HA 25.81 Medium Voltage Switchgear

Specifications

• Product Name: Medium-Voltage Switchgear Type NXAIR C
• Voltage Level: Up to 24 kV
• Current Rating: Up to 25 kA
• Insulation: Air-Insulated
• Manufacturer: Siemens
• Website: siemens.com/nxair

Product Usage Instructions

Application

The Medium-Voltage Switchgear Type NXAIR C is primarily used in
transformer and switching substations at the primary distribution
level. It is designed for various applications, including:

• R-HA25-700 jpg
• R-HA25-807 jpg
• R-HA25-805 tif
• R-HA25-806 jpg

Design

The NXAIR C switchgear features a platform concept with a
classification, basic panel design, compartments, and operation
mechanisms. It ensures smooth operation, exemplary availability,
and optimal safety.

Components

The switchgear is equipped with the following components:

• Vacuum circuit-breaker
• Switch-disconnector
• Current transformers
• Voltage transformers
• Low-voltage compartment
• Optical arc detection systems

Technical Data

The switchgear has the following electrical data:

• Product range
• Room planning
• Transport and packing

Standards

The Medium-Voltage Switchgear Type NXAIR C complies with various
standards, specifications, and guidelines.

FAQ

Q: What are the customer benefits of using NXAIR C

switchgear?

A: The customer benefits include:

• Ensures peace of mind
• Saves lives
• Increases productivity
• Saves money
• Preserves the environment

Q: How long is the service life of NXAIR C switchgear?

A: The switchgear has a service life of more than 30 years.

Q: Is the switchgear environmentally friendly?

A: Yes, the switchgear uses air as an insulating medium and
optimizes the total energy balance.

Catalog HA 25.81 · 2023
MEDIUM-VOLTAGE SWITCHGEAR
Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air-Insulated
siemens.com/nxair

Application
Typical uses

NXAIR C circuit-breaker switchgear is used in transformer and switching substations, mainly at the primary distribution level, e.g.:
Application Public power supply · Power supply companies · Energy producers · System operators.

R-HA25-700 jpg

R-HA25-807 jpg

R-HA25-805 tif

Application Industry · Automobile industry · Traction power supply systems · Mining industry · Lignite open-cast mines · Buildings · Chemical industry · Electrochemical plants · Emergency power supply installations · Textile, paper and food industries · Airports and ports · Healthcare · Iron and steel works · Power plants · Petroleum industry · Petrochemical plants · Pipeline installations · Shipbuilding industry · Steel industry · Rolling mills · Cement industry.
2 Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air- Insulated · Siemens HA 25.81 · 2023

R-HA25-806 jpg

MEDIUM-VOLTAGE SWITCHGEAR
Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air-Insulated
Catalog HA 25.81 · 2023 Invalid: Catalog HA 25.81 · 2020 siemens.com/nxair

Contents
Application
Typical uses
Customer benefit
Ensures peace of mind Saves lives Increases productivity Saves money Preserves the environment
Sustainability
NXAIR: A sustainable investment for today and tomorrow
Design
Classification Basic panel design Compartments Operation
Components
Vacuum circuit-breaker Switch-disconnector Current transformers Voltage transformers Low-voltage compartment Optical arc detection systems
Technical data
Electrical data Product range Room planning Transport and packing
Standards
Standards, specifications, guidelines

Page
2
4 5 6 7 8
9 and 10
11 12 and 13 14 and 15 16 and 17
18 19 20 21 22 23
24 25 to 28 29 and 32
33
34 to 36

The products and systems described in this catalog are manufactured and sold according to a certified management system (acc. to ISO 9001, ISO 14001 and BS OHSAS 18001).
Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air-Insulated · Siemens HA 25.81 · 2023 3

Customer benefit
Ensures peace of mind

Ensures peace of mind
For power supply companies and industrial plants, the platform concept introduced with the NXAIR family has very concrete advantages:
Smooth operation, exemplary availability, and optimal safety.

Features
· No handling of insulating gas and no pressure monitoring required · As insulating medium, air is always available · Factory-assembled, type-tested switchgear according to IEC 62271-200 · Platform concept introduced worldwide, centrally controlled development · Use of standardized block-type current transformers · Use of standard components available worldwide · More than 610,000 air-insulated switchgear panels of Siemens in operation
worldwide · Use of maintenance-free vacuum circuit-breakers · Type testing of the main switching devices and the make-proof
earthing switch in the panel · Flexibility regarding the low-voltage equipment (removable compartment,
plug-in wires) · Quality assurance in accordance with DIN EN ISO 9001.

4 Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air- Insulated · Siemens HA 25.81 · 2023

Customer benefit
Saves lives Saves lives Ensures personnel safety and uninterrupted operation with an arc-fault classification IAC A FLR and a service continuity category LSC 2, allowing to access the mediumvoltage connection compartment while keeping the busbar energized, enabling maintenance on one part while the rest of the system remains operational.
Features
· All operations can only be performed with closed and interlocked high- voltage door
· Metallic enclosure, earthed shutters and partitions · Internal arc classified switchgear according to IAC A FLR (front, lateral and
rear accessibility) for an arc duration of 1 s · Loss of service continuity category LSC 2
(separate partitioning of the busbar- and combined connection and switching- device compartments) · Partition class PM · Unambiguous position indicators and control elements on the high-voltage door · Use of vacuum circuit-breakers or switch-disconnectors · Standard degree of protection IP3X. IP4X is possible as an option · Positively driven busbar shutter (lockable) · Logical mechanical interlocking system.
Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air-Insulated · Siemens HA 25.81 · 2023 5

Customer benefit
Increases productivity

Increases productivity
Properties such as modular design, type tests of the switching devices in the switchgear, resistance to internal arcing, and thus maximum operational reliability, contribute to optimum operation and a remarkable increase of productivity.

