Siemens NXPLUS C User manual

Medium-Voltage Switchgear
Fixed-mounted circuit-breaker switchgear type NXPLUS C up to 38 kV, Extendable
Single busbar, metal-enclosed, gas-insulated
M edium-Volt age S witchgear
INSTALLATION AND
OPERATING
INSTRUCTIONS
Order No.: 806-9004.9
Revision: 02
Issue: 02-11-2018

2/266 Revision 02 • INSTALLATION AND OPERATING INSTRUCTIONS • NXPLUS C • 806-9004.9
About these Instructions
In order to provide a clear overview, these instructions do
not contain all detailed information on every product type.
They can also not provide for every possible contingency to
be met in connection with installation or operation.
For details about technical design and equipment such as
technical data, secondary equipment and circuit diagrams,
please refer to the order documents.
The switchgear is subject to continuous technical
development within the scope of technical progress. If not
stated otherwise on the individual pages of these
instructions, we reserve the right to modify the specified
values and drawings. All dimensions are given in mm.
For further details, including about additional equipment,
please refer to catalog HA 35.41.
If more information is desired or particular problems arise
which are not covered in sufficient detail by these
instructions, please contact the applicable Siemens
department to request the necessary information.
The contents of this instruction manual shall not become
part of or modify any prior or existing agreement,
commitment or relationship. The Sales Contract contains
the entirety of obligations of Siemens. The warranty
contained in that contract between the parties is the full
and only warranty provided. Any statements contained
herein do not create new warranties or modify the existing
warranty.

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Contents
Safety instructions ............................................. 6
1 Signal terms and definitions ............................... 6
2 General instructions ........................................... 7
3 IT security .......................................................... 9
4 Due application ..................................................9
5 Qualified personnel ............................................ 9
Description ....................................................... 10
6 Features........................................................... 10
7 Panel versions ..................................................11
8 Examples for panel versions ............................. 11
9 Components .................................................... 15
9.1 Circuit-breaker ................................................. 15
9.2 Vacuum contactor ............................................ 16
9.3 Three-position disconnector ............................. 16
9.4 Three-position switch-disconnector .................. 16
9.5 Operating mechanisms for
three-position switch........................................ 17
9.6 Voltage transformers........................................ 18
9.7 Current transformers ........................................ 20
9.8 HV HRC fuse assembly ......................................21
9.9 Busbar system ..................................................21
9.10 Cable connection ............................................. 22
9.11 Ready-for-service indicator ............................... 34
9.12 Interlocks ......................................................... 34
9.13 Voltage detecting systems................................ 35
9.14 Accessories ...................................................... 36
10 Technical data..................................................38
10.1 General technical data...................................... 38
10.2 Circuit-breaker panel ........................................ 39
10.3 Switch-disconnector panel................................ 43
10.4 Disconnector panel .......................................... 43
10.5 Vacuum contactor panel with HV HRC fuses......43
10.6 Bus sectionalizer panel ..................................... 44
10.7 Auxiliary transformer panel with
HV HRC fuses.................................................... 44
10.8 Metering panel (gas-insulated) ......................... 45
10.9 Metering panel (air-insulated) .......................... 45
10.10 Ring-main panel ............................................... 45
10.11 Current and voltage transformers ..................... 45
10.12 Classification of NXPLUS C according to
IEC 62271-200 ................................................. 45
10.13 Standards, specifications, guidelines................. 46
10.14 Selection of HV HRC fuse-links .......................... 47
10.15 Insulating gas................................................... 61
10.16 Rating plates .................................................... 62
11 End of life ........................................................ 63
Installation........................................................ 64
12 Building codes.................................................. 64
12.1 Switchgear room.............................................. 64
12.2 Construction data for the foundation................ 66
12.3 Transport units................................................. 74
13 Before installation ............................................ 75
13.1 Preliminary clarifications................................... 75
13.2 Intermediate storage ........................................ 75
13.3 Tools and auxiliary means................................. 76
13.4 Cleaning agents and cleaning aids.................... 77
13.5 Mounting paste................................................ 77
13.6 Tightening torques........................................... 78
13.7 Comments on electromagnetic compatibility .... 78
14 Unloading and erecting the switchgear............. 80
14.1 Packaging and transport unit ............................ 80
14.2 Completeness and transport damage................ 80
14.3 Unloading and transporting to the place of
installation....................................................... 81
14.4 Checking service readiness ............................... 83
15 Assembling the switchgear............................... 84
15.1 Aligning and joining the panels ........................ 85
15.2 Fastening the panel to the foundation ..............87
15.3 Removing transport braces ............................... 88
15.4 Installing the busbars ....................................... 88
15.5 Installing the busbar support ............................99
15.6 Installing a current transformer on
the busbar...................................................... 101
15.7 Installing a voltage transformer on
the busbar...................................................... 102
15.8 Interconnecting the earthing busbars .............109
15.9 Earthing the switchgear ................................. 110
15.10 Installing the low-voltage compartment ......... 110
15.11 Installing the horizontal pressure
relief duct ...................................................... 111
15.12 Installing the switchgear termination.............. 121
15.13 Installing the busbar covers ............................ 122
15.14 Extension with individual panels..................... 127
16 Installing the air-insulated metering panel ...... 128
16.1 Installing instrument transformers in
the metering panel......................................... 128

