Download 3. Construction – Functions

Specification for Tender
769844992
General Specification for 24kV Vacuum
circuit-breaker
General
Performances
Construction – Functions
Last update : 2017-04-30
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Specification for Tender
769844992
Table of contents:
1 General
………………………………………………………………………………………………………….. 3
2. Performances……………………………………………………………………………………….. 3
2.1 The general characteristics................................................................................................................. 3
2.2 The MVCB......................................................................................................................................... 3
2.3 Other characteristiscs........................................................................................................................... 3
3. Construction – Functions.................................................................................................................. 3
3.1 The operating mechanism...................................................................................................................
3.2 The MVCB………………………………………………………………………………………….
3.3 The following options........................................................................................................................
3.4 Indications..........................................................................................................................................
3.5 Earthing of the CB..............................................................................................................................
3.6 Sensor for Current Measurement and Protection...............................................................................
3.7 Monitoring function............................................................................................................................
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Last update : 2017-04-30
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Specification for Tender
769844992
1. General
Medium Voltage Circuit Breakers (MVCB) shall be using vacuum switching technology, and shall comply
with IEC 60694 and 62271-100 standards or with the corresponding standards applicable in the member
countries.
Production site organisation shall be certified to comply with ISO 9002 and ISO 14001 standards and
certificates shall be submitted together with the product.
MVCB shall be designed according to Eco-design complying with ISO 14062. Especially MVCB’s
materials shall be of halogen free type. They shall be supplied in recyclable packing complying with
European Directives.
The manufacturer shall implement non polluting production processes that do not make use of
chlorofluorocarbons, chlorinated hydrocarbons, ink for cardboard markings, etc
2. Performances
2.1 The general characteristics of the CB shall be in accordance with IEC standards:
IEC 60294 Edition 2-2 : Common specifications for high-voltage switchgear and control gear standards
IEC 62271-100 Edition 1.1 2003-05 : High-voltage alternating-current circuit-breakers
2.2 The MVCB shall have the following characteristics:
Rated voltage 24 kV
Power frequency withstand voltage (50Hz-1mn)
50 kV
Lightning impulse withstand voltage
125 kV
Rated normal current
(Ir to be given) A
Rated short-circuit breaking current
(Isc to be given) kA
Rated Short time withstand current
Isc (3sec)
Rated Short-circuit making current
2.5 x Isc (at 50Hz) or 2.6 x Isc (at 60Hz)
2.3 Other characteristics:
Mechanical endurance
Electrical endurance
Number of operations at full Isc value
Capacitive current breaking
Class M2 (10000 operations)
Class E2
50
Class C2 (Test duty LC1-LC2-CC1-CC2)
All the performances shall be certified by tests reports issued by a recognised international body such as
ESEF, ASTA, ASEFA or Kema.
3. Construction – Functions
The MVCB shall be available in a fixed version and withdrawable version with a cradle as an option for
interface in the cubicle.
MVCB shall be actuated by a spring operating mechanism with fast opening and closing, independant of the
operator, and that can be operated without any auxiliary supply.
3.1 The operating mechanism shall be equipped with:
3.1.1 Opening and closing push-buttons
3.1.2 A mechanical “open-closed” position indicator
3.1.3 A mechanical “charged-discharged” closing spring indicator
3.1.4 A block of auxiliary contacts
Last update : 2017-04-30
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Specification for Tender
769844992
3.2 The MVCB shall be fitted with a LV plug and socket for connection of the LV auxiliary circuit
associated with the opening and closing of the circuit-breaker.
3.3 The following options shall be available, if required:
3.3.1 Remote control to enable opening and closing of the circuit-breaker. The auxiliary devices (releases
and motors) shall accept auxiliary supply from 24V DC to 230V AC.
3.3.2 Mechanical operation counter.
3.3.3 Additional opening release (shunt or undervoltage type)
3.3.4 Low energy release as actuator for a self powered relay associated to the CB.
3.3.5 The MVCB shall be fitted with the following safety devices:
3.3.6 Locking the circuit-breaker in the open position by the mean of a key.
3.3.7 For the withdrawable version:
3.3.7.1 Interlocking between the LV plug connection and connected and disconnected positions, in
order to prevent the closing of the CB unless the auxiliary circuits are connected, and to prevent
disconnection of the auxiliary circuit with the CB closed in the service position.
3.3.8 Full proof protection to avoid mismatch between cradle and circuit breaker
3.3.8.1 Padlocking of the safety shutters to lock the shutters in closed position
3.3.8.2 Anti-drop function in the cradle in order to prevent involuntary drop of the CB when extracting out
of the cradle.
3.3.9 Padlocking in the disconnected position.
3.3.9.1 When applicable, interlocking between the cubicle door and the racking in/out of the CB : the
racking in shall be possible only when the door is closed, and the opening of the door shall be possible only
when the CB is disconnected.
3.4 Indications
3.4.1 4NO/NC+1 change over contacts shall be available to indicate Open closed position of the CB
3.4.1.1 1 auxiliary contact shall be available to indicate the end of charging of the operating mechanism
3.4.2 For the withdrawable version:
- a mechanical position indicator for connected /disconnected position shall be located at the front of CB
compartment door
- A block of 4 auxiliary contacts shall be available on the cradle to indicate the connected position of the CB
3.5 Earthing of the CB
As an option , it shall be possible to add a specific device in order to earth the CB during the racking in/out
operation.
3.6 Sensor for Current Measurement and Protection:
For flexibility of the current measurement, it shall be possible to install on the cradle, as an option, a
dedicated current sensor such as Low powered current transducer in accordance to IEC60044/8.
Last update : 2017-04-30
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