Features
· Loss of service continuity category LSC 2 · Partition class PM · Positively driven shutter · Use of standardized block-type current transformers · Cable testing possible without isolating the busbar · Use of maintenance-free vacuum circuit-breakers or switch-disconnectors · Control cables in metallic wiring ducts · Easy access to all switchgear components · Rapid interruption of an internal arc optionally possible
by installation of arc detection systems.

6 Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air- Insulated · Siemens HA 25.81 · 2023

Customer benefit
Saves money Saves money The compact design of NXAIR C pays twice for owners thanks to the use of the new SION circuit-breaker series. On the one hand, building costs can be reduced in this way, and on the other hand, the maintenance-free circuit-breakers and the modular design enable continuous operation without expensive downtimes.
Features
· Use of maintenance-free vacuum circuit-breakers or switch-disconnectors · Maintenance-free switchgear for up to 10 years · Interruption of operation reduced to a minimum by
logical mechanical interlocking system · Minimized space requirements (reduced building investments) thanks to
compact design and flexible pressure relief duct systems.
Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air-Insulated · Siemens HA 25.81 · 2023 7

Customer benefit
Preserves the environment

Preserves the environment
Air used as insulating medium and a service life of more than 30 years optimize the total energy balance.

Features
· Air as insulating medium is absolutely neutral to the environment · A service life of more than 30 years optimizes the energy balance additionally · The materials used are fully recyclable without special knowledge · Easy disposal.

8 Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air- Insulated · Siemens HA 25.81 · 2023

Sustainability
NXAIR: A sustainable investment for today and tomorrow
NXAIR: A sustainable investment for today and tomorrow
At Siemens, we believe in sustainable development that meets current needs without compromising the future.

Siemens supports sustainability with a customized program, our “DEGREE framework”. Our DEGREE framework guides our efforts in six crucial areas of action that drive sustainability and continuously evolve.
Decarbonization: Support the 1.5 °C target to fight global warming Ethics: Foster a culture of trust, adhere to ethical standards, and handle data with care Governance: Apply state-of-the-art systems for effective and responsible business conduct Resource efficiency: Achieve circularity and dematerialization Equity: Foster diversity, inclusion, and community development to create a sense of belonging Employability: Enable our people to stay resilient and relevant in a permanently changing environment.
Air-insulated medium-voltage switchgear NXAIR C is a prime example for our commitment to sustainability. Decades of experience have made NXAIR C a leader in resource efficiency and decarbonization:
· Use of natural air as insulating medium and vacuum interrupters for switching
· Free of all materials harming the environment (e.g., asbestos, mercury, SF6 gas or other F-gases)

· Reduced fire load by using a minimum of insulating material
· Easily recyclable and reusable thanks to the use of homogenous material
· Use of maintenance-free vacuum circuit-breakers, and 10-year maintenance intervals for the switchgear
· Long product lifetime and serviceable life of more than 30 years
· Safe spare part supply over a period of minimum 10 years after phase-out
· Global service network close to the customer
· Possibility for remote factory acceptance tests (FAT) and remote support for commissioning, service and maintenance
· Upgradable with condition monitoring systems for predictive maintenance
· Continuous improvement of durability by means of simulation software for development, testing and production based on the corresponding international standards and design directives.

Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air-Insulated · Siemens HA 25.81 · 2023 9

Sustainability
NXAIR: A sustainable investment for today and tomorrow

Additionally, we as Siemens commit ourselves to comply with all legal provisions and regulations like REACh, the Minamata Convention, the Responsible Minerals Initiative, as well as the Stockholm Convention consequently to ensure a sustainable future for all.

With its environmentally friendly design, resource-efficient production, and long-lasting performance, NXAIR C is the ideal solution for your power supply.

For NXAIR C, Life Cycle Assessments (LCA) are performed, and Environmental Product Declarations (EPD) for reference installations are available.

NXAIR C ­ Your natural choice

Explanations:
REACh (Registration, Evaluation, Authorization and Restriction of Chemicals) REACh – Regulation (EC) 1907/2006 is the European Chemicals Regulation concerning the registration, evaluation, authorization and restriction of chemicals. It has been in force since 2007 and replaces 40 individual laws. The REACh Regulation is considered to be one of the world’s most stringent chemicals laws.
Environmental Product Declaration (EPD) An Environmental Product Declaration (EPD) is used to provide the customer with information about the

“ecological footprint” of a product. Siemens has a clearly formulated strategy for the development of EPDs. EPDs are based on independently verified data from life cycle assessments, life cycle inventory analyses, or information modules, which comply with the ISO 14040 series of standards.
Life Cycle Assessments (LCA) We use Life Cycle Assessments (LCA) to help us calculate the ecological footprint of our products and systems over their entire life cycle. Siemens follows the strict requirements of the ISO 14040 and ISO 14044 standards when applying an LCA.

10 Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air- Insulated · Siemens HA 25.81 · 2023

Design
Classification
Classification
Circuit-breaker switchgear NXAIR C is factory-assembled, metal-enclosed and type-tested switchgear for indoor installation according to IEC 62271-200, and corresponds to the following classifications.

Loss of service continuity category and partition class

Loss of service continuity category Partition class

LSC 2 PM

Accessibility to compartments ­ Busbar compartment ­ Combined switching-device
and connection compartment

Tool-based Interlock-controlled

Internal arc classifications

The following internal arc classifications are fulfilled: IAC A FLR, Isc, t

IAC

Internal Arc Classification

300 mm distance of indicators for test

A

(installation in closed electrical service

location)

F

Front arrangement of indicators for test

L

Lateral arrangement of indicators for test

R

Rear arrangement of indicators for test

Isc

Test current for NXAIR C up to 25 kA

t

Arc duration 1 s

In this way, NXAIR C switchgear is suitable for unrestricted application (wall- or free-standing arrangement) in electrical service locations up to the maximum short-circuit current ratings.

