Megger VLF CR-40 User manual

Operating Manual
VLF Test System
VLF CR
−
40 / 60 kV
Issue: 3 (01/2010) – EN
128312953

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man_vlf_cr_40_60_standalone_en_03-4.doc 3
Consultation with Megger
The present system manual has been designed as an operating guide and for
reference. It is meant to answer your questions and solve your problems in as fast and
easy a way as possible. Please start with referring to this manual should any trouble
occur.
In doing so, make use of the table of contents and read the relevant paragraph with
great attention. Furthermore, check all terminals and connections of the instruments
involved.
Should any question remain unanswered or should you need the help of an authorized
service station, please contact:
Megger Limited
Seba Dynatronic
Mess- und Ortungstechnik GmbH
Archcliffe Road
Kent CT17 9EN
T: [phone]
F: [phone]
E: [e-mail]
Dr.-Herbert-Iann-Str. 6
D - 96148 Baunach
T: +49 / 9544 / 68 – 0
F: +49 / 9544 / 22 73
E: [e-mail]
Hagenuk KMT
Kabelmesstechnik GmbH
Megger USA
Röderaue 41
D - 01471 Radeburg / Dresden
T: +49 / 35208 / 84 – 0
F: +49 / 35208 / 84 249
E: [e-mail]
4271 Bronze Way
Dallas, Texas 75237-1019 USA
T: 1-800-723-2861
F: 1-214-331-7399
E: [e-mail]
Megger
All rights reserved. No part of this handbook may be copied by photographic or other means unless Megger have before-hand
declared their consent in writing. The content of this handbook is subject to change without notice. Megger cannot be made liable for
technical or printing errors or shortcomings of this handbook. Megger also disclaims all responsibility for damage resulting directly or
indirectly from the delivery, supply, or use of this matter.

4 man_vlf_cr_40_60_standalone_en_03-4.doc
TERMS OF WARRANTY
Megger accept responsibility for a claim under warranty brought forward by a customer
for a product sold by Megger under the terms stated below.
Megger warrant that at the time of delivery Megger products are free from manufactur-
ing or material defects which might considerably reduce their value or usability. This
warranty does not apply to faults in the software supplied. During the period of warranty,
Megger agree to repair faulty parts or replace them with new parts or parts as new (with
the same usability and life as new parts) according to their choice.
This warranty does not cover wear parts, lamps, fuses, batteries and accumulators.
Megger reject all further claims under warranty, in particular those from consequential
damage. Each component and product replaced in accordance with this warranty
becomes the property of Megger.
All warranty claims versus Megger are hereby limited to a period of 12 months from the
date of delivery. Each component supplied by Megger within the context of warranty will
also be covered by this warranty for the remaining period of time but for 90 days at
least.
Each measure to remedy a claim under warranty shall exclusively be carried out by
Megger or an authorized service station.
This warranty does not apply to any fault or damage caused by exposing a product to
conditions not in accordance with this specification, by storing, transporting, or using it
improperly, or having it serviced or installed by a workshop not authorized by Megger.
All responsibility is disclaimed for damage due to wear, will of God, or connection to
foreign components.
For damage resulting from a violation of their duty to repair or re-supply items, Megger
can be made liable only in case of severe negligence or intention. Any liability for slight
negligence is disclaimed.
Since some states do not allow the exclusion or limitation of an implied warranty or of
consequential damage, the limitations of liability described above perhaps may not
apply to you.

man_vlf_cr_40_60_standalone_en_03-4.doc 5
TABLE OF CONTENTS
1. GENERAL INTRODUCTION..................................................... 8
1.1 Safety Precautions.................................................................................... 9
1.1.1 General Safety Precautions...................................................................... 10
1.1.2 Supplementary Guidelines........................................................................ 11
1.1.3 Danger Due To Returning Voltage From Space Charge .......................... 12
1.1.4 General Rules for Dealing with High Voltage............................................ 13
2. TECHNICAL DESCRIPTION .................................................. 14
2.1 Technical Specification.......................................................................... 14
2.1.1 VLF Test System 40 kV ............................................................................ 14
2.1.2 VLF Test System 60 kV ............................................................................ 15
2.1.3 Accessory equipment................................................................................ 16
2.2 Description of the VLF Test System...................................................... 17
2.3 Description of components of the VLF Test System 40 / 60 kV.......... 20
2.3.1 Operating module ..................................................................................... 20
2.3.2 Display of the Operating module............................................................... 21
2.3.3 VLF Test System as a whole .................................................................... 22
2.3.4 Protection covers of the modules ............................................................. 24
2.3.5 Transportation protection bottom from the Operating module .................. 25
3. DESCRIPTION OF THE TEST METHOD ............................ 3-27
4. SETTING-UP OPERATION ................................................. 4-28
4.1 Safety Precautions............................................................................... 4-28
4.2 Electrical Connection of the VLF Test System.................................. 4-30
4.2.1 General Rules for Making Connections ................................................. 4-30
4.2.2 Connecting the Earth Cable................................................................... 4-30
4.2.3 Connecting the Test Object ................................................................... 4-31
4.2.4 Connecting the Mains Cable.................................................................. 4-31
5. EXECUTION OF TESTS...................................................... 5-32
5.1 VLF / DC Test ....................................................................................... 5-32
5.2 Sheath Fault Location ......................................................................... 5-34

