ABB Transformer Installation Manual
ABB Transformer Installation Manual
ABB Transformer Installation Manual
Installation manual
1ZVN460100 – B 2 / 18
CONTENT
1.Scope ............................................................................................................................................ 2
2. Safety Notations............................................................................................................................................. 2
3. General .......................................................................................................................................................... 4
4. Preparation .................................................................................................................................................... 4
5. External Assembly ..........................................................................................................................................4
5.1 Radiators, Coolers and Pumps .................................................................................................................5
5.2 Mounting the COPS Oil Preservation System......................................................................................... .5
5.3 Mounting the Nitrogen Blanket Oil Preservation System ..........................................................................5
5.4 Load Tap-Changers...................................................................................................................................5
6. Internal Assembly .......................................................................................................................................... 7
6.1 General .................................................................................................................................................... 7
6.2 Bushing Installation .................................................................................................................................. 8
6.3 De-energized Tap-Changer...................................................................................................................... 9
6.4 Bushing Current Transformers ................................................................................................................. 9
7. Closing the Transformer and Final Dewpoint Measurements ........................................................................10
8. Electrical Tests................................................................................................................................................11
1. Scope
These instructions are intended to help in the installation of transformers to maintain their quality and
reliability.
The recommendations are not a complete manual for all the operations during the field assembly of a large
transformer. It is assumed that competent and responsible supervision and workforce are available for the
job - that good order, cleanliness and personal safety precautions are observed - in accordance with
common sense and local regulation.
The following text highlights a few particular procedures and precautions that are specific for the ABB
Transformer make, or are of critical importance for a good result.
1ZVN460100 – B 3 / 18
2. Safety Notations
Safety notations are intended to alert personnel of possible personal injury, death, or property damage.
They have been inserted in the instruction text prior to the step in which the condition is cited.
The safety notations are headed by one of three hazard intensity levels, which are defined as follows:
1) Danger - immediate hazard that will result in severe personal injury, death, or property damage.
2) Warning - hazard or unsafe practice that could result in severe personal injury, death, or property
damage.
3) Caution - hazard or unsafe practice that could result in minor personal injury, death, or property damage.
1ZVN460100 – B 4 / 18
3. General
The transformer should not be opened during periods of inclement weather or when condensation is forming
on the internal surfaces of the transformer.
Never enter a transformer with dirty or wet clothing. Clean cloth overshoes or nitrile rubber overshoes
should be worn.
All tools, equipment and material entering the transformer shall be listed and checked to verify all material
has been removed from the transformer.
Tools must have working surfaces hardened so that they will not peel or chip during normal use; also,
working surfaces must not be coated in any way such as painting or plating. Tools that are polished metal or
have black oxide body finish are preferred.
To prevent accidental disassembly during normal use, all tools with movable parts must use double side
flush-riveted joints and or all fasteners or moving parts must be retained by staking or deforming the last
thread by welding or coating.
Tools such as hammers and screwdrivers must have one piece heads. Molded-on plastic or fiberglass
handles are preferred; if the handle is wood, it must be retained by a wood or plastic wedge.
Nameplates or tags attached to tools should be removed. If a nameplate is necessary for tool identification,
the plate must be non-metallic and be secured with non-conducting tape.
While the transformer is open, do not permit anyone access to the transformer until they have emptied all
pockets, checked for loose objects, and removed watches, rings, and other objects.
Dry air must be used to ventilate the inside of the tank when it is opened for internal fitting. The air must
have a dew point less than -40°C and sufficient airflow for the number of operators in the tank must be
maintained.
Do never use nitrogen or other gases than air for ventilation.
Nitrile gaskets should be changed during the assembly operations. New gaskets are provided with
transformer detail parts. Dumbbell gaskets used for Tap-Changer inspection doors can be reused. They are
to be compressed to 5/16” (8mm) when resealing the doors.