R-HA25-800 psd

Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air-Insulated · Siemens HA 25.81 · 2023 11

Design
Basic panel design
Basic panel design ­ circuit-breaker panel (example)

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1 Door to low-voltage compartment 2 Protection device 3 Locking device for the door to the low-voltage compartment 4 Option: Capacitive voltage detecting system for feeder
and busbar 5 High-voltage door 6 Rotary button to close and open the actuating opening
located below 7 Actuating opening for opening the circuit-breaker 8 Actuating opening for closing the circuit-breaker 9 Operation counter for circuit- breaker 10 Operating slide for opening and closing the actuating
opening for racking the withdrawable circuit-breaker / circuit-breaker truck 11 Actuating opening for racking the withdrawable circuit-breaker / circuit- breaker truck 12 Mechanical position indicator for withdrawable circuit- breaker / circuit-breaker truck 13 Opening for charging the spring energy store in the circuit-breaker manually (covered) 14 Spring state indicator for the closing spring 15 Handle for opening the high-voltage door 16 CLOSED/OPEN indicator of the circuit-breaker 17 Actuating opening for inserting the double-bit key to control racking of the withdrawable circuit-breaker / circuit-breaker truck 18 Operating slide for opening and closing the actuating opening for operating the feeder earthing switch 19 Actuating opening for operating the feeder earthing switch 20 Mechanical position indicator for feeder earthing switch

21 Pressure relief duct 22 Busbar 23 Block-type current transformer 24 Cable connection 25 Feeder earthing switch 26 Metallic shutters 27 Operating and interlocking unit
for circuit-breaker 28 Voltage transformer (optional)

A Switching-device / connection compartment
B Busbar compartment C Withdrawable circuit-breaker /
circuit-breaker truck D Low-voltage compartment

12 Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air- Insulated · Siemens HA 25.81 · 2023

Design
Basic panel design
Basic panel design ­ switch-disconnector panel with or without HV HRC fuses (example)

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1 Door to low-voltage compartment 2 Protection device (optional) 3 Locking device for the door to the low-voltage compartment 4 Option: Capacitive voltage detecting system for feeder
and busbar 5 High-voltage door 6 Inspection window to identify the switch positions of the
switch-fuse combination / switch-disconnector 7 Instruction label for operating the switch-disconnector 8 Operating slide for opening and closing the
actuating opening for operating the switch-disconnector 9 Actuating opening for operating the switch-disconnector 10 Handle for opening the high-voltage door 11 Operating slide for opening and closing the actuating
opening for operating the feeder earthing switch 12 Actuating opening for operating the feeder earthing switch 13 Mechanical position indicator for feeder earthing switch

14 Pressure relief duct 15 Busbars 16 Blades of the switch-disconnector 17 HV HRC fuse-links 18 Block-type current transformer 19 Cable connection 20 Feeder earthing switch

A Switching-device / connection compartment
B Busbar compartment C Switch-fuse combination /
switch-disconnector D Low-voltage compartment

Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air-Insulated · Siemens HA 25.81 · 2023 13

Design
Compartments of circuit-breaker panel

Compartments of circuit-breaker panel

Switching-device/connection compartment · Enclosure made of sendzimir- galvanized sheet steel · Pressure relief upwards · Panel front powder-coated with epoxy resin · Standard color RAL 7035 · Separate shutter mechanism for opening and closing the
busbar compartment · Metallic shutter · High-voltage door pressure-resistant in the event of
internal arcs in the panel · Lateral metallic wiring duct for laying the control cables · Low-voltage plug connector for connection of
control cables between primary part and secondary part · For different panel versions with withdrawable devices:
­ Vacuum circuit-breaker ­ Withdrawable disconnector link ­ Withdrawable metering part · Endurance classes for ­ Circuit-breaker: E2, M2, C2 ­ Isolating distance (withdrawable part): M0 · Earthing busbar · Option: Installation of bushing-type insulators or block-type current transformers · Option: Coupling electrode for capacitive voltage detecting system · Connection from front/bottom · Suitable for connection of: ­ Single-core XLPE cables up to 4 × 500 mm² per panel
depending on the rated continuous current and other built-in components ­ Three-core cables up to 2 × 300 mm² per panel depending on the rated continuous current and other built-in components

· Installation of voltage transformers ­ Cast-resin insulated ­ 3 × 1-pole ­ Fixed-mounted, without primary fuses
· Make-proof earthing switch ­ In addition to the standard interlocking: Earthing switch optionally lockable or electromagnetically interlocked against the withdrawable switching device
· Endurance classes for earthing switch: M0, E1 · Surge arresters for protecting the switchgear against
external overvoltages.
Busbar compartment · Enclosure made of sendzimir-galvanized sheet steel · Pressure relief upwards · Transverse partition from panel to panel · Busbars made of flat copper, bolted from panel to panel · Shutter can be locked in both positions (open or closed) · Bushing-type insulators for supporting the busbars
and for accommodating the upper fixed contacts for the switching device · Options: Possibility of installing the following components (for possible versions, see also section product range): ­ Voltage transformers ­ Current transformers in the course of the busbar ­ Coupling electrode for capacitive voltage detecting
system ­ Make-proof earthing switch (endurance classes: M0, E1).

Note: See also product range 14 Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air-Insulated · Siemens HA 25.81 · 2023

Design
Compartments of switch-disconnector panel

Compartments of switch-disconnector panel with or without HV HRC fuses

Busbar compartment · Enclosure made of sendzimir-galvanized sheet steel · Pressure relief upwards · Transverse partition from panel to panel · Busbars made of flat copper · Positively driven shutter between busbar compartment and
switching-device/connection compartment · Shutter made of insulating material, partition class PI · Option: Coupling electrode for capacitive voltage
detecting system.

