Installation Manual
Bushings, IEEE/ANSI Standard
Type COTA 150….2050 for Transformers
Type COBA for OCB Bushing Replacement
E 8322.72 2007
Contents
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
2
Introduction
Scope
Construction
Nameplate
Application Packaging and Transportation
Receiving and Initial Inspection
Cleaning
Installation
Commissioning
Maintenance
Storage
After Sales Service
Draw Lead Adapters
Technical Ordering Data
Notes
Page
3
3
3-5
5
6-9
9
9
10
10-17
17-18
18-19
19
19
19-20
20-22
23
1. Introduction
This manual is protected by copyright. Imparting to any
third party and reproduction of any kind without written
permission from Trench is strictly prohibited.
Trench is not responsible for any damage or failure that
would result from improper operation, customer
furnished materials or failure to observe the
recommendations contained in this manual. This
applies even if there is no specific instruction included
for the erection or operation of the particular bushing.
All information contained in this manual is subject to
change without notice and does not represent a
commitment on the part of Trench.
Based on Trench's experience and industry standard
practices the highest level of reliability is achieved when
the recommendations regarding handling, operation
and maintenance, as outlined in this manual, are
followed.
2. Scope
The material that is provided in this manual does not
cover all possible conditions; any specific questions
regarding this manual should be directed to Trench or
its authorized service representative. Trench assumes
no liability or responsibility for any damage or failure that
would result from improper handling, application,
installation or use of this product.
This manual covers all Trench bushings, Type COTA,
that are designed for draw lead or fixed conductor
application mounted vertically or horizontally based on
the specific capability of the bushing applied on liquid
filled transformers and reactors. This manual also
covers all Trench bushings, Type COBA, which are
designed specifically for replacement of bushings for oil
circuit breakers.
3. Construction
3.1 Function
The COTA condenser bushings are constructed for
transformer applications and meet or exceed all
applicable dimensional, electrical and mechanical
requirements of the IEEE/ANSI Standard C57.19.00 1995 and IEEE/ANSI Standard C57.19.01 – 2000.
The COBA condenser bushings are constructed for oil
circuit breaker (OCB) applications and meet or exceed
all applicable dimensional, electrical and mechanical
requirements of the IEEE/ANSI Standard C57.19.00 1995 and IEEE/ANSI Standard C57.19.01 – 2000,
Annex A.
For typical construction details see cut view section
figures 1.1, 1.2 and 1.3.
3.2 Active Part (Condenser)
The active part of the bushing is made of an oilimpregnated insulating paper with layers of aluminum
foil positioned to ensure radial and axial homogeneity of
the electric field. The paper and foil are wound around
either a central aluminum tube or a copper conductor.
3.3 Housing
The housing is made of a cast aluminum head, outdoor
insulator, mounting flange, ground sleeve (COTA 250
and above), epoxy insulator (Fig. 1.1 & 1.3), or
fiberglass insulator (Fig.1.2) all held together by the
central aluminum tube or the copper conductor. Pretensioned cone spring washers provide mechanical
stability over the entire temperature range, ensuring a
leak free bushing. The sealing between all joints is
accomplished with 0 - Ring gaskets.
Each bushing is hermetically sealed and equipped with
its own independent oil system, separate from the
transformer’s oil.
3.4 Head
The cast aluminum head serves as an oil expansion
tank and is designed as a high voltage electrode. The
design of the head allows for horizontal storage,
shipping and inclination in service up to 40° from
vertical. The oil level can be monitored over the entire
temperature range using the oil level indicator in the
head.
When the design of the head is rectangular this bushing
will allow vertical or horizontal mounting without
modifying or de-rating the bushing. The oil level
indicator on this head will only indicate that the bushing
has an adequate level of oil.
3
4
Epoxy insulator
Grounding sleeve
Mounting flange
Voltage Tap
(COTA 550 and above)
Active part
Insulator
Head housing
Oil level indicator
Draw lead stud
Top terminal
Test tap
(COTA 350 and below)
Air escape plug
(COTA 1050 and above)
Name plate
Fig. 1.1 Typical Design COTA 250 COTA 1175 Draw Lead
Bottom terminal
Conductor
FRP tube
Mounting flange
Test tap
Active part
Insulator
Head housing
Oil level indicator
Top terminal
Fig. 1.2 Typical Design COTA 150
& COTA 200 Fixed Conductor
Bottom Terminal
Epoxy insulator
Grounding sleeve
Mounting flange
Voltage Tap
(COTA 550 and above)
Active part
Insulator
Head housing
Oil level indicator
Top terminal
Test tap
(COTA 350 and below)
Air escape plug
(COTA 1050 and above)
Name plate
Fig. 1.3 Typical Design COTA 250 COTA 1675 Fixed Conductor
3.5 Mounting Flange
The cast aluminum mounting flange on COTA and
COBA 550 and above has two lifting lugs and a
voltage tap. COTA 150…350 are equipped with a
test tap. On COTA and COBA 250 and above, the
porcelain insulator is secured to the mounting
flange using special cement and an 0-Ring gasket.
3.6 Inboard End Insulator
The inboard end insulator of the COTA 150, 200
and some models of the COTA 250 and 350 are an
explosion resistant, void free, fiberglass tube.
4. Nameplate
Each COTA and COBA bushing is supplied with a
nameplate incorporating the information required by
IEEE/ANSI C57.19.00. In addition to these minimum
requirements, Trench nameplates include the voltage
class and the weight. The weight shown will be
pounds. The ANSI “L” dimension shown on the
nameplate will be with and without the removable or
“Split-Conductor”. For the layout of the nameplate
information see figure 2.
Fig. 2
The inboard end insulator of the COTA and COBA 250
and above are protected by a cone shaped, shatter
resistant, vacuum molded, epoxy-resin insulator.
The epoxy-resin insulator is designed to be installed
during the in-tank drying process of the active part of
the transformer and can withstand temperatures up
to 130º C.
A special aluminum electrode is embedded into the end
of the epoxy-resin insulator to control the electrical field
strength in this area of the bushing.
3.7 Outdoor Insulator
The standard outdoor insulator for COTA and COBA
bushings is porcelain. The porcelain is manufactured
by the wet process, is homogeneous and free from
laminations, cavities or other flaws affecting its
mechanical strength or dielectric quality.
One-piece porcelain is standard on all COTA and COBA
bushings through 900 kV BIL. 1050 kV BIL and above
can be provided with one-piece porcelain upon request.
No porcelain will be provided with gasket joints
between pieces of porcelain.
All COTA bushings can be provided with a non-ceramic
insulator. These insulators consist of an explosion
resistant fiberglass tube with silicone rubber sheds
molded over the tube.
