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6
High Voltage Instrument Transformers | DDB/DFK/DDN/DFN
User manual
Always follow the Arteche Manual for instructions on transport,
storage, handling and installation.
ARTECHE instrument transformers do not require maintenance.
There are no moving parts and no components susceptible to
wear and tear, so no active maintenance is required.
However, some companies perform some maintenance
operations on instrument transformers as part of a general
substation maintenance program. These maintenance programs
are not intended to extend the life of the units, as the measures
have no impact on the state of the insulation or the performance
of the units. These programs serve to know the state of the
isolation, so that the user can make decisions based on the
results obtained, as well as detect situations that may be causing
damage to the unit.
We at Arteche, as manufacturers, do not establish any specifi c
measures, since the decision depends on:
› the resources available to each user,
› the location of the instrument transformer (can be a position
which is more or less critical),
› the environmental and electrical conditions that the unit must
withstand at each specifi c point,
› the history of the unit,
› the specifi c types or the problematic units,
› etc…
The following inspection points are only a suggestion in case
they are within the user’s maintenance policy.
1. Physical
inspection:
a. a. Mechanical: Look for signs of impact, damage or loose
parts.
b. Electrical: Check the correct state of the electrical
connections.
c. Oil: Look for oil leaks and check the oil level.
2. Dielectric
tests:
d. Electrical tests to evaluate the insulation of the equipment.
For the test procedure, see
Annex III
.
3. Thermographic
testing:
e. Use of thermographic cameras.
ARTECHE off ers a diagnostic service for capacitive voltage
transformers in the fi eld. More information: www.arteche.com.
INSPECTION AND MONITORING
DANGER
ELECTRIC SHOCK AND/OR INJURY
› Everything should only be carried out by personnel who is qualifi ed in the maintenance and verifi cation
of the equipment
› Do not touch live parts
Final Considerations
DANGER
The transformer must be fi rmly grounded. A faulty or missing connection may cause damage or even
destroy the device
Once the installation has been completed, the short-circuit cable must be removed from each capacitor unit before
energizing the transformer (see fi g. 9.) This cable is used to prevent the capacitor from being charged during storage
and handling
If the transformer is equipped with a grounding switch for the electromagnetic unit, it should only be used for
maintenance purposes. It is not intended for permanent earthing of the electromagnetic unit in operation, as the
insulation of the capacitor part would be reduced (fi g. 10)
Resin block:
› Transformer adjustment
taps
and ferroresonance protection
circuit connection links, covered by a protective cap which is
sealed at the factory.
Do not open the box
.
› The main protection circuit is located on the protection cover,
connected to the terminals “RS1” and “RS2” marked on the
block itself.
Important
: This main protection circuit must be
always connected.
[1]
[2]
[3]
[1]
[3]
1. Protective cover for adjustment taps.
2. Main ferroresonance protection circuit (only accessible for the resin block).
3. Precinct.
Metal block:
› Transformer adjustment taps and ferroresonance protection
circuit connections, covered by a protective cap which is
sealed at the factory.
Do not open the box
.
The following elements are located on the right side of the terminal block: