RW-3WE + GPS IMPACT

STORAGE BOX FOR FALL ARRESTER PIPE L ROPE -

NAME PLATE<RATING,CDNNECTION,LIFTING PLATE> TLI650-AII,I2, 13

GAS MONITOR SYSTEM CALISTa

MOUNTING BRACKET FOR PROVISION 0. T. I & W. T. I -

BUSHING MONITOR SYSTEM DYNAMIC RATING BHM

MAN HOLE FOR SIDE DIA 15. 7'

FLAT PLATE FOR 5' CONDUIT TI'XIO'XIO'

FIBER OPTIC SENSOR H2<3EA),LV<3EA/PHASE)

WINDING TEMPERATURE INDICATOR AKM35

UNTANKING WEIGHT

' I94000 LBS

I I

UNTANKING DWG

RATINGS

PHASE 3 PH

FREQUENCY 60 Hz

CAPACITY 128 MVA

R~ TED VOLT ~GE 115/13, 2 kV

WEIGHT C LBS)

CORE/COIL ASSEMBLY 16840]

DIU 7741 US go_ l. ) 58200

TANK ~ FITTINGS 71000

SCrARATCLY DASC 7000

TOTAL WEIGHT 304600

OVERALL DIMENSION TOLERANCE ± 5 %

G : CCNTCR Dl G~AVITYC CDMrLCTC TR>

G' ' CENTER OF oRAV !TY

C SHIPPING JF MAIN BODY)

t ' JACKING POINT

Gl' TY I I I I I I

I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I

I

DSN CHK APP 3RD TITLE : 3PH 60fZ 128 MVA, ll5/l3. 2KV

INCH OUTLINE FOR TRANSFORMER

08C725 080725 080725

1/50 PROJECT

S. D. HAN H. P. KIM J. K. LEE SIZE AI CAD LA/I: 650o0 1 SHEET

[J={JV11[][KIJ[O)!p\[] REF. I

HEAVY INDUSTRIES CD. , LTD. DWG. TL165D-ADI REV. 10

SHIPMENT, STORAGE AND ERECTION

OF

OIL-IMMERSED TRANSFORMER

DOC. NO HHIS-WZ-TE-100(09)

SHIPMENT, STORAGE AND ERECTION HHIS-WZ-TE-100 (09)

- 1 -

IMPORTANT MESSAGES

Before attempting to install and operate this equipment, read this manual carefully to obtain important information regarding safety, handling, installation and maintenance procedures.

Signal words such as DANGER, WARNING, CAUTION, NOTICE and Safety instruction.

Such words are used to alert the reader that sections so marked contain important safety information that must be carefully reviewed to assure safe and efficient inspection of this equipment.

Indicates an imminently hazardous situation, which, if not avoided, will result in death or serious injury.

Indicates a potentially hazardous situation, which if not avoided, could result in death or serious injury.

Indicates a potentially hazardous situation, which, if not avoided, may result in minor injury or property damage.

Provides helpful information.

QUALIFIED OPERATORS ONLY

Only qualified personnel are authorized to install, inspect, operate and serivce his equipment according to all applicable codes and established safety practices.

The manual is written for a qualified person or a person who has knowledge of the transformer. When handling the equipment, please read the manual carefully and understand the contents and follow the instruction of the qualified person.

SAFETY

PRECAUTION

- 2 -

A qualified person must:

1) Carefully read this entire instruction manual.

2) Be skilled in the installation, construction or operation of the equipment and be aware of the hazards involved.

3) Be trained and authorized to safety energize, de-energize, clear, ground, lockout and tag circuits in accordance with established safety practices.

4) Be trained and authorized to perform the service, maintenance or repair of this equipment.

5) Be trained in the proper care and use of protective equipment such as rubber gloves, hardhat, safety glasses, face shield, nonflammable clothing, etc., in accordance with established practices.

6) Be trained in rending first aid.