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5.3 Starting the Test / Location................................................................. 5-34
6. ADDITIONAL FUNCTIONS ..................................................6-37
6.1 Adjustment of Language ..................................................................... 6-37
6.2 Viewing the System Information......................................................... 6-37
6.3 Viewing / Setting the System Parameters.......................................... 6-38
6.4 Entering / Changing the Administrator Password ............................ 6-39
6.5 Returning to the start menu ................................................................ 6-40
7. Optional Features ...............................................................7-41
7.1 Detection of Breakdown and Short Circuit........................................ 7-41
7.2 Measurement of Leakage Current ...................................................... 7-41
7.3 Internal Protocol Printout.................................................................... 7-42
7.4 Using a SystemCard ............................................................................ 7-44
7.4.1 Purpose of a SystemCard...................................................................... 7-44
7.4.2 Preparing a SystemCard........................................................................ 7-45
7.4.3 Logging to SystemCard ......................................................................... 7-46
7.4.4 Operating the Test System with a SystemCard ..................................... 7-48
7.5 Function User Setup / User Level....................................................... 7-49
7.6 Re-Setting the System Settings / Deleting the Print Templates....... 7-50
7.7 Adjustment of the System Timer ........................................................ 7-51
8. Maintenance and Troubleshooting....................................8-52
8.1 How to Exchange the Paper Roll or Ink Ribbon of the Printer......... 8-52
8.2 Replacing the Battery of the System Clock ....................................... 8-53
8.3 Connecting Cables, HV Couplings ..................................................... 8-54
8.4 Operational and Error Messages........................................................ 8-54
8.4.1 Classification of Messages .................................................................... 8-54
8.4.2Operational Messages about State of System....................................... 8-55
8.4.3 Operational Messages about Switching Conditions............................... 8-58
8.4.4 Error Messages and Warnings .............................................................. 8-60

man_vlf_cr_40_60_standalone_en_03-4.doc 7
Index Of Figures
Fig 1: Representation of the test voltage characteristics (Device option Plus).............. 19
Fig 2: voltage waveform during polarity inversion ......................................................... 19
Fig 3: Operating module, Front View ............................................................................ 20
Fig 4: Display of the Operating module (View of the standard operating mode) ........... 21
Fig 5: Connections at the right hand side of the VLF Test System ............................... 22
Fig 6: Connectors on the rear of the VLF Test System................................................. 23
Fig 7: Protection cover of the Operating module........................................................... 24
Fig 8: Shorting device / Protection cover of the HV module.......................................... 24
Fig 9: Transportation protection bottom from the Operating module............................. 25
Fig 10: Connection of the test object ...........................................................................4-31
Fig 11: Start menu.......................................................................................................5-32
Fig 12: Selection of the operation mode ......................................................................5-32
Fig 13: Selection of the test voltage.............................................................................5-33
Fig 14: Selection of the test time .................................................................................5-33
Fig 15: Selection of the pulse rate ...............................................................................5-34
Fig 16: HV on5-34
Fig 17: Cable test ........................................................................................................5-35
Fig 18: Start menu after the test has been finished .....................................................5-36
Fig 19: User Setup: Language.....................................................................................6-37
Fig 20: Setup: System Informationen ..........................................................................6-37
Fig 21: Setup: Parameters...........................................................................................6-38
Fig 22: Setup: Enter password ....................................................................................6-39
Fig 23: Setup: Entered password ok............................................................................6-39
Fig 24: Setup: Enter new password.............................................................................
6-40
Fig 25: Setup: New password stored ...........................................................................6-40
Fig 26: Setup: Return to start menu.............................................................................6-40
Fig 27: Breakdown detection .......................................................................................7-41
Fig 28: Setup: Protocol Printout Off .............................................................................7-42
Fig 29: Setup: Protocol Printout Standard ...................................................................7-42
Fig 30: Setup: Protocol Off ..........................................................................................7-46
Fig 31: Setup: Protocol Extended ................................................................................7-46
Fig 32: Start menu with SystemCard inserted..............................................................7-48
Fig 33: Start menu after new system settings have been stored .................................7-48
Fig 34: Setup: User Profile ..........................................................................................7-49
Fig 35: Setup, Memory ................................................................................................7-50
Fig 36: Setup Date / Time............................................................................................7-51
Fig 37: Setup Date / Time: adjusting the day of the week............................................7-51
Fig 38: Setup Date / Time: adjusting the minutes ........................................................7-51
Fig 39: Setup Date / Time: Saving by F1.....................................................................7-51
Fig 40: Unscrewing the printer front cover .......................... Fig 41: Removing the front cover 8-52
Fig 42: Removing the ribbon cartridge .......................... Fig 43: Inserting the ribbon cartridge 8-52
Fig 44: Inserting the paper roll into the printer ............................... Fig 45: Paper feed button 8-53