CAUTION: Special care must be taken when
handling COTA bushings with Silicone Rubber
Insulators (SRI). Slings must not be placed between
the sheds and lifting must follow recommendations
in Section 9.
4.1 Key to Nameplate:
1.Technical Ordering Number without accessories,
see Annex for details.
2. Voltage Class
3.Maximum Current Rating. (For draw lead
bushings this rating is based on the rating of
the “Split-Conductor”)
4. Maximum Line to Ground Voltage
5. Outline Drawing Number (As originally sold)
6. Lightning Impulse and Dry Test Voltage
7. Inboard end length
8. Percent Maximum Power Factor
9.Capacitance between Test Tap and
Conductor (150…350)
Capacitance between Voltage Tap and
Conductor (550…2150)
10.Capacitance between Voltage Tap and flange
(not available on 150…350)
11.Approximate weight including “Split-Conductor”
in pounds.
12. Year of Manufacture
13.Serial Number (Includes accessory codes as
originally sold)
5
5. Application
5.1 Bushing Mounting
5.1.1 Bushing for Vertical Mounting
Trench COTA bushings that are designed for vertical
mounting is very simple to apply. The only consideration
is the inclination of mounting from vertical and
orientation of the oil level indicator.
All COTA and COBA bushings designed for vertical
mounting may be inclined up to 40° from vertical. When
inclined, the oil level indicator must be orientated facing
out, allowing easy viewing of the oil level from the
ground.
Mounting at inclinations greater than 40° from vertical
may be allowed only after consultation with Trench. In
most cases of allowed mounting greater than 40° from
vertical the oil level indicator will be required to face the
ground. In this position the oil level indicator will not
provide true oil level indication. Trench will provide
special instructions for reading the oil level of the
bushing when inclined greater than 40° from vertical.
The oil level indicator on these bushings is only an
indication of the amount of oil in the bushing, not the
actual oil level. The oil level indicator has a red floater
behind the glass. In normal operation the red floater will
be at the top of indicator, indicating sufficient oil is in
the bushing. If the floater is at the bottom of the
indicator this indicates a low oil volume.
It is important to consider the location of the oil level
indicator when applying these bushings on new or
re-manufactured transformers. For proper location of
the oil level indicator for vertical or horizontal application
see figure 3, A and B.
It is sometimes desirable to incline vertically mounted
bushings. For these applications the following
guidelines are offered to maintain proper oil level
indication:
•W
ith the oil level indicator facing down the maximum
angle of inclination from vertical is 12º.
•W
ith the oil level indicator at its highest point (bushing
turned 90º) the maximum angle of inclination from
vertical is 18º.
5.1.2 Bushing for Vertical or
Horizontal Mounting
The heads of these bushings are rectangle and the
orientation of the bushing can affect the phase to phase
spacing in air. Consideration of this fact must be taken
into account when applying these bushings.
Trench COTA bushings that are designed for vertical
and horizontal mounting, are very simple to apply. The
only items that need to be considered are the location
of oil level indication and the orientation of the head.
Contact Trench if you have any questions on the
application of these bushings designed for vertical or
horizontal mounting.
Fig. 3 Proper location of Oil Level Indicator
6
5.2 Current Path Options
A key item to consider when applying bushings is the
current path options. Trench COTA bushings offer two
current path options, draw lead or fixed conductor.
5.2.1 Draw lead
5.2.1.1 Draw lead cable(s) application
Current path via the transformer’s copper cable(s) to a
silver-plated copper cable terminal through multi spring
contacts to the copper alloy top terminal. For selection
of the appropriate draw lead cable terminal refer to
section 5 or contact Trench.
Oil
Water
Particles
Oil Strength
Oil Condition
Mineral
<15 PPM
Max. 39,630 per gallon
Size 59 to 2362 µ inch
>70 kV per 0.1 inch
The following figure provides recommendations for
applying the insulated draw lead conductor to the
Trench COTA bushings.
Fig. 4.2
When the draw lead cable option is selected, the
embedded aluminum end shield allows simple, space
saving assembly without additional shields and barriers.
For reference, the following table provides typical
distances from the centerline of the bushing to the
nearest grounded part.
5.2.1.2 Draw Lead Cable Loading
Fig. 4.1
The following guidelines are offered for selecting and
applying flexible, copper draw lead conductor with
more than 200 strands with a strand diameter less than
.03 inch and the cable insulated with 5 mils of index
105 insulation.
COTA
BIL
Rating
150
and
200
COTA
150
200
250
350
550
650
750
900
1175
R Minimum
(mm)
65
75
85
120
145
180
225
270
300
(inch)
2.56
2.95
3.35
4.72
5.71
7.09
8.86
10.63
11.81
The above table is based on the following transformer
or reactor oil condition.
250
and
350
550
to
750
900
to
1175
Cross
Section
mm
70
95
150
285
350
70
95
150
285
350
70
95
150
285
490
95
150
285
450
665
Max.
Load
Amps
215
265
385
640
750
200
250
360
600
700
190
235
340
540
815
180
265
430
600
800
A/mm
3.10
3.07
2.57
2.25
2.14
2.86
2.63
2.40
2.11
2.00
2.71
2.47
2.27
1.89
1.66
1.89
1.77
1.56
1.33
1.20
7
The values on the previous page are based on a
maximum ambient temperature of 40°C, an average
24 hour ambient of 30°C at a frequency of 60 Hz and
a maximum rise of the transformer oil of 65°C.
Contact your local Trench representative with any
questions regarding the above recommendations.
5.2.1.3 “Split-conductor” Application
Current path via Trench’s copper “Split-Conductor”
draw lead conductor through multi spring contacts to
the copper alloy top terminal.
Application of “Split-Conductor” bushings, COTA 150
through 350, through 2,000 A, for new or
re-manufactured transformers require some special
consideration at the time the transformer is designed.
The split of the “Split-Conductor” is located 1/2” (12.5
mm) below the gasket surface of the bushing mounting
flange. The inside diameter of the mounting flange does
not allow enough space to assemble or disassemble
the “Split-Conductor”. For this reason the transformer
design must allow the “Split-Conductor” to be lifted
vertically 6” (150 mm). This additional vertical lift
capability is not required when these bushings are
applied as replacement bushings on existing
transformers.
When the 3,000 amp “Split-Conductor” is applied the
weight of the conductor as well as the winding leads
may make it difficult to allow vertical lift of the
conductor. For this reason the location of the split may
need to be changed from the location indicated above.
Please consult Trench on your specific requirement.
It is recommended that when selecting a “SplitConductor” application for new or re-manufactured
transformers that the Trench holding tool be supplied
with the transformer. It will make installation easier and
safer for the transformer.
8
Tool Type
150...350 up to 1,5000 A
150...200, 3,000 A
250...350, 2,000 A
550...750 up to 1,400 A
900...1175 up to 1,600 A
1300 up to 1,600 A
Part No.
