CHAPTER 1 General Information
CHAPTER 2 Technical Description
INSTRUCTION MANUAL CHAPTER 3 Getting Started
Teleflex M
CHAPTER 4 How to Operate the System
CHAPTER 5 How to Carry Out a Test
CHAPTER 6 Date of release:
03.98
Subject No:
9001341
How to Store and Print the Results
CHAPTER 7 Hagenuk KMT Kabelmeร technik GmbH
Cleaning, Maintenance and Repair
Rรถderaue D - 01471 Radeburg Phone: Fax:
(03 52 08) 84-0 (03 52 08) 84-249
CHAPTER 8 Annex
PREFACE CONSULTATION WITH HAGENUK KMT KABELMESSTECHNIK GMBH This instruction manual is for use as an operating guide and for reference. It is intended to help you in answering your questions and solving your problems in as fast and easy a way as possible. Please first refer to this manual whenever some trouble occurs. To this end make use of the table of contents and read the relevant paragraph(s) with care. Furthermore check all terminals and connections of your equipment. Should nevertheless some question remain unanswered, please contact:: Hagenuk KMT Kabelmesstechnik GmbH
Roederaue D - 01471 Radeburg / Dresden, Germany PHONE: FAX:
+49 / 35208 / 84 - 0 +49 / 35208 / 84 249
SERVICE HOTLINE: PHONE: FAX:
+49 / 35208 / 84 211 +49 / 35208 / 84 250
e-mail: internet:
sales@kmt.de http://www.kmt.de
ď›™ Hagenuk KMT Kabelmesstechnik GmbH All rights reserved. No part of this manual may be photocopied or duplicated by some other means unless Hagenuk KMT have beforehand declared their permission in writing. The content of this manual is subject to change without notice. Hagenuk KMT disclaims any responsibility for technical or printing errors or shortcomings of this manual. Hagenuk KMT also disclaims any responsibility for damages caused directly or indirectly by the supply, performance, or utilisation of this matter.
Teleflex M
I
TERMS OF WARRANTY Hagenuk KMT Kabelmesstechnik GmbH will accept a warranty claim brought forward by a customer for a product sold by Hagenuk KMT under the terms stated below and the General Terms of Supply of Products and Services of the Electrotechnical Industries, date of issue May 1993. Hagenuk KMT guarantees that at the time of delivery Hagenuk KMT products are free from faults in material or workmanship which would reduce their value and serviceability to a large degree. This warranty does not cover any error in the software supplied. During the warranty period Hagenuk KMT will repair faulty parts or replace them with new parts or parts as new (with the same usability and life as new parts) at their discretion. Further warranty claims, in particular those from consequential damage, cannot be accepted. Each component and product replaced in accordance with this warranty becomes the property of Hagenuk KMT. All warranty claims versus Hagenuk KMT expire after a period of 12 months from the date of delivery. Each component supplied by Hagenuk KMT in 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 warranty claim must be carried out exclusively by Hagenuk KMT or some authorised service station . It is a precondition for accepting a warranty claim that the customer has to complain about the fault, in case of an immediately detectable fault within 10 days from the date of delivery. This warranty does not cover 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 authorised by Hagenuk KMT. No claim will be accepted in case of wear and tear, will of God, or connection to foreign components. For damage resulting from a violation of their duty to repair or re-supply items, Hagenuk KMT can be made liable only in case of severe negligence or intention. Any liability for slight negligence is disclaimed.
II
TABLE OF CONTENTS 1.
GENERAL INFORMATION.......................................................1-1
1.1. 1.2.
Safety Precautions...........................................................................1-1 Symbols Used in This Manual .........................................................1-2
2.
TECHNICAL DESCRIPTION ....................................................2-1
2.1. 2.1.1. 2.1.2. 2.1.3. 2.2. 2.3. 2.3.1. 2.4. 2.5. 2.6.
Technical Specification....................................................................2-1 Electrical Characteristics .................................................................2-1 Mechanical Characteristics ..............................................................2-3 Environmental Limits ......................................................................2-3 Items and Accessories Supplied.......................................................2-4 Optional Extras ...............................................................................2-4 Control of the 3-Phase Current Decoupling Unit .............................2-4 Illustration of the Teleflex M Instrument .......................................2-5 Performance Features......................................................................2-6 Fields of Application and Modes of Operation.................................2-7
3.
GETTING STARTED ..................................................................3-1
3.1. 3.2. 3.3. 3.4. 3.5. 3.6. 3.7.
Connection to the Mains .................................................................3-1 Switching the Device On and Off ....................................................3-1 Device Setup...................................................................................3-1 Default Condition............................................................................3-2 Connection to a PC .........................................................................3-2 Connection to a Printer ...................................................................3-2 LCD Brightness and Contrast..........................................................3-3
4.