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1. GENERAL INTRODUCTION
The VLF Test System shall be used for the stated field of application in cable diagnosis
only. Any other application is strictly forbidden! Hagenuk KMT cannot be made liable for
any damage to persons or matter caused by using the system for some other
application.
This is why we advise you to absolutely abide by the safety precautions given in
chapter1 whenever you use the VLF Test Systems.
Each person involved in the assembly, operation, maintenance, and repair of the VLF
Test Systems is required to have read this handbook carefully.
Only trained and/or instructed staff are permitted to deal with the VLF Test System and
its periphery. Other persons have to stay away.
This handbook must be available to the supervising, operating, and maintenance staff
for reference.
Never use foreign components on the VLF Test System and its periphery, otherwise the
safety of the system is jeopardised.
The user is obliged to immediately report any occurring change in the system to the
supervisor in charge.
The operator is obliged to immediately shut down the system should any fault occur
that might pose a threat to the staff. The system is permitted to be switched on again
only after the fault has been eliminated.
The VLF Test System and all its supplementary equipment has to be connected and
operated according to instructions. All relevant standards (DIN, VDE) shall be met. Any
repair or maintenance operation may be carried out only after all circuits have been
shut down (are in a dead state) and only by an electrical expert. A person is regarded
an electrical expert if due to his or her practical training, knowledge, and experience as
well as knowledge of the relevant standards he or she is able to assess the operation to
be carried out and detect every possible risk.
Attention!
The VLF Test System 40 kV and VLF Test System 60 kV respectively, are upright
devices and have to be only transported and operated in upright position.

man_vlf_cr_40_60_standalone_en_03-4.doc 9
1.1 Safety Precautions
Each person involved in the assembly, maintenance, and repair of this system is
required to have read this manual carefully.
At the time of supply, this system and its supplementary equipment are in line with the
state of the art in safety control. Due to the operating procedures there may be parts
and places of the system and its peripherals, however, which cannot be protected
properly without unreasonably interfering with their function and control. This is why
comprehensive personal experience in safety matters is absolutely vital for the
protection of both staff and equipment.
This is why we advise you to abide by the following safety precautions!
GENERAL INSTRUCTIONS
Only trained or instructed staff are permitted to deal with this system and its
peripherals. Any other persons shall be kept away from it.
This manual shall be available to the supervising, operating, and maintenance staff for
reference.
Improper use may constitute a high risk of damage to the life and health of the operator
as well as the system and the equipment connected to it (UVV). Use the system
exclusively for the purpose it has been designed for by its manufacturer.
Always use the appropriate tools for each operation on and for running the system and
keep your tools in good condition.
Permanently supervise that during operation and maintenance all safety precautions
are obeyed.
This system is allowed to be run by authorised persons with sufficient expertise only.
Operate the system and its pertaining peripherals only when they are in good working
order.
Never use foreign components on the system and its peripherals, otherwise the safety
of the system and its environment is not ensured. Refrain from any operation which
might jeopardise the safety of the system.
The user is obliged to immediately report any arising change in the system to the
supervisor in charge.
The operator is obliged to immediately shut down the system whenever a fault occurs
which may be safety risk to the staff. The system is permitted to be switched on again
only after the fault has been remedied.
Attention! Owing to the physical processes which take place within the high-
voltage system, each person wearing a pacemaker is in potential
danger when getting close to it.

