Instruction Manual
© GE Grid Solutions
Never complete oil volume without prior
formal authorization of GE.
Important remark: During commissioning, it
is recommended to register the values
founded for each of the performed test to
compare with future measurements during
the VT lifetime. The measurements taken in
the factory are important and also the
measurements during commissioning of each
VT. Comparison between test results makes
sense to the field measured once it is
possible to follow the evolution of each
parameter.
9. MAINTAINENCE AFTER ENERGIZING
After installation and energizing, the VT
should not require any further intervention.
However, it is suggested to perform a visual
inspection during the first weeks of service
to:
•Confirm the position of oil level indicator. If
the indicator is significantly below or above
the central green area, in comparison with
other VT, it is recommend to check that there
is no oil leakage and, if an oil leakage is
discovered remove the VT from operation
and inform GE.
•With an infrared device, check if
connections are not overheating. Compare
with other VT from the same circuit.
After one year of operation, it is
recommended a detailed inspection of
tightening torques and oil leakage and
thereafter twice per year according to the
substation maintenance contract.
If posible GE suggests disconnecting the VT
and to perform the following examination:
•Insulator: Depending on the pollution level
it is necessary to clean the porcelain.
•Metallic components: check for corrosions.
•Tightening torque of primary and secondary
connections. Any adjustments should be
carried out.
•Secondary terminal box: If necessary clean
inside the terminal box.
•Confirm oil level indicator and if there is oil
leakage.
•Remove top cover to have access to the
bellows and confirm if there is an oil leakage
near the fixation of the bellows and / or if the
bellows is in good condition (no
deformations
10. TESTS AT SITE
The following test could be performed during
VT lifetime according to the best practice of
the user:
a) Voltage ratio (T.T. R)
b) Polarity (Polarimeter)
c) Winding resistance (Wheatstone
bridge).
e) Insulation resistance (Megger)
f) Infrared measurement.
11. FINAL DISPOSAL OF THE TRANSFORMER
PARTS AFTER LIFETIME
The high voltage instruments transformers
are made of the following components,
which after life time require a properly
disposal to prevent environmental
contamination:
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