HIGH VOLTAGE INSTRUMENT TRANSFORMERS UG

USER MANUAL

CONTENTSPRELIMINARY CONSIDERATIONS

INTRODUCTION

TRANSPORT AND HANDLING

INSTALLATION

INSPECTION AND MONITORING

QUICK TROUBLESHOOTING GUIDE

ANNEX I

ANNEX II

ANNEX III

HIGH VOLTAGE INSTRUMENT TRANSFORMERS

UG

1 High Voltage Instrument Transformers | UG

User Manual

OBSERVATIONS/

Keep the instruction manual in a safe and accessible place to ensure that any operation or maintenance task can be performed quickly and easily when necessary.

For safety reasons, only qualified staff can use this equipment.

Read the instruction manual and other documentation before the equipment’s installation, commissioning and maintenance.

Become familiar with all equipment information and safety precautions before using the equipment and during its operation.

Always use the equipment within the guidelines indicated in the instruction manual and in other relevant documents.

In order to prevent malfunctions, carry out proper controls and maintenance.

Do not use or handle the equipment in a manner contrary to what is expressly stated in this manual, do not modify the equipment with parts from other manufacturers. This behavior can lead to damage to the equipment and/or personal injury.

ARTECHE is not liable for accidents due to causes unrelated to our guidelines.

In the event of equipment malfunction or any other type of problem, communicate it immediately to the corresponding ARTECHE department, providing the following information:

› Evaluation of contents and the product’s nameplate (name, serial number, type and date of manufacture).

› Description of the problem (as detailed as possible, including the situation immediately before and after the problem occurred) and supporting photos or videos.

If you have any questions, please contact ARTECHE www.arteche.com.

› EMEA: [email protected]

› APAC: [email protected]

› NAM: [email protected]

› LATAM: [email protected]

PRELIMINARY CONSIDERATIONS

This product contains fluorinated gases covered by the Kyoto protocol, with a global warming potential of 22800 GWP. Take the necessary measures to prevent accidental spillage of SF6 into the atmosphere.

Disposal considerations:

Disposal or recycling will be done according to the applicable legislation. Garbage can be incinerated at the appropriate plants, in compliance with local regulations.

The metals are recyclable (copper, steel, aluminum, etc.).

SF6 must be recovered with appropriate methods so as to prevent its release into the atmosphere.

DANGER/ CAUTION

Indicates that improper use or handling may result in physical

damage to the equipment, serious injury or even death

SAFETY PRECAUTIONS/

For safety reasons, only qualified personnel can carry out maintenance and commissioning or operation.

Read the instruction manual and other documents before using the equipment. Become acquainted with every aspect of the equipment and its safety precautions before use.

Do not use, handle or modify the equipment in a way that is not expressly stated in these operating instructions and do not use or modify the equipment with parts from other manufacturers.

The safety precautions used in this manual are indicated by the following message:

Depending on the situation, mishandling can have serious repercussions, even when “Caution” is indicated in this instruction manual. Strictly observe all security measures.

These safety precautions are the manufacturer’s suggestions to ensure the safety of the equipment.

Users are requested to establish security measures so as to maintain safety and the equipment operating in accordance with various standards and requirements.

ARTECHE will not be liable for accidents caused by not carrying out the safety measures.

ENVIRONMENTAL CONSIDERATIONS/

2High Voltage Instrument Transformers | UG

User Manual

FOREWORD/

This manual describes the construction, installation, commissioning and monitoring for safe use of a high-voltage instrument transformer insulated by SF6 for Auxiliary Services.

INTRODUCTION

SCOPE OF APPLICATION/

The manual applies to the following transformers:

› Gas Insulated Voltage Transformers, UG Series, Models UG-72..550.

DESIGN/

Gas insulated voltage transformers are manufactured with a magnetic core inside a metal tank with its primary and secondary windings around it. These windings consist of heat-resistant electrical wires covered with synthetic resin and a plastic layer with high dielectric strength and an excellent thermal and mechanical performance. The SF6 and this plastic layer form the electrical insulation.