804-0001
804-0002
804-0005
804-0002
804-0004
804-0006
The only other consideration is the design of the
mounting flange shipping cover. (All COTA “SplitConductor” bushings) The shipping cover will require a
supporting bar welded to the center underside of the
shipping cover. This supporting bar must have
matching threaded holes to allow the inboard section of
the “Split-Conductor” to be secured during transport of
the transformer. In addition, some provisions should be
considered to lift the shipping cover when the bushing
is installed. “Split-Conductors” when attached to the
winding leads can be very heavy.
For specific shipping cover design requirements and
detailed drawings of the required “Split-Conductor”
contact Trench.
When the "Split-Conductor" option is selected
additional shields or barriers may be required
depending on the applied voltage and/or mounting
conditions, see figure 5.1-5.4.
5.2.2 Fixed conductor application
Current path via a fixed copper conductor.
When the fixed conductor option is selected additional
shields or barriers may be required depending on the
applied voltage and/or mounting conditions.
5.2.2.1 Terminals and Shields
The following figures 5.1-5.4 show some of the many
different terminals and shields that are available from
Trench for COTA bushings.
Fig. 5.1 Two Hole Spade
Fig. 5.2 Four Hole Spade
Fig. 5.3 Thread Stud
7. R
eceiving and
Initial Inspection
As a general rule, every bushing should be unpacked in
a dry place (shop). Once unpacked, the bushing should
be kept in a dry room and protected from atmospheric
influence.
Fig. 5.4 Typical Shield & Terminal
Before unloading, complete a visual inspection of the
crate and note any apparent damage on the bill of
lading. After unloading, open the top of the crate, being
careful not to damage the porcelain and other bushing
parts, and thoroughly inspect each bushing. The
following areas should be closely examined:
•V
isual inspection of insulator for chips cracks or other
visible damage.
•C
heck for extensive oil traces. Small traces of oil on
the inboard end are insignificant; they occur during
factory tests prior to shipping or after factory testing
of the transformer.
For additional application information on Trench COTA
bushings, contact the nearest Trench factory.
6. P
ackaging and
Transportation
Standard shipping crates, from the factory, contain
1, 3 or 4 bushings.
CAUTION: When the bushing is placed in the crate
the oil level indicator must be facing down and
remain in this position whenever the bushing is in a
horizontal position.
Factory shipping crates are marked with arrows
indicating the correct orientation requirement. Each
bushing designed for vertical mounting has a special
decal on the head as a reminder.
Should there be any signs of damage, evidence of
rough handling in transit and/or parts shortage, contact
the carrier at once. Also notify Trench or its authorized
representative.
For more information about unloading the bushings,
see section 9.1. Unpacking and handling.
We recommend not to damage or destroy the original
shipping crate(s). They may be re-used for the same
purpose when the transformer is delivered to its final
destination.
If it is desired to perform electrical tests on the bushing
before it is installed in the transformer refer to section
10, Commissioning for instructions.
PRECAUTION: The bushing must not be tested
while still in the shipping crate and the bushing must
be in a vertical position away from other structures.
Failure to follow these precautions may result in
inaccurate reading and test results.
9
8. Cleaning
Before mounting the bushing it should be thoroughly
cleaned.
8.1 Cleaning medium and accessories
The following cleaning medium may be used for wiping
oil remaining on the surface of the bushing:
two passes should be made with dry clean rags.
When a compressed air-bottle is available, all grooves,
comers, drillings and other cavities should be blown off
thoroughly.
A visual control should make sure that all residues of
oil, cleanser and cleaning accessories have been
removed. Including the central tube of draw lead
bushings.
• Industrial or similar solvents
9. Installation
Necessary accessories:
9.1 Unpacking and handling
•
•
•
•
•
•
Before lifting the bushing out of the shipping crate,
remove all supports from above and remove the bolts
connecting the mounting flange to the crate.
Dust and lint-free rags
A dust free brush or large paint brush
Washing bottle
Length of insulated wire or cotton cord
Compressed dry air
Silk Paper
8.2 Cleaning Procedure
The following areas of the bushing must receive a
thorough cleaning:
• The outdoor insulator
• The inboard insulator and metal ground sleeve if so
equipped
• The interior of the central tube of draw lead bushings
• The bottom terminal connection surface
• The inside area of the voltage tap or test tap
• The gasket surface of the mounting flange
• The gasket surface of the bolted top terminal on draw
lead bushings
• The oil level indicator sight glass
The insulator and metallic parts are to be wiped with
the specified rags with the indicated cleanser. Grooves,
corners and drillings or any other cavities are to be
rinsed with the washing bottle or the recommended
brush or paint brush.
Remaining residues, possible lint or hairs should be
wiped off by a final cleaning.
The insulator and the metallic parts should be
eventually wiped with a clean silk-paper.
A rag soaked with the available cleaning medium
should be attached to one end of the wire or cord and
the other end drawn through the central tube of the
bushing (draw lead bushings only). Pull the rag, one
direction only, through the tube several times. The last
10
A crane and two textile slings are required for lifting the
bushing out of the shipping crate. The following
procedure must be followed while lifting the bushing
(see figure 6.1):
CAUTION: The bushing shall not be subjected to
radial rotation in the crate or after removal. The oil
level indicator shall always be facing downward. The
bushing should be suspended with its head up. The
maximum permissible inclination with the head
downward is 15º as shown in figure 6.1.
Draw Lead bushings may require that the “SplitConductor” be installed prior to being installed into the
transformer. In this case the bushing should be
positioned horizontally outside of the crate, with the oil
level indicator facing downward, as shown in figure 6.1.
The maximum rotation tolerance is +30º, as shown in
Detail A. No additional radial rotation is permitted.
The “Split-Conductor” must be reassembled prior to
being installed into the bushing. Once assembled
carefully insert the “Split-Conductor” into the bushing
from the bottom following the instruction detailed later
in this section.
To place the bushing in the vertical position:
For COTA 150 and COTA 350 bushings, which are not
heavy, this is possible with only one sling. Attach the
sling under the uppermost shed around the insulator.
As you lift the bushing, hold the lower end with one
hand so that the bushing does not touch the ground
while it is moving to the vertical position. For putting
COTA 550 and above bushings to the vertical position,
one crane and one hoist is necessary because the
bushings are very heavy.
Fig. 6.1
The basic procedure with crane and hoist is as follows
(see figure 6.2):
Attach one end of each sling to each of the two lifting
lugs on the mounting flange. Attach the free ends to
the bottom of the hoist. Attach the hoist to the crane
hook. Adjust the hoist to ensure that the crane's
boom will be long enough to let down the bushing to
the vertical position.