The mechanical relief devices shall be installed prior to beginning the assembly operations to prevent
excessive pressure build-up on the tank.
The transformer tank shall be grounded prior to beginning any assembling operations.
4. Preparation
The transformer shall be moved into position on the substation pad and the base should be leveled. Install
shims under the base for leveling if necessary.
The transformer base shall be supported on the foundation pad or piers as noted on the transformer base
drawing detailed on the transformer outline drawing.
The transformer foundation should be prepared so that the transformer shall have adequate air circulation
necessary to cool the transformer.
5. External Assembly
The items removed and shipped separately are listed on the outline drawing, the outside assembly drawing,
or packing list. The items generally removed and shipped separately are the bushings, cooling equipment,
forced oil pumps (if the transformer has an FOA rating), arresters and arrester mounting brackets and the
sudden pressure relay.
The number of accessory items removed will vary depending on the physical size of the transformer.
1ZVN460100 – B 5 / 18
All air or gas fittings and all oil fitting joints that are preassembled at the factory must be checked for leaks
and resealed.
The radiators or coolers should be installed on the transformer the same day they are opened. Do not permit
thecooling apparatus to stand exposed after opening for inspection. The detailed illustrations for mounting
and pipingarrangements will be shown on the outside assembly or the outline drawings.
Use new gasket material when installing the radiators, coolers, or pumps.
Do not install the connected piping between the main tank and the COPS system until the vacuum filling
process of the main tank has been completed.
General
The UVT, UTT and RMT-1 Tap-Changers are usually shipped mounted on the transformer. The UZE and
UZF Tap-
Changers are also shipped mounted on the transformer.
1ZVN460100 – B 6 / 18
The compartment for Tap-Changers such as the Reinhausen M, T, and G and the ABB type UCG, UCL will
be removed for shipment unless shipping dimensions allow the compartment to remain attached to the
transformer or the Tap-Changers are mounted within the main tank. Temporary shipping braces are
sometimes used in the Tap-Changer compartment if it remains on the transformer. These braces will be
shown on the internal assembly drawing. The braces must be removed before the Tap-Changer is placed in
service.
WARNING
Before placing Tap-Changers in service, read the appropriate Tap-Changer instruction leaflet. The leaflets
are included in the transformer instruction book. Always follow the inspection and filling instructions given in
the Tap- Changer instruction leaflet.
Follow the taping drawings included in the instruction book for the transformer. This drawing shows where the
capacitor tissue is applied and how to apply the crepe tape over the capacitor tissue and lead.
Remove all items used during taping the leads before you close the Tap-Changer compartment.
Before final oil filling and placing the Tap-Changer in service, check the operation of the Tap-Changer as noted in
the instruction book.
6. Internal Assembly
6.1. General
When opening the transformer, take necessary precautions to prevent moisture or dirt from entering the transformer
or moisture condensation in the transformer.
Necessary confined entry procedures should be followed in compliance with company policy or local regulations.
WARNING
When transformer has been shipped with nitrogen, the gas should be replaced with dry air prior to making any
entrance into the tank. The oxygen content must be at least 19.5% prior to entering the tank.
To remove the nitrogen, it is advisable to pull vacuum to fully remove all nitrogen and break the vacuum with dry air.
CAUTION
Be certain the internal pressure in the transformer is a zero gauge before opening the manhole cover.
Open the transformer at the manhole cover. It is preferred to have only one manhole open at a time. It is also
recommended that the tank opening be covered with clear plastic or a tarp.
Purge the air hoses with dry air from the supply to remove any moisture and dirt in the hoses prior to use. Make the
connections for the dry air supply in the tank space below the working level in the tank.
WARNING
CAUTION
To prevent contamination of the transformer, only the manhole and the opening for the item being
installed should be opened. Cover all other openings with dry pressboard or a clean plastic sheet. This
will also minimize the flow of dry air from the unit.