The transformer is protected against accidental overpressure by a pressure relief device (rupture disk) located at the top of the transformer. Safety is increased by the use of synthetic insulators.

At the base of the transformer is the densimeter with temperature compensation, the densimeter indicates the internal pressure independently of the temperature, and it is equipped with two alarm contacts to warn of pressure losses, which can be connected to the control equipment for remote monitoring. In case of an operational pressure drop, the transformer can still withstand the nominal voltage with the internal atmospheric pressure of the gas.

The secondary terminals of the windings are located in the secondary terminal box at the base of the transformer, which also holds the alarm terminals of the densimeter.

1. Primary terminal2. Pressure relief device3. High voltage electrode4. Insulator

5. Low voltage electrode6. Lifting eye bolts7. Primary winding8. Secondary windings

9. Core10. Secondary Terminal Box11. Gas filling valve (DN-20)

› UG

4

3

12

5

7

89

10

11

6

6


User Manual

TRANSPORT AND HANDLING

STORAGE/

The storage area must maintain the necessary cleanliness and safety conditions so as to avoid damage to the transformer. Follow the safety markings on the packaging at all times.

› Storage in vertical position: The transformers can be stored in an upright position after unpacking and must always be firmly anchored to the ground without any time restriction.

› Storage in horizontal position: The transformers can be stored upright in their original packaging, which was designed to

this end, for a of limited period of time. We recommend not keeping them in this position for more than 6 months if stored outdoors, or 12 months if sheltered from bad weather. In any case, they should be placed on firm, horizontal ground.

The final holder will be responsible for delivering the used packaging or its waste for environmental management according to the legislation in force in their country.

Unpacking: Remove the top and sides of the box, if any, to allow free handling of the unit.

Annex I, contains the figures mentioned below.

If the transformer is in a horizontal position, to place it in a vertical position, proceed as indicated in Fig. 1 and Fig. 2. During the lifting process, the slings must always be kept in an upright position.

When the device is in a vertical position, movements can be made:

› If the tank is not equipped with lifting eyes, as shown in Fig. 3.

› If the tank is equipped with lifting eyes, as shown in Fig. 4.

Once the equipment has been placed in an upright position, a visual inspection is suggested so as to detect possible damage.

Precautions will be taken throughout the process to avoid damaging the sheds of the synthetic insulator.

TRANSPORT/

ARTECHE’s packaging guarantees a correct transport to destination.

These transformers can be transported both horizontally and vertically. For transport, the transformer should be properly attached to the packaging so as to avoid movement.

› Load and unload the transformer slowly and avoid sudden movements.

› It must be secured to the truck to avoid movement.

› Keep truck acceleration under 5G, and the speed under:

• Unpaved road ___________ Max. 30 km/hour

• Secondary roads ___________ Max. 60 km/hour

• Highway (motorway) ___________ Max. 90 km/hour

DANGERINJURIES from falls and tipping

› Do not place the equipment upside down or on its side

› Do not transport the equipment in conditions other than those mentioned

RECEIPT/

After receipt, check the packages for signs of shock, tampering, etc. Any anomaly must be indicated on the transport company’s receipt sheet and communicated to ARTECHE or the equipment supplier.

Once the transformer has been unpacked, check that none of the screws holding the insulator have become loose during transport. If they have, tighten them according to the torque indicated in Annex II. If any other type of anomaly appears, inform ARTECHE or the supplier of the equipment.

Attach photos of the damaged transformers to the report.

› Possible damage to the packaging: Dents on the outside, open packaging, etc.

› › Possible damage to equipment: Broken or defective insulator, dented metal parts, damaged secondary terminal box, etc.