Lift the bushing high enough to ensure that it will not
touch the ground when it is moving to the vertical
position. Actuate the hoist until the bushing is
positioned vertically. Check the oil level as described in
section 11.1 "checking the oil level".
If the bushing is to be installed vertically (no inclination),
no further adjustments are necessary. It can be moved
to the transformer for installation.
Attach two guide slings around the outdoor insulator
between the head and the uppermost shed.
If the bushing is to be installed at an inclination (≤ 40º),
the following considerations must be done.
Attach two more long slings to the crane hook. Draw
the free ends of the slings through the guide slings
and then attach them to the lifting lugs on the
mounting flange using shackles.
If the oil level indication over the entire operating
temperature range is desired, the oil level indicator
must face to the side.
Adjust the suspension equipment to ensure that the
bushing will remain in the horizontal position with the
oil level indicator facing downward during lifting. If the
bushing is inclined during lifting, the head must be in
the highest position.
Other installation positions with the oil level indicator
facing down are acceptable under certain conditions.
Such installations may allow only minimum oil level
monitoring. Installation positions in which the oil level
indicator faces up are never permitted. To install the
bushing at an inclination (≤ 40º) with the oil level
indicator facing to the side, the following procedures
must be followed (see figure 6.3):
11
Fig. 6.2
For bushings COTA 150 through COTA 350, the
inclination can be adjusted by hand because the
bushings are not heavy. It is not necessary to change
the slings after lifting. For bushings COTA 550 and
above the following points must be followed:
The bushing can now be moved to the transformer for
installation.
•P
osition the bushing vertically in a frame or in a cavity
with its mounting flange resting on a soft surface.
•B
ushing must be in a vertical position for a minimum
4 hours then gradually tilted to the horizontal position
before mounting in the transformer. Care should be
taken with the sight glass location.
•R
emove the shackle connection, which were
positioned downward if the bushing is inclined.
•R
emove both slings connecting the bushing to the
hoist. A single sling through both lifting lugs and
around the body of the mounting flange will be used
to attach the bushing to the hoist.
•N
ow lift the bushing carefully. Set the desired
inclination by adjusting the hoist.
12
Bushings designed for horizontal mounting require the
following installation procedures.
•T
here are two considerations to be made when
positioning horizontally mounted bushings on the
transformer. First is to maintain the functionality of the
oil level indicator. Second is the ability to visually see
the oil level indicator from the ground. Take these
considerations into account before applying slings.
•W
hen these bushings are mounted horizontally on
the transformer sidewall the oil level indicator should
be positioned so that the indicator is located at the
highest point on the side of the bushing head.
Fig. 6.3
•W
hen these bushings are mounting vertically on the
transformer cover the oil level indicator should be
orientated so that the indicator can be viewed from
the ground.
•A
ttach the sling between the two lowest sheds of the
outdoor insulator. As you lift the bushing, hold the
inboard end with one hand to balance the bushing.
Now install the bushing into the transformer. Be
careful not to drag or bang the inboard end on the
mounting flange while it is moved into the transformer
sidewall.
The transformer and bushing mounting flange should
be clean and free of foreign material with the gasket
in place before the bushing is set. After the bushing
has been set in place on the mounting flange install all
the washers and bolts until finger tight. Then tighten
the bolts a fraction of a turn at a time, working
progressively in a crisscross (star) pattern until all bolts
are uniformly tight.
Typical Torque Values
Bolt Size
9.2 Bolting to the transformer
The following instructions are only valid when the
gasket between the bushing and the transformermounting flange is a 0-Ring. For flat gaskets, the
instructions are valid if the mounting flange is equipped
with a mechanical gasket stop. For all other
arrangements, the torque requirement depends on the
type of gasket system used. Trench takes no
responsibility for damage caused by over torque in
other arrangements.
1/2” – 13 threads
5/8” – 11 threads
3/4” – 10 threads
1” – 8 threads
1 1/8” – 8 threads
Foot pounds
Newton meters
35
65
100
260
260
47
88
135
352
352
Trench recommends washers when bolting the bushing
to the transformer.
13
9.3 External electrical connections
External connections to the bushing must be sufficiently
slack or flexible to avoid putting a mechanical strain on
the bushing parts. Terminal connectors should be of
ample size to minimize bushing overheating during
possible overloads.
Ridged buss connection to bushings is not
recommended in areas of seismic concern and
because of transformer tank flexing during vacuum
filling operations.
9.4 Connection to transformer
9.4.1 Top terminal assembly
The typical top end of a COTA draw lead bushing is
shown in figure 7. If the bushing is applied with draw
lead cable(s) or a “Split-Conductor” the top terminal has
to be removed. If the bushing is equipped with a “SplitConductor” and is replacing a bottom connected
bushing there is no need to remove the top terminal.
To remove the top terminal the procedure is as follows:
Remove the four fixing screws. The terminal can be
pulled off axially using a force of approximately 44 lb.
(200 N).
The bolts, cone spring washers and the 0-Ring gasket
must be stored in a safe place.
If lifting off the top terminal is difficult, use two of the
bolts removed and thread them into the two threaded
holes as shown in figure 7. By tightening the bolts
into these holes the top terminal will become lose and
further removal by hand will be possible.
Fig. 7
CAUTION: Do not attempt to rotate the top
terminal. The top terminal itself is not threaded to
the draw lead cable terminal or the top of the
“Split-Conductor”.
For the procedure to reassemble the top terminal after
draw lead cable or “Split-Conductor” installation, see
sections 9.4.2.
9.4.2 Draw lead cable connection
COTA draw lead bushings are designed with a hollow
tube through which the flexible draw lead cable(s) can
be pulled. The cable is considered a component of the
transformer and is not supplied as part of the bushing.
For new transformers there are two ways to connect a
draw lead cable terminal to the transformer cable,
crimping or brazing. Trench makes no endorsement on
which method used. It is entirely up to the transformer
manufacturer and their customer. However, brazing the
cable to the terminal requires special care to avoid
effecting the silver-plating that provides the high current
interface between the draw lead cable terminal and the
multiple spring contacts in the bolted top terminal.
CAUTION: When brazing, the temperature at the
current interface should not exceed 650º C.
The selection of the draw lead cable terminal for the
specific connection method and size cable is covered
by the technical ordering data in section 5.
CAUTION: Once the draw lead cable terminal has
been attached and before it is installed in the
bushing it must be protected from damage to the
contact surface. If it becomes damaged it will have
to be replaced
After mounting the bushing on the transformer, secure
the draw lead cable terminal with the retaining pin and
locking device. The retaining pin must pass through the
corresponding hole in the central tube of the bushing.
Install the 0-Ring and place the top terminal over the
draw lead cable terminal. Fasten the top terminal to the
head with the four screws and cone spring washers
provided (torque = 15 ft. lb. /20 Nm).