Start the air flow into the transformer. The volume must be sufficient to maintain continuous air flow outward
through the tank openings.
1ZVN460100 – B 8 / 18
CAUTION
Failure to disconnect the leads from the temporary shipping braces before the blind flanges or shipping
covers are lifted can cause damage to the leads, bridge structure and associated coils, and may necessitate
return of the transformer to the factory for repair and retesting.
The bushings removed for shipment should remain in the shipping crates until they are required for the
transformer assembly provided that the shipping crates maintains a 7 Degree angle of inclination. Note the
requirements in the bushing instruction leaflet for temporary storage. Clean the bushing thoroughly before
installing it in the transformer. It is recommended to perform a power factor and capacitance test of the
bushings as noted in the bushing instruction leaflet prior to installation in the transformer.
Install the bushings in the transformer. When a draw-through-lead or draw-rod design is used, this will be
noted on the outline drawing. The procedure for installing the bushing and connecting the leads is described
in the bushing instruction leaflet. For bottom connected bushing designs, the connection details will be shown
on the outline drawing or the internal assembly drawing. Ground the external bushing terminals after they are
installed and connected.
The inside assembly drawings or taping sketch furnished with the instruction book contain taping
requirements and lead clearances. The internal assembly drawings identify all internal items requiring field
taping.
Non-metallic bolts, nuts and studs are sometimes used on insulation structures. Nuts of this type should be
tightened to a snug fit only since breakage or thread stripping may occur. Bolts and studs installed at the
factory will either have the nuts cemented on or use a second nut as a jamb nut so that retightening should
not be necessary.
1ZVN460100 – B 9 / 18
CAUTION
If the exposure time has been excessive or there are others factors that suggest the transformer may have
been exposed to excessive moisture contamination, then it is advised that transformer be evacuated to 2
Torr (.266 Pascal) or less and held for 4 hours. The vacuum shall then be broken with dry air or nitrogen until
the pressure reaches 20 kPa 3 PSI (.2 bar)
The transformer shall remain under pressure for at least 12 hours until equilibrium is reached, and then
measure the dewpoint. If the surface moisture is less than 0.8%, based upon the dewpoint of the gas and
the insulation temperature, proceed with the final vacuum filling procedures. If the dewpoint is unacceptable,
the transformer insulation must be dried.
When taking dewpoint measurements, it is advisable to take the measurement in the early morning hours
prior to sunrise. When this is done, the insulation temperature can be taken to closely match the gas
temperature. When taking the dewpoint during periods of extreme ambient temperature variation or during
the afternoon hours, the insulation temperature should be measured directly after the dewpoint is taken
1ZVN460100 – B 11 / 18
8. Electrical Tests
If the following electrical tests have not been made as part of the receiving inspection, make the following
tests before beginning any oil filling procedures. Please refer to the “Site test and commissioning”
(Paragraph 11)
CAUTION
If the transformer tank is not filled with oil, the test voltage on the windings must be limited to
1,000 volts or less.
1. Measure the power factor and capacitance of the bushings before installing the bushings in the
transformers.
Refer to the appropriate bushing instruction leaflet for the proper procedures. (Optional Test)
2. Measure the core resistance to ground.
The minimum acceptable value is 500 kOhm when measured at 1000 volts.
3. Measure the core clamp resistance to ground.
The minimum acceptable value is 500 kOhm when measured at 1000 volts.
4. Measure the ratio of all bushing current transformers and verify proper polarity..
5. Check the turns ratio of the transformer (TTR) at all tap positions.
The measured turns ratio should be + 0.5 % of the nameplate voltage ratio.
1ZVN460100 – B 12 / 18
CONTENT
1.General.............................................................................................................................................. 12
2. Different types of oil, characterised by origin and chemical composition.....................................................….. 12
2.1 Inhibited oils.............................................................................................................................................. 12
3. Supplier certificate ............................................................................................................................................. 13
4. Sampling on site. .............................................................................................................................................. 13
5. Testing of samples. Oil characteristics. ............................................................................................................ 14
6. Treatment of the oil before filling the transformer.............................................................................................. 15
1. General
This Instruction lists the main quality requirements that are to be fulfilled when transformer oil is delivered to
an installation site for filling into the transformer.
