Haefely Hipotronics DDX 9101 User manual

Operating Instructions
Page 1
PD Detector DDX-9101
System Operation
Operating Instructions
HAEFELY TEST AG
DDX 9101
PD Detector
Version 1.15.0
4843098

PD Detector DDX-9101
System Operation
Operating Instructions
Page 2
Revision History
Version
Date
By
Comments
V1.2.0
15/10/01
TJF
Initial release of the document
V1.2.1
25/10/01
CNH
Document modified to include information regarding the
Remote control network settings screen
V1.3.0
28/11/01
TJF
Modifications to the discharge calibration procedure to clarify method
V 1.4.0
07/01/02
CNH
Release of version 1.4.0 of the DDX9101 software.
V1.6.0
08/04/02
TJF
Modifications To Calibration Window, to coincide with 1.6.0 release
V1.10.0
17/06/02
TJF
Modifications to factory setup screen to include phase correction
V1.14.0
22/08/02
TJF
Note added on Gate position start and how affected by phase shift.
V1.15.0
27/07/15
PM, BM
Remote Software manual added. Minor upgrades and manual review.

Operating Instructions
Page 3
PD Detector DDX-9101
System Operation
Warning!
This system is designed to operate with hazardous voltages.
It is imperative that this manual is read and understood before attempting to operate the DDX-9101
Partial Discharge Detector.
Only persons who are duly authorised to do so, and who have been correctly trained in the safe
operation of High Voltage systems must operate this equipment.
It is the responsibility of the customer to ensure that the system is installed and operated in a manner
that meets all relevant safety legislation, standards of good practice, insurance or other codes,
company regulations and any other limitations pertaining to the installation and operation of high
voltage systems.
Warning!
Under transient and or flashover conditions, or where the equipment is operated close to a source of
RF interference the PD Calibration of the system may be rendered invalid. It is the responsibility of
the user to ensure the unit is correctly calibrated immediately prior to making any measurement and
to ensure that after any disturbance to the system, the PD measurement system is recalibrated
Important
Unauthorised opening of the unit may damage the EMI protection of the system and will reduce its
resistance to interference and transients. It may also cause the individual unit to be no longer
compliant with the relevant EMC emission and susceptibility requirements.
This equipment contains exposed terminals carrying hazardous voltages. There are no user
serviceable components in the unit. All repairs and upgrades that require the unit to be opened must
be referred to Hubbell High Voltage Test or one of their nominated agents
In all correspondence, please quote the exact type number of the instrument, the serial number of
the instrument and the version of software that is currently installed on it. The software version can
be found on the configuration screen.
Note
Hubbell High Voltage Test has a policy of continuing improvement on all their products. The design of this
instrument will be subject to review and modification over its life. There may be small discrepancies
between the manual and the operation of the instrument, particularly where software has been upgraded
in the field. Although all efforts are made to ensure that there are no errors in the manuals, Hubbell High
Voltage Test accepts no responsibility for the accuracy of this manual.
Hubbell High Voltage Test accepts no responsibility for damage or loss that may result from errors within
this manual. We retain the right to modify the functionality, specification or operation of the instrument
without prior notice.
All rights reserved. No section of this manual may be reproduced in any form, mechanical or electronic
without the prior written permission of Hubbell High Voltage Test.