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ELECTROTECHNICAL INSTRUCTIONS
The system and all its peripherals shall be connected according to instructions. All
relevant standards such DIN and VDE respectively, have to be met.
Any repair or maintenance operation may be carried out only after all circuit have been
shut down (are in a dead state) and only by an electrical expert according to UVV. A
person is regarded an electrical expert to UVV (Prevention of Accidents Regulation) if
due to his or her practical training, knowledge, and experience he or she is able to
clearly understand the operation to be carried out and detect any possible risk.
1.1.1 General Safety Precautions
Abide by the relevant Accident Prevention Regulations in the first place when you carry
out maintenance and repair operations.
Mark all components before you start any repair operation.
Always use new sealing and locking elements when you re-assemble fittings and
devices.
Leave all screw joints dry when assembling them (do not lubricate!).
Only trained staff are permitted to carry out maintenance and repair work.
Check the system for functionality whenever you have finished maintenance and repair
operations; this has to be particularly accepted in the case of existent safety equipment.
De-energise the system and make the site safe.
Before starting any operation on electrical units: De-energise all components you are
going to work on.
This applies even in the event that the repair seems to be marginal.
Make the place(s) of disconnection safe against any unintentional circuit reclosing.
After de-energising the system, before starting any work on the site: Check all
components of the system for all-pole disconnection.
Do so using a circuit tester or meter the functionality of which has been tested on a live
member of the system a short time before using it.

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Fuses
It is absolutely inadmissible to patch or bridge a fuse or to use a patched fuse.
When replacing a fuse: Always use a fuse of identical or lower current rating and
characteristic (slow, fast, superfast action).
Never unscrew or pull out a fuse while it is under load. It is inadmissible to use a fuse
for switching a circuit.
Further important safety instructions:
- High-voltage installations has to be only operated in rooms with
protection according to regulations or behind appropriate barriers.
Never bypass nor render inactive any safety device.
- At least two persons must be present whenever a high-voltage
installation is in operation. The second person shall be able to
recognise any risk and, in case of emergency, immediately actuate the
emergency-shutdown.
1.1.2 Supplementary Guidelines
The following guidelines which cannot be directly derived from the instructions should
be added to the above mentioned regulations.
- Always connect all metal parts in the vicinity of a high-voltage
installation to earth in order to avoid dangerous charging. Particularly
great attention should be paid to non-stationary (mobile) operation.
- Open a circuit only when you are absolutely sure it does not carry any
current or voltage (danger of arcs).
- High-voltage testing and burning devices are short-circuit-proof. This
involves the danger of the voltage running up as soon as the short-
circuit is removed. Connect a bleeder in parallel to the meter (e. g., a
90 V glow-type bleeder) when making a short-circuit test.
- Even after circuits have been properly disconnected and discharged,
you are permitted to contact components which had been under voltage
and disconnect any measuring or test equipment only after the
installation has been visibly earthed and shorted by an appropriate
device.

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1.1.3 Danger Due To Returning Voltage From Space Charge
- Remove earth connection and short circuit only when the object under
test is going to be put into operation again.
- As a basic principle capacitors and cables which are out of operation
must be earthed and shorted!
Attention! The test object has to be connected to earth and shorted after terminating
of the test.
You are not excused from this duty even the complete discharge by the
internal discharging unit and the zero positioning of the residual voltage
(Fig 3, item 2) have been performed.
In the case of an incomplete discharge of the test object the complete
discharging must be carried out by a suitable discharge rod.
Attention! The HV module of the VLF Test System 40 / 60 kV contains electrical
energy storage devices also. These devices are discharged in the same
way like the test object by the internal discharging unit of the test device.
To avoid the re-charging by space charges the HV module has to be
immediately equipped by means of the provided shorting device (Fig 8)
after disconnection of the both components HV module and Operating
module. The shorting device has to be remained at the HV module even in
the case of transportation and storage and may not be removed until the
Operating module had been put on.
Instructions How to Handle Fixed and Flexible Cables and Leads
Do not use mains cables and their fixtures for attaching, fixing, or hanging up devices,
clothes, etc.
Make sure that the cables are not bent while being disconnected. Prevent any moisture
from infiltrating into the cable ends. Affix an appropriate moisture shelter, if need be.
Do not expose flexible leads to excessive tensile force while in operation or during
transport. In particular, make sure that the instruments are not hung by their leads and
that plugs are not pulled out of sockets by their leads.

