GE PHI 530.1425.2500 Manual

Rev. Description Date Prepared Controlled Service
Approval
0 Emission 06/02/2017 G.Testin P.Cardano M.Campana
1 Rev. Rated filling pressure value, Outline drawings & relevant
doc.18/04/2
18/04/2017 G. Testin P. Cardano M. Campana
2 Rev. Transport pressure gauge installation, management &
check list
14/03/2018 G. Testin P. Cardano M. Campana
IS 2664 GB
GE Energy Connections reserves all rights in this document and in the information
contained therein. Reproduction, use or disclosure to third parties
without express authorization is strictly forbidden.
© 2011 GE Energy Connections
HVDC TRANSFORMER BUSHINGS
PHI 530.1425.2500
PHI 265.850.1500
Kepco project
OPERATING
AND
MAINTENANCE INSTRUCTIONS

HVDC TRANSFORMER BUSHINGS
PHI 530.1425.2500
PHI 265.850.1500
Kepco project
IS 2664 GB
Page 2of 70
LIST OF CONTENTS
1 Introduction................................................................................................................................ 3
2 Safety ........................................................................................................................................ 3
2.1 Safety prescriptions and operative information.................................................................... 4
3 Transport and storage conditions............................................................................................... 6
3.1 Transport conditions ........................................................................................................... 6
3.2 Lifting conditions ................................................................................................................. 7
3.3 Storage conditions .............................................................................................................. 7
4 Technical characteristics............................................................................................................ 8
5 Bushing preparation................................................................................................................... 9
5.1 Bushing unpacking ........................................................................................................... 10
5.2 Bushing controls activities at the arrival ............................................................................ 11
5.3 Tools and equipment ........................................................................................................ 12
5.4 Lifting procedure............................................................................................................... 14
5.4.1 Lifting tools installation............................................................................................... 14
5.5 Bushing installation on the transformer ............................................................................. 15
6 Bushing oil characteristics and accessories ............................................................................. 17
6.1 Oil pressure vs average temperature ................................................................................ 18
6.2 Oil pressure gauge ........................................................................................................... 18
6.3 PHI Bushing filtering & bypass valves............................................................................... 19
7 Transformer turret arrangement and oil parameters................................................................. 21
8 Gas SF6 characteristics and gas filling instructions.................................................................. 24
8.1 Gas first filling operation and control of alarm and tripping signals.................................... 25
8.2 Gas refilling during the bushing normal operation ............................................................. 25
8.3 Gas characteristics before the energization ...................................................................... 26
9 Procedure for bushing gas compartment decontamination....................................................... 26
9.1 Procedure for bushings equipped with the gas filling station ............................................. 26
9.2 Procedure for bushings not equipped with the gas filling station ....................................... 27
10 Gas density monitor ............................................................................................................. 27
11 Power factor tap ................................................................................................................... 28
12 Voltage divider unit............................................................................................................... 29
13 Composite insulators maintenance....................................................................................... 30
14 General maintenance plan ................................................................................................... 32
15 Disposal at the end of life ..................................................................................................... 34
Appendix 1 – Bushing outline drawing ............................................................................................ 36
Appendix 2 – Electrical scheme ...................................................................................................... 38
Appendix 3 – Lifting tools ................................................................................................................ 52
Appendix 4 – Gas density monitor Electronsystem ......................................................................... 60
Appendix 5 – Oil pressure gauge .................................................................................................... 65
Appendix 6 - Composite insulators maintenance and repairing....................................................... 66
Appendix 7 – Bushing installation check list.................................................................................... 67
Appendix 8 – Gas filling check list................................................................................................... 70

HVDC TRANSFORMER BUSHINGS
PHI 530.1425.2500
PHI 265.850.1500
Kepco project
IS 2664 GB
Page 3of 70
1 Introduction
These instructions are applicable to the hybrid type HVDC transformer bushings of the PHI series and provide
all information relevant to:
•Safety aspects.
•Transport conditions.
•Technical characteristics.
•Controls at the arrival and preparation activities.
•Lifting and installation operation.
•Oil filtering and recirculation.
•Gas filling operation.
•Service and maintenance plan and procedures.
The PHI bushings are manufactured and tested in compliance with the following standards:
IEC 62199 – 2004 Bushings for DC application.
IEC 60137 - 2003 Insulated bushings for alternating voltages above 1000V.
2 Safety
In this document important safety requirements are highlighted by the word WARNING. Mandatory safety
actions are evidenced by the word OBLIGATION,while important operative instructions are evidenced by the
word NOTE.
This manual must be available to the personnel responsible of the installation, operation and maintenance of
the bushings.
The transformer bushing is a high voltage DC device, filled under pressure with SF6 gas, that realizes the
interface between the transformer and the convertor. The arrangement of the bushing allows the passage
through the wall of the valve building.
The preparation and the installation of the bushing, the oil filtering and treatment process, the gas filling and the
periodical maintenance operations must be performed by qualified operators.
They have to be trained to operate in accordance with the guidelines described in this instruction manual.
Every operator must use the prescribed tools and the prescribed safety devices.
Non-compliance with the following procedures and instructions can result in serious and dangerous situations
for the personnel and in risks of damages of the equipment and the property and environment pollution.