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16.2 Replacing instrument transformers in
the air-insulated metering panel .................... 140
16.3 Mounting earthing accessories in
the air-insulated metering panel .................... 141
17 Installing the auxiliary transformer panel........ 144
17.1 Mounting the lateral cable connection ........... 144
17.2 Installing the transformer in the auxiliary
transformer panel .......................................... 149
18 Electrical connections .................................... 157
18.1 Installation work at the floor cover ................. 157
18.2 Connecting cable T-plugs ............................... 159
18.3 Installing the surge arresters .......................... 164
18.4 Installing the surge limiter.............................. 164
18.5 Connecting auxiliary circuits........................... 165
19 Installation of the IP31D, IP32D and
IP34D degree of protection designs ................ 170
19.1 IP31D - protection against
vertically falling water drops .......................... 170
19.2 IP32D - protection against
vertically falling water drops for
switchgear inclined up to 15° ......................... 173
19.3 IP34D - Protection against
splashing water from any direction ................ 174
20 Commissioning.............................................. 175
20.1 Final work...................................................... 175
20.2 Checking the accessories................................ 176
20.3 Instructing operating personnel ..................... 176
20.4 Functional test/test operation......................... 177
20.5 Performing the power-frequency
voltage test.................................................... 180
20.6 Primary injection test ..................................... 181
20.7 Correcting circuit diagrams ............................ 181
20.8 Applying operating voltage ............................ 182
21 Recurring activities......................................... 184
21.1 Removing and mounting the front cover ........ 184
21.2 Removing and mounting the connection
compartment covers ...................................... 185
Operation........................................................ 187
22 Control elements and indicators..................... 188
22.1 Position indicators.......................................... 189
22.2 "Spring charged" indicator.............................. 189
22.3 Operations counter ........................................ 189
22.4 Ready-for-service indicator ............................. 190
22.5 Control gate with locking device .................... 190
22.6 Locking device for pushbutton ....................... 191
22.7 Circuit-breaker locking device for
"feeder earthed"............................................. 191
22.8 Service flap.................................................... 192
22.9 Operating tools.............................................. 193
23 Operating the circuit-breaker ......................... 195
23.1 Closing the circuit-breaker.............................. 195
23.2 Opening the circuit-breaker............................ 195
23.3 Charging the closing spring............................ 195
23.4 Circuit-breaker test operation......................... 196
24 Operating the three-position disconnector ..... 197
24.1 Switching the three-position disconnector
from OPEN to CLOSED position....................... 197
24.2 Switching the three-position disconnector
from CLOSED to OPEN position....................... 197
24.3 Switching the three-position disconnector
from OPEN to READY-TO-EARTH position ........ 198
24.4 Switching the three-position disconnector
from READY-TO-EARTH to OPEN position ........ 198
24.5 Operating the three-position switch with
motor-operating mechanism.......................... 199
24.6 Emergency operation of the three-position
switch with slow motion mechanism.............. 199
25 Operating the three-position
switch-disconnector....................................... 202
25.1 Switching the three-position
switch-disconnector from
OPEN to CLOSED position............................... 202
25.2 Switching the three-position
switch-disconnector from
CLOSED to OPEN position............................... 203
25.3 Switching the three-position
switch-disconnector from
OPEN to EARTHED position............................. 203
25.4 Switching the three-position
switch-disconnector from
EARTHED to OPEN position............................. 203
25.5 Operating the three-position switch with
motor-operating mechanism.......................... 203
25.6 Protection tripping of
the switch-fuse combination .......................... 204
26 Work-in-progress earth................................... 205
27 Verification of safe isolation from supply ........ 207
27.1 LRM plug-in sockets ....................................... 207
27.2 VOIS and CAPDIS indications .......................... 209
27.3 WEGA indications........................................... 211
28 Replacing HV HRC fuse-links ........................... 212
29 Operating the feeder voltage transformer ...... 215
29.1 Switching off the feeder
voltage transformer ....................................... 215
29.2 Switching on the feeder
voltage transformer ....................................... 216

