ABB ST-E Series User manual

— ST-E Earthing switch 24 kV
—
INSTRUCTION MANUAL
ST-E Earthing switch
24 kV
• Safety
• Reliability
• Flexibility

—
Table of contents
005
005
006 – 007
008
009
1 Summary
2 Technical data
3 Structure and function
4 Maintenance
5 Drawings

4ST-E EARTHING SWITCH INSTRUCTION MANUAL
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Safety always comes first！
That's why our instruction manual begins with
these recommendations.
• Only install switchgear in enclosed rooms
suitable for electrical equipment
• Ensure that installation, operation and
maintenance are carried out by specialist
electricians only
• Fully comply with the legally recognized
standards, the connection conditions of the
local electrical utility and the relevant safety
at work regulations
• Observe the relevant information in the
instruction manual for all actions involving
switchgear
Danger!
• Pay special attention to the hazard notes in the
instruction manual marked with this warning
symbol
• Make sure that the specified criteria are not
exceeded under switchgear operation and
maintenance
• Ensure the instruction manual is accessible to
all personnel involved in installation , operation
and maintenance
• The user’s personnel must act responsibly in
all matters relating to safety at work and
correct handling of the switchgear
If you have any further questions on this instruction manual, the
members of our field organization will be pleased to provide the
required information.

5SUMMARY/TECHNICAL DATA
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1 Summary
1.1 General
Earthing switches of series ST-E are determined
for indoor installation and conform to the
requirements of GB/T 1985 and IEC 62271-102.
They are fitted with snap-action operating
mechanisms for positive high-speed closing and
sufficiently dimensioned to conduct the rated
short-circuit making current when closed under
load. This mechanism is capable of achieving up
to 2,000 mechanical operations.
The earthing switches are supplied as kits with
a pre-assembled active part and corresponding
earthing contacts supplied loose. Correct
installation of these parts in a switchgear panel
results in a functioning earthing switch.
Routine tests to GB/T 1985 or IEC 62271-102 are
to be carried out at assembling site accordingly.
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2 Technical data
Earthing switch
Type
ST-E-210
ST-E-275
Pole centers
P
mm
210
275
Rate voltage
U
kV
24
24
Rated lightning impulse
withstand voltage
U1
kV
125
125
Rated short-time
withstand current
Ik
kA
31.5
25
50
31.5
25
50
Rated short-circuit
duration
tk
s
3
4
1
3
4
1
Rated peak
tolerance current
Ip
kA
80
80
125
80
80
125

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3 Structure and function
Earthing switches of series ST-E have three pairs
of earthing blades which are located on the
operating shaft and are able to move freely. The
pairs of earthing blades are electrically connected
to each other by a short-circuiting bridge and to
earth potential at the bearing brackets by two
stranded copper conductors. Driver levers and
toggle springs located between the bearing
brackets are used to transmit the force during
the switching process. Fixing the active part on
a torsionally rigid switchgear panel wall or
crossbeam provides it with the necessary stability.
The earthing contacts designed to suit the relevant
switch type are to be bolted to the conductor bars
supported on suitable insulating parts, e.g. pintype
insulators, on the opposite side and parallel to
each other, and the position adjusted until it
conforms to that show in the dimensional
drawings.
6ST-E EARTHING SWITCH INSTRUCTION MANUAL
123456
1 Driving shaft
2 Toggle spring
3 Actuating shaft
4 Earthing conductor
5 Short-circuiting bridge
6 Earthing blade
—
Figure 1: Example of
the active part of an
earthing switch
mounted on a
switchgear panel
partition (without
fixed earthing
contacts)
—
Figure 1
The earthing switch has a snap action closing
mechanism which functions independently of
the rotation of the drive shaft. The switching
speed and torque achieved in this process are
independent of the actions of the operating
mechanism.
In the opening process, in contrast, the toggle
springs have no effect on the speed of contact
separation.
A ring lever or suitable manual or motorized
operating mechanism with the necessary torque
for the type of switch and an operating angle 90°
can be fitted for operation of the switch.
Note:
Always open earthing switches by turning until
the stop is reached.
The earthing switches can also be fitted with an
auxiliary switch for indication purposes.

7STRUCTURE AND FUNCTION
6 Earthing blade
7 Fixed earthing contact
6 7 6 7
—
Figure 2: Example of
an earthing switch
mounted in a
switchgear panel,
shown in the closed
position
—
Figure 2

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4 Maintenance
Closing of the switch several times under load
conditions (maximum two closing operations at
100 % of the rated short-circuit making current)
makes inspection and possibly maintenance
necessary. The electrical and mechanical
functions of the switch must not be adversely
affected, and only slight contact welding is
permissible. The pairs of earthing blades and
the earthing contacts should be replaced if
necessary.
Otherwise, it is advisable to carry out inspection
and maintenance of the earthing switches at
appropriate intervals together with the switchgear,
particularly in exceptional operating conditions
and/or under adverse environmental influences
such as pollution and aggressive air.
• Check whether the operating mechanism
functions smoothly and easily
• Carry out general visual examination for the
condition of mechanical fasteners, dirt, moisture
and corrosion
• Remove any dust deposits on insulating parts
with a dry, soft cloth (do not use cleaning wool)
• Regrease the mechanically movable parts and
contacts (applying grease thinly) using Isoflex
Topas NB 52 lubricant
8ST-E EARTHING SWITCH INSTRUCTION MANUAL

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5 Drawings
9DRAWINGS
Earth position
Open position

1YHA000250_EN 2018.12
© Copyright 2018 ABB. All rights reserved.
Specifications subject to change without notice.
—
ABB Xiamen Switchgear Co., Ltd.
No.885, FangShanXiEr Road, Xiang'an District,
Xiamen, Fujian, 361101
Tel: [phone]
Fax: [phone]
ABB China Customer Service Hot Line:
TEL: [phone]
mail: [e-mail]
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