Switching-device / connection compartment · Enclosure made of sendzimir- galvanized sheet steel · Pressure relief upwards · Panel front powder-coated with epoxy resin · Standard color RAL 7035 · Shutter mechanism coupled with switch-disconnector
operation · High-voltage door pressure-resistant in the event of
internal arcs in the panel · Lateral metallic wiring duct for laying the control cables · Firmly wired cable harness for connection of control
cables between primary part and secondary part · Switching-device/connection compartment with
fixed-mounted switch-disconnectors · Endurance classes for switch- disconnectors
­ Mechanical endurance: M1 ­ Electrical endurance: E1 · HV HRC fuses tested according to IEC 60282-1 ­ 1 fuse per phase ­ Reference dimension: 292 mm or 442 mm depending on
the rated voltage · Earthing busbar · Option: Installation of post insulators or block-type
current transformers · Option: Coupling electrode for capacitive voltage
detecting system · Connection from front/bottom · Suitable for connection of:
­ Single-core XLPE cables up to 2 × 300 mm² per panel depending on the rated continuous current and other built-in components
· Make-proof earthing switch with endurance classes: M0, E1.

Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air-Insulated · Siemens HA 25.81 · 2023 15

Design
Operation ­ circuit-breaker panel

Operation ­ circuit-breaker panel

Features · Integrated mimic diagram · Indication of the respective switch positions for circuit-breaker
CLOSED/OPEN, disconnected position, and earthing switch CLOSED/OPEN on the integrated mimic diagram · Unambiguous assignment of actuating openings and control elements to the corresponding position indicators · All switching operations can only be performed with closed high-voltage door · Ergonomically favorable height for all control elements and indicators · Option: Verification of safe isolation from supply for feeder or busbar by means of the capacitive voltage detecting system with panel front closed.

Interlocks · Interlocking conditions specified according to
IEC 62271-200 are fulfilled · Feeder earthing switch can only be operated with
switching device in disconnected position · Switching device can only be racked on the movable part
with the associated switching device in OPEN position and with earthing switch OPEN · Switching device can only be operated in interlocked disconnected or service position.
Beyond the specifications of the standards · Coding prevents insertion of switching devices with a lower
rated continuous current into panels with a higher rated continuous current · Interlocking between the high-voltage door and the position of the withdrawable part · Interlocking between the high-voltage door and the position of the cable earthing switch · Option: Electromagnetic interlocks, padlocks.

16 Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air- Insulated · Siemens HA 25.81 · 2023

Design
Operation ­ switch-disconnector panel with or without HV HRC fuses

Operation ­ switch-disconnector panel with or without HV HRC fuses

Features · Integrated mimic diagram · Indication of the respective switch positions for switch-
disconnector CLOSED/OPEN, disconnected position via inspection window in the high-voltage door, and earthing switch CLOSED/OPEN on the integrated mimic diagram · Unambiguous assignment of actuating openings and control elements to the corresponding position indicators · All switching operations can only be performed with closed high-voltage door · Ergonomically favorable height for all control elements and indicators · Option: Verification of safe isolation from supply for feeder or busbar by means of the capacitive voltage detecting system with panel front closed · “HV HRC fuse tripped” visible with closed door · Option: Electrical signal “HV HRC fuse tripped” via signaling switch.

Interlocks · Interlocking conditions specified according to
IEC 62271-200 are fulfilled · Feeder earthing switch can only be operated with
switching device in disconnected position · Switching device can only be operated with
earthing switch OPEN.
Beyond the specifications of the standards · Interlocking between the high- voltage door and the
position of the switch-disconnector · Interlocking between the high-voltage door and the posi-
tion of the cable earthing switch.

Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air-Insulated · Siemens HA 25.81 · 2023 17

Components
Vacuum circuit-breaker
Vacuum circuit-breaker
Features · The circuit-breakers conform to the following standards:
­ IEC 62271-1 ­ IEC 62271-100 · All circuit-breakers fulfill the endurance classes C2, E2, M2 and S1 according to IEC 62271-100, as well as the shortest rated operating sequence O ­ 0.3 s ­ CO ­ 15 s ­ CO · Suitable for all switching duties · Stored-energy spring mechanism with motor operation, manual operation always possible · 64-pole low-voltage plug connection between circuit-breaker and fixed part · The circuit-breakers are maintenance-free: ­ Under normal ambient conditions according to
IEC 62271-1 ­ Up to 10,000 operating cycles, maintenance-free
­ No regreasing ­ No readjusting.

Electrical data for Rated operating voltage Rated short-circuit breaking current Rated short-time withstand current Rated short-circuit making current Rated peak withstand current Rated continuous current Endurance class

NXAIR C up to 24 kV up to 25 kA up to 25 kA / 3 s up to 63 kA up to 63 kA up to 2000 A E2, M2, C2

Vacuum circuit-breaker

HA25-2820 eps

R-HA25-801 png

SION vacuum circuit-breaker 3AE5 with withdrawable module
18 Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air- Insulated · Siemens HA 25.81 · 2023

Switch-disconnector
Features Switch-disconnector with or without fuse combination according to IEC 62271-105 or IEC 62271-103. · For switching and protecting auxiliary transformers and
small distribution transformers up to 2250 kVA with fuse combination · Also as cable switch without fuse combination · Fixed-mounted switch-disconnector, endurance classes M1 and E1 · Stored-energy mechanism, manual operation · Use of HV HRC fuses with a reference dimension of 292 mm or 442 mm depending on the rated voltage · With all-pole mechanical tripping through the striker of the HV HRC fuse · Option: ­ Tripping through electrical shunt release ­ Fuse trip indication through signaling switch (electrical) · Earthing switch with short-circuit making capacity, endurance classes M0, E1 · Maintenance-free operating mechanisms under normal ambient conditions and for the max. permissible number of operating cycles.