HOW TO OPERATE THE SYSTEM .........................................4-1
4.1. 4.2. 4.3. 4.3.1. 4.3.2. 4.3.3. 4.3.4. 4.3.5. 4.3.6. 4.3.7. 4.3.8. 4.3.9. 4.3.10. 4.3.11. 4.3.12. 4.3.13.
Controls..........................................................................................4-1 Device Status ..................................................................................4-4 Menu Structure ...............................................................................4-5 Power-On Menu - Main Menu ........................................................4-5 System Menu ..................................................................................4-6 Setup Menu ....................................................................................4-7 TDR Menu......................................................................................4-9 TDR-Mode Menu .........................................................................4-11 Teleflex Menu ...............................................................................4-12 Trace Selection Menu ...................................................................4-13 Trace Comparison Menu ...............................................................4-14 Menu HV Prelocation ...................................................................4-16 Menu Arc Burning ........................................................................4-18 Menu Arc Reflection Method (ARM)............................................4-19 Menu Current Decoupling.............................................................4-21 How to Use the Memory - The Memory Menu..............................4-23
Teleflex M
III
4.4.
How to Operate the 3-Phase Current Decoupling Unit .................. 4-27
5.
HOW TO CARRY OUT A TEST................................................ 5-1
5.1. 5.1.1. 5.1.2. 5.1.3. 5.1.4. 5.1.4.1. 5.1.4.2. 5.1.4.3. 5.1.5. 5.2. 5.2.1. 5.3. 5.3.1. 5.3.2. 5.3.3. 5.3.4.
General Information........................................................................ 5-1 Fault Display on the Screen............................................................. 5-1 Optimum Pulse Width and Range of Measurement.......................... 5-2 Compensation of the Transmitter Pulse ........................................... 5-3 How to Determine the Location of the Fault ................................... 5-5 How to Measure the Fault Distance ................................................ 5-5 The Cursor and Marker Technique.................................................. 5-6 The Shifting Technique ................................................................... 5-8 Determination of v/2 From a Known Cable Length ......................... 5-9 Teleflex Reflection Test (TDR)....................................................... 5-9 How to Carry Out a Teleflex Test................................................. 5-13 Tests Involving High Voltage........................................................ 5-15 Surge Prelocation ......................................................................... 5-15 Decay (Voltage Decoupling)......................................................... 5-17 Arc Reflection Method (ARM) ..................................................... 5-19 Arc Burning.................................................................................. 5-22
6.
HOW TO STORE AND PRINT THE RESULTS....................... 6-1
6.1. 6.2.
Using the Memory .......................................................................... 6-1 Printing........................................................................................... 6-1
7.
CLEANING, MAINTENANCE, REPAIR .................................. 7-1
7.1. 7.2. 7.3.
Cleaning ......................................................................................... 7-1 Maintenance ................................................................................... 7-1 Repair............................................................................................. 7-1
8.
ANNEX ......................................................................................... 8-1
IV
INDEX OF FIGURES Fig 2-1 Fig 4-1 Fig 5-1 Fig 5-2 Fig 5-3 Fig 5-4 Fig 5-5
Teleflex M
Front View of type Teleflex M Showing its Controls and Screen...2-5 Display fields of the screen ..............................................................4-1 Typical Reflection Trace .................................................................5-1 Effect of Pulse Width on the Reflection Trace .................................5-3 Examples of Reflections and their Bases..........................................5-5 Idealised Reflection Traces............................................................5-12 Reflection Trace Pattern of a Cable with a Number of Ramifications and Branch Lines.....................................................5-12
V
VI
1.
GENERAL INFORMATION
1.1.