14
When the bushing is installed on the transformer, the
optional (Standard on COTA 1050 and above) air
escaping screw (7.4 ft. lb./10 Nm) located on the top
terminal can be used for the air release while oil filling
the transformer. This option is recommended when
bushings are installed on transformers with conservator
type oil preservation systems.
CAUTION: Once the lower end of the “SplitConductor” has been attached to the winding lead and
before it is installed in the bushing the split joint must
be protected from damage to the contact surface. If it
becomes damaged it will have to be replaced.
9.4.3 “Split-Conductor” connection
9.5 “Split-Conductor” installation
When the applied current exceeds the rating of draw
lead cable(s), the COTA bushing can be supplied with
Trench's "Split-Conductor". The “Split-Conductor” is an
accessory supplied by Trench as part of the bushing.
The “Split-Conductor” can be removed from the
bushing for connection to the transformer winding lead
or installed in the bushing and connected to the
winding leads after the bushing has been installed in
the transformer
The “Split-Conductor” joint is designed to be located
1/2” (12.5 mm) below the gasket surface of the
bushing mounting flange. (For 3,000 amp “SplitConductors” the split may have a different location.
Refer to the outline drawing of the bushing to confirm
location.) Because of the limited space of the mounting
flange inside diameter on bushings through 69 kV it is
necessary to lift this joint above the gasket surface of
the mounting flange and hold the conductor in this
position during assembly of the “Split-Conductor”.
Trench has designed a tool for holding the conductor in
place. If not available a hardened steel rod, 1/4” (6 mm)
in diameter, 12” (300 mm) long can be used. If a rod is
used, extra care must be taken to avoid dropping any
hardware into the transformer tank.
If the “Split-Conductor” has been shipped separately
from the bushing and the bushing is to be installed
with the “Split-Conductor” in place the following must
be done:
Installing the “Split-Conductor” is done with the
bushing in a horizontal position with the oil level
indicator facing down.
First remove the top terminal. Carefully slide the top of
the “Split-Conductor” into the bottom of the bushing
until the upper end extends beyond the central tube.
Care should be taken not to scratch the “SplitConductor” or the central tube of the bushing during
installation.
Next install the retaining pin with locking device and
re-install the top terminal. The locking pin rests on the
top of the central tube, not through the hole used for
draw lead. This allows the “Split-Conductor” to rotate
for easy alignment inside the transformer. Then install
the bushing in the transformer and make the
connection to the bottom of the bushings in the same
manner as a COTA bushing with a fixed conductor.
The other method is to separate the “Split-Conductor”
at the joint, take the lower end with the bottom terminal
and make the connection to the transformer active part
winding lead. Then re-connect the upper part of the
“Split-Conductor” as shown in figure 7.0 when ready to
install the bushing. Use only the screws and washers
provided with the Split-Conductor.
Installation steps:
•P
repare the bushing for installation by removing the
top terminal and retaining pin with locking device,
then place a cord or wire through the central tube of
the bushing.
• Locate the upper part of the “Split-Conductor”, which
should be located in the crate with the bushing or it
may have been installed in the bushing during
transport. At the top end of the upper part of the
“Split-Conductor” you will find a 5/16” - 18 UNC
tapped hole. Install an eye bolt into the hole for
attachment of the cord or wire from the bushing.
CAUTION: Care must be taken to protect the
contact surfaces at both ends of upper part of the
“Split-Conductor”. If it becomes damaged it will have
to be replaced
•R
emove the hardware from the bushing flange
shipping cover and lift the cover 6” (150 mm). The
lower end of the “Split-Conductor” will be attached to
the underside of the shipping cover. The lower end of
the “Split-Conductor” will weigh between 5.7 and 7.5
kg (12.5 and 16.5 lb.) and will be connected to the
transformer winding lead, adding additional weight.
15
Fig. 8 Split Conductor Assembly
•W
ith the shipping cover lifted install the Trench
holding tool (or steel rod) using the small through hole
located 1/2” (12.5 mm) below the joint of the “SplitConductor”.
•W
ith the lower end of the “Split-Conductor”
supported remove the hardware that attaches the
shipping cover to the “Split-Conductor”. This will be
the same hardware that will be used to assemble the
upper part of the “Split-Conductor”. An 8 mm or
5/16” Allen wrench can be used to remove the cap
screws.
CAUTION: if the steel rod is used care must be taken
not to drop any hardware into the transformer tank.
16
•A
ssemble the upper part of the “Split-Conductor”
using the hardware used the secure the shipping
cover. Torque the cap screws to 17 ft. lb. (23 Nm).
•A
ttach the cord or wire, which exits the lower end of
the bushing, to the lifting eye previously installed to
the top of the Split-Conductor.
CAUTION: When handling the bushing in a horizontal
position make sure that the oil level indicator is
always facing down to prevent the gas in the head
from entering the condenser part of the bushing.
•B
egin to install the bushing over the “Split-Conductor”
while pulling on the cord or wire. As the bushing is
being lowered over the “Split-Conductor” align the oil
level indicator to the desired final position.
•A
s the bushing lower end approaches the Trench
holding tool (or steel rod) remove the holding tool (or
steel rod). At this point the full weight of the “SplitConductor”, between 11.2 and 17.5 kg (24.6 and
38.5 lb.), will be supported by the cord or wire. The
“Split-Conductor” must not be allowed to drop into
the transformer tank.
•C
ontinue lowering the bushing, while pulling on the
cord or wire until the bushing rests on the mounting
flange. With the “Split-Conductor” still supported by
the cord or wire install the retaining pin with locking
device through to small hole near the top of the
“Split-Conductor”.
•S
ecure the bushing to the mounting flange and install
the top terminal to the head using the four screws
and washers provided. Torque to 15 ft. lb. (20 Nm).
CAUTION: For “Split-Conductor” applications, the
retaining pin does not pass through the
corresponding hole in the central tube of the
bushing. The retaining pin with locking device will
rest on top of the central tube, supporting the “SplitConductor” during service.
After the bushing has been installed in the transformer,
the optional air escape plug (7.4 ft. lb./10 Nm) located
on the top terminal can be used for air release while
filling the transformer.
If the “Split-Conductor” is delivered installed in the
bushing and it is to be removed, the following should
be done:
With the bushing in a horizontal position with the oil
level indicator facing down, remove the top terminal.
With the top terminal removed, remove the retaining pin
and carefully pull the ”Split-Conductor” from the bottom
of the bushing. Caution must be used in removing the
“Split-Conductor”, as it can be heavy and as long as
the bushing. Care must also be taken not to scratch
the “Split-Conductor” or the central tube of the
bushing.