HVDC TRANSFORMER BUSHINGS
PHI 530.1425.2500
PHI 265.850.1500
Kepco project
IS 2664 GB
Page 4of 70
Main safety risks related to the bushing handling and its operative conditions are:
•Transport and handling of heavy and large parts.
•Lifting and moving of heavy and not well-balanced goods.
•Work operations under the crane and suspended materials.
•Work at height. All operation at height must be performed on a suitable certified platform.
•Risk of falling down of heavy parts during the installation.
•Risks deriving from un-proper balancing of the masses that can cause un-expected rotation during the
installation of the bushing on the transformer or on the test turret.
• Risks related to the use of un-proper tools or wrong operations.
•Risks deriving from un-proper installation or operation on the bushing when filled by SF6 gas at rated
filling pressure (risk of explosion).
•Environmental risks related to dispersion of SF6 gas in the atmosphere or mineral oil in the environment.
•Severe electrical shock risk related to the extremely high voltage DC level of the equipment.
•Severe electrical shock risk due to un-proper realization of the bushing grounding connections.
•Severe electrical shock risks deriving by the fact that the composite insulator and the other main parts of
the bushing remain electrically charged at high voltage for a long period of time after the plant de-
energizing and the bushing grounding. Before starting any work on the de-energized bushing, check the
discharge by touching all surface of the composite insulator and all other parts of the bushing with an
insulated grounding rod which length must be ≥3m. During this operation the workers must wear
protective insulating gloves and boots and helmets with protective transparent face shield.
2.1 Safety prescriptions and operative information
The following notes are mandatory for personnel involved in transformer bushing installation. All problems
detected during the bushing installation must be reported to the Foreman and to GE Energy Connections RPV
Supervisor.
WARNING: The PHI bushing is a gas pressurized device. Operations on valves,
pressure gauges, pipes, protective devices must be performed by qualified operators,
with the proper equipment.
Foreman and operators have to take careful for handling the pressurized equipment.
It is strictly forbidden to move, lift and install equipment that is under pressure. Check
through appropriate gauge that the gas side of the bushing is at a pressure less than
or equal to 0.125 MPa abs (0.25 bar gauge) before operate on it.
WARNING:
Never use damaged or not certified lifting equipment.
WARNING:
Lifting equipment must be under a planned maintenance routine.
Operators must be qualified and properly trained.
WARNING:
Work in quote will be done by trained operators on adequate and certified moving
platforms. Workers that will operate in quote must use the prescribed safety devices
and in addition they must wear certified safety harnesses.
WARNING: Lifting equipment will be entrusted only to specialized personnel, kept in
efficiency and clean. Identification and rating plates must be always present and visible
on the equipment. Do not use the equipment when rating plates are missed or
unreadable.
WARNING: The equipment is filled with SF6 gas. This gas is not environmentally
friend. Always use an appropriate gas filling machine that allows the SF6 recovery.
Avoid any dispersion of the gas in the environment.

HVDC TRANSFORMER BUSHINGS
PHI 530.1425.2500
PHI 265.850.1500
Kepco project
IS 2664 GB
Page 5of 70
WARNING: PHI type bushing is filled and impregnated with mineral oil. Managing oil
equipment and processing the oil must be done by qualified operators. Immediately
remove oil stains on the shop floor, stairs, elevating platforms and equipment. Fix oil
leakages from pipes, equipment and tools in order to prevent pollution and accidents.
Provide adequate equipment for oil absorption or oil spills containment. Immediately
inform the shop Responsible and the Authorities in case of heavy oil spills. Avoid
dispersion in the environment. Oil is a flammable material. Provide adequate firefighting
equipment and extinguishers.
OBLIGATION: The use of a safety helmet is mandatory during the use of the lifting
equipment and during all bushing installation operation. The helmet must comply with
the standard EN 397.
OBLIGATION: During all activities, it is mandatory to use safety gloves complying with
the standard EN 388 with performance index not less than 4131.
OBLIGATION: During all activities, it is mandatory to use safety shoes complying with
the standard EN 345 with of performance index not less than S2.
OBLIGATION: During works activities carried out at a height greater than 2m it is
mandatory to use a safety harness in accordance with the standard EN 361, equipped
with a snap-hook in accordance with the standard EN 362, a rope in accordance with
the standard EN 354 and a shock absorber in accordance with the standard EN 355.
Tools and pieces of clothes or no-fibre fabric used during the assembly must be clean.
The composite insulators sheds are made by silicone that can be mechanically damaged if not properly
handled. Protect the insulators with clean plastic foils during the bushing installation and immediately report
to Foreman and to GE Energy Connections RPV Supervisor any event which could have caused a damage
of the composite insulators.