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30 Short instructions ........................................... 217
30.1 Switching circuit-breaker panels and bus
sectionalizer panels with one three-position
disconnector .................................................. 217
30.2 Operating vacuum contactor panels ............... 223
30.3 Operating the disconnector panel................... 225
30.4 Operating ring-main panels and
metering panels (gas-insulated) ..................... 226
30.5 Operating the bus sectionalizer panel with
2 three-position disconnectors ....................... 229
30.6 Operating the circuit-breaker panel with
busbar earthing switch................................... 236
30.7 Switching the air-insulated metering panel
with two three-position disconnectors............ 242
30.8 Operating the auxiliary transformer panel
and switch-disconnector panel ....................... 246
31 Cable testing .................................................. 248
Service information........................................ 250
32 Maintenance.................................................. 250
33 Checks and maintenance work in case of
special operating conditions ........................... 251
33.1 Checks on three-position switch operating
mechanisms................................................... 252
33.2 Visual check of circuit-breaker operating
mechanism .................................................... 253
33.3 Visual check of vacuum contactor
operating mechanism..................................... 254
33.4 Connection compartment interlock check ....... 254
33.5 Fuse tripping check ........................................ 255
33.6 Cleaning, greasing and lubricating
the operating mechanisms ............................. 256
33.7 Test operation of
the operating mechanisms ............................. 257
34 Permissible lubricants ..................................... 257
35 Extending the switchgear or
replacing panels and components .................. 257
Annex ............................................................. 258
36 MCU-MH
(Motor Control Unit - Module Housing)........... 258
36.1 Extract from the Technical Description............ 258
36.2 Application..................................................... 258
36.3 Design, function............................................. 258
36.4 Technical data................................................ 259
36.5 Fault signals................................................... 259
36.6 Terminal assignment of motor control unit .....260
Siemens Service Hotline ................................. 261
Index............................................................... 262

Safety instructions
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Safety instructions
1 Signal terms and definitions
The signal words "danger," "warning" and "caution" used in this instruction manual indicate
the degree of hazard that may be encountered by the user.
Symbols used ➭Operation symbol: Identifies an operation. Asks the operator to perform an operation.
✔Result symbol: Identifies the result of an operation.
DANGER
Danger - Indicates an imminently hazardous situation.
If this hazardous situation is not avoided, death or serious injury will be the consequence.
➭Observe the safety instructions.
WARNING
Warning - Indicates a potentially hazardous situation.
If this hazardous situation is not avoided, death or serious injury can be the consequence.
➭Observe the safety instructions.
CAUTION
Caution - Indicates a potentially hazardous situation.
If this hazardous situation is not avoided, minor or moderate injury can be the consequence.
➭Observe the safety instructions.
NOTICE
Notice - Indicates a potentially hazardous situation.
If this hazardous situation is not avoided, damage to property or environment can be the
consequence.
➭Observe the notes.
INFORMATION
Information - Indicates an important information or facilitation of work.
➭Observe the information.

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Safety instructions
2 General instructions
Important • The personnel must read and understand this manual before starting to work.
• Observe all safety instructions and warnings in this manual, and follow the instructions.
• Store this manual carefully, and so that it is accessible to the personnel at any time.
• This manual is a part of the product. When the switchgear is transferred, supply this manual
as well.
The switchgear corresponds to the relevant laws, prescriptions and standards applicable at the
time of delivery. If correctly used, it provides a high degree of safety by means of logical
mechanical interlocks and shockproof metal enclosure of live parts.
Independently of the safety instructions given in these operating instructions, the local laws,
ordinances, guidelines and standards for operation of electrical equipment as well as for labor,
health and environmental protection apply.
The switchgear operator or owner must keep the technical documents supplied with the
switchgear throughout the entire service life, and keep them up-to-date in case of
modifications of the switchgear.
NOTE
The illustrations included in this manual are simplified and serve to create a general
understanding. The illustrations may therefore deviate from the actual product.
INFORMATION
Preconditions for perfect and safe operation of the switchgear:
➭Observance of operating and installation instructions.
➭Qualified personnel.
➭Proper transportation and correct storage of the switchgear.
➭Correct installation and commissioning.
➭Diligent operation and maintenance.
➭Observance of the installation, operation and safety regulations applicable at the place of
installation.
WARNING
Any kind of modification on the product or alteration of the product must be coordinated
with the manufacturer in advance.
Uncoordinated modifications or alterations can cause the expiration of warranty claims,
cause danger to life, limb and other legally protected interests.
The fulfillment of the type tests (according to IEC 62271-200) may not be guaranteed
anymore. This applies especially though not exclusively to the following actions,
e.g. in the course of maintenance or repairs.
➭Use Siemens original parts only.
➭Service technicians performing replacement are trained and certified by Siemens.
➭Install or adjust parts properly.
➭Perform settings in accordance with Siemens specifications.
➭After installation and setting, have a final check performed by a service engineer approved
by Siemens, including documentation of the test results.
➭Perform maintenance according to the operating instructions of the Siemens products.

Safety instructions
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Five Safety Rules of
Electrical Engineering
The Five Safety Rules of Electrical Engineering must be complied with during operation of the
products and components described in these operating instructions:
• Isolate.
• Secure against reclosing.
• Verify safe isolation from supply.
• Earth and short-circuit.
• Cover or barrier adjacent live parts.
Hazardous substances If hazardous substances are required to perform the work, the relevant safety data sheets and
operating instructions must be observed.
Personal protective
equipment (PPE)
For switchgear with proof of internal arc classification according to IEC 62271 Part 200,
no personal protective equipment must be worn for operating the switchgear.
For switchgear without proof of internal arc classification according to IEC 62271 Part 200,
personal protective equipment must be worn for operating the switchgear.
If covers have to be removed to work on switchgear, personal protective equipment must be
worn. In case of internal arc, full personal protection is not provided, even if the personal
protective equipment is worn.
To select the protective equipment, the local laws and regulations must be observed and
accomplished.
The personal protective equipment consists of:
• Protective clothing
• Safety shoes
• Gloves
• Helmet and face protection
• Ear protection
Removing the front cover from the operating mechanism compartment
WARNING
Risk of injury due to high-speed moving parts
Parts behind the front cover can automatically move quickly and cause serious injury. Do not
remove the front cover of the operating mechanism until the following actions have been
performed:
➭To avoid impermissible switching operations, switch off auxiliary voltage, e.g.:
- Switch off the auxiliary voltage supply of the motor.
- Trip the MCB.
- Disconnect the control cables from the low-voltage compartment.
➭To discharge the spring energy store in the operating mechanism, execute the following
instructions:
- Push the manual OFF pushbutton.
- Push the manual ON pushbutton.
- Push the manual OFF pushbutton again.
➭Check if the "spring charged" indicator shows "spring not charged".
Fig. 1: "Spring not charged"
indication
Fig. 2: "Spring charged"
indication

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Safety instructions
3 IT security
The Siemens software is regularly checked for safety. If weak points are identified in the
process, which may allow third parties to access protection devices, information thereto is
distributed through the SIPROTEC and SICAM Security Update Report Newsletter.
The Newsletter can be subscribed to at the following website:
www.siemens.com/gridsecurity
Before commissioning the switchgear, it must be verified that the current firmware version is
installed on the protection devices. The latest version of firmware can be obtained from the
following website:
http://w3.siemens.com/smartgrid/global/en/products-systems-solutions/downloads/
Pages/Overview.aspx
For information to updates for other makes of protection devices, please contact the
respective manufacturer.
4 Due application
Extendable fixed-mounted circuit-breaker switchgear NXPLUS C with single busbar is used in
transformer and distribution substations as well as for switching duties in industrial plants.
The application area extends to rated voltages up to 38 kV and rated operating currents up to
2500 A. In distribution networks up to 38 kV, a maximum short-circuit current of 31.5 kA is
permissible (type-dependent).
5 Qualified personnel
Qualified personnel in accordance with these instructions are persons who have been instructed
by the Switchgear Factory Frankfurt (participation in an assembly and installation training with
certificate), who are familiar with transport, installation, commissioning, maintenance and
operation of the product, and who have appropriate qualifications for their work.
• Training and instruction or authorization to switch on, switch off, earth and identify power
circuits and equipment / systems as per the relevant safety standards.
• Training regarding the applicable specifications for the prevention of accidents and the use
of appropriate safety equipment.
• Training in first aid and behavior in the event of possible accidents.