Safety Precautions Each person involved in the assembly, operation, maintenance, and repair of this device is required to have read this manual with care. At the time of supply, the instrument and its accessories are in line with the current state of the art in safety control. Due to certain operational procedures there may be places and parts of the instrument and its peripherals, however, which cannot be protected completely without unreasonably interfering with its functionality and user control. This is why comprehensive personal experience in safety matters is absolutely vital for protecting both the staff and the instruments. When the instrument is installed in a motor vehicle or is used in some other way as a mobile station, these safety precautions apply in their general sense. This is why we request you to observe the following safety precautions without fail! GENERAL INSTRUCTIONS This manual shall be permanently available to the supervisory, operating, and maintenance staff for reference. Only trained and /or instructed staff are permitted to deal with this system and its peripherals. Keep any other person away from it. Only authorised persons with sufficient expertise are allowed to operate the device. Make sure the instrument and its peripherals are in good working order when they are put into operation. Improper use may constitute a high risk of damage to the life and limb of the operator and to the instrument and equipment connected to it. This is why you are allowed to employ the instrument only to the purpose it has been designed for by its manufacturer. Always use the appropriate tools for any operation on the system and for running it and keep your tools in good repair. Permanently supervise the observance of all safety instructions during operation and maintenance. Never use any foreign parts on the instrument and its peripherals, otherwise the necessary degree of safety cannot be ensured. Do not carry out any operation that may jeopardise the safety of the instrument. The operator is required to immediately report any change in the system to the supervisor in charge. The operator is required to shut the equipment down without delay whenever some functional disorder occurs that may jeopardise the safety of persons. The instrument must not be put into operation again unless the fault has been repaired. Teleflex M
1-1
ELECTROTECHNICAL INSTRUCTIONS Connect the instrument and all its accessories according to instructions and regulations. Make sure the relevant regulations such as EN, DIN, VDE or national standards, respectively, are observed. Every repair or maintenance operation shall be carried out only after the equipment has been switched off (is in a dead state) and only by an electrotechnical expert. A person is regarded an electrotechnical expert when due to his or her training, knowledge, and experience as well as knowledge of relevant regulations he or she is able to assess the operations to be carried out and detect any possible risk. Any intervention in the system shall only be carried out by a service station authorised by Hagenuk KMT.
1.2.
Symbols Used in This Manual Important instructions concerning the protection of staff and equipment as well as technical safety are labelled with one of the following symbols: CAUTION:
"Caution" stands for working an operating instructions which shall be observed meticulously to preclude any danger to persons. This includes information about special risks when handling the device.
ATTENTION: "Attention" stands for working and operating instructions which shall be observed meticulously to preclude any damage to or destruction of the device and / or its peripherals.
NOTE: "Note" stands for special technical requirements which the user of the instrument shall take into particular consideration when running the system.
1-2
2.
TECHNICAL DESCRIPTION
2.1.
Technical Specification
2.1.1.
Electrical Characteristics Modes of operation
Max. number of connected conductors
Reflection method L → L (balanced) Reflection method L → N (unbalanced) Arc reflection method (ARM) Surge prelocation Decay Arc burning 3
Pulse width and pulse voltage
50 ns 100 ns 200 ns 500 ns 1 µs 2 µs 5 µs
Rate of measurement
≥ 5 traces / s
Range of measurement
Pulse width 50 ns 100 ns 200 ns 500 ns 1 µs 2 µs 5 µs
≥ 17 VSN ≥ 26 VSN ≥ 32 VSN ≥ 36 VSN ≥ 37 VSN ≥ 40 VSN ≥ 40 VSN range of measurement (at v/2 = 80 m/µs) 1,6 km 3,2 km 6,4 km 16 km 32 km 64 km 160 km
Display range
80 m to 160 km (settable in steps)
Distance measurement
- Trace shifting technique - Cursor and marker technique Indication of distance in m, ft, or µs
Maximum resolution
0.2 m
Accuracy of measured distance ± 0.2 % of range of measurement ±1 m (when travel time has been set precisely) Setting range of v/2
10,0 m/µs to 149,9 m/µs in ft/µs or corresponding values of NVP (nominal velocity of propagation) settable in steps of 0.1 m/µs
Teleflex M
2-1
Output impedance
approx. 50 Ω
Internal balancing network
25,4 Ω to 1.6 kΩ, settable in steps
Sampling frequency
1 MHz to 100 MHz depending on range of measurement
Storage range
2048 measured samples
Dynamic range of measurement
≥ 86 dB
Modes of measurement
Single test Continuous test Averaging of 256 test results Reflection test with internal or external balancing Reflection test L → L (balanced) (conductor-to-conductor test) Differential test L → N (unbalanced) (conductor-to-earth test)
Memory size
35 individual memory positions for measured traces and test parameter setups the content of which is retained after poweroff
Screen
Type LC:
10,4” monochrome 640 x 480 pixels
Type MC:
10,4" colour TFT 640 x 480 pixels
Type HC:
10,4” monochrome 640 x 480 pixels
Power Supply Mains
90 to 250 V, 50 / 60 Hz
Power consumption
approx. 50 VA
Electrical Safety and Electromagnetic Compatibility Electrical safety Electromagnetic compatibility (EMC) Interelement protection
2-2
according to DIN EN 61010-1 according to DIN EN 50081-2 DIN EN 50082-2
and
Class I according to DIN-VDE 0106, T. 1
2.1.2.
