Megger HV DAC-300 User manual

1
HV DAC-300
Partial discharge measuring system
USER GUIDE
Issue: C (04/2022) - EN
Article number: 84020

2

Consultation with Megger
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 Megger Germany GmbH (Baunach)
Archcliffe Road
Kent CT17 9EN
T: [phone]
F: [phone]
E: [e-mail]
Dr.-Herbert-Iann-Str. 6
D - 96148 Baunach
T: [phone] – 0
F: [phone]
E: [e-mail]
Megger Germany GmbH (Radeburg) Megger USA
Röderaue 41
D - 01471 Radeburg / Dresden
T: [phone] – 0
F: [phone]
E: [e-mail]
Valley Forge Corporate Centre
2621 Van Buren Avenue
Norristown, PA 19403 USA
T: [phone]
F: [phone]
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 information in this document is subject to change without
notice and should not be construed as a commitment by Megger. 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.

Terms of Warranty
4
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 manufacturing
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.

Contents
5
Contents
Consultation with Megger...............................................................................................3
Terms of Warranty ...........................................................................................................4
Contents ...........................................................................................................................5
1Safety Instructions ...........................................................................................7
1.1 General Notes ....................................................................................................7
1.2 General Safety Instructions and Warnings.........................................................8
2Technical Description ......................................................................................9
2.1 Abbreviations......................................................................................................9
2.2 System Description ..........................................................................................10
2.3 Technical Data .................................................................................................16
2.4 Connections, Controls and Indicators ..............................................................20
2.5 Technical Background......................................................................................23
3Commissioning ..............................................................................................25
3.1 Assembly and Electrical Connection................................................................25
3.1.1 Setting Up the Coupling Unit............................................................................28
3.1.2 Setting Up the Support Capacitor (optional) ....................................................31
3.1.3 Setting Up the Inductor.....................................................................................34
3.1.4 Setting Up the Switch .......................................................................................39
3.1.5 Making the HV Connections between the individual components ...................42
3.1.6 Setting Up the HV Source ................................................................................45
3.1.7 Connecting the Coupling Unit to the Cable Under Test ...................................48
3.1.8 Installing the Corona Ring at the Remote End of the Cable (optional) ............51
3.2 Switching On ....................................................................................................52
4Basic Operation of the Software...................................................................53
4.1 Start Screen .....................................................................................................53
4.2 Useful Features of the Software.......................................................................54
5Conducting Measurements ...........................................................................56
5.1 Starting or Resuming a Measurement Task – ...........................................56
5.2 Calibrating the Partial Discharge Measuring Circuit – ...............................58
5.2.1 Connecting the Calibrator.................................................................................58
5.2.2 Conducting the Calibration ...............................................................................59
5.2.3 Disconnecting the Calibrator ............................................................................63
5.3 Measuring – ..............................................................................................64
5.3.1 Basic Information Regarding the Measurement Screen ..................................64
5.3.2 Available diagram types ...................................................................................65
5.3.3 Setting the Measurement Parameters .............................................................69
5.3.4 Performing the Measurement...........................................................................71
5.3.4.1 Typical Procedure for PD Diagnosis ................................................................74

Contents
6
5.3.4.2 Typical Procedure for Monitored Withstand Testing ........................................75
5.3.5 Stopping / Finishing a Measurement................................................................76
6Evaluating Measurement Results and Creating a Report ..........................77
6.1 Manual Evaluation of Partial Discharges .........................................................80
6.1.1 Determining Possible Sources of PD Faults ....................................................80
6.1.2 Analysing Individual PD Events .......................................................................81
6.2 Preparing and Printing the Report....................................................................84
7Configuring Settings and Managing Data....................................................87
7.1 Adjusting the Settings – .............................................................................87
7.1.1 Managing Devices............................................................................................89
7.1.2 Managing Report Templates............................................................................90
7.2 Cable Manager – ...................................................................................94
7.2.1 Viewing Cable Data and Administrating Measurement Tasks.........................94
7.2.2 Managing Cables .............................................................................................97
7.2.2.1 Entering / Changing General Cable Data.........................................................97
7.2.2.2 Specifying the Sections of the Cable ...............................................................99
7.2.2.3 Saving Cable Data .........................................................................................103
7.2.2.4 Managing Segment Templates ......................................................................104
7.2.3 Managing Measuring and Cable Data............................................................105
7.2.3.1 Exporting Data................................................................................................106
7.2.3.2 Importing Data................................................................................................107
7.2.3.3 Backing Up Data ............................................................................................109
8Switching Off and Disassembling the System..........................................110
9Storage and Transport.................................................................................111
10 Maintenance and Care .................................................................................112
11 Troubleshooting ...........................................................................................114