The packed units can be moved by forklift or with slings or chains. Follow the safety markings on the packaging

DANGERINJURIES AND/OR FIRE

› Do not use damaged equipment

HANDLING/

DANGER

INJURIES from falls and tipping

› Do not place the equipment upside down or on its side

› Handle the transformer according to the instructions in this manual

› Never manipulate the transformer with internal pressure

› The slings used must be in good condition and suitable for handling the equipment according to its weight, which is indicated on the nameplate

Under no circumstances should a transformer be manipulated by pulling on the primary terminalsThis may cause damage to the equipment and void its warranty


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 SF6 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 SF6 has been filled to the nominal pressure

GAS FILLING/The transformer will be delivered with a pressure of approx. 0.5kgf/cm2 (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 SF6 to the atmosphere can constitute a punishable offense

SF6 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 SF6 gas into the atmosphere may constitute a punishable offense.

For more details, please refer to the ARTECHE gas filling manual.


User Manual

ELECTRICAL CONNECTIONS/Primary connections

The primary terminal material is aluminum. They can have a tin or silver coating with so as to prevent galvanic pair corrosion and improve their contact.

Do not bring aluminum into contact with copper-based materials unless special precautions are taken.

Material Finish Cleaning

Aluminum

Silver or tinned It is recommended to clean the contact surfaces with a soft cloth (do not use a metal brush)

UnfinishedWe recommended vigorously brushing the contact

surfaces with a soft metal brush (preferably stainless steel) or sandpaper, until you see the

characteristic shine of the clean metal

Only impregnate the contact surfaces to be used with contact grease, keeping the others clean. Remove excess grease to avoid contamination.

Tightening must be carried out using a torque wrench, as shown on the diagram plates and in Annex II.

Check the correct external wiring.

Secondary connections

The secondary winding(s) must be connected to earth through one of its terminals, preferably in the secondary terminal box itself.

In case of secondary with intermediate taps, the common terminal must be grounded.

Check that the secondary connections are correctly tightened and the contact surfaces are clean.

The screws of the lower cable gland cover, the block cover and the terminals must be tightened to the torque specified Annex II.

In the terminal box there is a terminal block where the secondary wires are connected. The disposition of the terminals

is indicated on the secondary marking plate on the inside of the box cover.

A faulty contact or a bad connection can lead to rapid transformer deterioration

Avoid excessive torque, as the connector may suffer damage such as cracks which may expand in the future and cause it to break

An inadequate torque may cause improper contact and cause the terminals to heat up during operation

Any secondary one that is not loaded must be open and grounded at a single point

The current in a short-circuited secondary can reach dangerous values and can even destroy the device

CAUTION

Do not use the secondary terminal block as a stepTo make or check the primary connections, a lifting platform or a ladder should be used, maintaining the necessary safety conditions for work at height. In no case may the terminal block be used as support


User Manual

Grounding

The ground terminal of the transformer must be properly connected to the ground network by a connection capable of carrying the network’s fault current. Check that the connection is tightened correctly and that the contact surfaces are clean.

The low voltage terminal of the primary voltage winding must always be grounded when the transformer is in service. This terminal is located inside the secondary terminal box (Fig. 8).

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 monitoring 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 specific 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 specific point,

› the history of the unit,

› the specific 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. Mechanical: Look for signs of impact, damage or loose parts.

b. Electrical: Check the correct state of the electrical connections.

c. Gas. Check the gas pressure as indicated on the densimeter.

2. Dielectric tests:

d. Electrical tests to evaluate the insulation of the equipment. For the test procedure, see Annex III.

3. Gas tests:

e. Tests performed on gas samples. The gas tests analyze the state of the insulating liquid and show the properties of the system in general.

4. Thermographic testing:

f. Use of thermographic cameras.

INSPECTION AND MONITORING

DANGER

ELECTRIC SHOCK AND/OR INJURY

› Everything should only be carried out by personnel who is qualified in the maintenance and verification of the equipment

› Do not touch live parts

Densimeter alarm connections

Check that the alarm connections on the densimeter are tightened correctly and that the contact surfaces are clean.