The oil shall fulfil the requirements in material specification.
The user of the transformer may have issued an oil specification of his own, or may have specified oil of a
particular trade mark from an internationally recognised supplier. This may add to, but does not relieve any of
the requirements specified in this Instruction. They are necessary for long-time reliable operation of the
transformer.
Note. The chemical short name for the usual inhibitor substance is DBPC (di-butyl-para-cresol).
This must not be confused with the objectionable class of compositions, called PCBs (poly-
chlorinated biphenyls - "askarels"
DBPC is not environmentally noxious - as a matter of fact it has an alternative use as a stabiliser
agent in foodstuffs.
3. Supplier certificate
The supplier of transformer oil shall guarantee, and supply a certificate that the oil, delivered from the refinery,
fulfils the list of requirements specified in the actual ABB material specification 1ZBA 117001-1, 2, 3 or 4.
The quality of the oil at delivery condition shall be guarantied through certificates of the oil characteristics
from the oil in the transportation containers or through sample tests.
This certificate or tests shall include Power factor/Dissipation Factor at 100°C or 90°C and the Interfacial
Tension against
water. These tests are to assure that no contamination of the oil has occurred during transportation and
storage.
In the purchase contract for the delivery to the site, it may also be agreed to sample the oil on arrival for
additional laboratory investigation to verify the quality of the material as delivered.
4. Sampling on site
Bulk deliveries of oil in tank trailers are normally scheduled to arrive just in time for the filling procedure, and
will be checked right away. Oil in drums will be kept in storage with unbroken seals up to the time when filling
procedures are to be commenced.
The drums shall be stored in horizontal position, with the openings horizontal (at same height).
When the oil is delivered in drums and if it has to be tested the extent of sampling shall be as follows
When the oil is delivered in tank trailers: Take two samples from each separate tank compartment.
Most of the properties of insulating oil are affected by impurities, particularly water. Care must be taken in
order to avoid contamination of the oil-samples. All equipment used in obtaining samples and the sample
container shall be clean and dry.
1ZVN460100 – B 14 / 18
Observe that the above values refer to the oil coming out from the vacuum filter equipment and it does not refer to
oilsamples from the transformer.
For new oil that never has been in contact with the equipment the
Power factor/Dissipation Factor 0.005
at 100°C or 90°C and 50 or 60 Hz
Interfacial Tension against water ≥ 40 Nm/m at 25 °C
Note. Oil with Power factor at 100°C or 90°C > 0.2 or Interfacial tension against water
< 20 Nm/m shall be regenerated or substituted.
Oil that is filled into the transformer tank through a valve at the lower part of the transformer tank shall
have a maximum gas content of 0.2 % by volume.
Oil that is filled into the transformer tank through a valve at the cover of the transformer tank shall have
a maximum gas content of 0.5 % by volume.
The maximum humidity content of the oil at filling into the transformer shall be < 10 ppm.
This is normally verified at periodical control of the degassing filter and than controlled by the
temperature and pressure in the degassing chamber
1ZVN460100 – B 15 / 18
This Assembly Instruction applies to transformers with nominal voltage below 200 kV
shipped with oil nearly up to the cover.
Filling up the oil to nominal oil level can in these cases be done with a filter press. The quantities of oil to be filled in
are in these cases less than 16 % of the total oil volume in the transformer
Figure 1. The oil, stored in drums or in a storage tank, is pumped through the filter
1ZVN460100 – B 17 / 18
Document Title
Maintenance Manual
Document No. Date & Rev. Ind. No. of Pages Page
1ZVN460100-B 1 18 18