Safety Instructions
7
1Safety Instructions
1.1 General Notes
This manual contains basic instructions for the commissioning and operation of the device
/ system. For this reason, it is important to ensure that the manual is always available to
the authorised and trained operator. He needs to read the manual thoroughly. The
manufacturer is not liable for damage to material or humans due to non-observance of
the instructions and safety advices provided by this manual.
Locally applying regulations have to be observed!
The following signal words and symbols are used in this manual and on the product itself:
Signal word /
symbol
Description
DANGER Indicates a potential hazard which will result in death or serious
injury if not avoided.
WARNING Indicates a potential hazard which may result in death or
serious injury if not avoided.
CAUTION Indicates a potential hazard which may result in moderate or
minor injury if not avoided.
NOTICE Indicates a potential hazard which may result in material
damage if not avoided.
Serves to highlight warnings and safety instructions.
As a warning label on the product it is used to draw attention to
potential hazards which have to be avoided by reading the
manual.
Serves to highlight warnings and safety instructions that
explicitly indicate the risk of an electric shock.
Serves to highlight important information and useful tips on the
operation of the device/system. Failure to observe may lead to
unusable measurement results.
It is important to observe the generally applicable electrical regulations of the country in
which the device will be installed and operated, as well as the current national accident
prevention regulations and internal company directives (work, operating and safety
regulations).
After working on the system, it must be voltage-free and secured against reconnection as
well as having been discharged, earthed and short-circuited.
Use genuine accessories to ensure system safety and reliable operation. The use of other
parts is not permitted and invalidates the warranty.
The system may only be installed and operated by an authorised electrician. DIN VDE
0104 (EN 50191), DIN VDE 0105 (EN 50110) and the German accident prevention
regulations (UVV) define an electrician as someone whose knowledge, experience and
familiarity with the applicable regulations enables him to recognise potential hazards.
Anyone else must be kept away!
Safety precautions
Labelling of safety
instructions
Working with products
from Megger
Operating staff

Safety Instructions
8
1.2 General Safety Instructions and Warnings
The operating safety is only guaranteed if the delivered system is used as intended (see
page 10). Incorrect use may result in danger to the operator, to the system and the
connected equipment.
The thresholds listed in the technical data may not be exceeded under any circumstances.
Five safety rules
The five safety rules must always be followed when working with HV (High Voltage):
1. De-energise
2. Protect against re-energising
3. Confirm absence of voltage
4. Earth and short-circuit
5. Cover up or bar-off neighbouring energised parts
Using cardiac pacemaker / defibrillator
Physical processes during operation of high voltage may endanger
persons wearing a cardiac pacemaker or defibrillator when near these
high voltage facilities.
Fire fighting in electrical installations
•According to regulations, carbon dioxide (CO2) is required to
be used as extinguishing agent for fighting fire in electrical
installations.
•Carbon dioxide is electrical
ly non conductive and does not leave
residues. It is safe to be used in energized facilities as long as
the minimum distances are maintained. A CO2fire extinguisher
must be always available within electrical installations.
•If, contrary to the regulations, any other extinguishing agent is
used for fire fighting, this may lead to damage at the electrical
installation. Megger disclaims any liability for consequential
damage. Furthermore, when using a powder extinguisher near
high-voltage installations, there is a danger that the operator of
the fire extinguisher will get an electrical shock from a voltage
arc-over (due to the powder dust created).
•It is essential to observe the safety instruction on the
extinguishing agent.
•Applicable is DIN VDE 0132.
Intended application

Technical Description
9
2Technical Description
2.1 Abbreviations
In this manual the following abbreviations are used:
PD Partial Discharge
DAC Damped AC
PDIV Partial Discharge Inception Voltage
PDEV Partial Discharge Extinction Voltage
TDR Time Domain Reflectometry (or Time Domain Reflectometer)
VWD Voltage Withstand Diagnosis
AKV Ankoppelvierpol (Quadripole)
MWT Monitored Withstand Test

Technical Description
10
2.2 System Description
The HV DAC-300 is a partial discharge measurement system that allows for the
identification, classification and location of PD faults in the insulation and the accessories
of all kinds of high voltage cables. It essentially consists of a DC voltage source, a
travelling wave resistor, a switch, an inductor and a coupling unit with integrated
measuring impedance and PD detector.
Both, the control of the voltage source and the visualization and analysis of the
measurement data are made through a notebook that is connected via a network
interface. All operational actions that are required for measuring and locating PD can be
executed with the help of the preinstalled software. The analysis and management of the
measurement data can be conducted either immediately after the measurement or later
in the office.
For the purpose of measuring partial discharge, the test object is charged to the desired
voltage using the HV source and then discharged using the switch and the specially
designed inductor. Thus a sinusoidal DAC voltage with low damping is created.
Depending on the capacitance of the test object the frequency varies in the range from
tens to hundreds of Hz. PD instigated during this process are decoupled via the coupling
unit and processed in the PD detector.
Functional description
Travelling wave resistor
HV source
Switch
Inductor
Coupling unit
PD detector