HVDC TRANSFORMER BUSHINGS
PHI 530.1425.2500
PHI 265.850.1500
Kepco project
IS 2664 GB
Page 6of 70
3 Transport and storage conditions
The bushing is shipped in a wooden box suitable for marine transport, designed to provide protection of the
bushing in accordance with the specified transport conditions.
The complete crate must be lifted, loaded on vehicles and transported with great care to prevent damages of
the bushing or its accessories. Stacking of crates is not allowed. Shock indicators are fixed on the crate walls.
GE Energy Connections RPV will not respond of any damage due to un-proper operations.
The total mass of the bushing packed and crates dimensions, as a function of the type, are listed in Table 1.
Centre of gravity and lifting points are painted on the crate walls. Top electrostatic shields are shipped in
separate crates.
Bushing type Crate mass
[kg]
Dimensions
L x W x H
[cm]
PHI 530 kV 4300 1020x170x220
PHI 265 kV 2500 800x120x220
Table 1 – Bushing mass and crate dimensions by bushing type
3.1 Transport conditions
The bushing can be transported by truck, ship, airplane. The bushing is filled with SF6 gas at a pressure of 0.125
MPa abs (0.25 bar gauge) and mineral oil at a pressure of 1 bar gauge at 20°C (see curve in Figure 8).
To check the gas pressure during the transportation or the long storage conditions, the bushing is equipped with
a Transport pressure gauge (see Figure 1) installed on a Dilo valve. This device must be removed during the
installation phase on the transformer, before the bushing filling at rated pressure and it has to be reused for the
bushing shipment at site.
In order to prevent dangerous movement of the crate during the transport it is responsibility of the transport
company to carefully fix it on the vehicle by suitable retain systems like ropes, synthetic pulling bands or any
other method.
The maximum allowed transport acceleration along the three axis is 5g (49.05 m/s
2
). In case of transport by
truck along very bad roads (‘bumpy roads’) the speed must be adequately reduced to max 30 km/h.
Trucks to be used for road transportation must have a platform of sufficient dimensions to accommodate the
overall crate. Crate overhang from any platform and hauling are not allowed.
The top of the crate is protected by a PE tarpaulin suitable for protection from rain. During the transport by road
or ship the good must be protected from rain, sea water and other exceptional environment conditions by
additional tarpaulins, not provided by GE Energy Connections RPV, suitable to cover completely the crate.
Sea transportation on the ship main deck is allowed providing the above mentioned additional protection.
Transportation in ship hold is preferred.
Figure 1 – Transport pressure gauge
WARNING: The Transport pressure gauge must be removed from the bushing before the gas filling operation
at rated pressure. It must be used only at the transport pressure value. Higher pressures will damage it.