Description
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Description
6 Features
Technology • Factory-assembled, type-tested and metal-enclosed switchgear for indoor installation
• Stainless-steel vessel welded gas-tight
• Gas-insulated switching-device compartment
• Cable connection and busbar, single-pole insulated
• Installation and extension of the switchgear can be performed without gas work
• Screened busbar, silicone-rubber insulated
• Cable connection with cable plugs from the front
• Maintenance-free under normal operating conditions
Insulating gas Insulating gas insulates live parts from each other and from the vessel wall. In panels with
switch-disconnectors, the insulating gas is also used to extinguish the arc.
The switchgear is delivered ex works with gas filling ready for service. The gas filling is
provided to last the total service life of the switchgear.
Personal safety • Safe-to-touch due to metal enclosure of live parts
• Clear mimic diagram with mechanical switch position indicators
• HV HRC fuses are accessible only when outgoing feeders are earthed
• Logical mechanical interlocking
• Capacitive voltage detecting system to verify safe isolation from supply
• Earthing of feeders by means of make-proof earthing switch (this does not apply to
disconnector panels)
• Resistance to arcing
- Pressure-resistant design of connection compartments
- Rear pressure relief duct
Security of operation and
availability
• Hermetically sealed primary enclosure independent of environmental effects, such as dirt,
humidity and small animals
• Welded switchgear vessel, sealed for life
• Circuit-breaker operating mechanism accessible outside the switchgear vessel
• Incorrect operation is virtually eliminated due to interlocks and logical arrangement of
elements of the operating mechanism
• Self-monitoring ready-for-service indicator, easy to read, independent of temperature and
environmental pressure variations, with contactless measured-value acquisition and with
signaling switch (option) 1 changeover contact for telecommunication
• Minimum fire load
• Switchgear vessel designed as a "sealed pressure system" according to IEC 62271-200,
i.e. the insulating gas filling requires no maintenance
Cost-efficiency Extremely low lifecycle costs and maximum availability thanks to:
• Maintenance-free design under normal operating conditions (for the service life)
• Minimum space requirement
• Long service life
Seismic withstand
capability (option)
NXPLUS C switchgear can be upgraded for regions at risk from earthquakes. For this upgrade,
earthquake qualification testing has been carried out in accordance with the following
standards:
• IEC 60068-3-3 "Guidance – Seismic test methods for equipment"
• IEC 60068-2-57 "Test Ff: Vibration – Time-history method"
• IEC 60068-2-59 "Test Fe: Vibration – Sine-beat method"

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Description
• IEEE 693-2005 "Recommended Practice for Seismic Design of Substations".
For installation on even and rigid concrete or steel structure (without considering building
influences), the tested ground accelerations meet the following requirements:
• Uniform Building Code 1997 (UBC) – Zone 4
• California Building Code 1998 (CBC) – Zone 4
• IEEE 693-2005 – High required response spectrum.
7 Panel versions
8 Examples for panel versions
Panel type Panel width
[mm]
LS Circuit-breaker panel 450/600
TR Switch-disconnector panel with HV HRC fuses 600
ME Metering panel 600
VS Vacuum contactor panel with HV HRC fuses 600
RK Ring-main panel 450
LK Bus sectionalizer panel (single bay) 1 x 600
1x 900
Bus sectionalizer panel (double bay) 2 x 600
TS Disconnector panel 600
aME Air-insulated metering panel 900
EB Auxiliary transformer panel with switch-fuse combination 900
Fig. 3: Circuit-breaker panel
①Voltage transformer at the busbar (option)
②Current transformer at the busbar (option)
③Pressure relief duct
④Busbar
⑤Switching-device vessel with circuit-breaker and
three-position disconnector
⑥Current transformer at the cable connection
(option)
⑦Voltage transformer (option)
⑧Feeder cables with cable plugs
⑨Current transformer (option)
⑩Cable compartment cover
⑪Front cover with control board
⑫Bay controller (option)
⑬Low-voltage compartment