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How to Deal With Connectors and Cable Accessories
Connect every electrical removable appliances only by the connectors (plug, socket)
intended for this purpose.
Do not use any adapter or plug which matches a socket for some other voltage.
Use appropriate lock washers and spring washer to make every cable connecting
terminal safe against becoming detached.
When re-connecting a cable to a device or installation: Make sure that the cable shield
is connected to earth (by an earthing cone) and the cable inlet is sealed (in accordance
with the enclosure protection of the connected device).
As a rule, such installations contain a great number of connecting leads to the
components of the system and between individual components. Never misuse a
connecting lead, which is not insulated for operation under medium of high voltage, for
making an HV connection. Do not use patch cords for making HV connections. There
might be discharges between such a lead and other system components which would
immediately destroy the insulating capacity of this lead and so do away with its safety.
Use only cables and connectors intended for application under high voltage
(HV cables or leads without insulation)!
1.1.4 General Rules for Dealing with High Voltage
Dealing with high voltage and related equipment requires utmost care. This applies in
particular to cases of non-stationary (mobile) operation, i.e. such instances where there
is no special room which is permanently furnished with the appropriate safety
equipment to provide for safety from the start.
Absolutely abide by the VDE directive 0104 "Installation and operation of electrical test
systems" or relevant IEC standards, respectively.

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2. TECHNICAL DESCRIPTION
2.1 Technical Specification
2.1.1 VLF Test System 40 kV
Output voltage, DC 3 - 40 kV
Output current source 7 mA
Range of indication,
Leakage current measurement 0 -7 mA
Resolution of indication 10 µA
Output voltage, VLF 0 - 40 kV
Frequency 0,1 Hz
Waveform rectangular cosine
Sheath fault location voltage 3 … 10 kV
Pulse rate for sheath fault location 4s 1:3
4s 1:5
6s 1:5
6s 1:9
Cable capacitance to be tested
VLF Test System 40 kV Basis 2,2 µF (for full operating temperature range)
2,4 µF (at common temperatures (≤20° C)
and with limited accuracy of the measured
leakage current values)
VLF Test System 40 kV Plus 4,4 µF (for full operating temperature range)
4,7 µF (at common temperatures (≤20° C)
and with limited accuracy of the measured
leakage current values)
Discharging unit integrated, 4,4 µF per 5 s

man_vlf_cr_40_60_standalone_en_03-4.doc 15
Supply voltage 230 V ±10 %, 50 ... 60 Hz
Option 120 V ±10 %, 60 Hz
Power consumption 500 VA at maximum
Operating temperature range -25 °C ... +55 °C
Operating humidity 30 °C, 93 % rel. humidity
Storage temperature range -40 °C ... +70 °C
Protection class I to DIN VDE 0140 T.1
Enclosure protection IP 20 to EN 60529
Dimensions (W x H x D) ca. 550 x 1000 x 420 mm
Weights ca. 55 kg + 48 kg (Basis) / 55 kg (Plus)
(according to stage of expansion)
2.1.2 VLF Test System 60 kV
Output voltage, DC 3 - 60 kV
Output current source 5 mA
Range of indication,
Leakage current measurement 0 -5 mA
Resolution of indication 10 µA
Output voltage, VLF 3 - 60 kV
Frequency 0,1 Hz
Waveform rectangular cosine
Sheath fault location voltage 3 … 10 kV
Pulse rate for sheath fault location 4s 1:3
4s 1:5
6s 1:5
6s 1:9
Cable capacitance to be tested
VLF Test System 60 kV Basis 0,8 µF (for full operating temperature range)
1,0 µF (at common temperatures (≤20° C)
and with limited accuracy of the measured
leakage current values)
VLF Test System 60 kV Plus 1,6 µF (for full operating temperature range)
2,0 µF (at common temperatures (≤20° C)
and with limited accuracy of the measured
leakage current values)

