MR TAPCON LV User manual

Voltage monitoring
TAPCON® LV
Operating Instructions
7370895/00 EN . Limit Volt

© All rights reserved by Maschinenfabrik Reinhausen
Dissemination and reproduction of this document and use and disclosure of its content are strictly prohibited
unless expressly permitted.
Infringements will result in liability for compensation. All rights reserved in the event of the granting of patents,
utility models or designs.
The product may have been altered since this document was published.
We reserve the right to change the technical data, design and scope of supply.
Generally the information provided and agreements made when processing the individual quotations and orders
are binding.
The original operating instructions were written in German.

Table of contents
Maschinenfabrik Reinhausen GmbH 2020 37370895/00 EN TAPCON® LV
Table of contents
1 Introduction......................................................................................................................... 7
1.1 Manufacturer....................................................................................................................................... 7
1.2 Completeness..................................................................................................................................... 7
1.3 Safekeeping........................................................................................................................................ 7
1.4 Notation conventions .......................................................................................................................... 7
1.4.1 Hazard communication system .............................................................................................................................7
1.4.2 Information system................................................................................................................................................9
1.4.3 Instruction system .................................................................................................................................................9
1.4.4 Typographic conventions ....................................................................................................................................10
2 Safety................................................................................................................................. 11
2.1 Appropriate use ................................................................................................................................ 11
2.2 Fundamental safety instructions ....................................................................................................... 11
2.3 Personnel qualification...................................................................................................................... 14
2.4 Personal protective equipment ......................................................................................................... 15
3 IT security.......................................................................................................................... 16
4 Product description.......................................................................................................... 19
4.1 Scope of delivery .............................................................................................................................. 19
4.2 Function description.......................................................................................................................... 19
4.3 Performance features ....................................................................................................................... 20
4.4 Design............................................................................................................................................... 21
4.4.1 Power supply.......................................................................................................................................................21
4.4.2 CPU (central processing unit) I ...........................................................................................................................21
4.4.3 UI 1 voltage measurement and current measurement........................................................................................22
4.4.4 DIO28-15 digital inputs and outputs...................................................................................................................23
4.5 Visualization...................................................................................................................................... 24
4.5.1 Main screen.........................................................................................................................................................24
4.5.2 Operating concept...............................................................................................................................................24
5 Packaging, transport and storage .................................................................................. 28
5.1 Suitability, structure and production ................................................................................................. 28
5.2 Markings ........................................................................................................................................... 28
5.3 Transportation, receipt and handling of shipments........................................................................... 28
5.4 Storage of shipments........................................................................................................................ 29

Table of contents
Maschinenfabrik Reinhausen GmbH 202047370895/00 ENTAPCON® LV
6 Mounting ........................................................................................................................... 30
6.1 Preparation ....................................................................................................................................... 30
6.2 Electromagnetic compatibility ........................................................................................................... 30
6.2.1 Wiring requirement of installation site ................................................................................................................31
6.2.2 Wiring requirement of operating site ..................................................................................................................31
6.2.3 Wiring requirement in control cabinet..................................................................................................................32
6.3 Minimum distances ........................................................................................................................... 33
6.4 Installing the individual components on a cap rail ............................................................................ 33
6.4.1 Fastening the cap rail..........................................................................................................................................34
6.4.2 Installing the bus rail on the cap rail....................................................................................................................34
6.4.3 Installing the assembly at a distance on the cap rail...........................................................................................35
6.5 Connecting the device ...................................................................................................................... 36
6.5.1 Cable recommendation .......................................................................................................................................37
6.5.2 Connecting cables to the system periphery ........................................................................................................37
6.5.3 Wiring the CPU assembly ...................................................................................................................................38
6.5.4 Wiring the UI assembly .......................................................................................................................................39
6.5.5 Wiring the DIO assembly ....................................................................................................................................41
6.5.6 Wiring the QS3.241 assembly.............................................................................................................................45
6.5.7 Connecting the power supply..............................................................................................................................47
6.6 Checking functional reliability ........................................................................................................... 48
7 Commissioning................................................................................................................. 49
7.1 Performing tests................................................................................................................................ 49
7.1.1 Ground test .........................................................................................................................................................49
7.1.2 Performing a dielectric test..................................................................................................................................51
7.2 Establishing connection to visualization ........................................................................................... 53
7.3 Setting the language......................................................................................................................... 54
7.4 Commissioning wizard...................................................................................................................... 55
7.5 Function tests ................................................................................................................................... 56
7.5.1 Checking measured values and status of digital inputs and outputs ..................................................................56
7.5.2 Testing voltage monitoring ..................................................................................................................................56
7.5.3 Testing blocking of switching commands from the voltage regulator..................................................................57
7.5.4 Testing voltage regulator monitoring...................................................................................................................57
8 Operation........................................................................................................................... 59
8.1 Establishing connection to visualization ........................................................................................... 59