Electrical data for

Switch-disconnector

Rated voltage
Rated short-circuit breaking current (max.), 3 s Rated peak withstand current (max.) Rated short-circuit making current (max.) Rated continuous current with fuse combination Rated continuous current without fuse combination

7.2 kV 25 kA 63 kA 63 kA 200 A 1) 630 A

12 kV 25 kA 63 kA 63 kA 200 A 1) 630 A

1. Depending on the HV HRC fuses installed

24 kV 25 kA 63 kA 63 kA 200 A 1) 630 A

Components
Switch-disconnector
Switch-disconnector/fuse combination

HA25-2822 eps

R-HA25-802 png

Switch-disconnector/fuse combination
Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air-Insulated · Siemens HA 25.81 · 2023 19

Components
Current transformers according to IEC/EN 61869-1 and -2
Block-type current transformer 4MA7
Features · Inductive indoor support-type current transformer
in block-type design · Cast-resin insulated · Insulation class E · Standardized · Narrow design according to DIN 42600 Part 8 · Secondary connection by means of screw-type terminals
Options · Secondary multiratio possible · Current transformer with type approval and
declaration of conformity
Mounting location · Factory-assembled · In the connection compartment · In the course of the busbar, without requiring a special
panel.
Zero-sequence current transformer 4MC96
Features · Inductive indoor ring-core current transformer · Cast-resin insulated · Insulation class E · For earth-fault current detection · Divisible · Secondary connection by means of screw-type terminals
Mounting location · Inside a deep bottom pan or below the panel.

R-HA25-716 png

Block-type current transformer 4MA72 Zero-sequence current transformer 4MC96

R-HA25-347 eps

Electrical data for
Rated insulation level Rated primary current Rated frequency Rated short-time thermal current Rated peak withstand current Duration of short-time withstand current Number of secondary cores Rated secondary current Accuracy classes ­ Measuring ­ Protection Rating

Block-type current transformer 4MA7 up to 24 kV up to 2000 A 50 Hz up to 25 kA up to 63 kA 1 s or 3 s up to 3 1 A or 5 A

Zero-sequence current transformer 4MC96 0.72 / 3 / ­ kV up to 100 A 50 Hz up to 25 kA up to 63 kA 1 s or 3 s 1 1 A

0.2 / 0.5 / 1.0 5P / 10P
up to 30 VA

1FS10 ­
1.25 VA

20 Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air- Insulated · Siemens HA 25.81 · 2023

Voltage transformer 4MR
Features · Inductive indoor support-type voltage transformer
in block-type design · Single-pole · Cast-resin insulated · Insulation class E · Standardized · Narrow design according to DIN 42600 Part 9 · Without primary fuse · Secondary connection by means of screw-type terminals
Options · With earth-fault winding · Voltage transformer with type approval and declaration
of conformity
Mounting location · Factory-assembled · In the connection compartment · In the busbar compartment · In the air-insulated metering panel, on withdrawable part
with primary fuses.

Electrical data for Rated operating voltage
Rated secondary voltage
Rated frequency Accuracy classes ­ Measuring ­ Protection Rating

Voltage transformer 4MR up to 24 kV up to 120 V or up to 120 V / 3 50 Hz
0.2 / 0.5 / 1.0 3P / 6P up to 150 VA

Components
Voltage transformers according to IEC/EN 61869-1 and -3
Voltage transformer 4MR

R-HG24-057 tif

Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air-Insulated · Siemens HA 25.81 · 2023 21

Components
Low-voltage compartment
Low-voltage compartment
Features · Low-voltage compartment for accommodation of all
protection, control, measuring, and metering equipment · Partitioned safe-to- touch off the high-voltage part · Low-voltage compartment can be removed, as all bus wires
and control cables are plugged in · Option: Higher low-voltage compartment · Option: Separation wall from panel to panel · Low-voltage cables are flexible and
protected by metal covers · Connection of withdrawable part wiring and panel wiring
to low-voltage compartment via 10-pole, coded plug connections · Bus wires can be plugged from panel to panel.
Low-voltage compartment

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R-HA25-800 psd

R-HA25-719 psd

Low-voltage compartment with built-in components (example)

Door of low-voltage compartment (example)

22 Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air- Insulated · Siemens HA 25.81 · 2023

Optical arc detection systems
Description · Optical arc detection systems recognize internal arcs by
means of optical sensors. This allows to detect arising internal arcs reliably and quickly. Accordingly, the protection device can trip quickly and without delay times. · The internal arc is interrupted within 100 ms and prevents damage to the switchgear, which would otherwise occur due to the thermal phase of the internal arc.
Benefits · Reliable detection of internal arcs · Extremely fast break times 100 ms
incl. the total break time of the circuit-breaker · Clear reduction of the arc energy · Minimization of thermal damage · Increase of personal safety · Minimization of downtimes · EMC-safe thanks to purely optical sensors.
Design and function · Basic components
­ Optical sensors in every compartment ­ Bay controller ­ Circuit-breaker · Internal arcs are detected optically, almost without delays and by using an additional current criterion for preventing overfunctioning, e.g. due to external light · Tripping of the circuit-breaker and interruption of the arc fault current within 100 ms.
Versions Siemens SIPROTEC 5 with arc protection module · Optical point sensors with optical fiber for signal
transmission · Line sensors in the busbar compartment possible as an
option · Arc protection module with three inputs for connection of
optical point sensors or line sensors · SIPROTEC 5 with protection function.
On request, selected optical arc detection systems can be installed as autonomous devices.