DANGER The transformer must be firmly grounded. A faulty or missing connection may cause damage or even destroy the device


User Manual

Type Code Test Observations

Phy

sica

l ins

pec

tio

n

A1 Packaging Look for signs of rough handling.

A2 Insulator Check that is not damaged and is clean. Check that it is not loose, bent or broken.

A3 Primary Terminals Check that they are not loose, bent or broken.

A4 Secondary Terminal

Box

Check that it is not damaged and that it is securely fastened to the tank or transformer holder.

Check that no water enters the terminal box due to rain.Check that the ventilation openings are not blocked.A5

A6 Metal parts Check for dents, scratches or signs of corrosion.

A7 Unusualbehavior Check for unusual noises, vibrations or odors.

A8Densimeter and other

accessoriesCheck for damage.

B1 Primary connections

Check that there is good contact, that there are no signs of corrosion and that all nuts and bolts are properly tightened. The use of conductive grease is recommended to improve contact, such as Penetrox A13.

B3 Secondary circuits

Check that all screws are properly tightened, and that there are no signs of corrosion. In the case of secondary windings with intermediate taps, check that the connection matches the real transformer ratio. Check that the unused secondary voltages are in open circuit.

B4 Grounding Check that the grounding terminal is correctly connected to the substation grounding network, that the screws are correctly tightened and that there are no signs of corrosion.

B6

Voltage transformer

neutral connection

Check that the neutral terminal (N) of the primary winding is grounded. Leaving it open when the transformer is energized will cause surges and damage to the

transformer.

B7 Readings Check that the reading values of the secondary match the values expected.

C1 Internalpressure Check that the densimeter reading is in the green zone.

Die

lect

ric

test

s

D2

Measurementof the

Insulation resistors

For field tests, the use of the megohmmeter (Megger) is very common, and the tests that are usually done are: › Among the secondaries › Each secondary against ground › N/P2 against secondary and Ground

In the case of new equipment, the value obtained does not provide any information, unless a short circuit is detected. Generally, values above 100 MΩ should be expected. However, the comparison of long-term values can help determine if a device is still in good working conditions. Do not test at voltages above 3 kV AC or 1 kV DC. Do not test for more than one minute. It is not recommended to repeat this test often as the

internal insulation could be damaged. For details on the test procedure, follow Annex III

D3 Ratio test

The Portable Transformer Ratio Meter is commonly used to measure the ratio, excitation current and polarity of windings. The values obtained are a reference that the transformer is in good condition and can be energized. They should not be compared with the results of factory tests carried out in the manufacturing plant laboratory.Due to the high precision required for this measurement, the actual uncertainty of the test must be taken into account when testing on site.For details on the test procedure, follow Annex III

Gas

test

s

E1 Dew point Checks for presence of moisture in the gas.

E2 Purity Checks the quality of the SF6.

E3 SO2 The concentration of SO2 is an indicator of the presence of decomposition products in SF6 gas.

Ther

mog

rapi

c te

sts

F1 Thermographic analysis

Using thermographic cameras, hot spots can be detected during the operation of transformers. In most cases, hot spots on instrument transformers occur at the primary terminals’ connection point to the line. If present, check the integrity of the connectors, as well as their correct position and whether they are correctly tightened.


User Manual

TESTS PROGRAM/

When WhatOn arrival of the transformers at the warehouse or substation A1

After unpacking A2 - A3 - A4 - A6 - A8

During assembly A2 - A3 - A4 – A5 - A6 - A8 - B1 - B3 - B4 - B6 - C1 - D2 - D3

After energizing A7 - B7 - C1 - F1

Routine checks (weekly or monthly) A2 - A7 - B7 - C1

Annual checks A2 - A3 - A4 - A5 - A6 - A7 - A8 - B1 - B3 - B4 - B6 - B7 - C1 - F1

After re-connections, the load changes A7 - B1 - B3 - B4 - B6 - B7 - F1

After the fault conditions, the short circuits, etc. A3 - A7 - B1 - B3 - B4 - B6 - C1See also “Careful check of the transformer” below.