Description
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Fig. 4: Switch-disconnector panel
①Pressure relief duct
②Busbar
③Switching-device vessel with three-position switch-
disconnector
④Fuse assembly with HV HRC fuses
⑤Current transformer (option)
⑥Feeder cables with cable plugs
⑦Cable compartment cover
⑧Front cover with control board
⑨Low-voltage compartment
Fig. 5: Metering panel
①Pressure relief duct
②Current transformer at the busbar (option)
③Busbar
④Switching-device vessel with three-position
switch-disconnector
⑤Fuse assembly with HV HRC fuses
⑥Voltage transformer (option)
⑦Instrument transformer compartment cover
⑧Front cover with control board
⑨Low-voltage compartment
Fig. 6: Vacuum contactor panel with HV HRC
fuse assembly
①Pressure relief duct
②Busbar
③Switching-device vessel with vacuum contactor
and three-position switch-disconnector
④Fuse assembly with HV HRC fuses
⑤Current transformer (option)
⑥Cable compartment cover
⑦Front cover with control board
⑧Low-voltage compartment

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Description
Fig. 7: Ring-main panel
①Pressure relief duct
②Busbar
③Switching-device vessel with three-position switch-
disconnector
④Feeder cables with cable plugs
⑤Cable compartment cover
⑥Front cover with control board
⑦Low-voltage compartment
Fig. 8: Bus sectionalizer panel
①Pressure relief duct
②Busbar
③Switching-device vessel with three-position
disconnector
④Connection compartment cover
⑤Front cover with control board
⑥Low-voltage compartment
Fig. 9: Disconnector panel
①Pressure relief duct
②Busbar
③Switching-device vessel with three-position
disconnector
④Feeder cables with cable plugs
⑤Cable compartment cover
⑥Front cover with control board
⑦Low-voltage compartment

Description
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Fig. 10: Air-insulated metering panel
①Pressure relief duct
②Busbar
③Switchgear vessel
④Current transformer
⑤Voltage transformer
⑥Instrument transformer compartment cover
⑦Front cover
⑧Low-voltage compartment
Fig. 11: Auxiliary transformer panel
①Pressure relief duct
②Busbar
③Switching-device vessel
④Fuse assembly with HV HRC fuses
⑤Auxiliary transformer
⑥Transformer compartment cover
⑦HV HRC fuse assembly cover
⑧Control board
⑨Low-voltage compartment

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Description
9 Components
9.1 Circuit-breaker
Design The Siemens vacuum circuit-breaker (VCB) is a three-pole indoor circuit-breaker for rated
voltages from 7.2 kV to 38 kV.
The operating mechanism accommodates all electrical and mechanical components required
for closing and opening the circuit-breaker. The removable front cover of the operating
mechanism contains the openings for the control elements and indicators.
The circuit-breaker is closed by pressing the ON pushbutton. After closing, the motor
recharges the closing spring. If the motor supply voltage fails, the closing spring can be
charged manually.
Equipment The basic version of the circuit-breaker is equipped as follows:
• Electrical operating mechanism (charging motor) with mechanical and electrical anti-
pumping device (-M1)
• Closing solenoid (-Y9)
• Shunt release (-Y1)
• Low-voltage plug connector (-Q0)
• Auxiliary switch with 4NO + 4NC or 3NO + 4NC freely available (-S1)
• Position switch for "closing spring charged" signal (-S4)
• Circuit-breaker tripping signal, cutout switch (-S6)
• Operations counter
• Feeder locking device
• Interlocking between feeder locking device and three-position disconnector (circuit-breaker
only lockable in earthed position)
Can be ordered optionally.
• Extended auxiliary switch with 10NO + 6NC or 9NO + 6NC freely available (-S1)
• Shunt release (-Y2)
• Undervoltage release (-Y7)
• Current-transformer release (-Y4)
• Low-energy current-transformer release (-Y6)
• Closing solenoid (-Y8)
• Circuit-breaker tripping signal (-S7/-S8)
• Interlocking of feeder locking device against three-position disconnector and cable
compartment cover
- Circuit-breaker only lockable in earthed position
- Cable compartment cover only removable in earthed position
Possible release combinations
Release Release combination
1 2 3 4 5
1st shunt release Type 3AY1410 X X X – X
2nd shunt release Type 3AX1101 – X – – –
C.t.-operated release Type 3AX1102; 0.5 A or – – X X –
Type 3AX1104; 0.1 Ws
Undervoltage release Type 3AX1103 – – – – X
X: 1 no. of each release. A maximum of 2 releases can be combined only.