R-HA25-706 tif

Components
Optical arc detection systems
Bay controller of the SIPROTEC 5 series Arc protection module ARC-CD-3FO
Point sensor with optical fiber and connection Supply cable for line sensor with connection

R-HA25-707 tif

R-HA25-705 tif

R-HA25-703 tif

R-HA25-704 tif

Line sensor
Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air-Insulated · Siemens HA 25.81 · 2023 23

Technical data
Electrical data

Electrical data

Rated values up to 25 kA

Rated voltage

Rated frequency

Rated short-duration power-frequency

withstand voltage (phase-to-phase, phase-to-earth)

Rated lightning impulse withstand voltage

(phase-to-phase, phase-to-earth)

Rated short-circuit breaking current

Rated short-time withstand current, 3 s

Rated short-circuit making current

Rated peak withstand current

Rated continuous current of the busbar

Rated continuous current With circuit-breaker

of the feeders

With withdrawable

disconnector link

With switch-disconnector / fuse combination 1)

With switch-disconnector

without fuse combination

Bus sectionalizer

Busbar connection panel

kV Hz kV
kV max. kA max. kA max. kA max. kA max. A max. A
max. A A
A max. A max. A

7.2 12 24 50
20 28 50
60 75 125 25 25 63 63
2000 2000
2000 200
630 2000 2000

Internal arc classification
Rated voltage Arc fault current Arc fault duration Classification

kV max. kA
s

7.2 12 24 25 1
A FLR

Degree of protection Enclosure
Between the compartments

Standard Option
Standard

IP3XD IP4X IP2X

Loss of service continuity category

Panel with circuit-breaker

LCS 2

Panel with withdrawable disconnector link

LCS 2

Panel with fixed-mounted switch-disconnector

LSC 2

Busbar connection panel

LSC 1

Panels without connection compartments are not assigned a loss of service continuity category according to IEC 62271-200.

Partition class Panels in withdrawable design Panel with fixed-mounted switch- disconnector

1. Current values dependent on HV HRC fuses

PM Partitions made of metallic material
PI Partitions made of non-metallic material

R-HA25-800 psd

24 Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air- Insulated · Siemens HA 25.81 · 2023

Circuit-breaker panel

Disconnecting panel

and (option)

and (option)

and (option)

and (option)

and (option)

and (option)

and (option)

and (option)

and (option)

and (option)

and (option)

and (option)

and (option)

and (option)

Technical data
Product range
Cable sealing ends 1) max. 4 × 500 mm² per phase
Current transformer
Make-proof earthing switch
Voltage transformer
Capacitive voltage detecting system
Arrester
Withdrawable circuit-breaker
Withdrawable disconnector link

HA25-2803 eps or or
HA25-2804 eps or or

1. The details refer to conventional single-core sealing ends and depend on the rated continuous current and other built-in components.
   Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air-Insulated · Siemens HA 25.81 · 2023 25

Technical data
Product range
Cable sealing ends 1) max. 4 × 500 mm² per phase
Current transformer
Voltage transformer
Capacitive voltage detecting system
Arrester
Withdrawable voltage transformers with primary fuses
Make-proof earthing switch

Busbar connection panel
and (option) and (option) and (option) and (option) and (option)

Metering panel
and (option) and (option)

HA25-2805 eps or
HA25-2806 eps or

1. The details refer to conventional single-core sealing ends and depend on the rated continuous current and other built-in components.
   26 Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air- Insulated · Siemens HA 25.81 · 2023

Bus sectionalizer (mirror-image installation also possible)

HA25-2807 eps or or or

and (option)

Withdraw- Bus riser and (option) able panel panel

and (option)

and (option)

and (option)

and (option)

and (option)

and (option)

1. and (option)

and (option)

Technical data
Product range
Current transformer
Voltage transformer
Make-proof earthing switch
Capacitive voltage detecting system
Withdrawable circuit-breaker
Withdrawable disconnector link
Withdrawable voltage transformers with primary fuses

1. Voltage transformers not possible with withdrawable disconnector link. Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air-Insulated · Siemens HA 25.81 · 2023 27

Technical data
Product range
Current transformer
Make-proof earthing switch
Capacitive voltage detecting system
Cable sealing ends 1) max. 1 × 240 mm² per phase
Switchdisconnector with HV HRC fuses
Switchdisconnector without HV HRC fuses

Switch-disconnector panel with / without HV HRC fuses
and (option) and (option)

HA25-2808 eps or

1. The details refer to conventional single-core sealing ends and depend on the rated continuous current and other built-in components.
   28 Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air- Insulated · Siemens HA 25.81 · 2023

12 KV Pressure relief inside switchgear room

Technical data
Room planning

600

³ 2800 ³ 150

351 ³ 1700

³ 1200

800

(11205205)2

2100

³ 150

³ 150 351

HA25-2816 eps

Switchgear installation · For single-busbar application:
­ Wall-standing arrangement ­ Free-standing arrangement.

Room and door dimensions See dimension drawings above.

Weight 12 kV panels: 12 kV panels:

600 mm: approx. 410 kg 800 mm: approx. 505 kg

1 Width of the end wall 2 1250 mm including LV compartment
Recommended control aisle (depending on national requirements)
For replacement of switching devices For extension / panel replacement
Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air-Insulated · Siemens HA 25.81 · 2023 29

Technical data
Room planning
12 KV Pressure relief outside switchgear room

600

³ 2200 ³ 150

351 ³ 1420

³ 1200

800 (11205205)2
2100

³ 5003

³ 150 351

HA25-2817 eps

Switchgear installation · For single-busbar application:
­ Wall-standing arrangement ­ Free-standing arrangement.

Room and door dimensions See dimension drawings above.

Weight 12 kV panels: 12 kV panels:

600 mm: approx. 410 kg 800 mm: approx. 505 kg

1 Width of the end wall 2 1250 mm including LV compartment 3 Pressure relief channel outgoing duct could also be configured on the left or on the
right side of the switchgear. In that case, minimum distance to wall from that side shall be 500 mm.
Recommended control aisle (depending on national requirements)
For replacement of switching devices
For extension / panel replacement

30 Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air- Insulated · Siemens HA 25.81 · 2023

24 KV Pressure relief inside switchgear room

Technical data
Room planning

HA25-2818 eps

800

³ 3000 ³ 150

351

³ 1880

³ 1200

1000

(11524000)2

2300

³ 150

³ 150 351

Switchgear installation · For single-busbar application:
­ Wall-standing arrangement ­ Free-standing arrangement.