Mechanical Characteristics Dimensions
481 mm x 221 mm x 258 mm (W x H x D) (19" slide-in module, 5 Height Units)
Weight
2.1.3.
plug-in unit
approx. 9 kg
in case
approx. 15 kg
Environmental Limits Climatic limits Type MC: Operating temperature Storage temperature Relative humidity
0 °C to 50 °C -25 °C to 60 °C 93 % at 30 °C
Type LC: Operating temperature
0 °C to 50 °C
Storage temperature
-25 °C to 60 °C
Relative humidity
93 % at 30 °C
Version HC: Operating temperature
-25 °C to 50 °C
Storage temperature
-40 °C to 60 °C
Relative humidity
93 % at 30 °C
Teleflex M
2-3
2.2.
Items and Accessories Supplied The device can be supplied configured as a plug-in unit for use in a test van and test system or as a portable unit in a case of its own.
Type designation
Items supplied
Ordering number
Teleflex M Type LC
Teleflex M (monochrome screen) Instruction manual
9000.608
Teleflex M Type MC
Teleflex M (colour screen) Instruction manual
9000.223
Teleflex M Type HC
Teleflex M (monochrome screen -25 °C to +50 °C) Instruction manual
9000.609
Teleflex M portable Teleflex M portable Type LC (monochrome screen) Instruction manual Connecting cable K208 Connector head A505 Mains cable
9000.671
Teleflex M portable Teleflex M portable Type MC (colour screen) Instruction manual Connecting cable K208 Connector head A505 Mains cable
9000.672
2.3.
Optional Extras
2.3.1.
Control of the 3-Phase Current Decoupling Unit The 3-phase Current Decoupling Unit is an optional extra for the test van. It can be used for locating faults in heavily branched networks. Control is provided by the Teleflex M.
2-4
Illustration of the Teleflex M Instrument
2.4.
Fig 2-1 shows the front view of Teleflex M and its controls.
2
3
4
5
6
7
8
1
1
mains switch
5
help key
2
softkeys
6
softkeys
3
controls of brightness and contrast
7
phase selection keys with status indicators
4
screen
8
soft knob with pressure mode
Fig 2-1 Front View of type Teleflex M Showing its Controls and Screen
Teleflex M
2-5
2.5.
Performance Features • digital acquisition of measured data using highly advanced Flash technology in all modes and ranges of measurement • connection of all three conductors of the object to be tested • automatic and simultaneous display of results for all three phases • easy menu-based operator guidance with context-related help in several languages • Large-size high-contrast display on monochrome or colour screen (10,4”) • Pulse output in bridge configuration for suppressing the display of the transmitter pulse • Internal compensation in order to enhance fault location at short distance • High local resolution by using short pulses • Long locating range due to wide dynamic range • Quasi-real time operation due to high rate of measurement • Enhanced fault detectability even in difficult conditions due to averaging of measured values • Evaluation of reflectograms either by cursor and marker or by the trace-shifting technique, as desired • Integrated memory for storing the results of all measurements taken in all modes and the data related to them together with the device setups • Convenient method of comparing present and stored results and calculating their difference (e.g. comparison between conductors or with former test results / reference traces) • Interface to printer and PC
2-6
2.6.
Fields of Application and Modes of Operation The Pulse echo meter Teleflex M is for locating cable faults in power cables and lines. Due to its variety of trigger modes the device can be used for implementing the test procedures made available by the test van such as -
Time delay reflection testing (TDR)
-
Surge prelocation
-
Arc reflection method (ARM)
-
Decay
-
Arc burning.
The instrument includes a wide variety of storage facilities for all modes and ranges of measurement. Apart from comparative and differential tests the device also allows the measured test results to be compared with older test ones (reference traces). Mode of operation: The Teleflex M resembles a radar meter in that it makes use of the well-known pulse echo technique, too. To this end, appropriately shaped test pulses are transmitted into the cable under test. The pulses travel along the cable at a speed specific for this cable. A fraction of the transmitter pulse is reflected from each place where the cable has changed its electrical characteristics and these reflected components are visualised on the screen. The mentioned changes in the electrical characteristics of a cable can be attributed to a possible fault in the cable or local particularities such as sleeves or the end of the cable. The type of fault and its distance can be evaluated from the shape and the delay time of the reflections. This way the screen of the Teleflex M shows a clear and transparent image of the cable under test.
Teleflex M
2-7
2-8
3.
GETTING STARTED
3.1.
Connection to the Mains The Teleflex M is powered from the mains. The built-in mains unit allows the device to be operated from any supply network with a voltage as specified in paragraph 2.1.1.. To this end the device is equipped with a convenience receptacle on the rear.
3.2.
Switching the Device On and Off Use the mains switch on the front panel of the Teleflex M to switch the device on and off. The lamp within the switch is alight when the device has been switched on. Approx. 15 s after power-on the screen reads out the following message: HAGENUK KMT KABELMESSTECHNIK GMBH
TELEFLEX M
INITIALIZING
The device carries out internal initialisation and test procedures for as long as this message is indicated.
