Instruction Manual
© GE Grid Solutions
12
Confirm that the secondary circuit of
the voltage transformer part is not
shorted.
Make sure that no secondary winding
of the current transformer part is
open circuited.
Verify the correct position of the
primary terminal (transformer with
reconnection primary bars). Refer to
the set of drawing.
Verify that the oil level indicator is in
the green strip area.
Whilst all care is taken in the factory
during oil filling, the surface near of
screws and bellows could have a small
quantity of oil. This shall not be
considered as an oil leakage provided
the bellows are positioned within the
green strip area.
It is not necessary to remove oil
samples for analysis. The CIT is
hermetically sealed
If required, small quantity of oil can be
taken. Always verify oil level indicator
before take oil samples.
Never complete oil volume without
prior formal authorization of GE.
Important remark
:
During
commissioning,
it
is
recommended to register the values
acquired for each of the performed tests
in order to compare with future
measurements during the CIT
’s
lifetime.
The measurements taken in the factory
are important as so the measurements
during
commissioning
of
each
transformer. The comparison between
test results measured at the field allows
following the evolution of each
parameter.
9.
MAINTAINENCE AFTER ENERGIZING
Besides regular cleaning of the
transformer surface and especially the
insulator, no routine maintenance is
required on the transformers. However,
the oil level indicator position should be
checked regularly, along with visual
inspections
during
the
normal
scheduled maintenance periods. It is
good practice to compare the oil level
indicator position of neighboring units.
Also, the inside of the terminal box and
the ventilation screens should be
checked for cleanliness.
After installation and energizing, the
transformers shall not require any
further intervention. However, it is
suggested performing visual inspections
during the first weeks of service in order
to:
Verify if there is no oil leakage near the
fixation base and secondary terminal
box.
With an infrared imaging device, check if
the primary terminal connections are
not overheating. Compare with other
CITs in the same circuit.
After one year of operation, it is advised
a detailed inspection of tightening
torques and oil leakage and thereafter
twice per year according to the
substation maintenance contract.