- 3 -

CONTENTS

1. GENERAL ………………6

2. SAFETY REGULATIONS ……………… 7

2.1 General ……………… 7

2.2 In installation ……………… 7

2.3 Safety ……………… 9

3. SHIPMENT ……………… 11

3.1 Main transformer ……………… 11

3.2 Bushing ……………… 11

3.3 Detail parts ..……………. 12

3.4 Impact recorder: If requested ……………… 12

3.5 Handling ……………… 12

3.6 Equipment of dry air or nitrogen gas for Transportation ……………… 15

3.6.1 Check of equipment

3.6.2 Operation of equipment

3.6.3 Replacement of empty gas bottle

4. INSPECTION OF THE EQUIPMENT AFTER DELIVERY ……………… 18

4.1 Document ……………… 18

4.2 Main tank ……………… 18

4.2.1 External Inspection

4.2.2 Impact recorder (If provided)

4.2.3 The gas pressure and dew point of transformer

4.2.4 Internal Inspection

4.3 Accessories ……………… 21

4.4 Checklist of transformer after delivery ……………… 22

5. STORAGE TRANSFORMER PRIOR TO ENERGIZATION ……………… 23

5.1 General ……………… 23

5.2 Gas used for filling the tank ……………… 23

5.3 Preparations for Storage ……………… 23

- 4 -

5.4 Temporary storage of a transformer in dry nitrogen gas or dry air ……………… 24

5.5 Storage of transformer in oil ……………… 24

5.5.1 Completely assembled

5.5.2 Without Assembly

5.6 Accessories & Detail parts ……………… 26

6. TRANSFORMER INSTALLATION ……………… 27

6.1 General ……………… 27

6.2 Caution for transformer installation ……………… 27

6.2.1 Work in the tank

6.2.2 Weather

6.2.3 Clothing

6.2.4 Pressure Relief

6.2.5 Handling

6.2.6 Lifting and accessories

6.2.7 Fastening with bolts and nuts

6.2.8 Transformer oil

6.3 Installation procedure of the transformer ……………… 29

6.4 Preparation for installation ……………… 30

6.4.1 Arrangement of a location for its installation

6.4.2 Equipment and tools for installation works

6.5 Setting up ……………… 32

6.6 Internal inspection ……………… 33

6.7 Assembling the transformer ……………… 33

6.7.1 Cooling equipment

6.7.2 Piping

6.7.3 Bushing

6.7.4 Other accessories

6.7.5 Wiring

6.7.6 Gas monitor

6.7.7 Bushing Current Transformer

6.7.8 Grounding

6.7.9 Connection of terminal lug

6.8 Complete oil filling ……………… 44

- 5 -

6.8.1 Cautions for vacuuming and oil filling

6.8.2 Draining the insulation oil while filling with nitrogen gas

6.8.3 Installation

6.8.4 Valve operation

6.8.5 Vacuum treatment

6.8.6 Oil filling

6.9 Moisture content verification ……………… 51

6.10 Oil level adjustment ……………… 56

6.11 Touch-up painting ……………… 57

6.11.1 Outdoor transformer

6.11.2 Indoor transformer

6.12 Spill prevention control and countermeasures plans ……………… 58

6.12.1 Spill prevention plan for transformer

6.12.2 Spill cleanup procedures

6.12.3 Personnel safety procedures

7. SITE TEST ……………… 61

7.1 Insulation resistance measurement ……………… 61

7.2 Polarity and phase rotation ……………… 62

7.3 Turn ratio test ……………… 64

7.4 Insulation power test ……………… 65

7.5 Applied potential test ……………… 65

7.6 Resistance measurement ……………… 65

7.7 Oil test ……………… 66

7.8 Bushing Current Transformer Test ……………… 67

7.9 Test of alarm devices and control units ……………… 67

7.10 Leakage test of transformer ……………… 67

7.11 Operational test of other equipment ……………… 67

7.12 Valve check ……………… 67

7.13 Visual inspection ……………… 67

8. ENERGIZATION ……………… 68

9. FACTORY REPAIR PROCEDURE (CONTACT POINT) ……………… 68

10. SUMMARY OF THE STORAGE METHOD OF THE LARGE POWER TRANSFORMER

……………… 69

- 6 -

1. GENERAL

These instruction manuals are intended as a guide to the installation and maintenance of our transformer. Every man who works on the receiving, installation, storage, commissioning and maintenance of a power transformer should be constantly aware of what he should and should not do to protect the quality and reliability of the transformer. When installed and commissioned with care, transformers usually require less maintenance than any other kind of electrical power apparatus. A regular program of inspection should be established and consistently carried out. The frequency of such inspections being determined by the conditions under which the transformers operate. For example, a transformer operating under arduous conditions requires more maintenance than one operating under light-load conditions. Similarly, atmospheric pollution, temperature, humidity and altitude all affect the transformer. Therefore, the inspection and maintenance routine is a matter for local consideration. But all of possible contingencies, which may arise during installation and maintenance, and all details and variations of this equipment do not purport to be covered by these instruction manuals. If further information is required by purchaser regarding his particular installation or maintenance of his equipment, HYUNDAI HEAVY INDUSTRIES CO., LTD. would furnish sufficient information willingly.

Before dealing with transformer, one must read and remember these manuals especially section 2. SAFETY REGULATIONS!

Not following these instructions may cause personal injury or property damage.

- 7 -

2. SAFETY REGULATIONS

2.1 General

Safety regulations are intended to alert personnel who are in charge possible personal injury, death or property damage. One must avoid improper working mentioned in this manual.

Safety levels are defined in three levels as follows in this manual. These have mark or are printed in bold characters.

Extreme hazardous working that can cause severe personal injury, death or property damage.

Hazardous or unsafe working that has possibility of injury, death or property damage.