3.3.
Device Setup The user can make the following adjustments in the setup menu: -
Date and time of the internal clock of the system
-
Language to be used for reading out results on the screen and for printed reports
-
Selection whether the results of a distance measurement shall be read out as propagation time in Âľs or as distance in m or ft
-
Printer supported by the setup and configuration of the serial interface
-
Unit of propagation speed expressed as NVP (nominal velocity of propagation) or as v/2
-
Colour composition of the image on the screen
-
Mode of displaying the traces on the screen and on a hardcopy
-
configuration of the PC interface
Teleflex M
3-1
-
3.4.
selection of mode standard/expert for filter and trigger treshold.
Default Condition The user can select by himself the default settings of the Teleflex M which the device shall use after having been started up (e.g. unit, type of printer, etc.). To this end make your adjustments as desired and acknowledge your choice by pressing key 'Save Setup' in the system menu. Next time when the instrument is started up once again it will use the stored parameter setup. You can cancel this setup by selecting 'Delete Setup' during ‘System Reboot'.
3.5.
Connection to a PC The Teleflex M is equipped with a serial interface for storing the test results on a PC. This socket is in the rear of the Teleflex M or it is accessible on the operating panel of the test van. The interface can be configured in the Setup menu.
3.6.
Connection to a Printer The Teleflex M allows the test results to be printed out by a standard printer which can be connected through a socket on the operating panel of the test van or in the rear of the instrument. The following printers and their corresponding compatibles are supported: -
IBM-Proprinter (8-needle printer) Epson 24-needle printer Printer emulation language PCL 3, e.g. HP-Deskjet
Almost all common printers can emulate at least one of these three printer languages. Use a multiple-shielded printer cable such as TO 41243 by Inmac to exclude any interference when running your Teleflex M in the vicinity of devices and systems which generate high voltage
3-2
3.7.
LCD Brightness and Contrast Use key ‘Contrast / Brightness’ and the soft knob to adjust the contrast or brightness of the screen. The mode of adjustment depends on the specific version of the device since different settings are required for each type of screen Type LC:
contrast has to be set
Type MC:
brightness has to be set
Press key ‘Contrast’ and keep it depressed when you wish to adjust the screen and use the soft knob to make the adjustment.
Teleflex M
3-3
3-4
4.
HOW TO OPERATE THE SYSTEM
4.1.
Controls As a matter of principle, the screen is subdivided into display fields arranged in fixed places. This subdivision is retained in all modes of operation of the Teleflex M. Fig 4-1 shows these display fields. 1 a e k
f l
b g m
c h n
d i o 2
5
4
3
1
Status field
3,5
Softkey labelling
2
Message line
4
Operating window
Fig 4-1 Display fields of the screen
Teleflex M
4-1
The individual display fields read out the following information: Field 1: Status field The Status field gives information on the values of specific system parameters. To this end the Status field is broken down into several boxes in which the following information is read out: a
mode of operation
h
cursor position or distance cursor - marker
b
number of averages
i
trace labelling
c
display range
k
date
d
trace labelling
l
time
e
m pulse width
f
n
v/2
g
o
trace labelling
Field 2: Message line The message line serves the following purposes: - To guide the operator - To indicate possible errors Field 3: Softkey labelling This box informs about the function of the key positioned next to it. -
empty box: this key is currently without function
-
box in elevated representation without number: pressing the key will trigger the function indicated by the box
-
box in sunk representation without number: the condition as indicated in the box is active
-
box in elevated representation with number: The number can be changed by means of the soft knob but has yet to be selected beforehand
-
box in sunk representation : The number can be adjusted by means of the soft knob
4-2
-
box with one text in normal and one in inverted representation: The function as indicated by the inverted text is active. Pressing the key will enable the function of the text in normal representation. When either text is read out in normal representation, neither is active.
Field 4: Operating window -
To display measured traces
-
To display help texts
Field 5 is identical with field 3
Help mode Press key ‘ ? ’ any time if you wish to call the context-related help system of the Teleflex M. Press the key the function of which you want to be explained. The labelling of the key will disappear and the relevant explanation will be indicated. Press key ‘Return’ to return to the normal labelling of the key. You may now press another key which you want to be explained, if need be. Press key ‘ ? ’ one more time to shut the help system down.
Error messages The message field of the screen may read out an error message (such as 'paper missing'). If this is the case, please first eliminate the cause of the error and after that press key ‘F1’ to acknowledge the error message. When some error cannot be acknowledged, please carry out function ”System Reboot” in which case it is standard procedure that the selected setup will not be cancelled. When this error occurs again and again we suggest to select option "Cancel Setup" when carrying out "System Reboot". Any error message caused by a malfunction of the Teleflex M is labelled with a 6digit error code. This error code facilitates a possible remote diagnosis when discussing the error with Hagenuk KMT.
4.2.
Device Status
Teleflex M
4-3
Depending on the device setup and the course of measurement, the status of the Teleflex M will change. This is indicated by a symbol in the upper left corner of the operating window. One of the following symbols may be on display: stop condition for viewing test is running currently stop / viewing status after a measurement has been taken The Teleflex M is waiting for a high-voltage event (trigger)
4-4
4.3.
Menu Structure Operator control of the Teleflex M is by means of a few easy-to-understand menus. The user is further supported by a context-related help function. These menus are described in the following paragraphs.
4.3.1.
Power-On Menu - Main Menu Approximately 40 sec after the Teleflex M has been switched on by means of its mains switch, the following main menu appears.
TDR (intern)
HV-Methods (external)
Current Decoupling
System Teleflex M Release X.X
As a matter of principle, it is this menu where the method of testing is selected and the menus for adjusting the system setup are called. TDR (intern)
To select the time-delay reflection method (TDR) and call the TDR menus. This key corresponds to the selection of ”internally” in older instruments.
HV Methods (external)
To select the test methods where high voltage is involved such as ARM, surging, etc. This key corresponds to the selection of ”externally” in older instruments.
Current Decoupling System
To select the test methods with 3-phase current decoupling (optional feature of the test van) To call the system menu
After key "HV Methods" has been pressed the Teleflex M will communicate with the control unit of the test van and automatically synchronise itself with the mode of operation selected in the test van.
Teleflex M
4-5
4.3.2.
System Menu After key 'System' has been pressed in the system menu the following menu for adjusting the system parameters of the device will appear.
Return
Setup
Save settings
Default values
System info Teleflex M
Click on Click off
Release X.X
Reboot system
Return Save settings
To return to the main menu. To save the complete Setup of all device parameters currently adjusted. The parameters saved in this way will be used as the default Setup when the device is switched on another time. In order to cancel this Setup, select ‘Delete Setup' in ‘System Reboot’.
System info Setup
To read out some information about the Teleflex M such as software version, optional features, etc. To call the Setup menu for adjusting the system parameters
Default values
To reset all device parameters to their standard values
Click on Click off
For switching the key-click on/off
Reboot system
To restart the system. After this key has been pressed, a menu will appear containing a key 'Delete Setup'. Press this key if you want to cancel the complete system Setup. Press key 'Reboot system' to initiate rebooting.
4-6
4.3.3.
Setup Menu After key ‘Setup’ has been pressed in the System menu the following menu for adjusting the system Setup of the device will appear.
Return
Units Teleflex
Languages
Clocksetting
Standard Expert Teleflex M Release X.X Display options
Select printer
Return Languages Standard Expert
PC-Port
To return to the main menu To select the user's language for running the system To select either mode 'Standard' or mode 'Expert' In the 'Standard' mode all the operating and adjusting means needed for the location of faults are accessible to the user. The 'Expert' mode offers the additional possibility to adjust the filter for taking the measurement. In the 'Standard' mode this filter is set to a default value that is dependent on the range of measurement. The possibility to adjust the filter individually enhances the chance to detect a fault even in an extremely difficult application. The filter is reset to its default value whenever one of the following operations is carried out: -
The mode of operation is changed. Pulse width is changed in reflection testing In any test involving high voltage: the range is changed.
Display options
To adjust the screen background and the line format for the display and printout of the traces
Select
To select the type of printer and the interface to be used
Teleflex M
4-7
printer
4-8
Units Teleflex
To adjust the units used for measuring distance and for setting v/2
Clocksetting
To set date and time
PC Port
To set the parameters (Baud rate, parity) of the serial interface
4.3.4.
TDR Menu Press key 'TDR' in the main menu in order to get into this menu. It contains most of the functions needed for locating faults by the Teleflex method (TDR). reflection measurement
Return
Reflection Difference
Y gain 0 dB
L → N L → L
X range 800.0 m
memory
Cursor 0.00 m
Active Stop
Teleflex menu
TDR-mode
Return
To return to the main menu
Y gain
To adjust gain
X Range
To adjust the range on display by means of the soft knob
Cursor
To shift the cursor and set the marker by means of the soft knob
Teleflex menu
To call the Teleflex menu for setting additional parameters needed for testing such as v/2. You can toggle between the menus while a test is running
Reflection
To select either mode Reflection test or mode Differential test
Difference L→N L→L
To select either conductor-to-earth testing (L → N) or conductor-to-conductor testing (L → L).
memory
To call the Memory menu for saving or downloading test results.