Technical Description
11
The DAC voltage allows a cable-friendly PD diagnosis in conformity with IEC 60270. One
major benefit of this voltage waveform is the similarity between the DAC slope and the 50
Hz power frequency (“50 Hz Slope Technology”) which can be clearly seen in the following
figure:
This is particularly important for PD diagnosis, since reliable evaluation of the measured
results requires a direct comparability with the power frequency. It is widely known that
PD characteristics change in case of large frequency differences, making reliable
evaluation impossible.
The system offers the following features and functions:
•Standard-compliant test with DAC voltage of up to 300 kV
•Standard-compliant cable diagnosis with a voltage of up to 270 kV (increased
internal noise level for voltages >>270 kV)
•Intuitive control and analysis software, suitable for the universal use with
different systems of Megger
•Quick and fully automatic calibration in one step
•PD mapping and statistical evaluation in real time
•Fully automatic report generation directly after a measurement possible
•Cable database with individually adaptable segment templates
•Import of measurement data from other PD measurement systems, e.g.
Oscillating Wave Test System (OWTS) (optional)
Features

Technical Description
12
The transport boxes include the following transport boxes:
QTY
Box label Box content Article number
1 “Source” HV source 2010124
1 “Switch” Thyristor switch 2004322 (with content)
90006260 (empty)
1 “Inductor/Top” HV Inductor 2005395 (with content)
90007045 (empty)
1 “Inductor/Middle” HV Inductor 2006183 (with content)
90007045 (empty)
1 “Inductor/Bottom” HV Inductor 2006184 (with content)
90007045 (empty)
1 “Coupler” Coupling unit 2004518 (with content)
2010931 (empty)
1 “Inductor/Base” Inductor base 2005865 (with content)
90012210 (empty)
1 “Accessory Box 1” See table below 2005863 (with content)
2006158 (empty)
1 “Accessory Box 2” See table below 2005864 (with content)
90012209 (empty)
The box labeled with “Accessory Box 1” contains the following accessories:
QTY
Accessory Description Article number
1 Notebook With preinstalled software and case language-
dependent
1 Software license 3 dongles included 90011937
1 Travelling wave resistor HV connection between HV source
and switch
2004216
1 External safety device
with operating function
2008203
1 External safety device 2010012
1 Hybrid cable with red
markings
Connects the HV source to the
switch
2007840
1 Hybrid cable with blue
markings
Connects the switch to the coupling
unit
2007842
1 Connection cable Connects the notebook and the HV
control box to the HV source
2008039
1 Connection cable Connects the external safety device
to the HV source
2005398
1 Three-phase power
extension cable
Length: 10 m 90011077
Current rating: 32 A
Plug type: CEE
(red, 3P+N+E)
Scope of delivery

Technical Description
13
QTY Accessory Description Article number
1 Protective earth lead Length: 10 m 2005396
Cross section: 16 mm2
Color: cupreous
1 Earth lead for inductor
support feet
Length: 3 m 2005880
Cross section: 10 mm2
Color: green/yellow
3 Earth lead Length: 3 m 2005334
5 m 2005335
10 m 2005336
Color: black
Cross section: 25 mm2
Plug type: MC10
1 Flat ribbon earth cable Length: 15 m 90015481
Width: 110 mm
1 Adapter MC10 to hook 2005378
1 Adapter MC10 to screw clamp 2005379
1 PD calibrator CAL1 Conformity: IEC 60270 2008807
PD range: 100 pC ... 100 nC
Power supply: 9-volt battery
3 Adapter For easier connection to HV cables
with a conductor diameter…
<30 mm 2005871
<50 mm 2005463
<70 mm 2005872
2 Foldable aluminum
working platform
90012235
1 Tool bag Contains the following assembly
tools:
2006315
(complete)
•Metric tube spanner,
13 x 17 mm
90012238
•Double open-ended
wrench (SW19/SW24)
90014512
•Tommy bar, 8 x180 mm 90012237
•Crowfoot spanner, 13 mm 90012236
•Wrench for tightening
round M18 nuts
2005795
•Hex key SW 4 890453331
1 Carrying device for
inductor modules
2004485

