"Real" metalclad switchgear which answers the requested IEC
298 standards and even more...
IEC
298
Metalclad Definition
Metal enclosed switchgear in which components arranged in
seperate compartments with METAL partitions intended to be
earthed.
PVP 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 type single and double busbar switchgears had been fully
type tested in CESI (Italy) laboratories and all have IEC 298
(BS 5227) "Conformity Certificates" concerning the performed
type tests.
Internal arc tested switchgear for rated voltages up to and
including 36kV
PVP 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 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 type switchgear is provided with a draw-out trolley,rolling
on the floor, for PELKA PVB 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)..
SWITCHGEAR CONSTRUCTION
Each PVP 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 or epoxy coated flat
rectangular copper bars 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. 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 floatation, all
the live parts of PVP 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.
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High performance under extreme climatic conditions
PVP 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 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 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 maintenance free vacuum circuit breakers of
PELKA permits zero maintenance of the PVP type switchgear
under normal operating conditions.
Assurance of PELKA quality and ISO 9000
Having the ISO 9002 Quality System Certificate, an ISO 9000
based quality assurance system is applied in all of the
manufacturing steps of PVP 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 9000 certification or approval
from our quality assurance department according to ISO 9000.
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 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 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 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.
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.
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