Room and door dimensions See dimension drawings above.

Weight 24 kV panels: 24 kV panels:

800 mm: approx. 596 kg 1000 mm: approx. 625 kg

1 Width of the end wall 2 including LV compartment
Recommended control aisle (depending on national requirements)
For replacement of switching devices For extension / panel replacement
Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air-Insulated · Siemens HA 25.81 · 2023 31

Technical data
Room planning
24 KV Pressure relief outside switchgear room

800

HA25-2819 eps

³ 2400 ³ 150

351

³ 1600

³ 1200

1000 (11524000)2
2300

³ 5003

³ 150 351

Switchgear installation · For single-busbar application:
­ Wall-standing arrangement ­ Free-standing arrangement.

Room and door dimensions See dimension drawings above.

Weight 24 kV panels: 24 kV panels:

800 mm: approx. 596 kg 1000 mm: approx. 625 kg

1 Width of the end wall 2 1540 mm including LV compartment 3 Pressure relief channel outgoing duct could also be configured on the left or on the
right side of the switchgear. In that case, minimum distance to wall from that side shall be 500 mm.
Recommended control aisle (depending on national requirements)
For replacement of switching devices
For extension / panel replacement

32 Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air- Insulated · Siemens HA 25.81 · 2023

Technical data
Transport and packing

Transport and packing
Transport NXAIR C switchgear is delivered in form of individual panels. The following must be observed: · Transport facilities on site · Transport dimensions and transport weights · Size of door openings in building.
Packing Means of transport: Rail and truck · Panels on pallets · Open packing with PE protective film.

Means of transport: Seafreight · Panels on pallets · Sealed in PE protective film, with closed
wooden box · With desiccant bags · With sealed wooden base · Max. storage time: 12 months.
Means of transport: Airfreight · Panels on pallets · In wooden latticed crate with sealed upper and lower
PE protective film.

Dimensions, weights

Transport
12 kV Truck or rail Seafreight or airfreight
24 kV Truck or rail Seafreight or airfreight

Panel spacing
mm
1 × 600 1 × 800 1 × 600 1 × 800
1 × 800 1 × 1000 1 × 800 1 × 1000

Transport dimensions

Width mm

Height mm

760 930 830 1030

2320 2320 2380 2380

930 1230 1030 1230

2550 2550 2610 2610

1. Average values, depending on the degree to which panels are equipped

Depth mm
1375 1375 1605 1605
1600 1600 1830 1830

Transport weight 1)

with packing kg

without packing kg

440

410

558

505

640

410

778

505

640

596

925

625

860

596

1145

625

Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air-Insulated · Siemens HA 25.81 · 2023 33

Standards
Standards, specifications, guidelines

Type of service location · The switchgear can be used at the following locations as an
indoor installation according to IEC 61936 ­ Outside lockable electrical service locations at places
which are not accessible to the public. Enclosures of switchgear can only be removed with tools. ­ In lockable electrical service locations. A lockable electrical service location is a place outdoors or indoors that is reserved exclusively for housing electrical equipment and which is kept under lock and key. Access is restricted to authorized personnel and persons who have been properly instructed in electrical engineering. Untrained or unskilled persons may only enter under the supervision of authorized personnel or properly instructed persons.
Dielectric strength · The dielectric strength is verified by testing the switchgear
with rated values of short-duration power-frequency withstand voltage and lightning impulse withstand voltage according to IEC 62271-1 (see table “Dielectric strength”). · The rated values are referred to sea level and to normal atmospheric conditions (1013 hPa, 20 °C, 11 g/m³ water content according to IEC 60071. · The dielectric strength decreases with increasing altitude. For site altitudes above 1000 m (above sea level), the standards do not provide any guidelines for the insulation rating, but leave this to the scope of special agreements. · Site altitude ­ The dielectric strength of air insulation decreases with
increasing altitude due to low air density. This reduction is permitted up to a site altitude of 1000 m according to IEC. ­ For site altitudes above 1000 m, a higher insulation level must be selected. It results from the multiplication of the rated insulation level for 0 to 1000 m with the altitude correction factor Ka.

Table for dielectric strength

Rated voltage (r.m.s. value)

kV 7.2 12 15 17.5 24

Rated short-duration power-frequency withstand voltage (r.m.s. value)

­ Between phases and to earth

kV 20 28 36 38 50

­ Across isolating distances

kV 23 32 40 45 60

Rated lightning impulse withstand voltage (peak value)

­ Between phases and to earth

kV 60 75 95 95 125

­ Across isolating distances

kV 70 85 105 110 145

Altitude correction factor Ka
For site altitudes above 1000 m, the altitude correction factor Ka is recommended, depending on the site altitude above sea level.

Altitude correction factor
HA40-2037b en eps

Site altitude in m above sea level
Rated short-duration power-frequency withstand voltage to be selected for site altitudes > 1000 m
Rated short-duration power-frequency withstand voltage up to 1000 m · Ka
Rated lightning impulse withstand voltage to be selected for site altitudes > 1000 m
Rated lightning impulse withstand voltage up to 1000 m · Ka
Example: 3000 m site altitude above sea level, 17.5 kV switchgear rated voltage, 95 kV rated lightning impulse withstand voltage Rated lightning impulse withstand voltage to be selected = 95 kV · 1.28 = 122 kV Result: According to the above table, switchgear for a rated voltage of 24 kV with a rated lightning impulse withstand voltage of 125 kV is to be selected.

