Siemens NXAIR M User manual

Medium-Voltage Switchgear
Air-Insulated Switchgear NXAIR M
24 kV / 25 kA / ≤ 2500 A Busbar Current
OPERATING INSTRUCTIONS
Order No.:
139-2021.9
Issue:
September 2018
Revision:
07
© Siemens AG 2018 All rights reserved.

2 NXAIR M 139-2021.9 / 07
About these Instructions
These instructions do not purport to cover all details
or variations in equipment. 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
like e.g. technical data, secondary equipment, 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, e.g. about additional equipment,
please refer to catalog HA 25.71.
Should further information be desired or should
particular problems arise which are not covered
sufficiently by these instructions, the matter should
be referred to the competent Siemens department.
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 entire obligations of Siemens.
The warranty contained in the contract between the
parties is the sole warranty of Siemens.
Any statements contained herein do not create new
warranties or modify the existing warranty.

139-2021.9 / 07 NXAIR M 3
Safety instructions
1 Safety instructions
Hazards are classified in accordance with ISO 3864-2 using the following keywords:
DANGER, WARNING or CAUTION, in case of personal injury
NOTICE for material damage
Hazards are classified and indicated in the Installation Instructions as follows:
DANGER
Signal word indicates an immediate and imminent hazardous situation.
If the hazard is not avoided, death or serious injury will be the consequence.
WARNING
Signal word indicates a potentially hazardous situation.
If the hazardous situation is not avoided, death or serious injury can be the
consequence.
CAUTION
Signal word indicates a potentially hazardous situation.
If the hazardous situation is not avoided, minor or moderate injury can be the
consequence.
Definitions and symbols
NOTICE
Indicates a potentially damaging situation.
If the damaging situation is not avoided, the product or something in its vicinity
may sustain damage.
HINT
Provides additional information to clarify or simplify a procedure.
Observe the hint.
Operation symbol:
Asks the operator to perform an operation.
Result symbol:

Identifies the result of an operation.

4 NXAIR M 139-2021.9 / 07
Contents
1Safety instructions................................................................................................................................... 3
2General instructions................................................................................................................................. 8
2.1 General instructions........................................................................................................................................ 8
2.2 Five Safety Rules of Electrical Engineering .................................................................................................... 8
2.3 Hazardous substances ................................................................................................................................... 8
2.4 Personal protective equipment (PPE)............................................................................................................. 9
2.5 Due application............................................................................................................................................... 9
2.6 Qualified personnel......................................................................................................................................... 9
2.7 Update of the firmware of protection relays....................................................................................................10
3Features................................................................................................................................................... 11
4Technical data......................................................................................................................................... 12
4.1 Complete switchgear .....................................................................................................................................12
4.2 Basic prescriptions and standards.................................................................................................................12
4.3 Electromagnetic compatibility - EMC .............................................................................................................13
4.4 Rating plates..................................................................................................................................................13
4.5 IAC classification............................................................................................................................................13
4.6 Panel dimensions...........................................................................................................................................14
4.7 Room planning...............................................................................................................................................14
4.8 Operating conditions......................................................................................................................................14
4.9 Vacuum circuit-breaker type 3AE...................................................................................................................15
4.10 Operating instructions for circuit-breaker type 3AE........................................................................................15
5Overview of panel types ........................................................................................................................ 16
6Panel design ........................................................................................................................................... 18
6.1 Basic design circuit-breaker panel, single-busbar system .............................................................................18
6.2 Basic design circuit-breaker panel with HV HRC fuse ...................................................................................18
6.3 Basic design circuit-breaker panel, double-busbar system............................................................................19
7Interlocks................................................................................................................................................. 20
7.1 Mechanical interlocks for single-busbar system.............................................................................................20
7.2 Mechanical interlocks for double-busbar system ...........................................................................................21
7.3 Additional electromagnetic interlocks (optional).............................................................................................21
7.4 Additional padlock interlock (optional)............................................................................................................22
7.5 Additional key-operated interlock (optional)...................................................................................................22
8Accessories ............................................................................................................................................ 23
8.1 Operating tools...............................................................................................................................................23
8.2 Service truck..................................................................................................................................................25
8.3 Service truck versions....................................................................................................................................25
9Customer support .................................................................................................................................. 28
9.1 Service...........................................................................................................................................................28
9.2 Repairs...........................................................................................................................................................28
9.3 Before you call...............................................................................................................................................28
9.4 Service contact ..............................................................................................................................................28
10 Operating the circuit-breaker panel...................................................................................................... 29
10.1 Control elements at the front side of the panel...............................................................................................29
10.2 Position indicators visible on high-voltage door .............................................................................................30
10.3 Access to compartments................................................................................................................................30
10.4 Opening the high-voltage door.......................................................................................................................30
10.5 Closing the high-voltage door ........................................................................................................................32
10.6 Positions of the withdrawable circuit-breaker.................................................................................................34
10.7 Racking the withdrawable circuit-breaker to service position.........................................................................35
10.8 Racking the withdrawable circuit-breaker to test position ..............................................................................37
10.9 Closing the circuit-breaker electrically............................................................................................................40
10.10 Opening the circuit-breaker electrically..........................................................................................................41
10.11 Closing the circuit-breaker manually..............................................................................................................42
10.12 Opening the circuit-breaker manually ............................................................................................................45
10.13 Discharging the spring energy store ..............................................................................................................47
10.14 Charging the spring manually ........................................................................................................................48
10.15 Earthing the feeder manually.........................................................................................................................51
10.16 De-earthing the feeder manually....................................................................................................................53
10.17 Removing the low-voltage connector.............................................................................................................56