16 man_vlf_cr_40_60_standalone_en_03-4.doc
Discharging unit integrated, 1,5 µF in 2 s
Supply voltage 230 V ±10 %, 50 ... 60 Hz
Option 120 V ±10 %, 60 Hz
Power consumption 300 VA at maximum
Operating temperature range -25 °C ... +55 °C
Operating humidity 30 °C, 93 % rel. humidity (60 kV)
30 °C, 70 % rel. humidity (50 kV)
Storage temperature range -40 °C ... +70 °C
Protection class I to DIN VDE 0140 T.1
Enclosure protection IP 20 to EN 60529
Dimensions (W x H x D) ca. 550 x 1000 x 620/420 mm
Weights ca. 85 kg + 48 kg (Basis) / 55 kg (Plus)
(according to stage of expansion)
2.1.3 Accessory equipment
Accessory equipment Mains connecting cable 2,5 m
Earth connecting cable 5 m
HV connecting cable 5 m
Phase clip
Terminal clip for earth connection
Instruction manual
Equipment case
Optional equipment Detection of breakdown
Leakage current measurement
Logging
Printout (Protocol printing)

man_vlf_cr_40_60_standalone_en_03-4.doc 17
2.2 Description of the VLF Test System
Based on comprehensive scientific research, relevant DIN and VDE standards which
we recommend to your attention, and more than 10 years of practical experience on
more than 300 VLF Test Systems, we can today take it for granted that the 0.1 Hz VLF
method for testing cables with plastics insulation outclasses any other test method
using DC voltage or power-frequency AC voltage as used so far.
A 0.1 Hz VLF Test System is required to meet the following demands:
•The repetition rate has to be so slow, that the power set free in any TE
channel that may already exist (TE = Teilentladung, partial discharge) is
small enough not to cause further erosion and so increase gas
pressure.
•The inversion of polarity, on the one hand, must be slow enough to
exclude any transients caused by travelling waves. On the other, it must
be fast enough that any space charge at the tip of a TE channel from
where it grows in the direction of the opposite electrode is preserved.
A system that meets these requirements has to supply a 0.1 Hz oscillation, with the
inversion of polarity taking place within the time duration of a 50 Hz half-wave.
Another vital characteristic to be considered when designing this system was to ensure
simple on-site testing by
−small dimensions,
−light weight, and
−low power consumption.

18 man_vlf_cr_40_60_standalone_en_03-4.doc
Every cycle starts with a charging phase in which the test object as well as the back-up
capacitor switched in parallel are charged from a DC source until the desired test
voltage is reached.
After a period of 5 seconds, the voltage source will be disconnected from the system by
S1(S2) and via R1(R2) discharged.
Subsequently, V1 initiates the desired inversion process through inductor L1.
The test object changes its polarity from minus to plus.
Depending on the capacitance of the connected test object, the ring-around time during
polarity inversion is between 2 and 10 msec.
Owing to the losses which occur in both the polarity inversion coil L1 and V1 during
polarity inversion, the positive voltage is decreased by these losses.
After a 5 seconds dwelling period at positive polarity (Device option Basis) or
equalisation of the polarity inversion losses due to recharging by the positive DC
voltage source (Device option Plus), the return to negative polarity. takes place by
means of V1.
The negative voltage source is no longer discharged and again connected to the test
object.
The drop in voltage caused by twice ringing around (Device option Basis) will now be
compensated for by recharging from the negative DC source.
In contrast to this at the device option Plus the polarity inversion losses of a single ring-
around event are consistently compensated.
The back-up capacitor has three tasks:
- It slows the ring-around event down to the msec range even for short cables,
- it compensates for part of the losses during the ring-around event,
- it reduces the polarity reversal stress caused by travelling waves.
Fig 2 represents the generated characteristics of the test voltage in the case of the
device option Basis.

man_vlf_cr_40_60_standalone_en_03-4.doc 19
Fig 1: Representation of the test voltage characteristics (Device option Plus)
Fig 2: voltage waveform during polarity inversion
36 kV = 3 x U0
Residual charging
33 kV
33 kV
33 kV
0 5 10 15 20 s
KV
30
0
-30
36 kV = 3 x U0
36 kV = 3 x U0
0 1 2 3ms 0 1 2 3ms
time

20 man_vlf_cr_40_60_standalone_en_03-4.doc
2.3 Description of components of the VLF Test System 40 / 60 kV
2.3.1 Operating module
2 3
11 10 9 8
Fig 3: Operating module, Front View
1 Key "Emergency Off"
2 Analogue indication instrument test voltage (kV)
3 Display
4 Menu key F1
5 Menu key F2
6 Knob / push-button
7 Intake slot for the System Card
8 Protocol printer
9 Key "HV Off" (red)
10 Key "HV On" (green)
11 Key-operated switch "Interlock"
12 Key "Mains On" (white)
1
1
4
5
6
7
1
12