Switchgear with withdrawable vacuum circuit-breaker 6 (10) kV, 17.5 kV

NEX switchgear is designed with due regard to the long experience of similar devices operation and meets basic requirements: reliability required for trouble-free operation, easy operation and maintenance, as well as personnel safety.

NEX is manufactured in 44 factories of 17 countries all over the world. Your local partner PLUTON provides the advantages of local production and service for internationally known product. Quality of the product is guaranteed by Schneider Electric (France) due to training, technical support and regular audit of the certified partner PLUTON.

NEX integrates innovative solutions based on proven techniques and includes: high performance switchgear, digital protection, monitoring and control systems.

Key features:

NEX is an AC metal-enclosed switchgear having voltage rating 6 (10) kV, 17,5 kV designed for indoor installation at step-down and distribution substations, as well as at power distribution centers;
the most effective control and protection means are used in NEX cubicles. NEX cubicles can be easily integrated in substation automated control system;
NEX cubicles technical features are confirmed by type tests. NEX is designed, manufactured, tested in accordance with requirements of international standards IEC 62271:1 and IEC 62271:200;
maintenance is performed no more than once in 5 years.

adaptability to technical requirements of the Customer

uninterrupted operation of your networks

easy installation, operation and maintenance

increased level of personnel safety

provision of environmental protection

Main advantages:

high mounting flexibility due to unified installation dimensions;
compact front width 650 mm for the cubicles up to 1250 A;
high-voltage circuit-breaker is withdrawable;
protective metal shutters reliably isolate high-voltage circuit breaker compartment and ensure safe operation;
high speed of the vacuum circuit-breaker provides reliable protection against arc effects at high currents;
each compartment of the switchgear has its own channel for pressure relief in case of internal arc. The channel has an outlet valve on the roof of the cabinet.

Application areas:

power industry and infrastructure (power generation facilities, airports, water supply facilities, offices, hotels, hospitals, shopping and building centers, farm enterprises, housing and public utilities, etc.);
transport (traction substations of metro and railway), step-down substations of city electric transport;
industry (mining, oil and gas, chemical industry, cement works, metallurgy, light industry enterprises, electric transport power supply at industrial enterprises, mines, mining and processing plants, etc.).

SAFETY
DESIGN
VACUUM CIRCUIT-BREAKER
EARTHING SWITCH
PROTECTION, CONTROL AND MONITORING SYSTEM

Internal arc protection

NEX cubicles are structurally protected against destructive influence of internal arc and provide safety of maintenance personnel. Immunity to internal arc is confirmed by localization property type tests. Internal arc detector — an electronic module with optical sensors can be optionally installed in NEX.

Interlocking

NEX cubicle integrates mechanical and electromagnet interlocks to prevent incorrect operation by personnel and ensure safety in case of:

access to cable compartment;
withdrawable components rolling in and out;
earthing switch closing;
high voltage circuit breaker compartment door opening.

Locks are additionally provided.

Cubicle is made up of 4 compartments separated internally with metallic partitions:

relay protection and automatics compartment. Compartment includes Sepam (or MiCom, Vamp57, Relion, upon Customer’s requirement) protection unit, energy monitoring and accounting units, terminal blocks and other auxiliary circuits equipment;
switching device compartment. Compartment includes not only withdrawable part with vacuum circuit-breaker (trolley with disconnector or earthing switch), but also moving metal shutters that close automatically upon circuit-breaker/disconnector /earthing switch maneuvering from operation to control position;
cable compartment. Compartment includes cable inputs, earthing switch, power-on indicator module, current transformers, voltage transformers;
busbars compartment. Compartment includes copper busbars, bushing insulators. Each compartment (except for relay protection compartment) has its own gas disposal channel with pressure relieve valve. Internal arc resistance (Class IAC AFLR acc. to IEC 62271:200).

NEX meets IEC 62271:200 requirements. It provides LSC2B safety class and this allows operations in separate compartments without voltage removal.

NEX includes Evolis vacuum circuit breaker manufactured by Schneider Electric (France) as a switching device:

rated voltage 6 kV and 10 kV;
operating voltage 7,2 kV and 12 kV;
short circuit breaking capacity up to 31,5 kA;
rated current: from 630 A to 2500 A;
lifetime: 10 000 trippings;
axial magnetic field (AMF) breaking technology;
withdrawable version.

Special configuration of operating contacts in circuit-breaker vacuum chambers and axial magnetic field during arc breaking provide maximum possible in this type of circuit-breakers "softness" of arc breaking even at high current values.

Evolis corresponds the highest mechanical endurance requirements (IEC 62271-100: class M2).

Earthing switch is used to earth cable leads before starting works in cable compartment. Earthing switch earths the switchgear busbar in voltage transformer functional module.

Earthing switch corresponds IEC 62271-102 and consists of:

earthing blades;
high speed closing mechanism independent of operator;
switch control unit;
three capacitive voltage dividers integrated in insulators, connected to voltage indicator. This indicator is installed in the front part of the cubicle and indicates availability of input voltage.