Technical Description
14
QTY Accessory Description Article number
2 Silca gel desiccator For humidity control within the
switch (bereits im Schalter
montiert).
90006470
1 Patch cable Connects the external safety device
with operating function to the
notebook
890021523
Length: 1 m
The box labeled with “Accessory Box 2” contains the following accessories:
QTY Accessory Description Article number
1 Base plate of inductor
support feet
2006314
4 Arms of inductor support
feet
2005504
1 HV connection tube Connects the coupling unit to the
cable under test
Length: 7.5 m
2006458
1 Corrugated hose HV connection between switch and
inductor
Length: 2 m
2006427
1 Corrugated hose HV connection between inductor
and coupling unit
Length: 2.5 m
2005328
1 Electrode, black To be mounted on top of the
inductor
2005405
1 Ring adapter Required for connection to cable
under test
2005394
Check the contents of the package for completeness and visible damage right after
receipt. In the case of visible damage, the device must under no circumstances be taken
into operation. If something is missing or damaged, please contact your local sales
representative.
Check contents

Technical Description
15
Should the following optional accessories not be part of the scope of delivery, these can
be ordered from sales:
Accessory Description Article number
Support capacitor PD-free support capacitor for
measurements at very low load
capacities.
The box also contains an additional
earth lead with connection accessories
and an additional corrugated hose
(2 m).
1010835
HV connection tube Different lengths of the HV connection
tube are available
on request
Silca gel desiccator For humidity control within the switch 90006470
Software license for
OWTS import
Enables the optional OWTS data import
function
2006507 (1 Dongle)
2006509 (2 Dongles)
Corona ring CPT300 Corona ring that can be installed at the
remote end cable termination for field
control purposes (shipped in own box)
2010654
Optional accessories

Technical Description
16
2.3 Technical Data
The HV DAC-300 system is specified by the following parameters:
Parameter Value
Output voltage125 kV … 300 kV DC
(diagnosis only up to 270 kV)
DAC frequency 20 Hz … 300 Hz
Testable load capacitance 35 nF … 8 µF
Input voltage 400 V ±10% 3PH, 50/60 Hz
Mains input power 4 kVA
PD measuring range 2 pC …. 100 nC
System noise level <2 pC
PD pulse repetition rate for charge
evaluation
100 kHz
Charge evaluation according to IEC60270
Coupling capacitor 5 nF
PD localisation
•Range 0 … 16.000 m / v/2 = 80 m/μs
•Minimum cable length 75 m
•Propagation velocity v/2 50 … 120 m/μs
•Sample rate 125 MHz (8 ns)
•Bandwith 3 / 20 MHz (switchable)
•Accuracy 1% of cable length
•Resolution ±1 pC / ±1 m
Filtering Analogue and digital
Support capacitor (optional)
•Capacitance 20 nF
•Maximum voltage 300200 kV
Operating temperature10 °C … 55 °C (except of notebook)
Storage temperature -20 °C … 70 °C
Relative humidity 80% bei 30 °C (non-condensing)
Ingress protection rating (in accordance
with IEC 60529 (DIN VDE 0470-1))
IP00
1the operating height- and temperature dependent restrictions described on the
following page must be observed
Technical parameters

Technical Description
17
The following diagram illustrates the dependence of the maximum permissible test voltage
on the operating altitude and the operating temperature:
Height-dependent
maximum voltage
UMAX [kV]
Operating height [m]

Technical Description
18
The individual main components of the HV DAC-300 have the following weight and
dimensions:
Component Data
“Source”
Dimensions
(W x H2x D)
840 x 1700 x 980 mm
Weight 117 kg
“Switch”
Dimensions
(W x H2x D)
700 x 1838 x 700 mm
Weight 146 kg
“Inductor” (assembled)
Dimensions
(W x H2x D)
1555 x 2350 x 1555 mm
Weight (assembled) 336 kg
Weight of one
inductor module
72 kg
Weight of inductor
base
50 kg
2The height required by the top-mounted connection cable is not included
Weight and dimensions

Technical Description
19
Component Data
“Coupler”
Dimensions
(W x H2x D)
700 x 2125 x 700 mm
Weight 125 kg
“Support Capacitor”
(optional)
Dimensions
(W x H2x D)
700 x 2150 x 700 mm
Weight 131 kg

Technical Description
20
2.4 Connections, Controls and Indicators
The following connection and control elements are located on the base of the HV source:
Element
Description
Socket for connection to the external safety device
Socket for connection to the external safety device with operating function and
to the notebook
Connection point for ribbon earthing cable
Connector for connection to the switch
Circuit breakers and fuses (see page 113)
“Mains ON” button
“Mains OFF” button
Protective earth connector
AC power cord
HV source