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8.2 General ............................................................................................................................................. 60
8.2.1 Setting general device functions .........................................................................................................................60
8.2.2 Set up automatic logout ......................................................................................................................................61
8.2.3 Activating/deactivating service user access........................................................................................................62
8.3 Configuring the network.................................................................................................................... 63
8.4 Setting the device time ..................................................................................................................... 64
8.5 Control of the motor-drive unit .......................................................................................................... 65
8.6 Regulation......................................................................................................................................... 66
8.7 Voltage monitoring............................................................................................................................ 70
8.8 Setting transformer data ................................................................................................................... 72
8.9 Configuring digital inputs and outputs............................................................................................... 72
8.10 Event management........................................................................................................................... 74
8.10.1 Displaying and acknowledging events ................................................................................................................75
8.10.2 Configuring events ..............................................................................................................................................75
8.10.3 Displaying event memory....................................................................................................................................77
8.11 User administration........................................................................................................................... 78
8.11.1 User roles............................................................................................................................................................78
8.11.2 Changing the password ......................................................................................................................................79
8.11.3 Creating, editing and deleting users....................................................................................................................80
8.11.4 Setting access rights to parameters and events .................................................................................................82
8.12 Information about device .................................................................................................................. 83
8.12.1 Hardware.............................................................................................................................................................83
8.12.2 Software ..............................................................................................................................................................84
8.13 Import/export manager ..................................................................................................................... 84
8.13.1 Exporting data .....................................................................................................................................................84
8.13.2 Importing data .....................................................................................................................................................86
9 Maintenance and care ...................................................................................................... 87
10 Fault elimination ............................................................................................................... 88
10.1 General faults ................................................................................................................................... 88
10.2 Regulation and monitoring................................................................................................................ 88
10.3 Unwanted on-load tap-change operation.......................................................................................... 88
10.4 Human-machine interface................................................................................................................. 89
10.5 Incorrect measured values ............................................................................................................... 89
10.6 Assemblies ....................................................................................................................................... 90
10.7 Other faults ....................................................................................................................................... 90

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Maschinenfabrik Reinhausen GmbH 202067370895/00 ENTAPCON® LV
11 Messages .......................................................................................................................... 91
11.1 Event messages ............................................................................................................................... 91
11.2 Digital inputs and outputs ................................................................................................................. 92
12 Uninstallation.................................................................................................................... 94
12.1 Uninstalling the CPU assembly ........................................................................................................ 94
12.2 Uninstalling the UI 1/UI 3 assembly.................................................................................................. 97
12.3 Uninstalling the DIO 28-15/DIO 42-20 assembly.............................................................................. 99
12.4 Uninstalling the QS3.241 assembly................................................................................................ 101
12.5 Uninstalling the bus rail................................................................................................................... 102
13 Disposal........................................................................................................................... 103
14 Overview of parameters................................................................................................. 104
15 Technical data................................................................................................................. 106
15.1 Voltage supply ................................................................................................................................ 106
15.2 UI 1 voltage measurement and current measurement ................................................................... 106
15.3 DIO28-15 digital inputs and outputs .............................................................................................. 108
15.4 CPU (central processing unit) I....................................................................................................... 110
15.5 Ambient conditions ......................................................................................................................... 112
15.6 Standards and directives ................................................................................................................ 112
Glossary .......................................................................................................................... 115
List of key words ............................................................................................................ 116