HVDC TRANSFORMER BUSHINGS
PHI 530.1425.2500
PHI 265.850.1500
Kepco project
IS 2664 GB
Page 7of 70
3.2 Lifting conditions
Lifting operation must be done by qualified operators and with certified ropes and equipment.
Lifting points are indicated on the crate and are reinforced by steel plates (see Figure 2). Lifting the crate by
fork lift is not allowed.
Figure 2 – Crate lifting arrangement
WARNING: The centre of gravity point of the crate could be not perfectly centred respect the crate geometry.
Care must be taken during the lifting and moving operation to prevent dangerous situations, damages or heavy
shocks to the good.
3.3 Storage conditions
For short period storage, up to 1 month, the package can be stored outside, just protected by a suitable additional
tarpaulin. The storage area must have a concrete floor made in such a way to ensure a sufficient drainage of
water.
For long time storage, it is necessary that the whole crate is placed inside a suitable warehouse and that a
periodical check, every six months, of the bushing, the gas pressure and of relevant accessories will be
activated.
In this case, it is also recommended to increase the gas pressure to 0.5 bar gauge (0.150 MPa abs).
GE Energy Connections RPV must be informed concerning the activation of the long storage condition.
The periodical controls must verify the bushing conditions, the gas pressure and its dew point and the overall
status of the electric instruments, the accessories and tools. All data must be recorded in a specific check list.
NOTE: Violation of the above prescriptions will cause the immediate termination of the warranty.
If the bushing is installed on the transformer and the complete transformer is stored as spare unit, it is necessary
to perform the following actions:
•Set the gas pressure to 0.5 bar gauge (0.150 MPa abs).
•Protect the composite insulator with a PE double thickness bag.
•Remove the top toroids and wrap them in bubble PE foils then put them in a suitable wooden box to be
stored in a covered warehouse.
•Record the gas pressure and the oil pressure and the ambient temperature for future reference.
•Control and protect the pressure gauges, PF tap and relevant accessories with PE foils and silica gel
bags.
•Seal all cable passages from the electrical cubicles and protect them with PE foils and silica gel bags.
•Activate a periodical check, at least every six months, to check the status of the bushing, the gas
pressure that must be ≥0.3 bar gauge (0.13 MPa abs) and oil pressure.

HVDC TRANSFORMER BUSHINGS
PHI 530.1425.2500
PHI 265.850.1500
Kepco project
IS 2664 GB
Page 8of 70
4 Technical characteristics
PHI bushings are based on the hybrid technology. This means that the bushing is based on two different
insulation technologies: The first, based on an Oil Impregnated Paper (OIP in the document) grading capacitor,
realizes the interface with the transformer. The second, based on a gas insulated section, realizes the interface
to the converter plant.
The bushing, filled at rated filling pressure with pure SF6 gas, is designed to operate at low temperatures down
to -25°C.
The Hybrid solution offers the following advantages:
•Complete separation between the gas compartment and the transformer turret. Gas leakages to the
transformer are not possible and they are detected by suitable pressure gauges at the level of the OIP
capacitor section.
•Full prevention of transformer oil spills into the valve hall due to the particular bushing structure.
•The mineral oil inside the grading capacitor OIP section provides an optimum cooling of the conductor
with excellent performances in case of high current ratings and harmonics presence.
•The grading capacitor winding is 100% protected from the risk of pollution during the bushing installation
on the transformer, as it is fully sealed by special fibreglass barriers.
Next Table 2 reports the main electrical technical characteristics of the two bushing types and Table 3 reports
the design environmental conditions. The complete outline drawings of the two bushing types are shown in
Appendix 1.
Bushing type PHI 530.1425.2500 PHI 265.850.1500
Voltage ratings
Rated continuous d.c. voltage per valve bridge U
dm
Number of six pulses bridges in series N
Rated continuous a.c. voltage
Maximum continuous a.c. voltage U
vm
265
2
220
230
265
1
220
230
kVdc
kV line to line
kV
rms
Current rating
Rated current
Distorted operation harmonics current
2500
See tech spec
.
1500
See tech spec.
Arms
Short circuit level 34 34 kApk
Rated frequency 60 60 Hz
Lightning impulse withstand (BIL) 1425 850 kVpk
Chopped wave 1567.5 935 kVpk
Switching impulse dry withstand (SIL) 1217 745 kVpk
DC 2h voltage test 964 508 kVdc
Polarity reversal test 688 308 kVdc
Power frequency withstand (1 min) 679 405 kVrms
AC PD test (1 hour) 715 391 kVrms
Rated filling pressure @ 20°C 0.63 0.63 MPa abs
Table 2 – Bushing electrical characteristics

HVDC TRANSFORMER BUSHINGS
PHI 530.1425.2500
PHI 265.850.1500
Kepco project
IS 2664 GB
Page 9of 70
Bushing type PHI 530.1425.2500 PHI 265.850.1500
Ambient conditions:
Max valve hall temperature
Min valve hall temperature
Max transformer oil temperature
+ 50
+5
+
85
+ 50
+5
+85
°C
°C
°C
Pollution condition
Indoor Very low Very low
Minimum creepage distance
Indoor >10080 >4125 mm
Minimum arcing distance
Indoor >4728 >2994 mm
Seismic condition 0.225 0.225 g
Altitude above sea level (up to) <1000 <1000 m
Installation angle 23°-33° 23-°40° From horizontal
Table 3 – Environmental conditions
5 Bushing preparation
All operators involved in components unpacking and assembly have to be careful not to damage the objects.
During the unpacking operation, it is necessary to check that all components supplied by GE Energy
Connections RPV are available and not damaged during the transportation.
All incoming goods must be stored in a covered area and prepared for the installation.
At the arrival, the crate must be inspected. Any damage of the crate or indication of the visual external shock
indicator (see Figure 3) must be reported to the Foreman and GE Energy Connections RPV Supervisor.
Figure 3 – Visual external shock indicator
A detailed control check list is listed in Table 4 at Paragraph 5.2.

