Air insulated switchgears

Medium voltage SNP 24.15 Kaldera switchgear (12 do 24 kV)

Description

This MV switch gear ( 12-36) KV, 2000 A, 25 KA, is part of the group of medium voltage switchgears with a metal enclosure, suitable for indoor installation. It consists of a unit that can be equipped with a circuit-breaker, contactor or switch-disconnector, as well as with any other accessories available for conventional switchgears.This medium voltage switch gear consists of the following compartments: circuit breaker, busbar, cable and low voltage compartment ,which houses all the extra instruments, also each compartment has a special channel designed for the discharge of hot toxic gases created as a product of combustion of materials. All compartments are available on the front and each are divided with metal partitions which are connected to ground.

It is approved and tested for IEC, GB/DL, GOST and CSA standards. The functional units of the switchgear are guaranteed arc proof in accordance with the IEC 62271-200 standards, appendix AA, accessibility class, criteria 1 to 5.
The switchgear does not require rear access for installation or maintenance, all the operations can be carried out from the front.
The range of the apparatus available for this switchgear is the most complete in the market, including:

  • withdrawable vacuum circuit-breakers with mechanical or magnetic actuator
  • withdrawable SF6 circuit breaker
  • withdrawable vacuum contactors with fuses,
  • fixed version of switch-disconnectors




  • The switchgear can be fitted with instrument transformers or sensors for voltage and current measurement and protection, as well as with any type of protection or control unit.
    Benefits for Users
    High level of personnel safety and protective equipment, simple use safe for the environment – no contact with gas during installation, various types of cable connections, integrated protective equipment system

    Application area:
    Installations for the production and distribution of electricity:
  • Power plants (hydro and thermal)
  • Substations
  • Disconnector areas
  • The main and auxiliary machinery.

  • Transportation: Airports, ports, railways

    Industry: Paper, chemical, food processing and cement, steel mills, mining services sector:
    Shopping centers, hotels, hospitals and other infrastructures and facilities
    Kaldera switchgear enables the user:
  • High availability and reliability of system
  • Safety for all operating personnel
  • Minimal maintenance
  • Inability to mishandling
  • Quick and easy installation.

  • Switchgear Characteristics
    Range from 12 kV, …2000 A, …25 kA to 36 kV, …2000 A, …25 kA

    Table 1: IEC electrical characteristics of the SNP Kaldera medium voltage switchgear shown in the following table.

    Rated voltage

    KV

    12

    24

    36

    Rated insulation voltage

    KV

    12

    24

    36

    Rated power frequency withstand voltage

    KV 1min

    28

    50

    70

    Rated lightning impulse withstand voltage

    KV

    75

    125

    170

    Rated frequency     

    Hz

    50/60

    50/60

    50

    Rated short time withstand current

    KA 3s

    ...25

    ...25

    ...25

    Peak current

    KA

    ...125

    ...80

    ...80

    Internal arc withstand current

    KA 1s

    ...25

    ...25

    ...25

    Main busbar rated current

    A

    ...2000

    ...2000

    ...2000

     

     

    Circuit-breaker rated current

     

     

     

     

     

    A

    630

    630

    630

    1250

    1250

    1250

    1600

    1600

    1600

    2000

    2000

    2000



    Standards


    The switchgear and main apparatus contained in it comply with the following standards:
  • IEC 62271-1 for general purposes.
  • IEC 62271-200 for the switchgear.
  • IEC 62271-102 for grounding switch.
  • IEC 62271-100 for circuit-breakers.
  • IEC 60071-2 for insulation coordination.
  • IEC 60470 for contactors.
  • IEC 60265-1 for switch-disconnectors.
  • IEC 60529 for protection rating


  • Protection Rating Protection rating of the switchgear conforms to the IEC 60529 standard. This switchgear is supplied with the following standard degrees of protection:
  • IP4X for enclosure.
  • IP2X for partitions between compartments


  • Upon request, the external housing can be supplied with a higher degree of protection; In this case, please contact your sales representative.


    Safety

    When developing a modern medium voltage switchgear, personnel safety must necessarily take priority. This is why this switchgear has been designed and tested to withstand an internal arc due to short-circuit. The tests show that the metal housing of this switchgear can protect the personnel near the switchgear in case of a fault which includes striking of an internal arc. This switchgear is fitted with all the available interlocks and accessories needed to guarantee the highest level of safety and reliability for both installation and personnel. The range of medium voltage cells for application in electricity distribution meets all the requirements, from the simplest to the most demanding processes. This switchgear is highly reliable and suitable for application in power utility and industrial networks, power plants and infrastructure facilities. This switchgear has been designed for voltages up to 24 kV and can be fitted with circuit-breakers or contactors, both the vacuum and the SF6 gas, and it has been designed to ensure safety of the operator and continuity of operation. The cells are accessed from the front and all operations are performed while compartment doors are closed. A system of mechanical blockages prevents operator’s faults and disables insertion of the lever unless it is completely safe to do so.

    The rated characteristics of the switchgear are guaranteed under the following ambient conditions:

  • minimum ambient temperature: -5 °C
  • maximum ambient temperature: +40 °C

  • Ambient humidity:

  • maximum daily average of relative humidity 95% RH
  • maximum average of water vapor pressure 2.2 KPa
  • maximum monthly average of relative humidity 90% RH
  • maximum monthly average of water vapor pressure 1.8 KPa
  • normal operating altitude is up to 1,000 m above the sea level.
    For installation at higher altitudes, please contact your sales representative.

    IEC clasification


    With the release of the IEC 62271-200 standard, new definitions and classifications of Medium Voltage switchgear have been introduced.
    Loss of Service Continuity (LSC) has been selected as a fundamental parameter for the user.According to the IEC 62271-200,
    Loss of service continuity ) LSC – 2B The various LSC categories describe the possibility of keeping other compartments and/or panels energized while a compartment in the main circuit is opened.


    The defined categories are:

  • LSC-1: The whole switchgear shall be put out of service for opening a main circuit compartment for normal operation and/or normal maintenance or for gaining access to any switchgear components.
  • LSC-2A: The same as LSC-1 with the exception that the main busbars and the functional units adjacent to the one under maintenance can remain energized
  • LSC-2B: The same as LSC-2A with the exception that the cable compartment can remain energized.



  • This switch gear is classified as LSC-2B because the busbar, circuit-breaker and cable compartments are physically and electrically segregated.This is the category that defines the possibility of accessing the circuit-breaker compartment with the busbars and cables energized.

    Instrument transformers and sensors