1 Introduction
Maschinenfabrik Reinhausen GmbH 2020 77370895/00 EN TAPCON® LV
1 Introduction
This technical file contains detailed descriptions on the safe and proper in-
stallation, connection, commissioning and monitoring of the product.
It also includes safety instructions and general information about the prod-
uct.
This technical file is intended solely for specially trained and authorized per-
sonnel.
1.1 Manufacturer
The product is manufactured by:
Maschinenfabrik Reinhausen GmbH
Falkensteinstraße 8
93059 Regensburg
Tel.: [phone]
E-mail: [email protected]
Further information on the product and copies of this technical file are avail-
able from this address if required.
1.2 Completeness
This technical file is incomplete without the supporting documents.
The following documents are considered supporting documents:
▪ Connection diagrams
▪ Quick reference guide
▪ Supplement (optional)
▪ Connection diagrams
▪ Supplement (optional)
1.3 Safekeeping
Keep this technical file and all supporting documents ready at hand and ac-
cessible for future use at all times.
1.4 Notation conventions
1.4.1 Hazard communication system
Warnings in this technical file are displayed as follows.

1 Introduction
Maschinenfabrik Reinhausen GmbH 202087370895/00 ENTAPCON® LV
1.4.1.1 Warning relating to section
Warnings relating to sections refer to entire chapters or sections, sub-sec-
tions or several paragraphs within this technical file. Warnings relating to
sections use the following format:
WARNING Type of danger!
Source of the danger and outcome.
► Action
► Action
1.4.1.2 Embedded warning information
Embedded warnings refer to a particular part within a section. These warn-
ings apply to smaller units of information than the warnings relating to sec-
tions. Embedded warnings use the following format:
DANGER! Instruction for avoiding a dangerous situation.
1.4.1.3 Signal words and pictograms
The following signal words are used:
Signal word Definition
DANGER Indicates a hazardous situation which, if not avoided, will result in
death or serious injury.
WARNING Indicates a hazardous situation which, if not avoided, could result
in death or serious injury.
CAUTION Indicates a hazardous situation which, if not avoided, could result
in minor or moderate injury.
NOTICE Indicates measures to be taken to prevent damage to property.
Table1: Signal words in warning notices
Pictograms warn of dangers:
Pictogram Definition
Warning of a danger point
Warning of dangerous electrical voltage

1 Introduction
Maschinenfabrik Reinhausen GmbH 2020 97370895/00 EN TAPCON® LV
Pictogram Definition
Warning of combustible substances
Warning of danger of tipping
Warning of danger of crushing
Table2: Pictograms used in warning notices
1.4.2 Information system
Information is designed to simplify and improve understanding of particular
procedures. In this technical file it is laid out as follows:
Important information.
1.4.3 Instruction system
This technical file contains single-step and multi-step instructions.
Single-step instructions
Instructions which consist of only a single process step are structured as fol-
lows:
Aim of action
üRequirements (optional).
► Step 1 of 1.
ðResult of step (optional).
ðResult of action (optional).
Multi-step instructions
Instructions which consist of several process steps are structured as follows:

1 Introduction
Maschinenfabrik Reinhausen GmbH 202010 7370895/00 ENTAPCON® LV
Aim of action
üRequirements (optional).
1. Step 1.
ðResult of step (optional).
2. Step 2.
ðResult of step (optional).
ðResult of action (optional).
1.4.4 Typographic conventions
The following typographic conventions are used in this technical file:
Typographic convention Purpose Example
UPPERCASE Operating controls, switches ON/OFF
[Brackets] PC keyboard [Ctrl] + [Alt]
Bold Software operating controls Press Continue button
…>…>… Menu paths Parameter > Control parameter
Italics System messages, error messages,
signals
Function monitoring alarm triggered
[► Number of pages]. Cross reference [► 41].
Table3: Typographic conventions