HVDC TRANSFORMER BUSHINGS
PHI 530.1425.2500
PHI 265.850.1500
Kepco project
IS 2664 GB
Page 10 of 70
5.1 Bushing unpacking
The crate is provided with a lid made in sections. Each section is provided with four lifting eyebolts placed at the
four corners.
On the crate side walls, there are two lines of screws. The upper line of screws is those that hold the lids.
Remove all the upper screws that hold the cover to the crate walls (see Figure 4).
Connect the lifting ropes to the eyebolts and remove the three lid sections (see Figure 5).
After the removal of the top lid, remove the crate upper wooden beams that provide support the top lid, then
remove the plastic foils that covers the bushing but do not remove the PE layer wrapped on the composite
insulator.
Inside the crate, the bushing is locked at the level of the central and the top flange by locking belts and bolts.
Figure
4
–
Lid
sections
locking screws
Figure
5
–
Removing the lid sections
WARNING: Composite insulator and the oil side fibreglass cone are protected by a PE plastic foils. Remove the
protection on the composite insulator only just before the transformer energization. The oil side cone protection
must be removed only just before the installation of the bushing on the transformer turret.
WARNING: It is not allowed to step on the composite insulators. The silicone sheds can be seriously damaged.
WARNING: The centre of gravity point is not centred respect the bushing geometry. Care must be taken to
compensate the mass unbalancing before and during lifting operations.
WARNING: Never wrap ropes (i.e. ‘tie’ lifting method) around the silicone sheds. The composite insulators will
be seriously damaged.
Remove these
screws
Do not remove
these screws

HVDC TRANSFORMER BUSHINGS
PHI 530.1425.2500
PHI 265.850.1500
Kepco project
IS 2664 GB
Page 11 of 70
5.2 Bushing controls activities at the arrival
Item
Control
Description
Actions on problems
1 Crate inspection Check for evidence of shocks on the crate
structure.
Check the status of the external shock
indicators.
•Take pictures of
evidences.
•In case of deviations
notify the Foreman and
the GE Energy
Connections RPV
Supervisor.
•Continue with the internal
inspection.
2 Gas filling residual
pressure and gas dew
point
Check gas pressure:
0.11 MPa abs ≤Gas pressure ≤0.125 MPa abs
(0.1 bar gauge ≤Gas pressure ≤0.25 bar gauge )
Check gas dew point ≤-30°C @
atmospheric pressure.
•Record the pressure
value and the gas dew
point
•In case of deviations
notify the Foreman and
the GE Energy
Connections RPV
Supervisor.
•Continue with the
inspection but:
Wait for instructions
.
3 Oil pressure Check if the oil pressure ≥1 bar gauge
@20°C (see Figure 8).
•Record the pressure and
the average bushing
temperature.
•In case of deviations
notify the Foreman and
the GE Energy
Connections RPV
Supervisor.
•Check for oil leakages.
•Continue with the
inspection but:
Wait for instructions
.
4 Bushing inspection Check the integrity of the oil side cone.
Check the bottom terminal and the
MultiContact blades.
Check the flange and the gas and oil
pressure gauges.
Check the oil expansion vessels, the oil
pipes and all oil valves.
Check the wiring and the electrical circuit.
Check the integrity of the valves warranty
seals and red warning tags.
Check for oil leakages.
Check the status of the composite insulator
and the silicon sheds.
Check the top terminal.
Check the toroids and relevant
accessories.
•Take pictures of the
various inspected parts.
•In case of deviations
notify the Foreman and
the GE Energy
Connections RPV
Supervisor.
•Continue with the
inspection but:
Wait for instructions.
Table 4 – Bushing controls activities at the arrival

