Nuova Via di Piano Comprensorio Vulcano
Sesto San Giovanni, MI 20099 Italy
Tel. 02-24105.001
IS 2653 GB
Page
17
of
18
Bushing locking to
the wall
When plant is off
Check that all bolts are properly
locked to the wall support.
Component
Time base
Description
Notes
Power factors taps
When plant is off
Open the taps and clean inside.
Check the internal spring loaded
contact and clean it.
Perform a Megger 1 kV insulation
test R
ins
> 1 MOhm.
Check for gas leakages by sniffing
the indoor side of the tap.
Carefully close and tighten the cap.
CAUTION:
PF tap cap
MUST
be
accurately
closed. Missing the cap
could be dangerous and
it can cause an electrical
discharge
at
bushing
energization.
Rupture
disk
protection cover
When plant is off
Inspect the closure cap and the fixing
screws.
CAUTION:
Do
not
remove the closure cap
and do not touch the disk
when the bushing is filled
with gas. An explosion of
the disk could be very
dangerous.
Gas density monitor
5 years
Check calibration and operation of
micro switches.
Check the effective and
correct operation of the
alarms & tripping signal
chain
from
the
instruments
to
the
substation systems.
Bushing overall gas
leakage
5 years
Check with SF6 leak-meter device all
the flanges joints and the gas valves.
Anticipate the control if
the
leakage
rate
is
excessive and gas re-
filling is frequent. Identify
the leakage areas.
In case of frequent re-
filling,
plan
for
the
replacement
of
the
bushing and contact GE
Grid Solutions RPV.
Gas quality
5 years
Check the moisture content in
accordance to IEC 60480.
Regenerate / replace the
gas if moisture exceeds
the limits stated in the
standard (>25 mg/kg).
Table 4 – Bushing general maintenance plan
