4
High Voltage Instrument Transformers | UG
User Manual
INSTALLATION
MOUNTING ON THE STRUCTURE OR PLATFORM/
Check the information on the nameplate to verify that the
electrical characteristics match those of the system.
Carefully check to make sure that all four legs of the device sit
perfectly on the platform, before tightening the anchor screws.
If this is not the case, correct the defect, by wedging metal
plates or similar. Failure to do so may result in insulator breakage
or gas leakage.
PLACEMENT OF THE EQUIPOTENTIAL RING/
If the transformer requires an equipotential ring in order to be
mounted, it will be delivered disassembled.
The placement of the equipotential ring should be done with the
equipment in a vertical position and, if possible, already mounted
on the structure (without connections), to avoid damage during
handling.
The equipotential ring is screwed to the upper cover of the
device as shown in the Fig. 5 or Fig. 6. It is important to touch the
indicated screws only, otherwise the tightness of the equipment
could be lost.
Tightening must be carried out using a torque wrench, following
the indications in
Annex II
.
DANGER
INJURY AND/OR FIRE
› Do not install the equipment without following our specifications
› Use the transformers under proper service conditions and according to specifications
› Do not loosen any screws or fastening nuts, it can cause gas leaks. The pressure drop of SF
6
gas
can cause dielectric breakdown
CAUTION
ELECTRICAL DISCHARGE
› Do not wire or connect when the equipment is energized
› The ground terminal of the apparatus must be solidly earthed by means of a connection capable
of withstanding and conducting the line’s fault current to earth.
› Do not short-circuit the secondary circuit of the transformer
› Before energizing the equipment, check that the SF
6
has been filled to the nominal pressure
GAS FILLING/
The transformer will be delivered with a pressure of approx.
0.5kgf/cm
2
(0.05MPa relative) inside. Do not energize the
transformer until it has been filled with gas in accordance with
the pressure and composition values indicated on the nameplate.
If the internal pressure drops, it must be refilled with gas before
the minimum operating pressure indicated on the rating plate is
reached. The densimeter is equipped with two alarm contacts to
indicate the pressure drop and allow filling (Fig. 7).
Operation of the densimeter
(Fig. 7):
›
Green Zone
: Normal operating zone.
›
Amber Zone
: Abnormal operating zone. The pressure is below
normal working pressure. The transformer maintains the
defined insulation level. Contact ARTECHE.
›
Red Zone
: Danger zone. Pressure drop below minimum level.
The transformer can still withstand the rated voltage with
the internal atmospheric pressure of the gas. Withdraw from
service and contact ARTECHE.
The densimeter is equipped with
two alarms
:
› The first alarm indicates the passage from the green to the
amber zone.
› The second alarm indicates the passage from the amber to the
red zone.
The handling of the gas, of the containers under pressure in which it is supplied and of the pressure
regulation instruments must be carried out by trained and certified personnel, and using appropriate
means, to reduce the risk of gas emission and possible damage due to the incorrect handling of
the containers. The emission of SF
6
to the atmosphere can constitute a punishable offense
SF
6
gas must comply with IEC 60376 or ASTM D2472.
The handling of the gas, of the containers under pressure in
which it is supplied and of the pressure regulation instruments
must be carried out by trained and certified personnel, and
using appropriate means, to reduce the risk of emission and of
possible damage due to incorrect handling of the containers.
The emission of SF
6
gas into the atmosphere may constitute a
punishable offense.
For more details, please refer to the ARTECHE gas filling manual.