Unsafe or improper working, which can result in minor personal injury or property damage.

All safety regulations with the symbol have to be strictly observed to prevent person related hazard or property damage. Each person–operator or who is in charge of transformer – has to read and aware of these regulations.

The whole part of section 2 is related with safety. These instructions must be obeyed during working on the transformer.

2.2 In installation

1) Supports for Climbing External valves, piping and miscellaneous fittings must not be used for climbing or support because they will not support a human’s weight and are not safe for climbing. Use ladders when climbing.

2) Lifting and jacking Lifting and jacking must be done using the proper lifting lugs and jacking pads. Many of

- 8 -the eyes and surfaces are not suitable for lifting or jacking and will not support the transformer weight. See the transformer outline drawing supplied with the transformer for correct location of these operations. Injury to personnel and damage to the transformer can result if improper fittings are used.

When lifting and skidding unit, be certain that the hooks, jacks and ropes are secured not to fall down or slip out of position. Failing to do this can cause severe personal injury or equipment damage.

3) Grounding The transformer tank must be grounded at all times. Windings must be grounded except when electrical tests are being made. Bushings (after installation) must be grounded. All oil handling equipment and vacuum pumps must be grounded. Maintain equipment grounds for six hours after oil filling. All test equipment must be properly grounded. Disregarding any of the above can result in static discharges injuring personnel and damaging the transformer.

4) Transformer Internal Pressure Do not open any covers or fittings unless zero gauge pressure exists inside the unit.

Failure to relieve the pressure could cause the part being removed to become a hazardous flying object. Always relieve internal pressure slowly through valves.

5) Transformer Internal Atmosphere Do not enter the transformer or breathe the internal atmosphere unless the oxygen content of the gas inside the transformer is 19.5%∼24%. Oxygen content less than this can cause drowsiness, injury or death. Transformers shipped in gas are not safe to enter. Always check the oxygen content. Whenever anyone is inside the tank, other personnel must be near the manhole on the cover.

6) Electrical Testing High turn ratios can transform very small input voltages into dangerous output voltages.

Never touch any leads or bushings with test equipment energized.

7) Fire Extinguishers Fire extinguishers should be available for emergency use. One should be available on top of the transformer when work is being done inside the tank. Smoking must not be permitted

- 9 -on top or inside of the transformer or in the vicinity of the oil handling equipment.

The use of a fire extinguisher inside the transformer will usually severely damage or ruin transformer insulation.

8) Care on Transformer Cover Extreme caution must be used when walking on the cover of a transformer because the cover may be slippery due to an oil film.

9) Condenser Bushings Caution must be used when grounding bushings because they may retain electrical charge after transformers have been disconnected from external circuits.

2.3 Safety

1) Working near Energized Transformer Never climb on any part of a transformer while it is energized. Injury or death can occur from electrical discharges.

2) Liquid Level Do not open any valves or plugs on the transformer or any of its accessories while the transformer is energized because the liquid level could drop below the minimum level. (The gas or oil sampling valves are the only exception.) An internal flashover may occur if the oil is allowed to drop below the minimum oil level.

3) Control Circuits The control circuits, inside and outside the control cabinet, utilize voltages that can be dangerous to personnel. Caution must be used when operating any of the switches or breakers. If work on the circuits is necessary, the power supply must be shut off.

4) Cooling Equipment When the transformer is energized, the proper cooling equipment must be in operation. If not, dangerous pressures can occur inside the transformer and possibly result in injury to personnel. Multiple pieces of protection equipment prevent the situation described from becoming dangerous while in operation.

- 10 -

5) Jacking When unloading the transformer or placing it in position, make sure the jack lugs or places designated for jacking on the outline drawing are used when jacking the unit. The use of jacks on any other part of the transformer may require costly repairs.

6) Pulling Eyes Always pull the transformer with pulling eyes supplied on the unit. Check the outline drawings for the proper fittings to use.

7) Current Transformers The secondary of any current transformer not connected in auxiliary circuits must be short-circuited and grounded.

8) Electrical Grounding The transformer tank must be solidly grounded.

- 11 -

3. SHIPMENT (and Transportation)

3.1 Main Transformer

Before shipping, the transformer is carefully filled and pressurized with dry air (or nitrogen by requirement) to minimize the likelihood of condensation or moisture entering the tank.

Transformers will be shipped in one of the following conditions:

1) The smaller transformers are shipped with the accessories mounted and completely filled with oil, when shipping clearance and weights permit.

2) With the tank filled with oil to a level to cover the windings, the space above the oil is filled with dry nitrogen or dry air. Before leaving the factory, the transformer tank is filled with dry nitrogen or dry air to a pressure of 2.0 PSI (0.14kg/㎠) at about 25℃ and is tested for leakage. A pressure gauge and bleeder is fitted to enable tank pressure to be monitored.