After 1 year from start-up and after 5 years from start-up, if the values are normal and there is no considerable increase, perform an analysis after 15 years from start-up, and then every 5 years

E1 - E2 - E3

CAREFUL CHECK OF THE TRANSFORMER/It is recommended that all regular tests be repeated after a long period of operation (about 20 years), or if a major network disturbance has occurred that could damage the

transformer (e.g. a short circuit with current or duration values higher than the nominal ones, or over-voltages caused by the malfunctioning of the switches).

QUICK TROUBLESHOOTING GUIDE

Phenomenon Control item Cause Countermeasure

Abnormal voltage

indication

› Visual control

› Load control

› Measuring insulation resistance

› Analyzing gas

Internal issue

Contact ARTECHEPartial discharges

Short circuit alarm in the secondary

Ferro-resonance

Loss of contacts Repairing the issue

Contact ARTECHE

1. Equipment name2. Serial number3. Type4. Manufacture date5. Description of the issue6. Results of the controls

Strange noises,

smells and vibrations

Winding short-circuit

Contact ARTECHEWinding error

Relay trip and non-trip Overload Correct loading

Gas pressure drop

› Locate gas leaks

› Determine pressure losses

Deteriorated sealing

Contact ARTECHESurface corroded by the

sealing parts

Oxidation and

corrosion

› Visual check

› Examine environment

Peeled-off coatingRepainting

Corrosive atmosphere

Insulation loss Wet or contaminated

Clean and dry off.If the resistance is not restored in

spite of your efforts, contact ARTECHE

User Manual - Annex I High Voltage Instrument Transformers | UG

ANNEX I

› UG-72..525

HANDLING AND CONNECTION

1

User Manual - Annex I

High Voltage Instrument Transformers | UG

› Fig. 1: Lifting

C

› Fig. 2: Lifting

› Fig. 3: Movement › Fig. 4: Movement

2

User Manual - Annex I


› Fig. 5: Placement of the equipotential ring

› Fig. 6: Placement of the equipotential ring

› Fig. 7: Densimeter › Fig. 8: Neutral grounding

User Manual - Annex II High Voltage Instrument Transformers | UG

ANNEX II

METRICS

HIGH VOLTAGE STEEL 8.8 (ZN-0) STAINLESS STEEL A2-70

GENERALMetal-Metal

InsulatorBushingValves

Rupture Disc

GENERALMetal-Metal

(except threadson copper)

InsulatorBlushing

ValesRupture Disc

M3 - - 0.6 -

M4 - - 2 -

M5 - - 4 -

M6 4.41 4.41 6 4.4

M8 10.8 10.8 15 10.8

M10 21.1 21.1 30 21.1

M12 36.3 24.5 48 24.5

M14 - - 60 30

M16 91.2 78.4 120 78.4

M20 177 90 230 90

M24 304 - 380 -

M30 608 - - -

TIGHTENING TORQUES

NOTE: If a torque different from that indicated in this table is indicated on the drawing or plates of the equipment, the torque indicated on the drawing or plate must be applied.

Tightening torque (N-m) with -5%,+0% tolerance.

User Manual - Annex III High Voltage Instrument Transformers | UG

ANNEX III

ELECTRICAL FIELD TESTING

All ARTECHE transformers are tested at our High Voltage laboratories, under the strictest criteria of international standards and/or under specific client standards/specifications when so requested. All of it under a thorough quality system, certified under ISO 9001. However, it is normal for pre-operative tests to be performed in order to confirm certain important equipment values. The following is a guide to the most common on-site tests and the proper way to perform them on ARTECHE brand transformers.

This annex applies to the following equipment:

› Gas Insulated Voltage Transformers, UG Series, Models UG-72..550.