Contents
139-2021.9 / 07 NXAIR M 5
10.18 Plugging on the low-voltage connector..........................................................................................................57
10.19 Taking the withdrawable circuit-breaker out of the panel...............................................................................59
10.20 Inserting the withdrawable circuit-breaker in a panel.....................................................................................64
11 Operating the disconnecting panel.......................................................................................................73
11.1 Control elements at the front side of the panel ..............................................................................................73
11.2 Position indicators visible on high-voltage door.............................................................................................73
11.3 Access to compartments ...............................................................................................................................74
11.4 Opening or closing the high-voltage door ......................................................................................................74
11.5 Racking the withdrawable disconnector link ..................................................................................................74
11.6 Removing or plugging on the low-voltage connector.....................................................................................76
11.7 Taking the withdrawable disconnector link out of a panel or inserting in a panel...........................................76
11.8 Earthing or de-earthing the feeder.................................................................................................................76
12 Operating the metering panel ................................................................................................................77
12.1 Control elements at the front side of the panel ..............................................................................................77
12.2 Position indicators visible on high-voltage door.............................................................................................77
12.3 Access to compartments ...............................................................................................................................78
12.4 Opening or closing the high-voltage door......................................................................................................78
12.5 Racking the withdrawable metering part........................................................................................................78
12.6 Removing or plugging on the low-voltage connector.....................................................................................78
12.7 Taking the withdrawable metering part out of a panel or inserting in a panel ................................................79
12.8 Replacing protection fuse-links......................................................................................................................79
13 Operating the circuit-breaker panel with HV HRC fuse.......................................................................83
13.1 Control elements at the front side of the panel ..............................................................................................83
13.2 Position indicators visible on high-voltage door.............................................................................................84
13.3 Access to compartments ...............................................................................................................................84
13.4 Opening or closing the high-voltage door ......................................................................................................84
13.5 Racking the withdrawable part.......................................................................................................................84
13.6 Closing or opening the circuit breaker / fuse combination .............................................................................85
13.7 Discharging or charging the closing spring....................................................................................................85
13.8 Earthing or de-earthing the feeder manually..................................................................................................85
13.9 Removing the low-voltage connector.............................................................................................................85
13.10 Plugging on the low-voltage connector..........................................................................................................87
13.11 Taking the withdrawable circuit-breaker / fuse combination out of a panel or inserting in a panel.................89
13.12 Replacement of HV HRC fuse-links...............................................................................................................89
14 Operating the circuit-breaker panel for double-busbar system.........................................................99
14.2 Position indicators visible on high-voltage door, panel A.............................................................................101
14.3 Position indicators visible on high-voltage door, panel B.............................................................................101
14.4 Access to compartments .............................................................................................................................101
14.5 Opening or closing the high-voltage door ....................................................................................................102
14.6 Positions of the withdrawable circuit-breaker...............................................................................................102
14.7 Racking the withdrawable circuit-breaker....................................................................................................102
14.8 Closing or opening the circuit-breaker.........................................................................................................102
14.9 Discharging or charging the closing spring..................................................................................................102
14.10 Earthing or de-earthing the feeder...............................................................................................................103
14.11 Removing or plugging on the low-voltage connector...................................................................................103
14.12 Taking the withdrawable part out of a panel or inserting in a panel.............................................................103
15 Operating the removable voltage transformers.................................................................................104
15.2 Opening or closing the high-voltage door ....................................................................................................104
15.3 Racking the removable voltage transformers to service position.................................................................105
15.4 Racking the removable voltage transformers to test position ......................................................................109
15.5 Taking the removable voltage transformers out of the panel.......................................................................113
15.6 Inserting the removable voltage transformers in a panel.............................................................................117
15.7 Replacing protection fuse-links....................................................................................................................122
16 Verifying safe isolation from supply...................................................................................................125
16.1 Application of voltage indicators ..................................................................................................................125
16.2 Overview of voltage indicating systems.......................................................................................................125
16.3 LRM system overview..................................................................................................................................126
16.4 Verifying LRM-ST voltage indicator .............................................................................................................127
16.5 Verifying safe isolation from supply with the LRM device system................................................................128
16.6 CAPDIS and VOIS systems overview..........................................................................................................129
16.7 Verifying safe isolation from supply with the CAPDIS or VOIS device system ............................................132
16.8 Supplier information.....................................................................................................................................132