3) The tank is completely drained of oil and filled with dry air or nitrogen under pressure

2PSI. During transit, however, a certain amount of oil may be extracted from the core and windings. An equipment (Fig 3-2) is installed during the transportation to maintain gas pressure inside transformer tank.

4) All valves should be closed and the blind covers or caps are attached to valves to prevent oil / air leakage during transportation.

3.2 Bushing

The bushings often have to be removed from the transformer for shipment. This is necessary to meet shipping clearances and to avoid shipping damage to the bushings. The bushing leads will be supported by temporary shipping braces which are an integral part of the blind flange cover or by the tank braces. The bushing leads must be disconnected from these temporary braces before the blind flange covers are removed.

The bushing leads, lead connections and coils can be severely damaged if you attempt to remove the covers without first disconnecting the shipping supports.

- 12 -

3.3 Detail Parts

All fittings are shipped mounted in place when possible. Detachable cooling equipment is removed for shipment. Packing list indicates the parts that are to be removed for shipment.

Those fittings subject to damage during transporting are packed in wooden crates of suitable size and type in accordance with the maker’s export standard.

3.4 Impact Recorder: If requested

An impact recorder is mounted on the transformer. See the operating manual of impact recorder.

3.5 Handling

Transformers must be handled in the normal up-right position. The angle between ropes must be below 60 degree for lifting the transformer main body with crane. Lifting lugs or eyes are provided for crane lifting. When the transformer is lifted, all of the correct hooks or eyes, per the outline drawing must be used. The lifting angle and size of wire ropes to be used for lifting the transformer must be determined in accordance with the relevant standard.

Similarly, jacking pads are provided for lifting the transformer with jacks. All such pads must be used when the transformer is to be jacked.

Never attempt to lift the transformer by using any part of the transformer other than the correct fittings provided for the purpose.

1) Unloading at the port Transformer shipped by boat from Korea will be unloaded at the main port of destination by cranes etc. Such unloading works should be executed by skilled works and it is desirable that a representative of the customer should be present during unloading operations.

Take care against the following

(1) Contact of transformer against a quay

(2) Contact of transformer against a ground

(3) Check nitrogen gas pressure positive or not.

Use a steel wire rope having sufficient strength to lift the transformer and accessories to prevent dropping. Not doing this may cause severe injury, death or equipment damage.

- 13 -

2) Inland loading Transformer is transported to site by trailer or by other means. It is undesirable to give severe shock to the transformer during transportation. The speed of the transport car (trailer etc.) should be regulated according to the condition of the road surface.

The normal speed is as follows.

(1) Complete paved road : Less than 50km/h

(2) Insufficient pave road : Less than 30km/h

(3) Unpaved road : Less than 10km/h

But, when the transformer is transported by rail, there is no problem while the train is running, however attention should be paid to preventing shock during loading and unloading work. It is undesirable to incline the transformer too much.

The angle of slope should be less than 10˚as shown FIG. 3-1. It is desirable to install an impact recorder on the cargo or the transformer itself.

θ : Less than 10˚

[ FIG. 3-1 ]

3) Detail parts

(1) By cranes

a) Put guide ropes on boxes to prevent swings.

b) Observe hanging position marks on boxes when hanging up.

c) Do not give shocks especially on porcelains of bushings and surge arresters.

(2) By freight car or truck.

a) Fix boxes on freight car or truck not to give damage.

b) Observe care marks on boxes when handling.

c) Do not give shocks especially on porcelains of bushings and surge arresters.

- 14 -

The accessories should be transported and stored according to the following care marks, which are printed on the boxes.

MARK

PRINTED

DESCRIPTION

MARK

PRINTED

DESCRIPTION

THIS MARK INDICATES

THAT THE TOP SIDE

MUST ALWAYS BE

FACING UPWARDS.

THIS MARK INDICATES

THE SLINGING

POSITION

THAT THE CONTACTS

ARE FRAGILE AND

THE PACKAGE MUST

BE KEPT FREE FROM

SHOCKS.

THE POSITION AT

WHICH THE WEIGHT OF

THE CONTENTS IS

BALANCED

THAT THE PACKAGE

MUST BE KEPT AWAY

FROM WATER.

THIS MARK INDICATES

THAT THE PACKAGE

MUST BE STORED

INDOORS.

THAT HAZARDOUS OR

POISONOUS OBJECTS

ARE CONTAINED

3.6 Equipment of dry air or dry nitrogen gas for transportation.

- 15 -

If transformer tank is transported filled with nitrogen gas, nitrogen gas cylinder is supplied instead of dry air cylinder.