PD Detector DDX-9101
System Operation
Operating Instructions
Page 4
Contents
1. Instrument Description .....................................................................7
1.1. Introduction...................................................................................................... 7
1.2. Technical Data................................................................................................. 7
1.2.1. General Technical Data....................................................................................................... 7
1.3. Connection To The Mains................................................................................ 8
2. System Installation............................................................................9
2.1. General Notes.................................................................................................. 9
2.2. Rear Panel Connectors.................................................................................... 9
2.3. Connection to Tettex 9230 coupling capacitor with AQS 9110a .................... 10
2.4. Connection to Tettex-Robinson Universal Quadripole System ...................... 11
2.5. Connection To Hipotronics PSF Systems...................................................... 12
2.6. Connection To a Robinson 701 Input Unit, Unbalanced Mode ...................... 12
2.7. Connection To a Robinson Type 701 Input Unit, Balanced Mode ................. 14
2.8. Ensuring Compliance With IEC-60270 and the Internal Calibrator ................ 16
3. System Operation............................................................................17
3.1. Front Panel Controls...................................................................................... 17
3.2. Switching the Unit On and Off........................................................................ 17
3.3. System Operating Modes .............................................................................. 18
3.4. Display Layout ............................................................................................... 18
3.4.1. Status Area Indicators....................................................................................................... 19
3.4.2. PD Meter Display Types....................................................................................................20
3.4.3. Scope Mode Display Types............................................................................................... 20
3.4.4. Entering Values.................................................................................................................21
3.5. Meter Mode Main Menu................................................................................. 23
3.6. Scope Mode Main Menu................................................................................ 23
3.7. Locked Mode Main Menu............................................................................... 24
3.8. Setting Up The System.................................................................................. 24
3.8.1. Setting The Calibrator Properties (Internal Calibration Option Only)................................24
3.8.2. Setting Up the Amplifier Characteristics............................................................................ 25
3.8.3. Setting Up The Gating System..........................................................................................26
3.8.4. Setting Up The Metering Mode ......................................................................................... 27
3.8.5. Setting The Acceptance Level .......................................................................................... 27
3.9. Calibrating The System.................................................................................. 27
3.9.1. Calibrating Systems Without The Internal Calibrator Option ............................................ 27
3.9.2. Calibrating Systems With The Internal Calibrator Option ................................................. 28
3.9.3. Calibrating From an External Calibrator, Internal Calibrator Installed............................... 30
3.10. Configuring the System............................................................................... 30
3.10.1. Setting The Language.......................................................................................................31
3.10.2. Setting The Calibration Injection Capacitance .................................................................. 32
3.10.3. Setting The System Protection Mode................................................................................32
3.10.4. Setting the Scope Display Mode.......................................................................................33
3.10.5. Setting The Partial Discharge Display Update Rate .........................................................33
3.10.6. Setting The Meter Display Mode....................................................................................... 33
3.10.7. Setting The Voltmeter Display...........................................................................................33
3.10.8. Setting The PD Meter Display Mode................................................................................. 34
4. Calibrating the Instrument..............................................................34
4.1. Voltmeter Calibration ..................................................................................... 34
4.2. Correcting for Phase Shift On the Voltmeter.................................................. 35
4.3. Internal Calibrator Setup................................................................................ 36

Operating Instructions
Page 5
PD Detector DDX-9101
System Operation
4.3.1. Calibrator Setup Using a Reference Calibrator................................................................. 37
4.3.2. Calibrator Setup Using A Digital Oscilloscope.................................................................. 37
5. Remote Control Network options .................................................. 39
5.1.1. ID....................................................................................................................................... 40
5.1.2. Use DHCP......................................................................................................................... 40
5.1.3. IP Address......................................................................................................................... 40
5.1.4. Mask.................................................................................................................................. 41
6. Remote Software for DDX 9101 (optional) –System Operation .. 43
6.1. Installing the remote software.........................................................................43
6.2. Starting the remote software...........................................................................43
6.3. Remote software layout..................................................................................44
6.3.1. Main window...................................................................................................................... 44
6.3.2. Toolbar controls ................................................................................................................ 44
6.4. Prepare a test.................................................................................................45
6.4.1. General test....................................................................................................................... 45
6.4.2. Test information................................................................................................................. 47
6.4.3. HTML report...................................................................................................................... 49
6.4.4. Regulator voltage profile ................................................................................................... 51
6.5. Run a test .......................................................................................................52
6.5.1. Calibrating the detectors ................................................................................................... 53
6.5.2. Start the test...................................................................................................................... 55
6.5.3. Running an NQP test ........................................................................................................ 56
6.5.4. Print results ....................................................................................................................... 58
7. Remote Software for DDX 9101 (optional) –System Control and
Settings................................................................................................... 59
7.1. Detector display window.................................................................................59
7.1.1. Window Size...................................................................................................................... 59
7.1.2. Hiding Unused Measurement............................................................................................ 59
7.1.3. Controls............................................................................................................................. 60
7.1.4. Setting The Display Shape................................................................................................ 61
7.1.5. Taking A Snapshot............................................................................................................ 62
7.1.6. Showing and Hiding the Display Controls......................................................................... 63
7.1.7. Setting the Synchronisation Source.................................................................................. 63
7.2. Detector control window .................................................................................63
7.2.1. Available Controls ............................................................................................................. 63
7.2.2. Communications Status Indication.................................................................................... 64
7.3. Detector PD control window ...........................................................................64
7.3.1. Controlling the PD Amplifier.............................................................................................. 64
7.3.2. Controlling the Gates ........................................................................................................ 65
7.3.3. Voltage Calibration Controls ............................................................................................. 65
7.3.4. Capture Controls............................................................................................................... 67
7.4. Detector control window preferences..............................................................67
7.4.1. Display Measurement Type .............................................................................................. 68
7.4.2. Display Size....................................................................................................................... 68
7.4.3. Save And Restore settings................................................................................................ 68
7.5. NQP Analysis Module.....................................................................................69
7.5.1. Tool bars ........................................................................................................................... 69
7.5.2. Data Properties Panel....................................................................................................... 69
7.5.3. File Commands................................................................................................................ 69
7.5.4. Display Commands.......................................................................................................... 69
7.5.5. View Commands.............................................................................................................. 70
7.5.6. Procedure for doing an analysis........................................................................................ 70
7.5.7. Detector Panel................................................................................................................... 71
7.5.8. File Panel .......................................................................................................................... 71
7.5.9. Filter Controls.................................................................................................................... 71
7.5.10. Time Spliced Data Displays.............................................................................................. 72

PD Detector DDX-9101
System Operation
Operating Instructions
Page 6
7.5.11. Other Displays................................................................................................................... 73
7.6. Set system properties .................................................................................... 74
7.6.1. Allow Voltage Cal ..............................................................................................................74
7.6.2. Snapshot Image Size ........................................................................................................74
7.6.3. File Paths........................................................................................................................... 74
7.6.4. Enable Detector Settings Save .........................................................................................75
8. Report...............................................................................................75
8.1. HTML report................................................................................................... 75
8.2. Tabular results............................................................................................... 76
8.3. Snapshot........................................................................................................ 76

Operating Instructions
Page 7
PD Detector DDX-9101
System Operation
1. Instrument Description
1.1. Introduction
The DDX-9101 partial discharge detector is designed to replace traditional analogue detectors in those
applications where the additional cost of a true digital discharge detector cannot be justified or where the
complexity of measurement of such an instrument is not required. It is designed for simple operation and
rapid measurement. For production applications, the system has a “locked” mode, which password
protects all settings that could affect the system operation.
The system emulates the look and feel of a traditional analogue PD detector making it easy for users to
make the transition to the new system. It is designed to be compatible with Tettex, Haefely and Robinson
detectors, making it easy to upgrade an older detector to the new system.
1.2. Technical Data
1.2.1. General Technical Data
Environmental
Minimum
Maximum
Unit
Ambient Operating Temperature
0
44
C
Storage Temperature
-20
60
C
Relative Humidity, Non-condensing
80
%rel.
Vibration/Shock
3
G
Mechanical
Maximum
Minimum
Unit
Instrument Width
For 19” Rack Mount Field
Instrument Height
3U (133mm)
Instrument Weight
5
kg
General
Maximum
Minimum
Unit
EMC Compliance
To EC Directive 89/336/EEC
Conducted & Radiated Emissions
To EN 50081-1 1992
(Residential, Commercial and Light Industry)
Conducted & Radiated Immunity
To EN 50082-2 1992 (Industrial)
Power Line Voltage
85
264
VAC
Power Line Frequency
47
440
Hz
Protective Fuse
4 Amp Anti-surge
Connection
Fused IEC-320 Connector
Grounding/Earthing System
System Ground/Earth direct to Case,
300H to Line Ground/Earth
Amplifier
Input Impedance
50

Common Mode Voltage wrt System Earth
Optional “Floating Input” Mode
50
V
High Pass Filter Settings
10,20,40,50,80
kHz

PD Detector DDX-9101
System Operation
Operating Instructions
Page 8
Low Pass Filter Settings
100,200,300,400,500
kHz
Input Attenuation Range
0 to 75dB in 5dB steps
Measurement System
Minimum
Maximum
Units
Voltage Measurement Impedance
30
k
Full Scale Input Voltage
10
VPeak
20
VPP
7.07
VRMS
Voltage Measurement IEC-60 Dynamic Range
10
100
% FSD
Uncertainty of Scale Factor Over Dynamic Range
1
%
Voltage Measurement Linearity Error
0.75
% FSD
Voltage Measurement Offset Error
0.2
% FSD
Voltage Measurement Resolution
0.05
% FSD
PD Measurement Linearity Error
Meets Requirements of IEC-270
%
PD Measurement System
Analogue Peak Detector Designed to
specification in IEC-270
PD Measurement Resolution
0.05
%FSD
PD Capture And Display System
Min
Max
Units
Pulse Phase Resolution
0.35
degrees
Line Frequency Synchronisation
20
400
Hz
Cycle Capture Capability
1
128
Cycles
Pulse Display Resolution
0.78
%FSD
Calibration Step-wave Generator (Optional)
Min
Max
Units
Injection Capacitance Range
50
1200
pF
Step-wave Voltage
10
V
Step-wave Rise-time
40
ns
Output Termination
50

Maximum Common Mode Voltage wrt Case
35
V
1.3. Connection To The Mains
The mains connector for the instrument is located on the rear panel. It uses an IEC-320 standard
connector. The input is auto-sensing and can be on any supply whose voltage is between 85VRMS to
264VRMS and whose frequency is between 47Hz and 440Hz. Operation on supplies outside this voltage
range will require the provision of a transformer to bring the voltage into the specified operating range.
Operation outside the specified range of frequencies is not possible
Connection of the system to a supply voltage outside its operating range will
result in damage to the system along with the risk of injury and fire

Operating Instructions
Page 9
PD Detector DDX-9101
System Operation
2. System Installation
2.1. General Notes
The correct installation of a partial discharge measuring system requires the balancing of two conflicting
demands: the arrangement of the test circuit to maximise the measurement circuit and the arrangement
of the test circuit to minimise the risk of damage from flash-over. The installation of a PD measurement
system requires an understanding of the mechanisms of PD measurement.
It is recommended that the HV system is provided with a low impedance ground/earth that is separate to
the main building earth system and has an impedance less than 1Flat braid or flat copper strip should
be for all ground/earth connections to minimize the effects of skin effect.
The case of the DDX-9101 is designed to be connected to the HV earth. It is linked to the mains earth via
a 300H choke and a varistor (for protection). If this conflicts with other grounding/earthing requirements,
it will be necessary to provide additional isolation to the system. Advice on this can be obtained from the
local agent or from the manufacturer.
FOR CONTINUED OPERATOR PROTECTION: The ground/earth connection in the
mains socket or the case of the instrument MUST be connected to a suitable
protective ground/earth. If this is not done there is a significant safety risk for the
operator in the event of a system or sample failure.
2.2. Rear Panel Connectors
Figure 2.1 shows the rear panel connectors of the DDX-9101.
Figure 2.1 –Rear Panel Connections
The Mains connection (1) must be connected to a suitable rated source of power. It carries the protective
earth connection. This must be connected to a suitable protective earth, otherwise there is a safety risk
for the operator.
The “System Earth” (2) connection must be connected to the main HV ground/earth point using a suitable
braid or copper foil connection. See the connection details for more information on this connection. For
continued protection of the system and the operator it is imperative that this connection is made, or an
equivalent provision is made.

PD Detector DDX-9101
System Operation
Operating Instructions
Page 10
The Network connector (3) provides connection to a 10BaseT Ethernet network utilising the TCP/IP
protocol. If this is being used to connect to a single PC, the PC must be running on the same mains
supply as the DDX-9101 and the two must be bonded together with a suitable braid ground/earth strap of
less than 50cm length. If the DDX-9101 is to be connected to a factory network or to a PC running on a
different mains supply, a suitable fibre optic isolation system should be used.
The PD Input (4) picks up the discharge pulses from the input unit, power separation filter or quadripole.
This input is grounded to the case of the unit. If galvanic isolation is necessary, advice from Hubbell High
Voltage Test or its authorised agents must be sought.
The VM input (5) connects to the HV divider to allow the DDX-9101 to measure the applied HV. It also
uses this input for synchronisation, so the divider output must be AC. The input is grounded with respect
to the system ground and no common mode voltage can be tolerated between the two, either in
continuous operation or under transient conditions.
The calibrator output (6) is only available if the internal calibrator option is installed. It provides a step-
wave output of up to 10V pk. When combined with a calibration injection capacitor that has been certified
in accordance with IEC-270, it forms the basis of an IEC-270 compliant calibration source. The calibrator
is galvanically isolated from the rest of the system, though the common mode voltage between the
calibrator and the rest of the system must be less than 35V.
2.3. Connection to Tettex 9230 coupling capacitor with AQS 9110a
Figure 2.2 Connection to Tettex 9230 coupling capacitor with AQS 9110a
The AQS 9110a advanced quadripole is a fully configurable quadripole system for use with partial
discharge detectors. To allow the system to be optimised for specific application and different test area
conditions, there are a whole range of selections available at commissioning. The quadripole has a
voltage divider low-arm fitted to it. This is a three range switchable unit that gives control of the division
ratio. This can be configured for specific applications during ordering. Ensure the selected ratios are
correct before using the low arm on your system. The AQS 9110a is operated as a fully passive
measurement system with enhanced sensitivity.

Operating Instructions
Page 11
PD Detector DDX-9101
System Operation
A “Star” grounding/earthing scheme should be used for the system with the star point formed at the
ground terminal of the Quadripole. Where the detector is being used with a power supply control system
and is sharing a housing, it is recommended that steps are taken to prevent the formation of ground loops
that could compromise the system performance and the flashover resistance of the system.
Note: The “System Earth” terminal on the rear of the DDX-9101 provides the connection to connect the
DDX-9101 to the system ground “Star” point described above. It does not provide a grounding/earthing
path for the rest of the system.
2.4. Connection to Tettex-Robinson Universal Quadripole System
Figure 2.3 Connection to Tettex-Robinson Universal Quadripole
The Tettex-Robinson Universal Quadripole is designed as a general purpose quadripole/coupling
impedance system for partial discharge measurement. It provides facilities for to use the blocking
(coupling) capacitor as the top arm of a voltage divider as well as an arc detection output for a series
resonant power supply. If the blocking capacitor is to be used as the voltage divider for the system, the
quadripole should be ordered with the appropriate low arm capacitance installed in it.
A “Star” grounding/earthing scheme should be used for the system with the star point formed at the
ground terminal of the Quadripole. Where the detector is being used with a power supply control system
and is sharing a housing, it is recommended that steps are taken to prevent the formation of ground loops
that could compromise the system performance and the flashover resistance of the system.
Note: The “System Earth” terminal on the rear of the DDX-9101 provides the connection to connect the
DDX-9101 to the system ground “Star” point described above. It does not provide a grounding/earthing
path for the rest of the system.

PD Detector DDX-9101
System Operation
Operating Instructions
Page 12
2.5. Connection To Hipotronics PSF Systems
Figure 2.4 Connection to Hipotronics PSF
The Method if connecting the DDX-9101 to a Hipotronics PSF is shown in Figure 2.3. It is essential that
the PSF used is of the PSFxx/y/DDX type (where xx is the rating in kV and yis the value in nF). If the
PSF is not of the /DDX type (Part numbers PSFxx/yor PSFxx/y/700 for example) contact the Hipotronics
factory for information on upgrading the PSF to the correct specification. Figure 2.4 also shows a
calibration injection capacitor (CICxx). This is an optional item where HV calibration is required and
requires the internal calibrator option to be installed in the DDX-9101. Where this option is not installed or
a low voltage injection is being used for the calibration, this part of the circuit can be ignored.
To help minimise the effects of ground loop and the risk of damage during flashover, a “Star”
ground/earth system is used with all the ground connections being connected together at the grounding
stud on the PSF assembly. The connections should be made with suitable braid or copper foil. This point
should then be connected to the HV system earth point or to the wall of the screened room. Where the
signals pass through the wall of a screened room to connect to the DDX-9101 suitable provision must be
made to maintain signal integrity and isolation.
Note: The “System Earth” terminal on the rear of the DDX-9101 provides the connection to connect the
DDX-9101 to the system ground “Star” point described above. It does not provide a grounding/earthing
path for the rest of the system.
2.6. Connection To a Robinson 701 Input Unit, Unbalanced Mode
Figure 2.4 shows the connection to a Robinson 701 series input unit. The input unit used should be
selected according to the series combination of the blocking capacitor value and the sample capacitance
value. When selecting the input unit, care should be taken to ensure the input unit is able to carry the
current that will be flowing through the sample. If the current exceeds the rating for the ideal input unit, as

Operating Instructions
Page 13
PD Detector DDX-9101
System Operation
determined from the “Max Current, Unbal.” column, the closest one with the required rating should be
used:
Tuning Capacitance
Input Unit To Use
Max Current.
Min.
Typ.
Max.
Unbal.
Bal.
6pF
25pF
100pF
701/1
30mA
250mA
25pF
100pF
400pF
701/2
60mA
500mA
100pF
400pF
1.5nF
701/3
120mA
1A
400pF
1.5nF
6nF
701/4
250mA
2A
1.5nF
6nF
25nF
701/5
500mA
4A
6nF
25nF
100nF
701/6
1A
8A
25nF
100nF
400nF
701/7
2A
15A
100nF
400nF
1.5F
701/8
4A
30A
400nF
1.5F
6F
701/9
8A
60A
1.5F
6F
25F
701/10
15A
120A
F
6F
15F
701/11
25A
200A
15F
60F
250F
701/12
50A
300A
Special Unit for Resistive Samples
701/7R
2A
N/A
Figure 2.6 does not show a voltage sensor for the system. If a capacitive or resistive divider is used, the
ground/earth point should be connected to the “earth” stud on the 701 input unit. The output of the divider
is connected to the VM Input on the DDX-9101. If the output of the divider is greater than full scale on the
Voltmeter input (10VPeak, 7.07VRMS), a resistor should be placed in series with the voltmeter input. The
value of this resistor is calculated using the following equation:





 1
07.7
.30 in
SV
R
where Rsis the required series resistance in k, and Vin is the maximum RMS
voltage to be measured.
If the system is to be used with a Robinson type 702 voltmeter resistor, a resistance of 4.7Kmust be
placed in parallel with the voltmeter input to provide the correct voltage scaling.
When using the DDX-9101 with a Robinson type 700 input unit in unbalanced mode, the GND connection
on the 701 must be used as the star point to which all HV ground/earth connections are brought. This
must be connected to the “Finish of Primary” terminal using the supplied metal bar.
Failure to connect using the earthing bar will result in risk of damage to the equipment and
expose the operator to hazardous conditions.
Note: If the optional calibrator module is installed, it cannot be operated in “Indirect” mode through the
input unit. An external HV or LV injection capacitor is required.

PD Detector DDX-9101
System Operation
Operating Instructions
Page 14
Figure 2.5 Connection to A Robinson 701 –Unbalanced Mode
Note: The “System Earth” terminal on the rear of the DDX-9101 provides the connection to connect the
DDX-9101 to the system ground “Star” point described above. It does not provide a grounding/earthing
path for the rest of the system.
2.7. Connection To a Robinson Type 701 Input Unit, Balanced Mode
Balanced mode is useful where there are two identical samples available. It allows the rejection of
airborne noise in the environment, or testing of two samples at once. By looking at the phase of the
discharge activity with respect to the HV cycle, it is possible in some cases to distinguish which of the two
samples are discharging.
The Input unit should be selected from the table in the previous section based on half the capacitance
value of one of the samples to be tested. Care should be taken to ensure that the current flow in each of
the samples does not exceed the figure quoted in the “Max. Current, Bal.” column on the table. If the
current does exceed that for the ideal input unit, the unit with the closest current rating should be
selected.
When setting up the system where voltage measurement is required on the detector, the same
constraints apply as when operating in unbalanced mode. The voltage sensor should be set up as
described in section 2.5

Operating Instructions
Page 15
PD Detector DDX-9101
System Operation
Figure 2.6 Connection to A Robinson 701 –Balanced Mode
The connection is virtually identical to the unbalanced mode, apart from two samples are used rather than
one sample and a blocking capacitor. One sample is connected to the start of the primary winding, while
the other connects to the finish. The centre tap on the winding forms the ground/earth point for the circuit.
All earth connections should be taken back to this point. It is essential that the centre tap is connected to
the ground stud using the supplied bar.
Failure to connect using the earthing bar will result in risk of damage to the equipment and
expose the operator to hazardous conditions.
Note: If the optional calibrator module is installed, it cannot be operated in “Indirect” mode through the
input unit. An external HV or LV injection capacitor is required.
Note: The “System Earth” terminal on the rear of the DDX-9101 provides the connection to connect the
DDX-9101 to the system ground “Star” point described above. It does not provide a grounding/earthing
path for the rest of the system.

PD Detector DDX-9101
System Operation
Operating Instructions
Page 16
2.8. Ensuring Compliance With IEC-60270 and the Internal Calibrator
If the system is supplied with the internal calibration stepwave generator installed, the combined system
will only be compliant with section 6 of IEC-60270 once the performance tests have been performed and
the calibration system as a whole (step-wave generator, injection capacitor and connecting cables) has
been shown to meet the requirements of the standard. Where a DDX-9101 has been supplied for use
with an injection capacitor, or the capacitor has been ordered separately, it will be necessary to have the
complete assembly tested before the system can be certified as compliant with IEC-60270.
The step-wave generator output cable requires termination for the system to operate correctly. This is
achieved using a 50resistor connected across the output of the cable at the input to the injection
capacitor. It is recommended that a BNC ‘T’ piece is used with a 50BNC terminator is used.

Operating Instructions
Page 17
PD Detector DDX-9101
System Operation
3. System Operation
3.1. Front Panel Controls
1 Mounting Holes. The unit provides four mounting holes spaced according to DIN41494
to allow the unit to be mounted into a standard 19” rack unit.
2 Protective Handles. The handles make it easy to mount the unit into a cabinet. They
also provide protection from glancing blows and accidental key presses caused by the
passage of people or equipment.
3 Power switch.
4 Display. The DDX-9101 uses a high performance TFT-LCD (Thin film transistor liquid
crystal display). This gives a fast, sharp display that is easy to read. Care should be
taken to avoid pressing, poking or touching the display with fingers or objects. This will
ensure that its operational life is maximised and that the screen does not become
obscured by a build up of grease, dirt and scratches.
5 Function keys. The system is operated by six function keys: F1 to F6. These are
linked to legends on the screen that indicate their function.
6 Up/Down keys. The Up/Down keys are used to change the value of parameters used
on the system. The parameter is selected by the function keys and will be indicated on
the screen. Pressing the ‘Up’ key will increase the value, pressing the ‘Down’ key will
reduce it.
3.2. Switching the Unit On and Off
The unit is switched on by pressing the ‘1’ end of the power switch (3). When pressed the system will
start the power up process. Initially the screen will glow, showing a striped pattern that may hold a residue
of a previous screen image. This is quite normal and does not indicate a problem, unless it does not clear
within a few seconds. After a few seconds the system should beep and the screen should clear to show
text indicating the processor is starting up. After a few more seconds, this screen will clear and a ‘splash
screen’ showing the company name and the instrument type will be displayed while the operating system
loads up. The screen will then display a uniform turquoise/blue shade, possibly with a white pointer in the
center. This will remain for a few seconds until the application starts properly. If there are any problems
during the start up procedure, the system will report any errors. These should be referred to an approved
service agent.

PD Detector DDX-9101
System Operation
Operating Instructions
Page 18
The unit is switched off using the ‘0’ end of the power switch. The system has been configured so the
normal requirements of the Windows™ operating system for an orderly shutdown sequence are not
required. It can be shut down at any time without adverse effect.
3.3. System Operating Modes
The system has three modes of operation: Meter mode, Scope Mode and Locked Mode. In Scope mode,
the system operated as a PD Scope with a phase based display of the discharge activity as well as a
digital readout of the PD activity. This is for use by an experienced operator to diagnose the source of
discharge within a sample.
Meter mode provides the user with either analogue or digital meters for discharge level and voltage level.
This provides a simple check on the activity of a system intended for pass/fail testing of a sample by an
operator. Locked mode is a variant of the meter mode, which restricts the actions an operator can
perform unless they enter a password. This mode allows the system to be set up for operation in a
production test environment where there is the risk of the settings of the instrument being accidentally or
deliberately altered and rendering the measurements invalid.
3.4. Display Layout
Figure 3.2 shows typical operating displays showing the options for the meters and also the different
operating modes. In meter mode and scope mode, the operator has full control of the instrument, while in
locked mode, they are only able to perform a calibration of the discharge measurement.

Operating Instructions
Page 19
PD Detector DDX-9101
System Operation
In all cases the display consists of three areas: the status area at the top of the screen, the menu option
buttons down the side of the screen and the results area. The status area indicates the current status of
the instrument, especially the measurement system. The menu option buttons indicate the available
linked by the graphics on the front panel to their corresponding buttons (F1 to F6). If there is no
corresponding legend on the display, the function button is disabled. The results area shows the results of
the measurements being taken.
3.4.1. Status Area Indicators
1 This indicates the current range of the amplifier in dB. The dB figure defines the
attenuation of the amplifier system. 0dB corresponds to maximum gain, or smallest
level of partial discharge. The higher the number, the lower the attenuation and hence
the higher the level of discharge that can be measured.
2 The state of the filters that control the bandwidth of the system are displayed on this
line. The value of the high-pass (bottom end) filter is shown on the left, the value of the
low-pass (top end) on the right
3 The current output level and status of the internal calibrator system is displayed on the
top line of the display when the optional calibration step-wave generator is installed. If
the calibrator option is not installed, this line of the display is blank.
4 The large, red indicator indicates high levels of PD on a sample. The user can set up
an acceptable level of PD for a sample using the “Acceptance Level” control on the
main menu. If the PD exceeds that level, the warning lamp is illuminated. It is
extinguished when the PD falls below the threshold.
5 This indicates the status of the autorange system. If the lamp is illuminated, the
system is set to autorange and will attempt to find the best setting for the PD activity it
is recording. If it is extinguished, the amplifier range has to be set manually.
6 The autoranging indicator shows when the system is automatically trying to set the
measurement range of the system. The lamp is illuminated during the process,
indicating that the PD reading is subject to change. When the system has set a
suitable range and settled, the lamp is extinguished.
7 If the voltage applied to the voltmeter input is close to the maximum measurable
value, the voltmeter overrange warning is illuminated. This indicates that the voltage
measurement system may not be reading accurately and the indicated value could be
below what is actually applied.

PD Detector DDX-9101
System Operation
Operating Instructions
Page 20
8 The PD overrange warning indicates when the PD measurement is close to full scale
and there is a risk of the measurement being inaccurate (reading at 90% of maximum
for the range). A higher gain range should be chosen in this situation.
3.4.2. PD Meter Display Types
The system supports two types of meter for PD, when operating in “Meter Mode”: analogue and digital
meters. These meter types are shown in figure 3.4
Both meters read out the PD level in true discharge magnitude. The accuracy of this reading, is however
dependant on the calibration of the system.
NOTE: If the system has not been calibrated correctly or the sample or test circuit configuration
has been changed since the last calibration, the recorded magnitudes will not be correct. It is the
responsibility of the user to ensure that correct partial discharge calibration procedures are
followed.
The scales of the meters are adjusted according to the range of the amplifier, using a 1-2-5-10 sequence.
The scale is chosen to ensure that the meter can display the maximum magnitude that can be recorded
on that range, while ensuring that it is easy to take measurements from the scale. The maximum range
may not correspond to the full-scale deflection of the meter. The user should always check the “PD Meter
O/R” lamp before making a measurement. If it is illuminated, the PD meter cannot be relied upon to be
correct.
As well as the meter display, the system provides a numeric readout of the PD level. In the analogue
meter mode, this changes colour according to its relationship to the acceptance level. If it exceeds the
acceptance level, the figure is displayed in red. The lower section of the meter is coded green to indicated
below the acceptance level, while the upper section is coloured red to indicate the region where the
acceptance level is exceeded.
A similar style on meter is used for the voltmeter display, if selected. The voltmeter display, though, does
not have an acceptance level indication and does not automatically range.
3.4.3. Scope Mode Display Types
Figure 3.5 shows the display types for the phase related display of the PD activity. The yellow markers
indicate the positions of the positive zero crossing and negative zero crossings on the display (note, these
markers are for illustrative purposes only and are not shown on the instrument display).
All the display modes show the partial discharge activity on a phase resolved display related to the HV
cycle. In the absence of an AC synchronising signal on the voltmeter input, the detector synchronises
itself to the waveform of the mains supply that is powering the instrument. Depending on the test circuit
configuration, there may be a phase difference between that and the actual HV waveform, which will shift
the position that the pulses appear to occur at.