Contents
6 NXAIR M 139-2021.9 / 07
17 Earthing and de-earthing the busbar system.................................................................................... 133
17.1 Earthing the busbar system manually..........................................................................................................133
17.2 De-earthing the busbar system manually.....................................................................................................138
18 Operating the shutters......................................................................................................................... 143
18.1 Operating the shutter to the busbar compartment in the switching-device compartment.............................143
18.2 Operating the shutter to the connection compartment in the switching-device compartment ......................146
19 Accessing the connection compartment through the front............................................................. 150
19.1 Preparations before accessing the connection compartment.......................................................................150
19.2 Accessing the connection compartment through the switching-device compartment ..................................152
19.3 Installing the vertical partition in the switching-device compartment............................................................153
19.4 Accessing the connection compartment through the switching-device compartment in panel versions with
ventilation system ........................................................................................................................................157
19.5 Installing the vertical partition and the ventilation duct in the switching-device compartment......................162
19.6 Accessing the connection compartment through the switching-device compartment in panel versions with
voltage transformer compartment................................................................................................................168
19.7 Installing the bushing plate, the vertical partition and the voltage transformer compartment in the switching-
device compartment.....................................................................................................................................172
20 Accessing the connection compartment through the rear.............................................................. 177
20.1 Accessing the connection compartment through the rear side of the panel.................................................177
20.2 Installing the rear wall on the connection compartment ...............................................................................180
20.3 Accessing the connection duct through the rear side of the panel...............................................................183
20.4 Installing the rear walls on the connection duct............................................................................................186
21 Key-operated interlocks....................................................................................................................... 189
21.1 Key-operated interlocks ...............................................................................................................................189
21.2 Key-operated interlocks for the busbar earthing switch ...............................................................................191
22 Fitting the earthing device................................................................................................................... 193
22.1 Design, application and inspection of the earthing accessories...................................................................193
22.2 Connecting the earthing device....................................................................................................................194
22.3 Removing the earthing device......................................................................................................................201
23 Panels with motor operating mechanism control............................................................................. 205
23.1 Overview of functionality..............................................................................................................................205
23.2 Opening the control door .............................................................................................................................209
23.3 Closing the control door...............................................................................................................................210
23.4 Selecting manual operation for racking........................................................................................................211
23.5 Selecting electrical operation for racking .....................................................................................................213
23.6 Selecting interlocking...................................................................................................................................214
23.7 Racking the withdrawable circuit-breaker to service position manually........................................................217
23.8 Racking the withdrawable circuit-breaker to service position electrically.....................................................220
23.9 Racking the withdrawable circuit-breaker to test position manually.............................................................221
23.10 Racking the withdrawable circuit-breaker to test position electrically...........................................................225
23.11 Opening the circuit-breaker manually ..........................................................................................................226
23.12 Closing the circuit-breaker manually............................................................................................................227
23.13 Charging / discharging the spring energy store manually............................................................................228
23.14 Earthing / de-earthing the feeder manually..................................................................................................230
23.15 Earthing / de- earthing the feeder electrically...............................................................................................232
23.16 Earthing / de-earthing the busbar system manually.....................................................................................233
23.17 Earthing / de-earthing the busbar system electrically...................................................................................233
23.18 Further operating options.............................................................................................................................234
23.19 Technical data / operating times..................................................................................................................235
23.20 Fault indication and fault evaluation.............................................................................................................236
24 Panel heater .......................................................................................................................................... 237
24.1 Heater versions............................................................................................................................................237
24.2 Mechanical temperature controller...............................................................................................................237
24.3 Electronic temperature and humidity controller............................................................................................238
24.4 Applications for temperature controller ........................................................................................................238
25 Service information.............................................................................................................................. 240
25.1 General maintenance...................................................................................................................................240
25.2 Time schedule for maintenance measures ..................................................................................................240
25.3 Visual inspection..........................................................................................................................................241
25.4 Preventive maintenance ..............................................................................................................................242