HVDC TRANSFORMER BUSHINGS
PHI 530.1425.2500
PHI 265.850.1500
Kepco project
IS 2664 GB
Page 12 of 70
5.3 Tools and equipment
The next Table 5 and Table 6 show the main parts of the lifting tool for the PHI 265 and the PHI 530 bushings.
The complete assembly drawing relevant to these two tools are included in Appendix 3
Item Description Reference code WLL
[
kg
]
Quantity Picture
1 Lifting plates RX380468-10
RX380468-11 1000 1 set
2 Tirfor T516 D
including steel rope RX38A162-01 1600 1
3 Lifting lug DN22 RX1A013-22 2000 1
4 Front plate lifting kit RX380463-02 2000 1
5 Front lifting rope Not included >1000 1 Not included
6 Bolts, nut &
washers kit - - 1 set -
Table 5 – PHI 265 Lifting and erection tool main parts
Item Description Reference code WLL
[kg]
Quantity Picture
1 Lifting plates RX38A164-01
RX38A164-02 2500 1 set
2 Tirfor T532 D
including steel rope RX38A162-02 3200 1
3 Rotating lifting lug
ADA 12 RX22A060-10 1000 1
4 Front plate lifting kit RX380464-03 3000 1
5 Front lifting rope Not included >3000 1 Not included
6 Bolts, nut &
washers kit - - 1 set -
Table 6 – PHI 530 Lifting and erection tool main parts

HVDC TRANSFORMER BUSHINGS
PHI 530.1425.2500
PHI 265.850.1500
Kepco project
IS 2664 GB
Page 13 of 70
Bolts and nuts of the lifting tools must be tightened at torque values listed in the following Table 7.
Screw / nut
type
Tightening
Torque
[Nm]
M12 60
M24 229
M30 460
Table 7 – Screws and nut tightening torques
To lift and install the bushings on the transformer the lifting crane shall have the following minimum
characteristics:
Solution with one overhead crane
•Single grinder crane.
•Crane capacity ≥2.5 t.
•Hoist lifting height ≥12m.
•Slow hoisting speed ≤1.3 m/min.
Or, as an alternative:
N. 1 mobile telescopic crane with the following technical characteristics:
•Single crane.
•Lifting boom working length ≥17m.
•Hoist lifting height ≥12m.
•The capacity of the crane must comply with the characteristics indicated in with the following Figure 6.
The crane operative working conditions must be within the limits set by the red area.
Figure 6 – Mobile crane working characteristics

HVDC TRANSFORMER BUSHINGS
PHI 530.1425.2500
PHI 265.850.1500
Kepco project
IS 2664 GB
Page 14 of 70
5.4 Lifting procedure
This paragraph refers to the bushing removal from the transport crate. All references are to the tool lists in Table
5for the PHI 265 and Table 6 for the PHI 530 and to the drawings RX380466-01 and RX380466-02 in Appendix
3
WARNING: Before proceeding with the installation of the bushing on the transformer, it is necessary that the
bushing gas pressure is set at the transport value (0.25 bar gauge, 0.125MPa abs).
5.4.1 Lifting tools installation
To install the lifting tools, it is necessary to follow this procedure
Remove the crate walls.
Check that the bushing pressure is set
at the transport pressure level.
•Install the Lifting Plates (Item 1) on the
bushing flange.
•Firmly tighten the bolts & nuts at the
prescribed torque (see Table 7).
•Install the lifting lug (Item 3) on the
Lifting Plates and lock it carefully.
PHI 265
PHI 530
•Install the Front Plate lifting kit (Item
4).
•Firmly tighten the bolts & nuts at the
prescribed torque (see Table 7).
•Control the correct locking on the
lifting lugs before installing the ropes.
PHI 265
PHI 530
•Install the Tirfor (Item 2) with its built-
in ropes on the Lifting Plates (Item 1).
•Connect the other side of the Tirfor
rope to the hook crane.
•Connect the Front lifting rope (Item 5)
to the Front Plate lifting kit (Item 4).
This side
UP

HVDC TRANSFORMER BUSHINGS
PHI 530.1425.2500
PHI 265.850.1500
Kepco project
IS 2664 GB
Page 15 of 70
5.5 Bushing installation on the transformer
The complete installation operation must be performed in presence of the transformer Manufacturer Foreman
and GE Energy Connections RPV Supervisor.
The transformer turret must be designed to withstand vacuum and provided with proper filtering valves to allow
the oil filling under vacuum and the oil recirculation inside the barrier system
After the bushing installation, the turret final oil filling must be done under vacuum. The oil characteristics inside
the barrier system must comply with the data listed in Table 13.
The residual air trapped inside the turret can be evacuated by the de-aeration screw located on the bushing
flange.
It is under the responsibility of the transformer Manufacturer to guarantee that the interface between the barriers
internal electrical shield and the bottom side of the bushing complies with the installation quote indicated in the
bushing Outline drawing (see Figure 7).
Bushing PHI 265 Bushing PHI 530
Figure 7 – Bushings bottom side and interface quote with the transformer barrier shield
WARNING: Before proceeding with the installation of the bushing on the transformer, it is necessary that the
bushing gas pressure is set at the transport value (0.25 bar gauge, 0.125MPa abs).
NOTE: Check that the oil inside the turret barriers complies with the parameters listed in Table 13.
Here below the complete installation procedure:
•Prepare the transformer turret for the
installation.
•Be careful to avoid any foreign material
from dropping inside the turret during
the bushing installation.
•It is recommended to install on the
flange of the transformer turret
minimum 4 centring pins to ensure the
proper alignment of the bushing with
the insulation pressboard barriers. (not
supplied by GE RPV).
•Start lifting the bushing in horizontal
from its wooden platform.
•Act on Tirfor (Item 2) in order to ensure
the horizontal lifting.
Install the guiding
pins on the
turret
flange
Mandatory interface quote
with the transformer barrier
system
Mandatory interface quote
with the transformer barrier
system