5

User Manual - Annex III


The measurement of the insulation resistance is done to check the integrity of the transformer insulation and to ensure that it has not been internally damaged during transportation. This test depends largely on the design of the transformer, the general configuration of the test, the instruments used, etc. The values obtained may not be representative of the actual state of the insulation. If this test is performed, it is recommended to contact the manufacturer.

For field tests, the use of the megohmmeter (Megger) is very common, and the tests that are usually done are:

› N/P2 against secondary and Ground.

› Each secondary against ground.

› Among the secondaries.

In the case of new equipment, the value obtained does not provide any information, unless a short circuit is detected. Generally, values above 100 MΩ should be expected. However, the comparison of long-term values can help determine if a device is still in good working conditions.

Do not test at voltages above 3 kV AC or 1 kV DC.Do not test for more than one minute. It is not recommended to repeat this test often as the internal insulation could be damaged.

INSULATION RESISTANCE MEASUREMENT

Primaries vs. Secondaries+ Ground N/S+G (Fig. 1)

› The line cable of the measuring equipment must be connected to the terminals of the primary winding (A-N) that are short-circuited with each other, and the grounding plate (N) must be disconnected from the primary winding.

› The ground cable of the measuring instrument must be connected to the short-circuited secondary terminals together with the ground terminals on the secondary terminal block as well as the tank.

Secondaries vs Ground S/G (Fig. 2) › Primary terminal A must be disconnected and the neutral connection of the (N) primary winding must be grounded.

› The line cable of the measuring equipment must be connected to the short-circuited secondary terminals.

› The grounding cable of the measuring equipment must be connected to the tank.

Between secondaries S/S › This test is only applicable to transformers having more than 1 secondary.

› Primary terminal A must be disconnected and the neutral connection of the (N) primary winding must be grounded.

› The secondaries to be assessed will be connected; one to the line cable and the other(s) to the ground cable of the measuring equipment.

› The test is repeated with each secondary.

INDUCTIVE VOLTAGE TRANSFORMERS/

› Fig. 1 › Fig. 2

A

N G+ -

A

NG+ -

6

User Manual - Annex III


The Portable Transformer Ratio Meter (TTR) is commonly used to measure the ratio, excitation current and polarity of windings.

The values obtained are a reference that the transformer is in good condition and can be energized. They should not be compared with the results of factory tests carried out in the manufacturing plant laboratory.

Due to the high precision required for this measurement, the actual uncertainty of the test must be taken into account when testing on site.

The TTR contains 4 terminals (this configuration may vary depending on the manufacturer):

› H1: Black excitation terminal.

› H2: Red excitation terminal.

› X1: Black secondary terminal.

› X2: Secondary red terminal.

TRANSFORMER RATIO TEST

This test verifies the transformer ratio and polarity, and displays a “+” signal if correct, and a “-” signal if inverted. To carry out the test, proceed as follows (Fig. 3).

› The excitation terminals (clamps marked “H”) will be connected to the transformer’s primary terminal:

• H1 will be connected to the primary terminal of equipment A.

• H2 will be connected to the ground terminal.

› The clamps marked “X” will be connected to the transformer’s secondary terminals:

• X1 will be connected to 1S1. When the secondary has sockets, you must connect X1 to the socket of the secondary terminal which is to be tested.

• X2 will be connected at the end of the secondary terminal.

• This test must be applied to each secondary separately; in case the transformer has more than 1 secondary, the secondary(s) which are not to be tested must be left open.

INDUCTIVE VOLTAGE TRANSFORMERS/

› Fig. 3

A

N

T.T.R.

H1IS1

H2X2X1

IS2 IS3 IS4

©ARTECHE

User Manual

For more detailed information, please visit us at arteche.com

Subject to change without notice

MU_HV_UG_ENV: A0 12/01/2021

HIGH VOLTAGE INSTRUMENT TRANSFORMERS UG

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