Contents
139-2021.9 / 07 NXAIR M 7
25.5 Lubricants to be used ..................................................................................................................................244
25.6 Overpressure sensors (optional), function test ............................................................................................245
25.7 Switchgear extension...................................................................................................................................248
25.8 Spare part orders.........................................................................................................................................248
25.9 Replacement of panels and components.....................................................................................................248
25.10 Disposal.......................................................................................................................................................248
26 Trouble shooting...................................................................................................................................249
26.1 Panels..........................................................................................................................................................249
27 Index.......................................................................................................................................................251
Document information:
Title: Operating Instructions
Order number: 139-2021.9
Additional order number: 8BX3300-0LA00-0AD3
Revision: 07
Issue: September 2018

8 NXAIR M 139-2021.9 / 07
General instructions
2 General instructions
2.1 General instructions
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.
Please do absolutely observe the following:
The personnel must read and understand these Operating Instructions before starting to work.
Observe all safety instructions and warnings in these Operating Instructions, and follow the
instructions.
Store these Operating Instructions carefully, and so that they are accessible to the personnel at any
time.
These Operating Instructions are a part of the product. When the switchgear is transferred, supply
these Operating Instructions as well.
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 fulfilment of the type tests
(according to IEC 62271 Part 200) may not be guaranteed anymore. This applies especially though not
exclusively to the following actions:
Original Siemens spare parts were not used.
Service technicians performing replacement were not trained and certified by Siemens.
Parts were fitted or adjusted incorrectly.
Settings were not made in accordance with Siemens specifications.
After installation and setting, no final check was performed by a service technician approved by
Siemens, including documentation of the test results.
Maintenance was not done according to the operating instructions of the Siemens products.
The edition of the standard is only mentioned in the test report applicable at the time of switchgear
manufacture.
These Operating Instructions should be used jointly with the Operating Instructions for circuit-breaker type
3AE.
2.2 Five Safety Rules of Electrical Engineering
The Five Safety Rules of Electrical Engineering must generally be observed 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.
2.3 Hazardous substances
If hazardous substances are required to perform the work, the relevant safety data sheets and operating
instructions must be observed.

General instructions
139-2021.9 / 07 NXAIR M 9
2.4 Personal protective equipment (PPE)
For switchgear with proven internal arc classification according to IEC 62271 Part 200, no protective
equipment is required for operating the switchgear.
To work on switchgear where covers have to be removed, personal protective equipment has to be worn
for protection against hot gases exhausting in case of internal arc.
To select the protective equipment, the national standards and specifications of the corresponding
authorities and professional associations must absolutely be observed.
The protective equipment consists of:
Protective clothing such as bib overall and long-arm jacket from NOMEX material
(see Internet: NOMEX work clothes)
Safety shoes
Gloves
Helmet and face protection
Ear protection
2.5 Due application
The air-insulated medium-voltage switchgear type NXAIR M is a type-tested and metal-clad switchgear for
indoor installation, with type of accessibility A and internal arc classification (IAC): IAC A FLR 25 kA 1 s or
IAC A FL 25 kA 1 s according to IEC 62271 Part 200.
The switchgear can be used as indoor installation according to IEC 61936 (Power Installations exceeding
AC 1 kV) and VDE 0101 in lockable electrical service locations. A lockable electrical service location is a
room or a place that is exclusively used for operating electrical equipment and which is kept under lock and
key. Access to such a room is restricted to skilled electricians.
In the basic version, the degree of protection of the enclosure of NXAIR M medium-voltage switchgear is
IP3XD according to IEC 60529.
When the switchgear is operated within the technical parameters defined in these instructions, the air-
insulated switchgear type NXAIR M is suitable for rated voltages up to Ur= 24 kV and a maximum rated
short-time withstand current of Ik= 25 kA.
The circuit-breaker to be used in a circuit-breaker panel must only be the Siemens type 3AE.
The air-insulated medium-voltage switchgear type NXAIR M is suitable for operational switching of
AC circuits in transformer substations of public power supply systems or in industrial plants.
The medium-voltage switchgear NXAIR M is available with the panel versions:
Circuit-breaker panel
Disconnecting panel
Metering panel
Bus sectionalizer
Bus coupler
Circuit-breaker panel with HV HRC fuse
2.6 Qualified personnel
Qualified personnel in accordance with these Operating Instructions are persons who are familiar with
operation and maintenance of the product and have appropriate qualifications for their work.
Furthermore, qualified personnel must have the following training and instruction or authorization:
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 and instruction regarding the applicable specifications for the prevention of accidents and
the care and use of appropriate safety equipment
Training in first aid and behavior in the event of possible accidents

General instructions
10 NXAIR M 139-2021.9 / 07
2.7 Update of the firmware of protection relays
NOTICE
Old firmware versions
If the firmware of the protection relays is not updated, it is theoretically possible for
third parties to access the protection relay through the Internet due to a weak point
in the firmware of the protection relays.
Verify the latest version of the firmware of the protection relays on the
specified website.
Update the firmware of the protection relays with the latest firmware
version.
Siemens protection relays are monitored for their firmware vulnerability. In case that any potential weak
points are identified which might allow third parties to access to the protection relay, information concerning
this will be distributed by newsletter.
Please visit below website to register to the SIPROTEC and SICAM security update report to receive latest
news.
www.siemens.com/gridsecurity
Before commissioning please ensure that the firmware of protection relays is up-to-date.
For latest firmware version for Siemens devices please visit below internet site.
http://w3.siemens.com/smartgrid/global/en/products-systems-
solutions/downloads/Pages/Overview.aspx
For protection relays of other manufacturers please get in touch with the Original Equipment Manufacturer.

Features
139-2021.9 / 07 NXAIR M 11
Features
3 Features
The air-insulated medium-voltage switchgear type NXAIR M has the following features:
Factory-assembled, type-tested, metal-enclosed and metal-clad switchgear for indoor installation
Type of accessibility A
Internal arc classification (IAC): IAC A FLR 25 kA 1 s or IAC A FL 25 kA 1 s according to IEC 62271
Part 200
Loss of service continuity category: LSC 2B (metal-clad)
Partition class: PM (metallic partition)
All switching operations can be carried out at the panel front with the high-voltage door closed
Standard degree of protection IP3XD for the metal enclosure according to IEC 60529
Metallic, positively driven shutters protect against accidental contact with live parts inside the panel
Logical interlock between actuation, circuit-breaker, disconnecting function and feeder
earthing switch operating mechanism prevent maloperation
Earthing of feeders by means of earthing switches with short-circuit making capacity
Mechanical position indicators for the withdrawable part and the feeder earthing switch integrated in
the mimic diagram at the panel front
Enclosure made of galvanized sheet steel
Front doors and lateral switchgear end walls are powder-coated with resistant epoxy resin material
Individual modular compartments in solid-wall design
Modular compartments bolted together
Further information to design features and design options is given in catalog HA 25.71.

12 NXAIR M 139-2021.9 / 07
Technical data
4 Technical data
4.1 Complete switchgear
Rated voltage
[kV]
24
Rated frequency
[Hz]
50/60
Rated power-frequency withstand voltage
[kV]
50/65
Rated lightning impulse withstand voltage
[kV]
125
Rated short-time withstand current, max.
[kA]
25
Rated duration of short circuit, max.
[s]
3
Rated peak withstand current
[kA]
63/65
Rated voltage
[kV]
24
Rated normal current of busbar, max.
[A]
2500
Rated normal current of feeders, max.
with circuit-beaker
[A]
2500
with disconnector
[A]
2500
as bus coupler
[A]
2500
as bus sectionalizer
[A]
2500
4.2 Basic prescriptions and standards
The indoor switchgear complies with the following prescriptions and standards:
IEC / EN standard
Switchgear
62271-1
62271-200
62271-210
Switching
devices
Circuit-breakers
62271-100
Disconnectors / earthing switches
62271-102
Circuit-breaker / fuse combinations
62271-107
Current limiting fuses
60282-1
Voltage detecting systems
61243-5
Insulation
60071-1
Degree of protection
60529
Instrument
transformers
Current transformers
61869-2
Voltage transformers
61869-3
Installation, erection
61936-1

Technical data
139-2021.9 / 07 NXAIR M 13
4.3 Electromagnetic compatibility - EMC
The a.m. standards as well as the "EMC Guide for Switchgear" 1) are applied during design, manufacture
and erection of the switchgear. Installation, connection and maintenance have to be performed in
accordance with the stipulations of the operating instructions. For operation, the legal stipulations applicable
at the place of installation have to be observed additionally. In this way, the switchgear assemblies of this
type series fulfil the basic protection requirements of the EMC guide.
The switchgear operator / 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.
1) Dr. Bernd Jäkel, Ansgar Müller; Medium-Voltage Systems - EMC Guide for Switchgear
4.4 Rating plates
Each panel has a rating plate fixed on the inside of the doors to the high-voltage and low-voltage
compartment containing the following information:
Fig. 1: Rating plate
(1)
Switchgear type
(5)
Number of operating instructions for the panel
(2)
Serial number
(6)
Year of manufacture
(3)
Technical data
(7)
Panel number
(4)
Internal arc classification
(8)
Loss of service continuity category,
partition class
The block-type current transformers and the voltage transformers have their own type plates. A copy is
provided on the inside of the high-voltage door.
4.5 IAC classification
The data (see Fig. 1) describes the internal arc classification of the panel according to IEC 62271-200.
The entries IAC A FLR 25 kA 1 s and accessibility type Ain the example shown mean:
IAC: Internal Arc Classification
F: Internal arc classification for the front side (Front)
L: Internal arc classification for the lateral sides (Lateral)
R: Internal arc classification for the rear side (Rear)
25 kA: Tested short-circuit current
1 s: Test duration
A: Type of accessibility A; for authorized personnel only
The IAC classification is referred to each panel. The data on the rating plate (see Fig. 1) describes the areas
classified for the corresponding panel.
1
2
3
4
5
6
7
8

Technical data
14 NXAIR M 139-2021.9 / 07
4.6 Panel dimensions
Width
Panel type
Ik[kA]
Ir[A]
Width [mm]
Circuit breaker panel,
disconnecting panel
25
≤1250
800
2000/2500
1000
Metering panel
─
800
Circuit breaker panel with
HV HRC fuse
─
800
Bus sectionalizer
≤1250
2 ×800
2000/2500
2 ×1000 or
1 ×1000 with 1 ×800
Bus coupler
≤1250
2 ×800
2000/2500
2 ×800 or
2 ×1000
Height
Panel design
Height [mm]
With standard low-voltage compartment
2510
With high low-voltage compartment
2550
With natural ventilation
2700
With pressure relief duct and arc absorber
2750
With additional compartment for busbar components
2770
Depth
Panel design
Depth [mm]
Single busbar
1600
Circuit-breaker panel for back-to-back arrangement (panel A)
1750
Disconnecting panel for back-to-back arrangement (panel A)
Circuit-breaker panel for back-to-back arrangement (panel B)
1600
Disconnecting panel for back-to-back arrangement (panel B)
4.7 Room planning
According to chapter 6 in the Installation Instructions with order number: 139-2019.9
4.8 Operating conditions
NXAIR M switchgear is designed for normal indoor operating conditions according to IEC 62271-1. In this
respect, the following limit values for the ambient air temperature must be complied with:
Limit value
Temperature [ºC]
Maximum value
+40*
Minimum value
-5
Maximum value of 24-hour mean
+35*
The site altitude may be 1000 m above sea level as a maximum.

