ABB VD4X, Instruction Manual

Page: 24 / 32

24
V D 4 X
I N S T R U C T I O N M A N U A L
—
Maintenance
Maintenance serves to ensure trouble-free
operation and achieve the longest possible
working life of the switchgear. In accordance
with DIN 31051, IEC 62271-1 it comprises the
following closely related activities:
Inspection: Determination of the actual
condition
Servicing: Preservation of a functional
condition
Repair: Measures to restore the functional
condition
5.1 5.1 General
Vacuum circuit-breakers are characterized by
their simple and robust construction. They have
a long life expectancy. Their operating mechanisms
have a low maintenance requirement, and the
interrupters are maintenance-free during their
working life. There is no adverse effect on the
vacuum, even from frequent switching of operating
and short-circuit currents.
The servicing intervals and scope are determined
by environmental influences, the switching
sequences and number of short-circuit breaking
operations.
Note
The following must be observed for all
maintenance work:
• The relevant specifications in section
“Standards and specifications”
• Notes on safety at work in section
“Commissioning / Operation”
• Standards and specifications in the country
of installation
Maintenance work may only be performed by fully
trained personnel, observing all the relevant
safety regulations. It is recommended that ABB
after-sales service personnel should be called
in, at least during the performance of servicing
and repair work.
While the work is in progress, all supply voltage
sources must also be disconnected and secured
to prevent reconnection.
Note
In order to prevent accidents
(particularly injury to hands!) extreme
care should be taken during all repair
work on the operating mechanism,
especially with front plate removed.
The spiral spring in the spring energy
storage mechanism, for instance,
retains a basic tension which is
independent of the charging and
discharging processes during
switching, so as to ensure correct
function. This spring energy can be
inadvertently released if work is
performed incorrectly on the spring
mechanism!
5.1.1 Service-life
Typical life-expectancies for VD4X circuit-breakers.
Vacuum interrupter
Up to 30,000 switching cycles (see section
“Permissible numbers of switching cycles” page 9)
Device
Up to 30,000 operating cycles, depending on
switch type and assuming conscientiously
performed inspection and maintenance work
and normal operating conditions.
5.2 Inspection and functional testing
5.2.1 Switching devices in general
• The proper condition of the switching device
is to be verified by regular inspection
• Inspection at fixed intervals may be waived if
the switchgear is permanently monitored by a
qualified personnel
• The checks first and foremost comprise visual
examination for contamination, corrosion and
moisture
• In unusual operating conditions (including
adverse climatic conditions) and/or special
environmental pollutions (e.g. heavy
contamination and aggressive atmosphere),
inspection may also be necessary at shorter
intervals
• If an incorrect condition is found, appropriate
servicing measures are to be initiated
5.2.2 Stored-energy spring mechanism
Functional testing of the operating mechanism
is to be performed:
• after 5,000 operating cycles or
• during servicing work as set out in section
“Inspection, switching devices in general”
Prior to functional testing, switch the breaker
off and isolate the outgoing feeder.
Note
Isolate and secure the working area in accordance
with the safety regulations specified by DIN
VDE/IEC.
Scope of functional testing
• Perform several switching operations under
no-load, above all with circuit-breakers seldom
operated in normal service
• Switch off the charging motor (if fitted) and
discharge the spring energy storage
mechanism by ON/OFF switching operations
• Examine visual the condition of the lubrication
on rotary bearings, sliding surfaces, etc
• Check the proper mechanical/electrical sequence
of the individual functions
5.2.3 Breaker pole
No inspection of the breaker pole above and
beyond the stipulations of section “Inspection,
switching devices in general” is necessary.
5.3 Servicing
5.3.1 Switching devices in general
All parts which are located within the gas
compartment and are therefore inaccessible
require no maintenance.
5.3.2 Stored-energy spring mechanism
Servicing of the operating mechanism is to be
performed after 10,000 operating cycles.
Prior to servicing, open the circuit-breaker,
isolate and secure the outgoing feeder to
prevent reconnection.
Scope of servicing
• Switch off the charging motor and release the
spring energy storage mechanism by closing
and opening the breaker
• As a precaution, replace parts subject to high
climatic and mechanical stresses
• For replacement of highly stressed
parts, release the pretension of the
spiral spring, noting the
pretensioning dimension. Take care
when handling springs
• Relubricate pawls, support shafts,
sliding and rotating bearing surfaces.
Lubricant: Isoflex Topas NB 52
• Check the fit of fasteners (e.g. locking
pins) in cranks, pins, bolts etc. Check
the tightness of fastening bolts
• Always replace any spring lock
washers, split pins and other
fasteners removed during the work
with new parts when reassembling
the equipment
• Check the general condition of the
operating mechanism and recharge
the spring to the pre-tensioning
dimension noted
• Perform comprehensive mechanical
and electrical functional tests
(Observe the setting instructions)
Note
Above mentioned work may only be performed
by servicing personnel from ABB or adequately
trained specialist staff.
5.3.3 Breaker pole
The breaker pole with the vacuum interrupter is
maintenance-free up to the permissible number
of operating cycles as sent down in section
“Permissible number of vacuum interrupter
switching operations”:
• When the permissible number of operating
cycles as a function of the breaking current has
been reached, the vacuum interrupters are to
be replaced (see section 2.3)
Note
The above activities may only be performed by
servicing personnel from ABB or adequately
trained specialist staff, as they require work on
the circuit-breaker itself.
5.4 Repair
5.4.1 Run-on block
Should irregularities occur in the area of the
internal control mechanism and the charging
function of the spring energy storage mechanism,
a run-on block blocks the next closing operation
in sequence.
This is a protective function to prevent damage
to the circuit-breaker.
Release of the run-on block may only be performed
by servicing personnel from ABB or adequately
trained specialist stuff.
5.4.2 Replacement of circuit-breaker parts and
ac cessories
• Only remove and reassemble circuit-breaker
parts and accessories when the breaker has
been switched off and the working area
properly isolated and secured to prevent
reconnection. The spring energy storage
mechanism must be discharged
• All supply voltage sources must be
disconnected and secured to prevent
reconnection during the removal and
installation work
• Connecting and adjusting elements 18 and 18.1
to 18.4 (see Figure 3/1) must be removed, inter
alia, prior to removal of the circuit-breaker
operating mechanism
• Only use original parts when replacing defective
components