Active
To stop and start a test. In condition ”Active” tests are carried out according to the selected mode, in mode "Stop" the test results are frozen. The test results can be evaluated in either mode.
Stop
If mode Single test has been selected, pressing the key twice will trigger another test.
Teleflex M
4-9
TDR-Mode
To call the TDR-mode menu for choosing a test mode from Single testing, Continuous Testing, or Averaging.
The keys ‘Reflection / Difference’, ‘L → N / L → L ‘ and ‘L1’, ‘L2’ and ‘L3’ can be used to bring about the following connections: ‘Reflection’ and ‘L → N’: L1 → GND L2 → GND L3 → GND ‘Reflection’ and ‘L → L’: L1 → L2 L2 → L3 L3 → L1 ‘Difference’ has been selected: (L1 - L2) → GND (L2 - L3) → GND (L3 - L1) → GND
4-10
4.3.5.
TDR-Mode Menu Select test method TDR and press softkey 'Mode' to call the TDR-mode menu. This menu is for declaring the way in which the test shall be performed. It is only in this menu where the setup can be changed.
reflection measurement
Single trace
Return
Continuous
Average
Return Single trace
To return to the TDR menu To select single testing In order to trigger another test, press key 'Active / Stop' in the TDR menu twice.
Continuous Average
To select continuous testing To select testing with averaging The average of 256 tests results is taken and the averaged trace is displayed each time. The number of tests taken and averages calculated is read out in the status line
Teleflex M
4-11
4.3.6.
Teleflex Menu The Teleflex menu can be called from the TDR menu or one of the menus of the HV prelocating modes. This is the most important menu for locating cable faults. It is for adjusting the complete test setup and, at the same time, for displaying and evaluating the measured traces. It depends on the selected number of traces or conductors which of the following key combinations are meaningful and, therefore, are made available. Example of a Teleflex test (in the Standard mode): reflection measurement
Return
Pulse width 50 ns
Y gain 0 dB
X shift 0.00 m
X range 800.0 m
compensation ∝Ω
Cursor 674.00 m
V/2 80.0 m/µs
Trace selection
Trace comparison
Return
To return to the previous menu
Y Gain
To set the Y gain
X Range
To set the range displayed on screen by means of the soft knob
Filter
To adjust the filter to be used for the acquisition of test data (only in the Expert mode). This key is available in this menu only when the operating mode ‘Expert’ has been chosen. The filter setting is automatically reset to its default value when one of the following operations is carried out: -
Cursor
The mode of operation is changed. Pulse width is changed in reflection testing In any test involving high voltage: the range is changed.
To enable shifting the cursor by means of the soft knob Depress the soft knob to set a marker
Trace selection
4-12
To call the trace selection menu In the trace selection menu the traces can be shifted vertically and, in addition, vertical magnification (zoom) can be
adjusted, while the screen is in the stop or viewing mode. Pulse width X Shift compensation v/2 Trace comparison
4.3.7.
To set pulse width by means of the soft knob To determine the fault distance using the shifting method To adjust the built-in compensation for suppressing the display of the transmitter pulse. To adjust the pulse propagation speed v/2 To call the trace comparison menu When more than one trace is on display, this menu is for selecting whether the traces shall be displayed alternatingly or whether their difference shall be shown.
Trace Selection Menu Press key 'Trace Selection' in the Teleflex menu to navigate to the Trace selection menu of the Teleflex M. This menu is for shifting a single trace or all trances in the X and Y directions and for magnifying them in the Y direction (Zoom).
reflection
measurement
Return
Separate Union
Trace 1
X shift 0.00 m
Trace 2
Y pos 3 0
Trace 3
Y zoom 3 0 dB
All traces
Return
To return to the Teleflex menu
Trace 1
To adjust the parameters of trace 1. This key is shown only when trace 1 is on display.
Teleflex M
4-13
Trace 2
To adjust the parameters of trace 2. This key is shown only when trace 2 is on display
Trace 3
To adjust the parameters of trace 3. This key is shown only when trace 3 is on display
All traces
To adjust the parameters of all traces equally (only in stop or viewing mode).
Separate Union
„separate“ the Y positions of the three curves union are shifted by 50 pixels against one another „union“ all three curves have identical Y positions.
X Shift
To determine the fault distance by using the shifting technique
Y Pos
To shift the selected traces in Y direction
Y Zoom
To magnify / zoom the selected traces in Y direction Y Zoom is automatically reset to 0 as soon as another test is started, e.g. when continuous testing has been selected.
4.3.8.