Technical data
139-2021.9 / 07 NXAIR M 15
When NXAIR M switchgear is used in regions with high air humidity or considerable temperature fluctuations,
there is risk of condensation. The formation of condensation should be an exception under normal operating
conditions. To prevent condensation, rusting or other serious consequences, the associated preventive
measures must be taken by installing electrical heating equipment in the switchgear.
The ambient air must not be significantly polluted by dust, smoke, corrosive and/or flammable gases, vapors
or salt.
* If NXAIR M is used under other service conditions than normal service conditions acc. to IEC 62271 Part 1
regarding ambient air temperature, the permissible current ratings of feeder and busbar can deviate. In this
case, please contact your regional Siemens representative to clarify the permissible current values.
4.9 Vacuum circuit-breaker type 3AE
The vacuum circuit-breaker type 3AE is a 3-pole indoor circuit-breaker for ratings of 24 kV. Depending on the
design of the NXAIR M switchgear, circuit-breakers type 3AE1 and type 3AE5 are used. The assignment of
the circuit-breaker matching with the respective panel is shown on the rating plate.
A rating plate is provided on the operating mechanism unit of every circuit-breaker type 3AE.
Fig. 2: Circuit-breaker type 3AE1
Fig. 3: Circuit-breaker type 3AE5
(1)
Rating plate on circuit-breaker
4.10 Operating instructions for circuit-breaker type 3AE
For circuit-breakers type 3AE, separate operating instructions are available with detailed instructions and
information. The operating instructions are supplied as standard with every circuit-breaker type 3AE.
Additional operating instructions in different languages can be ordered at the regional Siemens
representative.
Fig. 4: Operating instructions for
circuit-breaker type 3AE
Available operating instructions
Language
Order number
German
9229 0001 100 0F
Polish
9229 0001 155 0F
Russian
9229 0001 156 0F
Italian
9229 0001 172 0F
English
9229 0001 176 0F
French
9229 0001 177 0F
Spanish
9229 0001 178 0F
Portuguese
9229 0001 179 0F
Romanian
9229 0001 302 0F
1
1

16 NXAIR M 139-2021.9 / 07
Overview of panel types
5 Overview of panel types
The withdrawable circuit-breaker switchgear NXAIR M consists of various panel types, which can be freely
combined according to the requirements.
The following panel types are available:
Circuit-breaker panel
disconnecting panel
Metering panel
Bus sectionalizer, type 1
1 ×circuit-breaker panel plus 1 ×bus riser panel with withdrawable disconnector link
Bus sectionalizer, type 2
1 ×circuit-breaker panel plus 1 ×bus riser panel, optionally with withdrawable metering part
Bus coupler, type 1
1 ×circuit-breaker panel plus 1 ×bus riser panel with withdrawable disconnector link
Bus coupler, type 2
1 ×circuit-breaker panel plus 1 ×bus riser panel, optionally with withdrawable metering part
Circuit-breaker panel with HV HRC fuse
Further information to design features and design options is given in catalog HA 25.71.
Overview of panel types for single-busbar system:
Fig. 5: Circuit-breaker panel
Fig. 6: Disconnecting
panel
Fig. 7: Metering panel
Fig. 8: Circuit-breaker
panel with HV
HRC fuse

Error! Use the Home tab to apply Heading 1;ÜB 1 to the text that you want to appear here.
139-2021.9 / 07 NXAIR M 17
Fig. 9: Circuit-breaker panel
with removable voltage
transformers
Fig. 10: Panel version with
natural ventilation
Fig. 11: Bus sectionalizer to the right 1),
circuit-breaker panel and
bus riser panel
1) Can also be designed as a mirror image to the left
Overview of panel types for single-busbar system:
Fig. 12: Circuit-breaker
panel, panel A
Fig. 13: Circuit breaker
panel, panel B
Fig. 14: Circuit-breaker
panel, panel A
with natural
ventilation
Fig. 15: Circuit-breaker
panel, panel B
with natural
ventilation