Description
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9.2 Vacuum contactor
Design The Siemens high-voltage vacuum contactor is a three-pole indoor contactor for the rated
voltage range from 7.2 kV to 24 kV. The vacuum contactor can be controlled by remote and
has an electromagnetic operating mechanism suitable for high switching rates and unlimited
operating time. The electromagnetic operating mechanism is suitable for AC operation or
DC operation.
The operating mechanism box accommodates all electrical and mechanical components
required for closing and opening the vacuum contactor.
The vacuum contactor has opening springs to ensure that the vacuum contactor switches off
if the supply voltage fails.
Equipment The basic version of the vacuum contactor is equipped as follows:
• Electromagnetic operating mechanism for unlimited operating time
• Auxiliary switch with 3NO + 4NC freely available
Can be ordered optionally.
• Extended auxiliary switch with 5NO + 6NC freely available
• Mechanical closing latch
9.3 Three-position disconnector
The three-position disconnector combines the DISCONNECTING and READY-TO-EARTH
functions with the switch positions CLOSED – OPEN – READY-TO-EARTH.
Application:
• Circuit-breaker panel of 630 A to 1250 A
• Disconnector panel of up to 1250 A
• Bus sectionalizer panel of 1000 A to 1250 A
• Air-insulated metering panel
In circuit-breaker panels, earthing and short-circuiting the feeder is done by closing
the vacuum circuit-breaker.
In disconnector panels, earthing and short-circuiting the busbar is done by closing
the vacuum circuit-breaker.
Equipment The basic version of the three-position disconnector is equipped as follows:
• Auxiliary switch, freely available
- In READY-TO-EARTH function with 6NO + 6NC
- In DISCONNECTING function with 6NO + 6NC
• Manual operating mechanism
• Mechanical interlocking to the circuit-breaker
Can be ordered optionally.
• Motor operating mechanism
• Electromechanical interlock
9.4 Three-position switch-disconnector
The three-position switch-disconnector combines the LOAD BREAKING, DISCONNECTING and
EARTHING functions with the switch positions CLOSED – OPEN – EARTHED.
Application:
• Switch-disconnector panel
• Ring-main panel
• Vacuum contactor panel
• Metering panel
• Auxiliary transformer panel

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Description
Equipment The basic version of the three-position switch-disconnector is equipped as follows:
• Auxiliary switch, freely available
- In EARTHING function with 6NO + 6NC
- In DISCONNECTING function with 6NO + 6NC
• Manual operating mechanism
• Mechanical interlocking (connection compartment cover can be removed only in the
earthed position)
Can be ordered optionally.
• Motor operating mechanism
• Electromechanical interlock
9.5 Operating mechanisms for three-position switch
The three-position disconnector and the three-position switch-disconnector are operated from
the switchgear front using the operating mechanisms.
Operating mechanisms
Options for all operating
mechanisms
•Motor operating mechanism
- Remote operation (standard) applied to terminal
- Local operation by momentary-contact rotary control switch (option)
- Manual operation possible with operating lever
•Shunt release (f-release)
- Spring-operated/stored-energy mechanisms can be equipped with a shunt release. Remote
electrical tripping of the three-position switch-disconnector is possible via the magnetic coil
of the shunt release, e.g. transformer overtemperature tripping.
•Wiring
- Auxiliary switches, motor operating mechanisms or shunt releases are wired to terminal
strips in the low-voltage compartment.
Slow motion mechanism Spring-operated mechanism Spring-operated/stored-energy mechanism
Application:
• Circuit-breaker panel
• Air-insulated metering panel
• Disconnector panel
• Bus sectionalizer panel
Application:
• Ring-main panel
• Metering panel
• Vacuum contactor panel with HV HRC fuses
Application:
• Auxiliary transformer panel
• Switch-disconnector panel
Feature
• Rotary lever mechanism 180°
Feature
• Rotary lever mechanism 90°
Feature
• Rotary lever mechanism 90°
• Additional energy store for the "stored-energy
OPEN" function after tripping by HV HRC fuse or
shunt release