2 Safety
Maschinenfabrik Reinhausen GmbH 2020 117370895/00 EN TAPCON® LV
2 Safety
▪ Read this technical file through to familiarize yourself with the product.
▪ This technical file is a part of the product.
▪ Read and observe the safety instructions provided in this chapter.
▪ Read and observe the warnings in this technical file in order to avoid func-
tion-related dangers.
▪ The product is manufactured on the basis of state-of-the-art technology.
Nevertheless, risks to life and limb for the user or impairment of the prod-
uct and other material assets due to the function may arise in the event of
improper use.
2.1 Appropriate use
The product is a monitoring device and is used to monitor a voltage regulator
for power transformers with an on-load tap-changer. The product monitors
the entire control path of the voltage regulator (voltage transformer, voltage
regulator and motor-drive unit).
If used as intended, in compliance with the requirements and conditions
specified in this technical file and observing the warning notices in this tech-
nical file and attached to the product, the product does not pose a risk of in-
jury or damage to property or the environment. This applies throughout the
service life of the product, from delivery, installation and operation to re-
moval and disposal.
The following is considered appropriate use:
▪ You will find the standard valid for the product and the year of issue on the
nameplate.
▪ Operate the product in accordance with this technical file, the agreed-
upon delivery conditions and the technical data.
▪ Ensure that all necessary work is performed by qualified personnel only.
▪ Only use the equipment and special tools included in the scope of delivery
for the intended purpose and in accordance with the specifications of this
technical file.
▪ Only operate the product in industrial areas.
▪ Observe the notices in this technical file regarding electromagnetic com-
patibility and the technical data.
2.2 Fundamental safety instructions
To prevent accidents, malfunctions and damage as well as unacceptable ad-
verse effects on the environment, those responsible for transport, installa-
tion, operation, maintenance and disposal of the product or parts of the prod-
uct must ensure the following:

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Personal protective equipment
Loosely worn or unsuitable clothing increases the danger of becoming
trapped or caught up in rotating parts and the danger of getting caught on
protruding parts. This poses a danger to life and limb.
▪ Wear appropriate personal protective equipment such as a helmet, work
gloves, etc. for the respective activity.
▪ Never wear damaged personal protective equipment.
▪ Never wear rings, necklaces, or other jewelry.
▪ If you have long hair, wear a hairnet.
Work area
Untidy and poorly lit work areas can lead to accidents.
▪ Keep the work area clean and tidy.
▪ Make sure that the work area is well lit.
▪ Observe the applicable laws for accident prevention in the relevant coun-
try.
Working during operation
The product may only be operated in a sound, operational condition. Other-
wise it poses a danger to life and limb.
▪ Regularly check the operational reliability of safety equipment.
▪ Comply with the inspection work, maintenance work and maintenance in-
tervals described in this technical file.
Invisible laser radiation
Looking directly into the beam or the reflected beam can cause eye damage.
The beam is emitted at the optical connections or at the end of the fiber-optic
cables connected to them on the assemblies. Read the chapter "Technical
Data" [►Section 15, Page 106] for further information.
▪ Never look directly into the beam or the reflected beam.
▪ Never look into the beam with the aid of optical instruments such as a
magnifying glass or a microscope.
▪ In the event that the laser beam strikes your eyes, close your eyes imme-
diately and move your head out of the path of the beam.
Working with current transformers
Dangerous high voltages may occur when a current transformer is operated
with an open secondary circuit. This can lead to injuries and property dam-
age.
▪ Never operate a current transformer with an open secondary circuit; short-
circuit the current transformer to prevent this.
▪ Observe the information in the current transformer operating instructions.

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Handling electrical components
Electrical components can be damaged by electrostatic discharges.
▪ Never touch electrical components during commissioning, operation or
maintenance work.
▪ Take suitable measures (e.g. covers) to ensure that personnel cannot
touch components.
▪ Wear suitable personal protective equipment (e.g. grounded strap).
Explosion protection
Highly flammable or explosive gases, vapors and dusts can cause serious
explosions and fire.
▪ Do not install or operate the product in areas where a risk of explosion is
present.
Safety markings
Warning signs and safety information plates are safety markings on the
product. They are an important aspect of the safety concept.
▪ Observe all safety markings on the product.
▪ Make sure all safety markings on the product remain intact and legible.
▪ Replace safety markings that are damaged or missing.
Ambient conditions
To ensure reliable and safe operation, the product must only be operated
under the ambient conditions specified in the technical data.
▪ Observe the specified operating conditions and requirements for the in-
stallation location.
Modifications and conversions
Unauthorized or inappropriate changes to the product may lead to personal
injury, material damage and operational faults.
▪ Only modify the product after consultation with Maschinenfabrik Rein-
hausen GmbH.
Spare parts
Spare parts not approved by Maschinenfabrik Reinhausen GmbH may lead
to physical injury, damage to the product and malfunctions.
▪ Only use spare parts that have been approved by Maschinenfabrik Rein-
hausen GmbH.
▪ Contact Maschinenfabrik Reinhausen GmbH.