HVDC TRANSFORMER BUSHINGS
PHI 530.1425.2500
PHI 265.850.1500
Kepco project
IS 2664 GB
Page 16 of 70
•Lift the bushing in horizontal position
up to 2 m from the floor.
•Start inclining the bushing by acting on
the Tirfor (Item 2).
•Continuously check during the
inclining operation that the bottom part
of the bushing will not hit the floor or
any other part.
•Check the correct inclination on the
transformer side of the bushing flange
angle by a Quadranfix inclinometer or
by an electronic inclination gauge (not
supplied by GE RPV).
•Control with the same instrument the
effective inclination angle of the
transformer turret flange and adjust
the bushing inclination angle
accordingly by acting on the Tirfor
(Item 2).
•When the bushing axis will coincide to
the turret axis and the inclination angle
is OK, slowly proceed with the bushing
insertion inside the turret.
•By continuously controlling that the
turret and the bushings are aligned,
gradually insert the bushing inside the
transformer turret.
NOTE: During this operation, it is
mandatory to continuously check that the
bushing cone will remain centred respect
the turret flange and the CT coils
arrangement, normally placed inside the
turret.
Check that there are no interferences and
that no damages or scratches occur on the
cone and the metal parts of the oil side of
the bushing. In case of damages,
immediately contact GE Energy
Connections RPV Supervisor and the
Foreman and stop
the operation.
•Complete the installation of the other
bushings and after the completion of
the transformer preparation, install the
electrostatic top shields on the
bushings.
•Fill the bushing with SF6 (see Chapter
8).
•Complete all relevant activities for the
transformer preparation.
WARNING: Before proceeding with the
gas filling operation, remove the
Transport pressure gauge (see
Paragraph
3.1
and
Figure
1
).
Quadranfix
inclinometer

HVDC TRANSFORMER BUSHINGS
PHI 530.1425.2500
PHI 265.850.1500
Kepco project
IS 2664 GB
Page 17 of 70
6 Bushing oil characteristics and accessories
The PHI bushings are filled Nynas Nytro 4000 A mineral oil. The same type of oil must be used in case of re-
filling or oil reprocessing.
At the end of the drying and impregnation process in GE factory, the bushing oil parameters are in accordance
with the data listed in the following Table 8.
Parameter
Limit
Water content by Karl Fisher at 20°C ≤2 ppm
Breakdown voltage on 2.5 mm gap ≥80 kV
Total gas content ≤200 ppm (0.02%)
Total combustible gases < 10 ppm (0.001%)
Power factor at 90°C ≤0.0025
Resistivity at 30°C ≥15 10
12
Ohm x m
Particle content ISO11218 Class 00
Table 8 – Oil parameters for final oil filling and recirculation at the factory production
Concerning the ISO 11218 solid contamination limits classes, next Table 9 summarizes the quantities and the
size limits for each class.
Classes
Maximum Contamination Limits (particles/100ml)
ISO 11218 > 4
µm(c)
> 6
µm(c)
>14
µm(c)
> 21
µm(c)
> 38
µm(c)
> 70
µm(c)
000 195 76 14 3 1 0
00 390 152 27 5 1 0
0 780 304 54 10 2 0
1 1560 609 109 20 3 1
2 3120 1220 217 39 6 1
3 6250 2430 432 76 11 2
4 12500 4960 864 152 22 4
5 25000 9730 1730 306 45 8
6 50000 19500 3460 6012 90 16
7 100000 38900 6920 1220 180 32
8 200000 77900 13900 2450 360 64
9 400000 156000 27700 4900 720 128
10 800000 311000 55400 9800 1440 256
11 1600000 623000 111000 19600 2880 512
12 3200000 1250000 222000 39200 5760 1024
Table 9 – Solid contamination limits classes according ISO 11218
NOTE: The excellent quality of the oil process in the factory is such that the bushing does not require any
additional oil treatment before the transformer tests or before the installation on site.