① Joint connection by connecting valve ② 1ST pressure reducing

1.1 1ST pressure gauge (0~200 ㎏ /㎠ )

1.2 2nd pressure gauge (0∼30 ㎏ /㎠ ) ③ 2nd pressure reducing valve ④ Low pressure gauge (0∼1.0 ㎏ /㎠) ⑤ Pressure relief valve (0.3 ㎏ /㎠) ⑥ Coupling ⑦ Case ⑧ Cylinder ⑨ Cylinder valve

【 FIG 3-2 】 Schematic diagram of equipment (typical)

3.6.1 Check of equipment

When transformer arrival at site, check of the value of equipment (P1, P2, P3) P1 : ≥14 ㎏ /㎠

P2 : 3.5~5 ㎏ /㎠

P3 : 0.035~0.35 ㎏ /㎠

3.6.2 Operation of equipment

The schematic arrangement is shown in FIG 3-2.

1) Close the connecting valve. ①

2) Disconnect coupling to transformer (⑥).

3) Check the remained gas by checking the pressure on after opening cylinder valve. ⑨

4) Adjust 1st reducing valve ②until Item 2nd pressure gauge shows 3.5 ㎏ /㎠ .

5) Cover the coupling ⑥outlet with hand and adjust 2nd pressure reducing valve ③ until low pressure gauge ④ shows should be 0.35 ㎏ /㎠ or about (0.5 psi).

6) Adjust the 2nd pressure reducing valve ③ that low pressure gauge ④ shows 0 ㎏ /㎠

2.1

2.2

- 16 -and 0.035 ㎏ /㎠ when close and open the coupling ⑥ inlet with hand repeatedly.

7) If low pressure gauge ④ shows different value above procedure must be repeated.

8) If low pressure gauge ④ shows 0.035 ㎏ /㎠ connect the pipe line to the connecting valve ① . After opening the connecting valve ① transformer inside is filled with gas with pressure 0.035 ㎏ /㎠ automatically.

9) Inside pressure of transformer is changed 0.035∼0.35 ㎏ /㎠(0.5~5 psi) according to the variation of ambient temperature. (If inside pressure of transformer is less than

0.035 ㎏ /㎠ , according to low ambient temperature or leakage, nitrogen gas or dry air flows into transformer from cylinder.)

10) If shows the leakage of dry air or nitrogen gas that the pressure inside cylinder is rapidly reduced. In this case, leakage test must be carried out at expected points (Example: connecting point, gasket, welding point, etc.)

11) air pressure or nitrogen pressure should be maintained in accordance with FIG.4-1 during transportation and storage.

3.6.3 Replacement of empty gas bottle (Refer to FIG. 3-2)

The gas bottle (cylinder) must be exchanged according to below procedure when the internal pressure is less than approximately 14 ㎏ /㎠ .

1) Remove the cover plate from the case ⑦ .

2) Close the valve ⑨ .

3) Close the 1st pressure-reducing valve ② . (Turn locking screw (2) in an anti-clock wise direction)

4) Loosen cap nut of the gas pipe on the valve of the cylinder to be replaced.

5) Loosen the cylinder holder, exchange the cylinder and fix it.

6) Remove the protective cap from the head of the new cylinder and fix the gas pipe to cylinder valve using cap nut.

- 17 -

7) Slowly open cylinder valve ⑨

8) Slowly open 1st pressure reducing valve② until 2nd pressure gauge shows

3.5 ㎏ /㎠ .

9) Fill nitrogen gas after adjusting the low pressure gauge on 0.03∼0.04 ㎏ /㎠ by opening

2nd pressure reducing valve slowly.

2.2

- 18 -

4. INSPECTION OF THE EQUIPMENT AFTER DELIVERY

4.1 Document

Shipping documents, outline and wiring drawings, instruction leaflets and other relevant documents furnished with the transformer must be available for use during inspection.

Immediately after delivery to site, all equipment must be examined for possible transport damage. If any damage or oil leakage is discovered at the site management, the receiving inspection check sheet (Refer to section 4.4) must be completed by the transportation company, the transport insurer and customer’s representative, for each unit and informed to HYUNDAI HEAVY INDUSTRIES CO., LTD. (HHI), in order to maintain the warranty.

4.2 Main tank

Check the external damaged of the main tank, such as deformation, break-down, missing parts, etc.

4.2.1 External Inspection

Any external evidence of damage or evidence indicating the possibility of hidden damage must be reported to the carrier’s representative and to a HHI representative before unloading the transformer. Take pictures of external damage. The customer must assume all responsibility for unloading damaged transformers. The external inspection prior to unloading the transformer should include all of the following.

1) Are all tie rods undamaged and nuts tight?

2) Is all blocking tight and in good condition?

3) Is there any evidence of load shifting in transit?

4) Are there indications of external damage such as broken glass on gauges, broken welds on flanges?

5) Is the paint finish damaged?

6) Are all fittings which were shipped attached still in place and undamaged (see the outline or outside assembly drawings)?

7) Is there any evidence of oil leakage (units shipped in oil)?