9.6 Fixed conductor installation
Bottom connected bushings with a fixed conductor are
designed for highest current ratings. They carry the
current through the center conductor that is not
removable. It is not necessary to remove the top
terminal on such bushings. The connection to the
winding leads depends on the design of the
transformer.
10. Commissioning
10.1 General check
The following procedures must be completed before
placing the bushing under voltage:
•C
heck the oil level (see section 11.1, "Checking the
oil level").
•W
ait at least 24 hours after the bushing has been
placed in the vertical position before applying voltage.
•P
ower factor and bushing capacitance measurements
can be made for comparison with subsequent field
measurements.
10.2 Test tap
Bushings for insulation class of 69 kV and lower are
provided with a test tap. The test tap shown in figure
9.0 is located just above the mounting flange and
provides measuring power factor and capacitance of
the bushing. In order to connect to the test tap, remove
the threaded cap and connect the lead of the power
factor with the measuring equipment. After the
measurement has been completed, re-assembling the
sealing cap (torque = 15 ft. lb./20 Nm). This will ground
the test tap for proper operation of the bushing.
CAUTION: There is a high voltage output if the test
tap is not grounded. Always keep it grounded with
either an over-measuring circuit, sealing cap or
grounding link.
The test tap can withstand a power frequency voltage
test of 2 kV. Many bushing users measure the power
factor and the capacitance of the bushing as a field
test. For more information on this practice, refer to
section 11, "Maintenance".
17
Fig. 9
COTA 150…COTA 350 Test tap
Fig. 10
COTA 550 and above Voltage Tap
Sealing cap
Oil plug
Sealing cap
10.3 Voltage tap
Bushings for insulation class of 115 kV and higher are
provided with a voltage tap. The voltage tap shown in
figure 10.0 is located just above the mounting flange
and can be used for connecting voltage measuring
equipment (e.g. a bushing potential device) or for
measuring the power factor and capacitance of the
bushing. In order to connect the tap outlet, remove the
sealing cap and connect the measuring equipment.
If a bushing potential device is connected, remove the
oil plug and fill the cavity with clean, dry transformer oil.
To permit oil expansion, allow a 5/8" (16 mm) clearance
between the seal and the surface of the oil. Then
replace the plug and gasket with a torque of 7.4 ft. lb.
(1O Nm).
Under these conditions, the voltage tap will withstand a
20 kV power frequency voltage test.
It is not necessary to fill the cavity with oil for power
factors or capacitance measurement devices below
10 kV.
After the measurement has been completed,
re-assemble of the sealing cap (torque = 30 ft. lb./40
Nm) This will ground the voltage tap for proper
operation of the bushing.
CAUTION: There is a high voltage output if the
voltage tap is not grounded. Always keep it
grounded with either an over-measuring circuit,
sealing cap or grounding link.
As mentioned in section 11.1 many bushing users
measure the power factor and the capacitance of the
bushing as a field test. For more information on this
practice, refer to Section 11, "Maintenance".
18
11. Maintenance
Under normal operating conditions Trench type COTA
bushings require no maintenance. As a guideline the
following routine checks can be performed.
11.1 Checking the oil level
Trench COTA bushings covered by this instruction
manual have prismatic glass oil level indicators. As long
as oil is visible within the view of the prismatic glass oil
level is within acceptable limits. This rule is valid for all
acceptable mounting positions up to a 40º inclination
from vertical.
CAUTION: If the oil level is at the bottom of the oil
level indicator, it indicates a low oil level. The bushing
must be taken out of operation immediately. No
voltage may be applied to a bushing under such
conditions due to the danger of explosion. Check
the bushing for leaks and contact Trench.
11.2 PF and capacitance measurement
Field measurements of power factor and capacitance
can differ from measurements made under the
controlled conditions in the factory. The bushing power
factor and capacitance should be measured at the time
of commissioning and these values should be used as
a base to compare future measurements.
Please contact Trench should:
•T
he power factor doubles from the original
commissioning value.
•T
he capacitance increases to 110 % of the original
commissioning value.
CAUTION: These measurements may only be
performed when the bushing is not in operation.
Removing or replacing these caps under voltage is
strictly prohibited: Dangerous high voltage!
The test or voltage tap sealing cap must be screwed on
tightly during operation with the following torque values:
• Test tap sealing cap: 15 ft. lb. /20 Nm
• Voltage tap sealing cap: 30 lb. /40 Nm.
11.3 C2 Measurements 69 kV Class
and below.
Trench has conducted extensive investigations into the
phenomenon of erratic C2 and PF field measurement
on new Trench bushings, 69 kV and below. From the
results of this investigation Trench has determined,
without exception, that when the C1 and PF are as
indicated on the nameplate that the bushing is in good
working condition and fit for a lifetime of trouble free
service.
11.4 C2 Measurements 115 kV Class
and above.
Erratic field measurements of the C2 capacitance on
bushings 115 kV and above have been reported to
Trench. In these cases one or more of the following
situations existed, that when corrected, brought the
measured values back in line with the nameplate value.
•T
he bushing was not vertical with the inboard end
resting within the shipping crate.
• The leads connected to the test equipment were
long and not calibrated for the length.
• The test voltage was below 1 kV.
• The bushing was tested near a steel reinforced
concrete column or concrete floor.
• The voltage tap compartment was contaminated
with moisture.
factory shipping crate is not available the bushing must
be stored upright in a suitable support frame. The
preferred storage location is indoors, however, if indoor
storage is not available, the bushing may be stored
outdoors for short periods of time. If stored outdoors, it
is highly recommended to enclose the inboard end of
the bushing in protective plastic to prevent
contamination of this side of the bushing.
COTA and COBA bushing inboard ends are susceptible
to UV de-coloration when stored outdoors unprotected.
Extensive testing has shown that prolonged exposure,
more than 10 years, can damage this component of
the bushing. Shorter periods of exposure will not effect
the functionality of the bushing but may change its
appearance. Should this occur treat the insulator with
ethanol and a Scotch-Brite pad to restore the original
appearance.
13. After Sales Service
Should any malfunction occur with a COTA or COBA
bushing, inform Trench or its authorized representative.
Include with your report complete identification of the
bushing, including serial number, type designation and
nature of malfunction. This report must be in writing.
14. Draw Lead Adapters
When selecting Trench COTA bushings as replacements
for other brands of draw lead bushings it will be
necessary to apply a Trench draw lead adapter. For
most applications a thread-on type adapter can be
applied.
14.1 Instructions
The following instructions are offered for use when
applying the thread-on adapter: Before beginning the
installation refer to the preceding instruction in this
manual pertaining to the new COTA bushing.
11.5 Units with Oil Sampling Valve
14.2 Measuring
Contact Trench prior to taking an oil sample.