HVDC TRANSFORMER BUSHINGS
PHI 530.1425.2500
PHI 265.850.1500
Kepco project
IS 2664 GB
Page 18 of 70
6.1 Oil pressure vs average temperature
PHI bushings are sealed and pressurized devices. To compensate the oil volume variation by the temperature,
each unit is provided with a built-in expansion vessel system equipped with internal bellows (Prysmian expansion
vessel).
This expansion system allows to maintain a positive pressure at the minimum expected oil temperature,
generally equal to the minimum specified ambient temperature, and the maximum oil expansion volume related
to the oil maximum average temperature during the bushing operation.
On the basis of the above-mentioned design concepts and the specific technical characteristic of the selected
expansion vessels, the next Figure 8 shows the curves Pressure vs Average oil temperature for the two PHI
bushings.
Figure 8 – Oil pressure vs. average oil temperature
This curve is used in GE Factory to set the proper oil pressure at the end of the bushing production process and
it is also useful to check the bushing status during the operation by controlling the oil pressure on the built-in oil
pressure gauge, see next Paragraph 6.2.
6.2 Oil pressure gauge
To monitor the pressure important parameter each unit is provided by one or more pressure gauges, provided
with electrical contacts (see Figure 9).
The events that can be detected by this pressure gauge are:
•Low oil pressure, related to the possibility of an oil leakage from the oil impregnated paper section.
•High oil pressure, related to an internal fault in the oil impregnated paper section or a gas leakage from
the gas section of the bushing.

HVDC TRANSFORMER BUSHINGS
PHI 530.1425.2500
PHI 265.850.1500
Kepco project
IS 2664 GB
Page 19 of 70
Figure 9 – Oil pressure gauge
Each instrument is equipped with 4 Normally Open micro-switches that provide alarm / tripping signals. Table
10 shows the micro switches purpose and the pressure set up.
Micro switch Description Pressure set up
[bar gauge] [MPa gauge]
Low pressure
Tripping Too low pressure for operation 0.2 0.02
Low pressure
Alarm
Low pressure related to low oil
level 0.4 0.04
High pressure
Alarm
Overpressure inside the OIP
section 2.6 0.26
High pressure
Tripping
Too high pressure inside the
OIP section for operation 2.8 0.28
Table 10 – Alarm and tripping micro switches set-up
The pressure gauge is installed on a ball type valve for easy replacement in case on need and all electrical
cables are wired in the junction box provided with DIN type terminal blocks (see Appendix 2).
Additional information about the oil pressure gauge device are in illustrated in Appendix 5.
6.3 PHI Bushing filtering & bypass valves
PHI bushings are equipped with a special valve system located at the level of the central flange that allows:
•The oil filling under vacuum.
•The oil recirculation for filtering and the oil passage during the normal operation.
NOTE: Operation on the valves must be done by qualified and authorized operators only.
Depending on their specific function, they are named filtering and by-pass valves (see Figure 10). These valves
are installed inside some metallic protrusions on the bushing flange, protected by metal lids (see Figure 11).
The number of valve blocks is related to the size of the bushing.

HVDC TRANSFORMER BUSHINGS
PHI 530.1425.2500
PHI 265.850.1500
Kepco project
IS 2664 GB
Page 20 of 70
The valve blocks can be of two types, the type named Filtering valve block, that includes three different valves
(see Figure 10 a) and the type named By-pass valve block, that includes the by-pass valve only (see Figure 10
b).
a)
Filtering
valve
s
block
b)
By
-
pass valve
block
Figure 10 – PHI bushing valves
Vacuum pump and oil filling and filtering equipment can be connected to the filtering valves through two ¾” BSP
connections placed on the side of each filter valve block. These connections are protected by a removable cap
(see Figure 11).
By-pass valves are placed in both type of blocks and are necessary to ensure the proper oil circulation during
the normal bushing operation. The by-pass valve blocks are not equipped with the ¾” BSP connections.
Next Table 11 describes the correct valve positions as a function of the specific operative conditions on the
bushing.
Operative condition Filtering valves By-pass valves
Oil filling and filtering OPEN CLOSED
Bushing normal operation CLOSED OPEN
Table 11 – Filtering and by-pass valve position
Closed
Open
Closed
Open
Closed
Open
To the pump
To the pump
Filter valve
Filter valve
By-pass valve
Closed
Open
By-pass
valve