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2.3 Personnel qualification
The person responsible for assembly, commissioning, operation, mainte-
nance and inspection must ensure that the personnel are sufficiently quali-
fied.
Electrically skilled person
The electrically skilled person has a technical qualification and therefore has
the required knowledge and experience, and is also conversant with the ap-
plicable standards and regulations. The electrically skilled person is also pro-
ficient in the following:
▪ Can identify potential dangers independently and is able to avoid them.
▪ Is able to perform work on electrical systems.
▪ Is specially trained for the working environment in which (s)he works.
▪ Must satisfy the requirements of the applicable statutory regulations for
accident prevention.
Electrically trained persons
An electrically trained person receives instruction and guidance from an
electrically skilled person in relation to the tasks undertaken and the poten-
tial dangers in the event of inappropriate handling as well as the protective
devices and safety measures. The electrically trained person works exclu-
sively under the guidance and supervision of an electrically skilled person.
Operator
The operator uses and operates the product in line with this technical file.
The operating company provides the operator with instruction and training
on the specific tasks and the associated potential dangers arising from im-
proper handling.
Technical Service
We strongly recommend having maintenance, repairs and retrofitting carried
out by our Technical Service department. This ensures that all work is per-
formed correctly. If maintenance is not carried out by our Technical Service
department, please ensure that the personnel who carry out the mainte-
nance are trained and authorized by Maschinenfabrik Reinhausen GmbH to
carry out the work.
Authorized personnel
Authorized personnel are trained by Maschinenfabrik Reinhausen GmbH to
carry out special maintenance.

2 Safety
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2.4 Personal protective equipment
Personal protective equipment must be worn during work to minimize risks to
health.
▪ Always wear the personal protective equipment required for the job at
hand.
▪ Never wear damaged personal protective equipment.
▪ Observe information about personal protective equipment provided in the
work area.
Protective clothing Close-fitting work clothing with a low tearing strength,
with tight sleeves and with no protruding parts. It mainly
serves to protect the wearer against being caught by
moving machine parts.
Safety shoes To protect against falling heavy objects and slipping on
slippery surfaces.
Safety glasses To protect the eyes from flying parts and splashing liq-
uids.
Visor To protect the face from flying parts and splashing liq-
uids or other dangerous substances.
Hard hat To protect against falling and flying parts and materials.
Hearing protection To protect against hearing damage.
Protective gloves To protect against mechanical, thermal, and electrical
hazards.
Table4: Personal protective equipment

3 IT security
Maschinenfabrik Reinhausen GmbH 202016 7370895/00 ENTAPCON® LV
3 IT security
Observe the following recommendations to operate the product safely.
General
▪ Ensure that only authorized personnel have access to the device.
▪ Only use the device within an ESP (electronic security perimeter). Do not
connect the device to the Internet in an unprotected state. Use mecha-
nisms for vertical and horizontal network segmenting and security gate-
ways (firewalls) at the transition points.
▪ Ensure that the device is only operated by trained personnel who are fa-
miliar with IT security.
Commissioning
Observe the following recommendations for device commissioning:
▪ User IDs must be unique and assignable. Do not use a "Group account"
function or the "Auto login" function.
▪ Activate the "Auto logout [►Section 8.2.2, Page 61]" function.
▪ Restrict the rights of the individual user groups as much as is feasible; this
helps avoid errors during operations. A user with the "Operator" role, for
example, should only perform operations and should not be able to
change any device settings.
▪ Delete or disable the default "admin" user ID. This requires first creating a
new user account with the "Administrator" role. You can then use it to
delete or disable the default "admin" account.
▪ Deactivate service user access [►Section 8.2.3, Page 62].
▪ Enable SSL/TLS encryption [►Section 8.2, Page 60]; access to the de-
vice is then only possible using the SSL/TLS protocol. In addition to en-
crypting communication, this protocol also checks the authenticity of the
server.
▪ Use TLS version1.2 or higher wherever possible.
▪ Integrate the device into a public key infrastructure. Create your own SSL
certificates for this if necessary and then import them.
▪ Connect the device to a central log server by using the syslog interface.
▪ Only use the SNMP function if you can ensure that the communication is
protected by external security equipment.
Operation
Observe the following recommendations during device operation:
▪ Change the password at regular intervals.
▪ Export the security log at regular intervals.
▪ Check the log files regularly for unauthorized system access and other se-
curity-related events.

