Untitled Document

a7.2-36 kV Single and Double Busbar Switchgears

General :

"Real" metalclad switchgear which answers the requested IEC 60127-100 standards and even more...

Metalclad Definition
Metal enclosed switchgear in which components arranged in seperate compartments with METAL partitions intended to be earthed.
PVP and PELMCC type factory assembled metalclad switchgear has totally sheet steel encapsulated design with the protection degree of IP4X according to IEC/BS standards.

Type tested single and double busbar switchgear for rated voltages up to and including 36kV.
PVP and PELMCC type single and double busbar switchgears had been fully type tested in CESI (Italy) laboratories and all have (IEC 56, IEC 298, IEC 129, IEC 1233, IEC 60127) "Conformity Certificates" concerning the performed type tests.

Internal arc tested switchgear for rated voltages up to and including 36kV
PVP and PELMCC type switchgear is designed to protect the operator working in front of the panel door or around the switchgear in the event of an internal arc fault. PVP and PELMCC type switchgears had been internal arc tested successfully in CESI (Italy) laboratories fully complying IEC 298 (BS 5227) Annex AA.

Draw-out type switchgear
PVP and PELMCC type switchgear is provided with a draw-out trolley,rolling on the floor, for PELKA PVB and PELVAC type type-tested vacuum circuit breakers or vacuum contactors. Supplementary units for measurement, section isolation or external earthing are also supplied by voltage transformers, switch disconnectors and earthing switches, respectively.(Draw-out trolley equipped with SF6 circuit breaker is also available on request)..

High performance under extreme climatic conditions PVP and PELMCC type switchgear can be installed in any climate. As a standard, sheet steel parts of switchgear structure go under well accepted phosphated pre-surface treatment and come with electrocoated and wet (electrostatic) paint.This proven treatment has been worldwide accepted for several years to be eminently suitable even for the severest climatic conditions.

Safety interlocks preventing maloperations
PVP and PELMCC type switchgear comprises all the necessary interlocks to prevent any improper operations for minimizing the operator's fault.

Modular and extensible design
Modular construction assures that any future extension which will match to the both sides of PVP and PELMCC type switchgear easily and without the need of any special tools, by giving satisfaction both in technical and economical aspects.

Maintenance free switchgear
Usage of PVB and PELVAC maintenance free vacuum circuit breakers of PELKA permits zero maintenance of the PVP and PELMCC type switchgear under normal operating conditions.

Assurance of PELKA quality and ISO 9001
Having the ISO 9001 Quality System Certificate, an ISO 9001 based quality assurance system is applied in all of the manufacturing steps of PVP and PELVAC type switchgear. Besides from type-tested switchgear, vacuum circuit breakers and earthing switches of PELKA, all the other basic equipment installed in the switchgear are also carefully chosen and obtained from the sub-suppliers who has either ISO 9001 certification or approval from our quality assurance department according to ISO 9001.

Description :

SWITCHGEAR CONSTRUCTION
Each PVP and PELMCC type switchgear unit basically comprises a 3mm thick sheet steel mounting housing and a trolley carrying the vacuum circuit breaker. The application of computer controlled high precision punching, cutting, bending and welding techniques ensures all enclosers to be identical in every dimension; rigid and distortion resistant under short circuit conditions and during transportation.;
Each switchgear unit is subdivided into the following compartments
     -Busbar Compartment(s)
     -Circuit Breaker Compartment
     -Cable Connection Compartment
     -Low Voltage (LV) Compartment

     Against any improbable internal arc fault, all the high voltage compartments comprise individual pressure relief flap discharging from the top.

BUSBAR COMPARTMENT
The busbar compartment is devoid of any moving part. It contains high conductivity bare, painted or proper insulating material coated flat rectangular copper bars with rounded edges of proper current carrying cross section mounted on edge and supported by epoxy resin insulators. Flat tee off connections join the busbar directly to the isolating contact spouts. The busbars have been designed to be generally maintenance free, but access to them can be gained by removal of bolted pressure relief flap on the busbar compartment (for main busbar) and/or by opening of bolted quick access cover behind the circuit breaker compartment (for reverse busbar in double busbar system). The end covers are easily removable to permit extention work to be carried out without disturbing the existing facilities.