8) Is there either positive pressure or vacuum in the tank (Refer to 4.2.3)?

9) Are any porcelains chipped or otherwise damaged?

10) Is oil level in bushings normal?

11) Does the impact recorder tape indicate higher impacts

(If attached on the tank, refer to 4.2.2)?

- 19 -

4.2.2 Impact recorder (If provided)

If the indication of an impact has been recorded over the following values, carry out the special internal inspection as early as possible and must be informed to HHI.

- Lateral (X AXIS) : 2 G

- Longitudinal (Y AXIS) : 3 G

- Vertical (Z AXIS) : 2 G

4.2.3 The gas pressure and dew point of transformer

1) Check the gas pressure and dew point inside transformer tank after receiving the transformer.

2) It is desirable to maintain constant pressure of gas inside transformer tank. The gas pressure is changed in proportion to the temperature. The permissible pressure difference due to temperature change is shown in FIG. 4-1. If the gas pressure in the tank is above zero, it may be assumed that the tank seal is still effective. If the gas pressure is zero or negative, the possibility exists that moisture may have entered the tank and HHI should be notified.

3) Dew point of dry air;

(1) If the dew point check and humidity content is below 0.7% and/or kept as close as possible to the value as measured at the factory, it may be assumed that the transformer has not been contaminated with air or moisture in transit.

(2) If the dew point check and humidity content is above 2%, drying should be performed according to the method of clause 6.9 and HHI should be notified.

- 20 -

【 FIG. 4-1 】 Temperature difference versus pressure difference graph

Note:

“Temperature difference” signifies gas temperature at the time of arrival at site minus gas temperature at dispatch. “Press. Difference” means the gas pressure at the time of arrival at site minus gas pressure at dispatch.

Example:

- Temperature when dispatched 15℃

- Measured temp. at site 25℃

- Temp. difference +10℃

- Pressure when dispatched 0.06kg/㎠

- Measured press. at site 0.1kg/㎠

- Press. difference 0.04kg/㎠

When the gas pressure measured agrees with the value on the graph of FIG. 4-1, it says that the gas in the tank did not leak during transportation.

4.2.4 Internal Inspection

A preliminary internal inspection is normally not required unless suspected shipping damage is involved. The principle objective of the internal inspection is to locate any damage, which might have occurred in shipment. Particular attention should be paid to leads, tap changers,

- 21 -current transformers, and the insulation and lead support structure. Temporary shipping braces should be removed after the transformer is placed on its foundation.

If damage is observed, the following test may be made as part of the internal inspection.

1) A ratio test on all windings and tap positions.

2) A megger test of insulation resistance of each winding to all other windings and ground and from all windings to ground should be made with the windings. These readings should be comparable with the measurements made at the factory.

Do not enter the transformer until the inside gas is replaced by dry air when transformer has been shipped with nitrogen. Oxygen content inside transformer must be at least 19.5% ∼ 24% before entering for internal inspection. Oxygen content less than 19.5% may cause drowsiness, injury or death.

Always check that the inside pressure of the transformer is zero before opening the manhole/hand-hole cover.

4.3 Accessories

All accessories and detail parts should be checked against the packing list to make certain that there are no shortages. The crates and boxes should be carefully examined for evidence of damage. In making examinations of any parts or crates for shipping damage, check carefully for evidence of moisture entrance and for damage to the moisture barriers or waterproof wrappings. Accessories and detail parts must be placed in a location, which will minimize exposure to weather and the possibility of damage and loss. If the transformer is not to be installed immediately, the parts must be stored in accordance with section 5.

- 22 -

4.4 Checklist of transformer after delivery

REFERENCE : SERIAL No. :

INSTALLATION PROJECT No. :

TRANSFORMER SPECIFICATION :

DATE : SIGNATURE :

1. TRANSPORT

- With oil above the cover

- With oil …………. ㎜ below the cover

- Without oil and filled with gas

2. GAS GAUGE PRESSURE IN THE TANK.

- Kg/㎠ or psi

- None

3. GAS GAUGE PRESSURE IN CYLINDER

- kg/㎠ or psi ( )

4. IMPACT RECORDER

- Not provided

- Provided

- Recorded severe impacts

5. TANK DAMAGED

- No

- Yes (notified to)

6. PAINT FINISH

- Not damaged

- Slightly damaged

- Heavily damaged

7. ACCESSORIES

- Proper quantity provided

- Incomplete and damaged

8. TRANSFORMER OIL

- Proper quantity provided

- Insufficient quantity

- Drum damaged

9. OIL TREATMENT PLANT

- Required

- Not required

- Provided 1/hour

- Will be obtain from

10. INSTALLATION TOOLS

- Proper quantity provided

- Not provided

- Not required

- Will be obtain from

11. HHI COMMISSIONING ENGINEER 12. COMMISSIONING

- Will be carried out by

- Will be carried out by HHI

- Will be requested

- Will not be requested

- 23 -

5. STORAGE TRANSFORMER PRIOR TO ENERGIZATION

5.1 General

Some smaller transformers are dispatched with an oil preservation system mounted and completely filled with oil when shipping clearance and weights permit. If dispatch takes place without conservator, the tank is not completely filled with oil, but with an approx.