34 Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air- Insulated · Siemens HA 25.81 · 2023

Standards
Standards, specifications, guidelines

Standards

Switchgear

NXAIR C

Switching devices

Circuit-breakers
Disconnectors and earthing switches Switch-disconnectors

Switch-disconnector / fuse combinations Voltage detecting systems

HV HRC fuses
Surge arresters Degree of protection

Insulation Instrument transformers

Installation Environmental conditions Operation

IEC standard / EN standard 62271-1
62271-200
62271-100
62271-102
62271-103
62271-105
62271-213 62271-215 60282-1
60099-4 60529 62262 60071 61869-1 61869-2 61869-3 61869-6 61869-10 61869-11 61936-1 60721-3-3 EN 50110

Title
High-voltage switchgear and controlgear: Common specifications for alternating current switchgear and controlgear High-voltage switchgear and controlgear: AC metal-enclosed switchgear and controlgear for rated voltages above 1 kV and up to and including 52 kV High-voltage switchgear and controlgear: Alternating- current circuit-breakers High-voltage switchgear and controlgear: Alternating current disconnectors and earthing switches High-voltage switchgear and controlgear: Switches for rated voltages above 1 kV up to and including 52 kV High-voltage switchgear and controlgear: Alternating current switch-fuse combinations for rated voltages above 1 kV up to and including 52 kV Voltage detecting and indicating system (VDIS) Phase comparator used with VDIS High- voltage fuses: Current-limiting fuses Surge arresters Degrees of protection provided by enclosures (IP code) Degree of protection provided by enclosures (IK code) Insulation co-ordination Instrument transformers Current transformers Voltage transformers Low-power instrument transformers Low-power passive current transformers Low-power passive voltage transformers Power installations exceeding 1 kV a.c. Classification of environmental conditions Operation of electrical installations

Standards The switchgear complies with the relevant standards and specifications applicable at the time of type tests.

In accordance with the harmonization agreement reached by the countries of the European Union, their national specifications conform to the IEC standard.

Current-carrying capacity

· According to IEC 62271-200 or IEC 62271-1, the rated

continuous current refers to the following ambient air

temperatures:

­ Maximum of 24-hour mean

+ 35 °C

­ Maximum

+ 40 °C

· The current-carrying capacity of the panels and busbars

depends on the ambient air temperature outside the

enclosure.

Internal arc classification · Protection of operating personnel shall be ensured by
means of tests for verifying the internal arc classification · Internal arcing tests must be performed in accordance
with IEC 62271-200 · Definition of criteria:
­ Criterion 1: Correctly secured doors and covers do not open, limited deformations are accepted
­ Criterion 2: No fragmentation of the enclosure, no projection of small parts above 60 g
­ Criterion 3: No holes in accessible sides up to a height of 2 m
­ Criterion 4: No ignition of indicators due to hot gases
­ Criterion 5: The enclosure remains connected to its earthing point.

Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air-Insulated · Siemens HA 25.81 · 2023 35

Standards
Standards, specifications, guidelines

Recycling The switchgear can be recycled in ecological manner in compliance with existing legislation. Auxiliary devices such as short-circuit indicators have to be recycled as electronic scrap. Batteries have to be recycled professionally.

Terms “Make-proof earthing switches” are earthing switches with short-circuit making capacity according to IEC 62271-102.

Protection against solid foreign objects, electric shock and water NXAIR C switchgear fulfills according to the standards

IEC 62271-1 IEC 62271-200 IEC 60529 IEC 62262

EN 62271-1 EN 62271-200 EN 60529 EN 50102

the following degrees of protection:

Panel Degree of protection for the enclosure, optional Degree of protection for the partitions
Degree of protection for the enclosure against mechanical impacts from outside

NXAIR C IP3X IP4X IP2X
IK07

Color of the panel front RAL 7035 (light gray).

NXAIR C switchgear is suitable for application in indoor installations under normal service conditions as defined in the standard IEC 62271-1.

· Temperature

-5 °C to +55 °C

· Rel. air humidity

· Mean value over 24 h 1): 95 %

· Mean value over 1 month: 90 %

· Condensation

· Occasionally

· Frequently (with min. degree of

protection IP4X, with anticondensation heater in LV part 2))

· Site altitude

· Observe altitude correction

(see page 34)

· No significant pollution of the ambient air (dust, gases,

vapors, salts).

Furthermore, the high-voltage part of NXAIR C switchgear can be used in environmental conditions of the climatic categories 3K3 and 3K5 according to the standard IEC 60721-3-3.

For secondary devices in the low-voltage door, the stipulations of the IP degree of protection apply according to the definitions for the switchgear enclosure.

1. Secondary devices (e.g. protection devices, meters, measuring transducers, etc.) must be suitable for the given service conditions
2. Heater in the LV compartment and in the operating mechanism box of the circuit-breaker
   36 Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air- Insulated · Siemens HA 25.81 · 2023

Notes
Medium-Voltage Switchgear Type NXAIR C up to 24 kV, up to 25 kA, Air-Insulated · Siemens HA 25.81 · 2023 37

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Mediumvoltage systems
Published by Siemens AG Smart Infrastructure Electrification & Automation Mozartstrasse 31 C 91052 Erlangen, Germany For further information, please contact our Customer Support Center: Phone: +49 180 524 70 00 Fax: +49 180 524 24 71 E-mail: support.energy@siemens.com siemens.com/medium-voltage-switchgear siemens.com/nxair Article No. SIEA-C10101-00-7600 VO 237270 en KG 09.23 0.0
For the U.S. published by Siemens Industry Inc. 100 Technology Drive Alpharetta, GA 30005 United States
Status 09/2023 Subject to changes and errors. The information given in this document only contains general descriptions and/or performance features which may not always specifically reflect those described, or which may undergo modification in the course of further development of the products. The requested performance features are binding only when they are expressly agreed upon in the concluded contract. All product designations may be trademarks or other rights of Siemens AG, its affiliated companies or other companies whose use by third parties for their own purposes could violate the rights of the respective owner. © Siemens 2023

References

• Systems - Medium-voltage – Power distribution - Siemens Global Website
• NXAIR - Systems - Siemens Global Website
• Smart infrastructure - Businesses - Siemens Global Website
• NXAIR - Systems - Siemens Global Website

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