CIRCUIT BREAKER COMPARTMENT
The circuit breaker compartment is equipped suitable for insertion of the trolley mounted vacuum circuit breaker with horizontal isolation.The trolley has both SERVICE and TEST locations within the compartment. Access to the circuit breaker is possible via a hinged and lockable front door and the trolley can be kept in both positions when the door is closed.

The circuit breaker compartment door cannot be opened unless the circuit breaker is taken to the test position and opened.

The circuit breaker can be moved to the service position from test position and back only when the door is closed. All the functions of the circuit breaker can be performed when the door is closed.

An interlocking bracket is mounted on the base of the compartment to guide and lock the trolley and ensure the proper earthing of the movable structure on or between its two locations by means of a sliding earthing contact under the trolley. Each circuit breaker compartment comprises individually operated and separately padlockable shutters for BUSBAR(S) and CABLE connections.On withdrawal of the trolley from SERVICE to TEST position, safety shutters cover the isolating tulip contacts automatically. For double busbar systems, the trolley permits the usage of the same circuit breaker for both main and reserve busbars raising and lowering it by a special elevator system, which eliminates usage of any switch disconnector for busbar selection.

CABLE CONNECTION COMPARTMENT
The cable connection compartment normally contains isolating contact spouts, cast resin wound or ring type current transformers, fixed or withdrawable type voltage transformers, earthing switch and cable termination connections with cable glands on the cable access cover from the bottom. The horizontal bus connections between current transformers and cable terminals are held by epoxy resin support insulators whereever necessary. The type, quantity and technical characteristics of the equipment installed in this compartment are determined based on the customer's specifications and requests. To increase the security in case of any water flood, all the live parts of PVP and PELMCC type switchgear are positioned at least 300mm above the floor level.Similar to the other compartments, the cable termination compartment is normally maintenance free, but any access is possible just by removal of the lower back cover of the switchgear.

LOW VOLTAGE COMPARTMENT
The LV compartment is a solid sheet steel box on top of the circuit breaker compartment and encased seperately from the high voltage section. Based on customer's specifications relays, meters, control switches,indicating lamps and the other instruments are flush mounted on the hinged and lockable front door. Sufficient space is available inside the compartment to arrange all the secondary control equipment, miniature circuit breakers, auxiliary relays,terminal blocks, etc.

WITHDRAWABLE VOLTAGE TRANSFORMERS COMPARTMENT
Apart from the fixed type voltage transformers installed on the base of the cable connection compartment, as an alternative, withdrawable type voltage transformers can be supplied for feeder circuits, but connection to busbar circuit is also possible.In this part of the switchgear voltage transformers are installed on a handle operated withdrawal base enclosed in a seperate lockable metal housing with isolating tulip contacts and primary protection fuses. Being a part of appropriate cable termination compartment, this section has also its own pressure relief flap

EARTHING SWITCH
PVP and PELMCC type switchgear is normallysupplied with integral circuit earthing. In this case, a PELKA PTB type earthing switch fully interlocked with the circuit breaker is installed in the cable connection compartment of each feeder. The earthing switch can be operated from the front (or the back) of the switchgear. Busbar earthing can be provided as an option, alternatively, either through an integral fault making earthing switch or through a seperate busbar earthing trolley, whichever suits the customer's safety requirements.

SAFETY INTERLOCKS
PVP and PELMCC type switchgear is equipped with all necessary interlocks to prevent any mloperation.basically the following interlocks are performed in a PVP type switchgear.The circuit breaker trolley can be locked in SERVICE and TESTposition before the breaker is operated.

     The circuit breaker can only be operated in SERVICE and TEST position when the interlocks is engaged preventing the trolley from being moved in any direction.
     The trolley interlock can only be released if the circuit breaker is open. Therefore it is only possible to move the circuit breaker trolley in either direction between SERVICE and TEST position if the breaker is open.                                                                                               The circuit breaker compartment door can be opened if the circuit breaker is in test position.
     The movement of the trolley inside the circuit breaker compartment can not be done by a single effort. To release the interlock, between the trolley and switchgear base, the pedal in front of the trolley must be pressed (optional).
     The earthing switch can not be closed when the circuit breaker trolley is in SERVICE position or the circuit breaker trolley can not be moved into SERVICE position when the earthing switch is closed.
     Replacement of a circuit breaker trolley is only possible with the identical trolleys of the same ratings, and this is secured by means of interlock pins. The above mechanical interlocks are also supported by the usual and necessary electrical interlocks for each switchgear unit.