Transcript VHA PANEL WITH HPA CIRCUIT BREAKER

© ABB Ltd. PTMV, INDIA
JULY 2004
PRODUCT
PRESENTATION
UNISAFE PANEL WITH
VD4 CIRCUIT BREAKER
© ABB Ltd - 2
Unisafe:Indoor Metal Clad Switchgear Cubicle
© ABB Ltd - 3
UNISAFE PANEL

Designed and type tested to
meet requirements of
IEC60298 & 60694 / IS:3427

Air insulated indoor switchgear

Metal clad construction

Independent exhaust vents for
all HT compartments

Internal arc tested

IP4X degree of protection
externally - IP5X available as
option
© ABB Ltd - 4
UNISAFE PANEL

Integral Earthing Switch
optional

Normal service conditions:
Min ambient temp:-5oC
Max ambient temp:+40oC

Quality System CertificationISO 9001

Environmental Management
System- ISO 14001
© ABB Ltd - 5
BREAKER COMPARTMENT

Test position of circuit breaker
behind closed door

Racking in/out of breaker from
test to service position and
vice-versa with cubicle door
closed only

Mechanical interlock to
prevent racking in/out of
breaker, when breaker is in
closed position

Live parts covered by
automatic shutters when
breaker is racked out
© ABB Ltd - 6
METERING COMPARTMENT

Metering compartment with
numerical /static /electro-magnetic
relays, indicating meters, lamp
and control switches

Protection and measuring
apparatus customized as per
requirement

Option of REF542 plus, composite
unit for protection, measurement,
control, signalling, interlock,
automation and communication
© ABB Ltd - 7
CABLE AND CT COMPARTMENT

Spacious construction to
accommodate 1 set of CTs
and 2 runs of cables

Option of rear extension to
accommodate extra CTs or
cables

Adequate height for cable
termination
© ABB Ltd - 8
PT COMPARTMENT

Withdrawable line PT provided
in the breaker panel

Removable fuses mounted on
the PT

Safety shutters between PT &
Cable compartment close
automatically on PT
withdrawal
© ABB Ltd - 9
BUSBAR COMPARTMENT

Spacious busbar compartment
for adequate air clearances

Option for busbar insulation
available

Option for shrouds on joints
available
© ABB Ltd - 10
Construction details of Switchgear Cubicle type UNISAFE
© ABB Ltd - 11
Construction details of Switchgear Cubicle type UNISAFE
© ABB Ltd - 12
VD4 BREAKER

The VD4 type circuit breaker is
designed and tested to meet
requirements of IEC 62271100 / IS : 13118

Vacuum used as insulation
and arc interruption medium

Operationally safe and reliable

Capable of interrupting small
magnetizing and capacitive
currents
VD4 BREAKER
© ABB Ltd - 13
Features of operating mechanism

O-C-O operation without
recharging

Closing spring charged by
motor in less than 15secs

Electrical anti-pumping

Provision for manual charging

Synchronisation and fast auto
reclosure duty
Vacuum Interrupter
1) Stem / Terminal
2) Twist protection
3) Bellows
4) Interrupter lid
5) Shield
6) Ceramic insulator
7) Shield
8) Contacts
9) Terminal
© ABB Ltd - 14
10) Interrupter lid
Interruption principle
VACUUM ARC

Vacuum arc is initiated by the separation of current
carrying contacts and is maintained till the current zero

Two types of vacuum arc - Diffuse & Contracted
DIFFUSE TYPE

It occurs while interrupting the rated current

Single melting points form on the entire surface
of the cathode producing metal vapours which
support the arc

The diffuse vacuum arc is characterised by
expansion over the contact surface and by an
even distribution of thermal stress over the contacts
© ABB Ltd - 15
surfaces.

Negligible contact erosion
Interruption principle
CONTRACTED TYPE

Higher the interruption current, the arc tends
to be transformed from the diffuse into the
contracted type due to the Hall effect

The arc contracts at the anode and as the
current increases further it tends to become
sharply defined. In this area there is an increase
in temperature with consequent thermal stress
© ABB Ltd - 16
on the contact.
Interruption principle
SPIRAL CONTACTS

To prevent overheating and contact
erosion, the arc is kept rotating

The special geometry of the spiral contacts
generates a radial magnetic field in all the areas
of the arc column

An electromagnetic force is self generated and
acts tangentially causing rapid arc rotation around
the contact axis. The arc is forced to rotate and to
involve a wider surface than that of a fixed controlled arc

Apart from minimising thermal stress, contact erosion
also is reduced which makes high short circuit current
interruption possible.

Maximum dielectric strength is restored within microseconds as the rapid reduction of current charge and
© ABB Ltd - 17
rapid condensation of the metal vapours happens
simultaneously along with the current zero.
© ABB Ltd - 18
UNISAFE CROSS SECTIONAL DWG
© ABB Ltd - 19
VD4 BREAKER DIMENSIONAL DRAWING
UNISAFE PANEL
TECHNICAL DETAILS
Description
Unit
Rating
Voltage
kV
12
Frequency
Hz
50
Current
A
up to 2000
Short time withstand
current (for 3 secs)
kA
26.3
Peak withstand current
kAp
66
Insulation level
kVrms/kVp
28/75, 95kVp as option
up to 1250A b/b current
mm
600 x 1550 x 2500
above 1250A b/b current
mm
750 x 1550 x 2500
© ABB Ltd - 20
WidthxDepthxHeight
Weight with breaker (approx.) kg
1000
Degree of Protection-Enclosure
IP4X, IP5X on request
VD4 CIRCUIT BREAKER
TECHNICAL DETAILS
Description
Unit
Rating
Type
VD4
Voltage
kV
Current
A
800
800
1250
1600
Breaking capacity
kA
13.1
20
26.3
26.3
Short time withstand
current (for 3 secs)
kA
13.1
20
26.3
26.3
Peak withstand current
kAp
33
50
66
66
Insulation level
kVrms/kVp
12.0613E 12.06.20E 12.12.25 12.16.25
12
28/75
Operating sequence
© ABB Ltd - 21
Weight (approx.)
O-3min-CO-3min-CO/
O-0.3secs-CO-3min-CO
kg
110
110
110
120