18 NXAIR M 139-2021.9 / 07
Panel design
6 Panel design
6.1 Basic design circuit-breaker panel, single-busbar system
Fig. 16: Sectional view of circuit-breaker panel
design
A
Switching-device compartment
B
Busbar compartment
C
Connection compartment
D
Withdrawable circuit-breaker
E
Low-voltage compartment
(1)
Metallic shutters
(2)
Low-voltage connection
(3)
Operating and interlocking unit for
circuit-breaker
(4)
Vacuum interrupters
(5)
Operating and interlocking unit for racking the
withdrawable part and for earthing
(6)
Removable voltage transformers (optional)
(7)
Feeder earthing switch
(8)
Cable connection for up to 4 cables per phase
(9)
Voltage transformers (optional)
(10)
Contact systems
(11)
Block-type current transformers
(12)
Bushing-type insulators
(13)
Busbar
(14)
Pressure relief duct
6.2 Basic design circuit-breaker panel with HV HRC fuse
Fig. 17: Sectional view of circuit-breaker panel
with HV HRC fuse design
A
Switching-device compartment
B
Busbar compartment
C
Connection compartment
D
Withdrawable circuit-breaker / fuse combination
E
Low-voltage compartment
(1)
Metallic shutters
(2)
Fuse assemblies with HV HRC fuses
(3)
Low-voltage connection
(4)
Operating and interlocking unit for
circuit-breaker
(5)
Vacuum interrupters
(6)
Operating and interlocking unit for racking the
withdrawable part and for earthing
(7)
Connection for up to 2 cables per phase
(8)
Feeder earthing switch
(9)
Contact systems
(10)
Bushing-type current transformers
(11)
Bushing-type insulators
(12)
Busbar
(13)
Pressure relief duct
13
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12
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Panel design
139-2021.9 / 07 NXAIR M 19
6.3 Basic design circuit-breaker panel, double-busbar system
Fig. 18: Sectional view of circuit-breaker panel design
A
Switching-device compartment
B
Busbar compartment
C
Connection compartment
D
Withdrawable circuit-breaker
E
Low-voltage compartment
(1)
Panel A
(2)
Metallic shutters
(3)
Low-voltage connection
(4)
Operating and interlocking unit for circuit-breaker
(5)
Vacuum interrupters
(6)
Operating and interlocking unit for racking the
withdrawable part and for earthing
(7)
Feeder earthing switch
(8)
Connection for up to 4 cables per phase
(9)
Block-type current transformers
(10)
Contact system
(11)
Voltage transformers
(12)
Bushing-type insulators
(13)
Busbars
(14)
Pressure relief duct
(15)
Panel B
Further information to design features and design options is given in catalog HA 25.71.
8
7
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2
3
4
5
6
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10
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20 NXAIR M 139-2021.9 / 07
Interlocks
7 Interlocks
7.1 Mechanical interlocks for single-busbar system
Action
Internal preconditions
Inserting the withdrawable part in the panel
Withdrawable part on the service truck
Pulling the withdrawable part out of the panel
None
Racking the withdrawable part to service position
Withdrawable part inserted and interlocked
Low-voltage connector plugged on
High-voltage door closed
Circuit-breaker in OPEN position
Feeder earthing switch in OPEN position
Plugging on the low-voltage connector
Consistent coding between connector and
withdrawable part fulfilled
Racking the withdrawable part to test position
Circuit-breaker in OPEN position
Closing the circuit-breaker
Withdrawable part in interlocked end position
(test position or service position)
Closing the circuit-breaker
Undervoltage release not electrically operated
Opening the circuit-breaker
None
Operating the feeder earthing switch
Withdrawable part in test position
Operating the busbar earthing switch
None (see note given below)
Opening the high-voltage door
Withdrawable part in test position
Closing the high-voltage door
Low-voltage connector plugged on