250mm height of gas-cushion, due to the changes in volume, which takes place by temperature variations and as a protection against absorption of moisture. In special cases, shipment takes place without any oil, in the case, the transformer is filled with dried dry air (or nitrogen gas by requirement). A transformer may be stored in dry gas or oil. The storage period begins the day the transformer is received. If the transformer must be stored beyond 6 months, the preferred method is storage in oil.

When the transformer is filled with nitrogen gas, a well visible notice should be affixed to the tank wall or case of FIG 3–2.

5.2 Gas used for filling the tank

- Dry air : Dried and above 99.95% purity

- Nitrogen : Dried and above 99.90% purity

5.3 Preparations for Storage

Before the transformer is prepared for storage, the inspections outlined in section 4 should be made. The works carried out and the result should be demonstrated in checklist (section 4.4). If it turns out that the standards given in these instructions are not met, the necessary repairs should be made prior to storage. Transformers and accessories can be stored if the following conditions are prepared.

1) The area on which the transformer is placed must be adequately stable and protected against water flowing underneath.

2) Oil leakage must be prevented from having any adverse effect on the surroundings.

3) Provision must be made for adequate protection against oil and gas losses and for continuous monitoring with indication to immediately attract attention.

4) Moisture must be prevented from entering the tank or the transformer oil by replacing gas cylinders in changing time or by providing and servicing dehydrating breathers.

5) Suitable weather protection (shed, roof) must be provided to prevent condensation forming in the fittings. If required, use dehydrating silicagel in bags for the individual

- 24 -items of equipment.

6) Adequately protect the packing of the accessories against rotting.

7) Tank must be protected against corrosion and mechanical damage.

8) Transformers stored outside a fenced area should be secured and barricaded.

5.4 Temporary storage of a transformer in dry air or nitrogen gas If the transformer cannot be installed immediately upon arrival, and oil filling is impractical, it is possible to store the transformer under a positive dry air pressure upto six months from the day the transformer is received. The transformer must be placed on a solid, level foundation in the storage area. Ground the tank and any bushings that are mounted. The storage of transformers in gas requires positive assurance that the gas pressure is continuously maintained. The use of dry inert-gas pressure equipment is recommended. The inert-gas pressure equipment must be installed within one week after the transformer has been delivered. If the transformer is not equipped for inert-gas pressure, temporary pipe connections can be made using the upper filter press or vacuum filling connections. After installing the inert-gas pressure equipment with a full cylinder of dry air, carry out the pressure test of transformer for four hours at 5 psi gauge pressure to check the tank for leaks. And the 2 psi(0.14kg/㎠) at ambient temperature, transformer should be pressured inside tank during storage.

Transformer gas pressure and cylinder pressure should be recorded every day the first two weeks. These readings should preferably be taken at approximately the same time every day and the time and temperature also noted on the log.

After two weeks of daily logging with stable conditions, the frequency of pressure readings may be reduced to once a week. An accurate log of the pressure readings is required; it may be the determining factor in any decisions that may have to be made on further drying of the insulation. Use the procedure from section 6 for installing the transformer. When vacuum filling with oil, increase the vacuum period prior to oil filling by one hour for each month of storage. To prevent condensation forming, the control cabinet and motor drive unit with heater should be connected to a power supply unit.

5.5 Long tern storage of transformer in oil

5.5.1 Long term storage for more than one year

If the transformer must be stored for more than one year, complete assembly and vacuum filling with oil per section 6 is recommended.

If these operations can all be completed, the transformer will then be ready for service at any time, providing it receives the same inspection and maintenance during storage as a transformer in service. The oil preservation system must be in operation. Run the fans and pumps each month for 30 minutes.

- 25 -

Do not operate the fans and pumps if the temperature is below -15 degree C. An accurate log of inspection and maintenance data is required: This must be reviewed by the user prior to energizing the transformer. If the data is questionable, contact HYUNDAI HEAVY INDUSTRIES CO., LTD. At the end of the storage period, samples of oil must be drawn from the bottom of the transformer and from the tap changer compartments and tested for electrical strength, power factor, and water content. Make megger and power factor tests and compare with factory test values. If all test results are satisfactory, the transformer may be energized. To prevent condensation forming, the control cabinet with heater should be connected to a power supply unit.