Before removing the old draw lead bushing it is
recommended that the amount of slack in the draw
lead cable be measured. This is accomplished by
pulling up the draw lead terminal by hand to determine
the amount of slack that may exist. Note that in many
cases there may not be any slack. Take note of the
approximate slack or lack of slack that is present, this
information will be used when the new Trench COTA
bushing is installed.
12. Storage
Storage practices for COTA bushings depend on where
stored and for how long. It is always preferable to store
the bushing horizontally in its original factory shipping
crate, regardless of storage duration. If the original
19
14.3 Inspection
After removing old draw lead bushing inspect the draw
lead cable insulation for any signs of burning or over
heating. If there are indications of burning or over
heating you should note this condition, as it may be an
indication of severe overload or of an inadequately
sized draw lead conductor. If this condition exists,
consider replacing the insulation with a high
temperature, class F, insulation material.
14.4 Installation
With the existing threaded draw lead terminal held away
from the bushing opening on the transformer cover,
install the lock nut supplied with the adapter. The lock
nut must be threaded all the way onto the old threaded
draw lead terminal.
Thread the female end of the draw lead adapter onto
the existing threaded draw lead terminal until it is tight.
Then tighten the lock nut against the adapter using
wrenches on the flats of the lock nut and adapter.
With the draw lead adapter installed you can now install
the new Trench COTA bushing following the instructions
in this manual.
Before installing the retaining pin in the Trench draw
lead terminal again determine the amount of slack in
the draw lead cable. It should be the same as when
checked before the old bushing was removed. If there
is more than 2 inches (50 mm) of additional slack or if it
takes a large amount of force to pull the terminal to the
top of the bushing during the last few inches, it is
recommended to stop and contact Trench. Applying
too much force in pulling up the draw lead cable may
damage the transformer.
CAUTION: The above instructions do not cover all
possible conditions that can arise when replacing old
draw lead bushings. Trench assumes no responsibility
for any damage or failure, which would result from
conditions not known to Trench or by materials not
furnished as part of the Trench bushing.
14.5 Other adapter types
There may be some instances that a Trench thread-on
adapter can not be applied. In those cases an adapter
will be provided by Trench, which will require cutting off
the old draw lead terminal. If this type of adapter is
required Trench will provide detailed instructions to
perform the installation.
20
15. Technical Ordering
Data
Trench has developed a technical ordering data system
that is “user friendly”. It is designed to allow you to build
your own bushing from a selection of standard
accessories and options that meet your specific
application requirement.
The technical ordering data system is made from three
components, the bushing Type, the bushing Style
number and the bushing Options. At the end of this
section are Code tables that list the available options.
1. Type Code
COTA, which stands for Condenser Oil Transformer
bushing designed according to ANSI Standards. COBA,
which stands for Condenser Oil Breaker bushing
designed according to ANSI Standards. The type is
always at the beginning of the technical ordering data.
2. Style Number
The style number is made up seven sets of numbers
and/or letters that will provide specific information about
the specific bushing.
COTA __ __ __ - __ __ __ __ - __ __ - __ __ __ - __ __
Set
1
2
3
4 5 6
7
The first set of numbers states the BIL (Basic Insulation
Level) of the bushing. The table for Code 1 lists the
standard BIL available.
The next set of 1 letter and 3 numbers, state the
maximum through current rating of the bushing. The
letter designates the current path option, F for fixed
conductor or H for draw lead. The numbers designates
the maximum through current for the bushing X100.
(Example 015 = 1,500 amperes) A listing of available
ratings is listed in the table for Code 2.
The next set of numbers designates the CT pocket
length. The CT pocket is the space, just below the
mounting flange of the bushing, provided by the last
grounded foil layer of the bushing’s active apart. The
table for Code 3 lists the available CT pocket lengths
by style.
The next letter designates the mounting flange
configuration. The IEEE/ANSI Standards dictate the
mounting flange arrangements for most bushings,
however, there are a number of exceptions that must
be considered when applying bushings as
replacements. The table for Code 4 will provide specific
letter code designations for each available mounting
flange configuration by bushing style.
The next letter designates the outdoor insulator material
and color. There are 3 options available for the outdoor
insulator and are listed in the table for Code 5.
The next number designates the outdoor insulator’s
creep distance in accordance with the four
contamination levels as described in the IEEE Guide for
Application of Power Apparatus Bushings, C57.19.100.
The table for Code 6 list the 4 options.
The last set of numbers is the Trench factory code
designation that determines a specific bushing’s
compatibility with other bushings within the same
rating.
3. Options
The last sets of letters are the Option Codes. The
option codes are the accessories that are added to a
basic bushing to suit the specific requirement or
application. These option codes will appear on the
bushing nameplate as part of the serial number and will
appear on the bushing outline drawing. The specific
outline drawing number will appear on the bushing
nameplate. There are presently 4 sets of options
available for Trench bushings.
