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9.3 Inspection
•
Wherever necessary, the working area must be
isolated and secured against reconnection in
accordance with the Safety Regulations
specified by IEC and appropriate national
standards before inspection.
•
Correct condition of the switchgear should be
monitored by regular inspections.
•
Under normal operating conditions,
inspection should be carried out every year by
specially trained professional electricians /
engineers.
•
Under abnormal operating conditions
(including adverse climatic conditions) and/or
special environmental stresses (heavy
pollution and aggressive atmosphere among
others), inspection may be necessary at
shorter intervals.
•
Inspection is primarily to carry out a visual
check for grime, corrosion and moisture for:
-
Effects of high temperature on main
circuits
-
Traces of partial discharge on insulating
material parts
-
Traces of leakage current on the insulating
material parts
-
Effects on surfaces of the contact systems
However, inspection must also include verifying
the correct mechanical and electrical operation of
parts like switching devices, actuating,
interlocking, protection and signaling devices.
•
For switching devices, their separate
installation, operation and maintenance
manual should be referred.
•
Check all switchgear accessories and auxiliary
devices (e.g. storage batteries).
•
No discharge must 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
It is recommended to check whether isolating
contacts fixed are fully intact and do not show any
sign if damage. The contact points should be
cleaned if signs of overheating (discolored
surface) are visible. If any irrelevant repair
measures should be taken.
9.4 Servicing
The need for cleaning measures during the course
of an inspection in accordance with section 8.3,
has been established as follows:
•
Wherever necessary, the working area must be
switched off and secured against
reconnection in accordance with the Safety
Regulations specified by IEC and appropriate
national standards before cleaning
•
Clean the surfaces in general. For weakly
adhering dry dust deposits, use a softy dry
cloth. For more strongly adherent grime, use a
mild alkaline household cleanser or with
ETHANOL F 25M
•
Clean insulating surfaces and conductive
components with ETHANOL F 25 M
•
Wipe after cleaning using clean water and dry
properly
•
Should partial discharges occur as a result of
condensation, application of a thin silicone
film on the surface concerned is often
effective as a temporary remedy. It is
advisable to ask our after-sales service
department for advice regarding permanent
solutions to this type of unusual problem.
9.4.1 Maintenance of Busbar compartment
Checking of the tightening main busbars By
gaining access
•
From the top of the panel, dismount the roof
plate
•
From the rear side of panel: Remove the rear
cover and rear wall of busbar compartment
•
When the main busbars are visible, use a
dynamometric spanner, check tightness of all
the screws. Refer to the (Section 6) for the
tightening values
9.4.2 Maintenance in cable compartment
Checking tightening of the cable busbar
connections
•
Open the cable compartment rear cover; the
cable busbar connections are visible.
•
Using a dynamometric spanner, check
tightness of all the screws. Refer to the
(Section 6) for the tightening values.
•
Lower bar joints conductivity test
WARNING
The cable compartment door cannot
be opened if the earthing switch is
open
Earthing switches – type EK6; ST-E
Cleaning the kinematics to prevent faults on the
signalling contacts
•
Carry out a visual inspection of the kinematics
and check for any presence of dirt, humidity
and signs of corrosion on the moving parts.
•
Remove any deposits of dust using a dry cloth
that does not leave any deposits on the
treated surface (do not use woolen cloths).
•
If necessary, grease the mechanical moving
parts by applying a thin layer of mechanical
grease for moving parts.
Instrument transformers
Cleaning and checking of the current
transformers.
•
Open the cable compartment rear cover;
Instrument transformers are visible.
53
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