MAINTENANCE 39
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7 Maintenance
7.1 General
Maintenance serves to preserve trouble-free
operation and achieve the longest possible
working life of the switchgear. In accordance
with DIN 31 051, it comprises the following
closely related activities.
Inspection: Determination of the actual condition
Servicing: Measures to preserve the specified
condition
Repair: Measures to restore the specified condition
Note:
When carrying out all maintenance work, the
regulations in the country of installation must
be strictly complied with.
Maintenance work may only be performed in a
careful manner by trained personnel familiar
with the characteristics of the individual
switchgear, in accordance with all relevant safety
regulations to VDE/IEC and of other technical
authorities, and with other overriding
instructions. It is recommended that ABB service
personnel be called in to perform servicing and
repair work, and this is necessary for some of
the work detailed below.
The inspection and servicing intervals for some
of the equipment/components (e.g. parts subject
to wear) are determined by fixed criteria such
as switching frequency, length of service and
number of short-circuit breaking operations.
For other parts, on the other hand, the length
of the intervals may depend, for example, on
the different modes of operation in individual
cases, the degree of loading, and also
environmental influences (including pollution
and aggressive air).
The following service instructions must also
be observed together with this instruction
manual in the individual cases concerned.
Vacuum circuit breaker
VD4 BA 483/02E
SF6 circuit breaker
HD4 1YHA000046-en
Earthing switch
EK6 9AKK1074920025
If necessary, further details can be taken from
the technical documentation for the switchgear
instal-lation (including, for example, any agreed
special service conditions).
7.2 Inspection and servicing
Inspection
Inspection of the switchgear should be carried
out approximately every two to four years,
depending on the service conditions and local
environment, in accordance with VBG4 standard.
Isolate the area where work is to be performed
in accordance with the relevant safety regulations
to DIN VDE/IEC, and secure it against
reconnection.
The inspection may become necessary at shorter
intervals under unusual service conditions
(including advers climatic conditions) and/or
particularly injurious environmental influences
(e.g. heavy pollution and aggressive atmosphere).
The inspection should include but not be
limited to the following:
• Check the installation for abnormalities of
any kind, dirt and the effects of other
environmental influences
• Check the function of the switching devices
and the controls, interlocks, protection,
annunciation and other devices
• Check the surface condition of the isolating
contact system (for visual examination of
the contact pins with the withdrawable part
removed). When the galvanic silver coating
on the contact parts is worn to such an extent
that the copper conductor material below
becomes visible, or when their surfaces are
heavily corroded or show signs of other
damage or overheating (discoloured surface),
replace the contact parts. See also section 7.3
• Check all switchgear accessories and the
auxiliary equipment (e.g. storage batteries
etc.)
• No external discharge may occur on the
surfaces of equipment at operating voltage.
This can, for example, be detected by
characteristic noises, a clearly perceptible
smell of ozone, or visible glowing in the dark
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