CODE 1, Basic Insulation Levels
ODE
C
150
200
250
350
550
650
750
900
1050
1175
1300
1550
1675
1800
2050
DESCRIPTION
25 kV, 150 kV BIL
34.5 kV, 200 kV BIL
46 kV, 250 kV BIL
69 kV, 350 kV BIL
115 kV, 550 kV BIL
138 kV, 650 kV BIL
161 kV, 750 kV BIL
230 kV, 900 kV BIL
345 kV, 1050 kV BIL
345 kV, 1175 kV BIL
345 kV, 1300 kV BIL
500 kV, 1550 kV BIL
500 kV, 1675 kV BIL
500 or 765 kV, 1800 kV BIL
756 kV, 2050 kV BIL
CODE 2, Maximum Current Ratings
ODE
C
H014
H015
H016
H020
H030
F020
F023
F027
F030
F050
F075
F100
F125
DESCRIPTION
1,400 A, 250….1175
1,500 A, 150…200
1,600 A, 900…1300
2,000 A, 250…350
3,000 A, 150…200
2,000 A, 150…2050
2,350 A, 200
2,700 A, 150
3,000 A, 150…2050
5,000 A, 150…900
7,500 A, 150…200
10,000 A, 150
12,500 A, 150
CODE 3, CT Pocket Length
ODE
C
10
16
21
23
26
27
DESCRIPTION
10” CT Pocket (Special)
16.5 “ CT Pocket (Special)
21” CT Pocket (Std. 150…350)
23” CT Pocket (Std. 550….2050)
26.75” CT Pocket (Special)
27” CT Pocket (Special)
CODE 4, Mounting Flange Configuration
CODE
A
A
B
B
C
C
D
D
A
A
A
A
A
E
A
A
A
A
A
A
A
A
F
A
kV Class
25
34.5
25
34.5
25
34.5
25
34.5
35.5
46
46
69
69
69
115
115
138
138
161
230
345
500
500
765
Amps
Flange
1,500 7¼” – 4 HOLE
1,500 7¼” – 4 HOLE
3,000 7¼” – 4 HOLE
3,000 7¼” – 4 HOLE
3,000 8¼” – 4 HOLE
3,000 8¼” – 4 HOLE
3,000 9¼” – 6 HOLE
3,000 9¼” – 6 HOLE
5,000 14 ¼” – 9 HOLE
2,000 8¼” – 4 HOLE
3,000 9¼” – 6 HOLE
2,000 9¼” – 6 HOLE
3,000 10 ¼” – 6 HOLE
3,000 10.88” – 6 HOLE
3,000 13¼” – 6 HOLE
3,000 13¼” – 6 HOLE
3,000 14¼” – 6 HOLE
3,000 14¼” – 6 HOLE
3,000 15¾” – 8 HOLE
5,000 21” – 12 HOLE
3,000 21” – 12 HOLE
3,000 25” – 12 HOLE
3,000 31” – 16 HOLE
2,000 35” – 16 HOLE
21
CODE 5, Outdoor Insulator
CODE
G
B
C
DESCRIPTION
#70 Gray Porcelain
Brown Porcelain
#70 Gray Silicone Rubber
CODE 6, Minimum Insulator Creep Distance
CODE
1
2
3
4
DESCRIPTION
28mm/kV* (optional)
35mm/kV* (optional)
44mm/kV* (standard)
54mm/kV* (optional)
OPTION CODE 8, Top Terminal Plating
CODE
A
T
N
DESCRIPTION
Silver Plated
Tin Plated
No Plating
DESCRIPTION
ID = 0.433"
ID = 0.500"
ID = 0.625"
ID = 0.720"
ID = 0.830"
ID = 0.925"
Special
CABLE SIZE mm_
1/0
50
2/0
70
4/0
95
300 KCMIL 150
400 KCMIL 185
535 KCMIL 395
Specify
OPTION CODE 9, Draw Lead Terminal
when Ordering code 10 = W, Braze Type
CODE
M
P
Z
DESCRIPTION
0.315" Pilot Hole
Spade
Special Size
OPTION CODE 9, Bottom Terminal
when Ordering Code 10 = T, threads
CODE
X
K
L
Z
22
CODE
D
E
F
Z
DESCRIPTION
IEEE/ANSI FIG. 3.4
IEEE/ANSI FIG. 3.5
IEEE/ANSI FIG, 3.6
Special Plate
OPTION CODE 9, Bottom Terminal
when Ordering Code 10 = S, Spade
CODE
Y
X
Z
DESCRIPTION
2 Hole Spade
4 Hole Spade
Special Spade
OPTION CODE 10
OPTION CODE 9, Draw Lead Terminal
when Ordering Code 10 = R, Crimp Type
CODE
H
J
K
L
N
O
Z
OPTION CODE 9, Bottom Terminal
when Ordering Code 10 = P, Plate (Breaker)
DESCRIPTION
1 1/2" - 12 UNF Threads
2" - 12 UNF Threads
3" - 12 UNF Threads
Special Threads
CODE
P
R
S
T
W
Z
DESCRIPTION
Bottom Terminal is a Plate
Crimp Type Draw Lead Terminal
Bottom Terminal is a Spade
Bottom Terminal is a Threaded Stud
Braze Type Draw Lead Terminal
Special
OPTION CODE 11 & 12 (For future use)
Code Z indicates something special is required. If a
specific requirement is not covered by the above codes
the letter Z can be used in the option code. The
required special option or accessory must be fully
detailed and be reviewed by Trench before an order is
accepted. If a Z option code does not appear in a
specific option code table there can not be a special
requirement for the option or accessory.
If a bushing is ordered with or without a draw lead
terminal, option codes 9 and 10 will not appear on the
outline drawing. The draw lead terminal option codes
will appear on the order acknowledgment if ordered
with the bushing.
If a bushing is ordered with a draw lead adapter then
codes 9 and 10 will be Z. The Z will not appear on the
outline drawing for that bushing.
A special paint color on the bushing head would appear
as a Z in ordering code 11 and then be assigned a
specific option code for the color.
Notes
23
Trench Facilities
The Trench Group is your
partner of choice for electrical
power transmission and
distribution solutions today;
and for the development of
your new technology solutions
of tomorrow.
Trench® Austria GmbH
Paschinger Strasse 49
Postfach 13
A-4060 Linz-Leonding
Austria
Phone: 43-732-6793-0
Fax: 43-732-671341
Trench® Limited
Instrument Transformer Division
390 Midwest Road
Scarborough, Ontario
Canada M1P 3B5
Phone: 416-751-8570
Fax: 416-751-6952
Trench® Brasil Ltda
Via Expressa de Contagem, 2685
Contagem, Minas Gerais
CEP 32370-485
Brazil
Phone: 55-31-3391-5959
Fax: 55-31-3391-1828
Trench® Limited
Power Line Carrier Division
815 Middlefield Road, Unit 6A
Scarborough, Ontario
Canada M1V 1R9
Phone: 416-291-8544
Fax: 416-291-5581
Trench® China
MWB (Shanghai) Co., Ltd.
No. 3658, Jiancheng Road
Minhang, Shanghai
Peoples Republic of China
200245
Phone: 86-21-54720088
Fax: 86-21-54723118
Trench® France S.A.
16, Rue du Général Cassagnou
B.P. 70 F-68 302
St. Louis, Cedex
France
Phone: 33-3 89-70-2323
Fax: 33-3 89-67-2663
Trench® Fushun
Dong Er Dao, Shuncheng District
Fushun, Liaoning Province
Peoples Republic of China
113126
Phone: 86-413-7644009/7644007
Fax: 86-413-7641423
Trench® Limited
Bushing Division
432 Monarch Avenue
Ajax, Ontario
Canada L1S 2G7
Phone: 905-426-2665
Fax: 905-426-2671
Trench® Limited
Coil Product Division
71 Maybrook Drive
Scarborough, Ontario
Canada M1V 4B6
Phone: 416-298-8108
Fax: 416-298-2209
Trench® Germany GmbH
Nürnberger Strasse 199
D-96050 Bamberg
Germany
Phone: 49-951-1803-0
Fax: 49-951-1803-224
Trench® Switzerland AG
Lehenmattstrasse 353
CH-4052
Basel
Switzerland
Phone: 41-61-315-51-11
Fax: 41-61-315-59-00
Trench® (UK) Limited
South Drive
Hebburn
Tyne & Wear
NE 31 1 UW
Phone: 44-191-483-4711
Fax: 44-191-430-0633
www.trenchgroup.com
Bulletin E8322.72
Subject to change without notice (07.2007)
Printed in Canada.