3 IT security
Maschinenfabrik Reinhausen GmbH 2020 177370895/00 EN TAPCON® LV
Interfaces
The device uses the following interfaces for communication:
CPU
CAN 1
1
9
CAN 2
1
9
COM 1
1
9
COM 2
1
9
-
+
24V DC
RUN
INIT
ERR
USB2.0
462
A
8
C
H
TEST
PROG
RUN
462
AE
0 8
C
L
ETH 1 ETH 2.1 ETH 2.2
Figure1: CPU assembly interfaces
Interface Protocol Port Description
CAN 1 - - DIO assembly connection
CAN 2 - - No function
COM 1 - - Internal system interface
COM 2 - - No function
USB - - Import or export of data
ETH 1 - - No function
ETH 2.1 TCP 21 FTP1) (only for MR service)
ETH 2.1 TCP 80 HTTP for web-based visualization1)
ETH 2.1 TCP 443 HTTPS for web-based visualization1)
ETH 2.1 TCP 990 FTPS (only for MR service)
ETH 2.1 TCP 8080 HTTP for web-based visualization1)
ETH 2.1 TCP 8081 HTTPS for web-based visualization1)
ETH 2.2 - - No function
Table5: Interfaces and open ports of the CPU assembly
1) Port is closed if you activate the device's SSL encryption.
Encryption standards
The device supports the following TLS versions:
▪ TLS 1.0
▪ TLS 1.1
▪ TLS 1.2

3 IT security
Maschinenfabrik Reinhausen GmbH 202018 7370895/00 ENTAPCON® LV
The device uses the following cipher suites for a TLS-secured connection:
Key exchange Authentication Encryption Key length Operating
mode
Hash func-
tion
TLS ECDHE RSA WITH AES 128 CBC SHA1)
DHE SHA265
ECDHE ECDSA GCM SHA256
ECDH 256 CBC SHA1)
RSA1) SHA256
GCM SHA384
Table6: Cipher suite
1) Not available with TLS version >= 1.2
The device uses the SHA256 hash function to save passwords.
Also refer to
2General [►60]

4 Product description
Maschinenfabrik Reinhausen GmbH 2020 197370895/00 EN TAPCON® LV
4 Product description
4.1 Scope of delivery
The following items are included in the scope of delivery:
▪ TAPCON® LV
▪ Technical files
▪ Additional nameplate
Please note the following:
▪ Check the shipment for completeness on the basis of the shipping docu-
ments.
▪ Store the parts in a dry place until installation.
4.2 Function description
The product is a monitoring device and is used to monitor a voltage regulator
for power transformers with an on-load tap-changer. It measures voltage in-
dependently of the voltage regulator and blocks the voltage regulator's
switching commands if the voltage is outside of the permitted range. The de-
vice uses digital inputs to detect when the voltage regulator outputs a switch-
ing command to the motor-drive unit.
You can adapt the behavior of the device to your needs using adjustable pa-
rameters.
Motor-drive unit
TAPCON® LV
TAPCON®
V
Figure2: Function overview

4 Product description
Maschinenfabrik Reinhausen GmbH 202020 7370895/00 ENTAPCON® LV
Switching blocking
If the measured voltage is greater than the limit U> or less than the limit U<,
the device blocks the switching commands of the voltage regulator which
would lead to an even greater control deviation:
▪ Voltage less than limit U<: Operations are only possible in the direction of
higher voltage.
▪ Voltage greater than limit U>: Operations are only possible in the direction
of lower voltage.
High-speed return
If the measured voltage is greater than the limit U> or less than the limit U<,
the device generates a signal at the U<> output. You can combine this sig-
nal with the optional High-speed return input of the voltage regulator. With
high-speed return, the voltage regulator ignores the set delay time of auto-
matic voltage regulation.
Return
The return function is used to switch the on-load tap-changer to a certain tap
position if the measured voltage is less than the limit U<< (e.g. loss of trans-
former voltage). To do so, the device outputs switching commands to the
motor-drive unit until the motor-drive unit is in the desired tap position.
To use this function, the motor-drive unit must output a signal to communi-
cate to the device that the desired tap position or tap position range has
been reached.
4.3 Performance features
The device features the following functions:
▪ Voltage monitoring
– Voltage measurement monitoring
– Blocking of switching commands from the voltage regulator
– Return to desired tap position
– Activation of the voltage regulator high-speed return
▪ Display of all measured values