5.5.2 Long term storage for more than 6 months

If the transformer cannot be completely assembled and storage from 6 months to 12 months is anticipated, the oil preservation system should be assembled on transformer tank and transformer should be filled with oil according to clause 6.9. Oil level must be checked daily for the first two weeks. After two weeks the oil level must be checked once a week. The transformer should be completely assembled and filled with oil at vacuum condition according to section 6. If the transformer uses the sealed oil preservation system or the oil preservation system is conservator type and is not going to install before storage, a positive internal pressure must be maintained. If the conservator cannot be mounted, temporary pipe connections should be made. Fill oil in the transformer at vacuum condition until the oil level is approx. 250mm from the cover. Break the vacuum with dry air. After installing the oil preservation system, pressure test the transformer for four hours at 5psi gauge pressure.

Oil leakage inspection should be carried out. And the 2 psi(0.14kg/㎠) at ambient temperature, transformer should be pressured inside tank during storage. Transformer gas pressure and cylinder pressure should be recorded every day for the first two weeks. These readings should preferably be taken at approximately the same time every day and the time and temperature also noted on the log. After two weeks of daily logging with stable conditions, the frequency of pressure readings may be reduced to once a week. An accurate log of the pressure readings is required; it may be the determining factor in any decisions that may have to be made on further drying of the insulation.

At the end of the storage period, the records of pressure readings must be reviewed to make certain that positive pressure was maintained. Also, oil samples should be drawn from the bottom of the transformer and tested for electrical strength, power factor and water content to insure that moisture has not entered the transformer. If all tests are satisfactory, assemble transformer per section 6. To prevent condensation forming, the control cabinet and motor drive units with heater should be connected to a power supply unit.

- 26 -

5.6 Accessories & Detail parts

When accessories are not mounted immediately after the transformer is received, they must be given care to protect them from damage or loss during storage. The following general instructions and the more detailed instructions given in instruction leaflets for the accessories, when furnished, must be followed. In the event of conflict between this manual and instruction leaflets for the individual accessory, the latter shall take precedence. The box, containing details as shipped should be stored indoor and in a dry and clean place. The box contains internal connections, gaskets, internal bushing connectors, tape insulations, paint, control panel, relay, etc. as specified on the detail packing list.

The radiators and coolers, cooling fans, bushings should be stored indoors or in a weatherproof shed. Also the transformer oil is preferably to be stored indoors same as the accessories. However, where the oil is stored outdoors, place drums on square timbers so that the plugs are to be the same level as shown on FIG. 5-1.

【 FIG. 5-1 】

Do not open any parcels, just for checking, until the material is actually needed in the process of assembly.

- 27 -

6. TRANSFORMER INSTALLATION

6.1 General

Carry out the installation work as far as possible in sequence with this instruction and in accordance with the complete outline drawing. The smaller transformer, with output ratings up to 2000KVA and insulation levels up to 30KV is generally delivered as complete assembly condition for easy installation at the site.

Transformers that were shipped with a low oil level or without oil should be filled with oil within 4 weeks of their arrival at site if the nitrogen gas or dry air filling becomes ineffective.

At this time the conservator, piping, buchholz relay and dehydrating breather must be fitted.

There are two procedures for installing and oil filling a transformer.

6.2 Caution for transformer installation

6.2.1 Work in the tank

When opening the transformer tank, care must be taken to prevent moisture or dirt entering the transformer or moisture condensing in the transformer. If wet air enters the transformer, it may be cooled by the tank wall below its dew point and condensed, so it will reduce dielectric strength of the transformer. If internal working or inspection is required, nitrogen gas should be discharged by vacuuming and dry air with 99.95% purity must be filled. Dry air should be supplied through hand hole during working or inspection. Care especially must be taken not to drop tools or foreign substances. It is recommended that tools used in the tank be tied to worker with a cord. When the work in the tank is completed, the inside of the tank should be inspected. For inside cleaning, the dry, clean and lint-free cloths should be used.

Do not enter any transformer until the gas in the tank is replaced by dry air.

Oxygen content inside transformer must be at least 19.5%∼24% before entering for inside inspection. The oxygen content must always be checked. Oxygen

Only installed manholes or hand-holes should be opened to prevent contamination. Cover all other openings with dry, clean, pressboard or plastic.

This will prevent wet air from coming into the unit.

- 28 -

6.2.2 Weather

a. Do not open or leave opened during periods of rain or during rapidly changing weather conditions, unless the opening is completely protected from the weather through a double door lock.

b. The number of openings and the exposure time should be kept to a minimum especially of the ambient humidity exceeds 60%

6.2.3 Clothing

Never enter a transformer with dirty or wet clothing. Clean cloth and shoe covers or nitric rubber overshoes must be worn.

6.2.4 Pressure Relief

Do not open any cover or fittings unless zero gauge pressure exists inside the transformer.

Always relieve internal pressures slowly through valve.

Failure to relieve pressure could cause the part being removed to become a hazardous flying object.

6.2.5…