Description
18/266 Revision 02 • INSTALLATION AND OPERATING INSTRUCTIONS • NXPLUS C • 806-9004.9
9.6 Voltage transformers
Voltage transformers of the 4MT2, 4MT3, 4MT26, 4MU1 or 4MR type in the NXPLUS C
switchgear can be installed as an option.
Common features
• According to VDE 0414-9-3 and IEC 61869-3
• Cast-resin insulated
• Inductive type
• Arranged outside the primary enclosure (switching-device vessel)
Mounting locations
Features of the instrument transformer types
Busbar Panel connection Instrument transformer
compartment
Instrument transformer types
• 4MT2 (up to 24 kV) • 4MT26 (up to 38 kV) • 4MT3 (up to 24 kV) • 4MU1 (up to 38 kV) • 4MR (up to 24 kV)
Panel types
• Circuit-breaker panel
• Switch-disconnector panel
with fuses
• Vacuum contactor panel
with fuses
• Ring-main panel
• Auxiliary transformer panel
• Bus sectionalizer panel (LK-LS)
• Disconnector panel
• Circuit-breaker panel
• Disconnector panel
• Circuit-breaker panel (600 mm)
• Disconnector panel
• Metering panel
• Circuit-breaker panel
• Disconnector panel
• Air-insulated metering
panel
4MT2, 4MT26 4MT3, 4MU1 4MR
• Pluggable in the cross adapters of the busbar
• No separate metering panel required
• Repeat test at 80 % of the rated short-duration
power-frequency withstand voltage possible with
mounted voltage transformer
• Touchable due to metal enclosure
• Safe-to-touch due to the metal enclosure of
the switchgear
• Pluggable
• Switchable through gas-insulated disconnecting
facility in the switching-device vessel
• Switch position: "CLOSED" and "EARTHED"
• Operation of the disconnecting facility from outside
through a metal bellows welded in the switching-
device vessel.
• Voltage testing on switchgear and cable possible with
mounted and earthed voltage transformer
• Not suitable for 80 % of the rated short-duration
power-frequency withstand voltage (disconnect and
earth the voltage transformer through the
disconnecting facility)
• Block-type voltage transformer
• Mounted on instrument
transformer cassette
• Connection via flexible wire
• Air-insulated

806-9004.9 • INSTALLATION AND OPERATING INSTRUCTIONS • NXPLUS C • Revision 02 19/266
Description
Conformity of voltage
transformers
The voltage transformer can be used as measuring transformer.
The approval symbol for the voltage transformer is located on the type plate.
The approval symbol is valid throughout the entire service life of the voltage transformer.
Observe deviating country-specific statutory regulations, if applicable.
For an inspection by a calibration office or an officially recognized inspecting authority,
the test adapter (802-8061.3) shown below can be installed on voltage transformer 4MT3.
The test adapter can be procured from the regional Siemens representative.
Fig. 12: Installing the test adapter on
voltage transformer 4MT3
①Secondary lead
②Connection of measuring
equipment

Description
20/266 Revision 02 • INSTALLATION AND OPERATING INSTRUCTIONS • NXPLUS C • 806-9004.9
9.7 Current transformers
In NXPLUS C switchgear, the following current transformers can optionally be installed:
• Type 4MC4
• Type 4MA7
• Type 4MC7
Common features • Safe-to-touch due to the metal enclosure of the switchgear
• Insulation class E
Mounting locations
Busbar Panel connection Cable Longitudinal panel
interconnection
Instrument transformer
compartment
Instrument transformer type
4MC4 4MC4 4MC4 4MC7 4MA7
Panel types
• Circuit-breaker panel
• Auxiliary transformer
panel
• Air-insulated metering
panel (at busbar - busbar)
• Disconnector panel
• Switch-disconnector panel
with fuses
• Vacuum contactor panel
with fuses
• Ring-main panel
• Bus sectionalizer panel
(LK-TS)
• Circuit-breaker panel
• Disconnector panel
• Switch-disconnector panel
• Ring-main panel
• Vacuum contactor panel
with fuses
• Circuit-breaker panel • 2-panel bus sectionalizer • Air-insulated metering
panel
Features
• Diameter:
55/150 mm ≤1250 A
• Oval design >1250 A
• Max. height 170 mm
• Diameter:
106/190 mm at ≤1250 A
• Oval design >1250 A
• Max. height 122 mm at LS
(450 mm)
• Max. height 214 mm
for shielded cables
• Diameter:
55/150 mm ≤1250 A
• Oval design >1250 A
• Max. height 170 mm
• Diameter: 55/125 mm
• Max. height 150 mm
• Designed as indoor block-
type current transformer,
1-pole
• Dimensions according to
DIN 42600 Part 8
• Secondary connection by
means of screw-type
terminals
• Cast-resin insulated
• Arranged outside the primary enclosure (switching-device vessel) due to single-pole design of cable connection and
busbar
• Free of dielectrically stressed cast-resin parts (due to design)
Designed as ring-core current transformer:
• Ring core as carrier of secondary winding
• Main circuit corresponds to primary winding