Trace Comparison Menu Press key 'Trace Comparison' in the Teleflex menu to navigate to the Trace Comparison Menu of the Teleflex M. This menu is for making a choice whether 2 traces shall be shown concurrently or whether their difference shall be shown.
reflection measurement
Return
Trace 1 Trace 1-2
Trace 2 Trace 2-3
Trace 3 Trace 3-1
4-14
Separate Union
It depends on the selected number of traces or conductors which of the following key combinations are meaningful and, therefore, are made available. Labelling may differ accordingly. When keys L1, L2, L3 have been pressed the following adjustments can be made:
Return Traces 1
To return to the Teleflex menu Traces 1:
Trace 1, 2 and 3 are displayed concurrently.
Trace 1 - 2:
The difference trace 1 - trace 2 is displayed
Trace 1 - 2
The selected mode is displayed in inverted representation.
Traces 2
Traces 2:
Trace 1, 2 and 3 are displayed concurrently.
Trace 2 - 3:
The difference trace 2 - trace 3 is displayed
Trace 2 - 3
The selected mode is displayed in inverted representation. Traces 3
Traces 3:
Trace1,2 and 3 are displayed concurrently.
Trace 3 - 1:
The difference trace 3 - trace 1 is displayed
Trace 3 - 1
The selected mode is displayed in inverted representation. Identical colours are allocated to the boxes and the traces on display. Separate Union
Teleflex M
„separate“ the Y positions of the three curves union are shifted by 50 pixels against one another „union“ all three curves have identical Y positions.
4-15
4.3.9.
Menu HV Prelocation You can navigate to menu 'HV Prelocation' by pressing key 'HV Methods' in the main menu provided that an appropriate mode of operation such as Surge prelocation or Decay has been selected in the test van.
HV-Prelocation
Return
Y gain 4 dB
X shift 0.00 m
X range 4.0 km
memory
single Continuous
Cursor 2.31 km
Teleflex menu
Return
To return to the main menu
Y Gain
To adjust gain
X Range
To adjust the range displayed on screen by means of the soft knob
Cursor
To shift the cursor and set the marker by means of the soft knob
Teleflex Menu To call the Teleflex menu for setting additional parameters vital for testing such as v/2. You can toggle between the menus while a test is running. X Shift
To determine the fault distance by means of the shifting technique
memory
To call the Memory menu for storing or downloading the results of tests.
Single
Toggle key for selecting the test mode. Pressing the key several times will toggle between modes single test, continuous testing, and stop.
Continuous
The selected mode is displayed in inverted representation. The device is in the stop mode when there is no inverted text. Single: 4-16
After a one-time high voltage event the
Teleflex M changes over to the stop mode.
Teleflex M
Continuous:
A measurement is taken each time a high voltage event occurs. For quitting this mode press this key one more time.
Stop:
The trace which has been measured is 'frozen'. The triggering of another test by a high voltage event occurring later is disabled.
4-17
4.3.10.
Menu Arc Burning You can navigate to menu 'Arc Burning' by pressing key 'HV Methods' in the main menu provided that this mode of operation has been selected in the test van.
ARM burning
Return
Y gain 4 dB
X range 1.2 km
memory
Active Stop
Cursor 838.38 m
Teleflex menu
Return
To return to the main menu
Y gain
To adjust gain
X Range
To adjust the range displayed on screen by means of the soft knob
Cursor
To shift the cursor and set the marker by means of the soft knob
Teleflex menu
To call the Teleflex menu for adjsuting additional parameters required for testing such as v/2. You can toggle between the menus while a test is running.
4-18
memory
To call the Memory menu for storing or downloading the results of tests.
Active Stop
To stop and start a test. In mode �Active� tests are carried out continuously, in mode "Stop" the results of the last test are frozen.
4.3.11.
Menu Arc Reflection Method (ARM) You can navigate to menu 'Arc Reflection Method' by pressing key 'HV Methods' in the main menu provided that this mode of operation has been selected in the test van.
ARM reference trace
Return
Y gain 7 dB
Reference Fault
X range 1.2 km
memory
Single Continuous
Cursor 307.20 m
Single Difference
Teleflex menu
Return
To return to the main menu
Y gain
To set gain This adjustment can only be made when the reference trace is recorded.
X Range
To adjust the range displayed on screen by means of the soft knob
Cursor
To shift the cursor and set the marker by means of the soft knob
Teleflex
To call the Teleflex menu for adjusting additional parameters required for testing such as v/2.
menu
You can toggle between the menus while a test is running. Reference Fault
To toggle between taking a reference trace or a fault trace. The selected mode is displayed in inverted representation.
Memory
To call the Memory menu for storing or downloading test results.
Single
Toggle key for selecting the test mode. Pressing the key several times will toggle between modes single test, continuous testing, and stop. The selected mode is displayed in inverted representation.
Continuous
Single: Teleflex M
After a reference trace has been taken or a 4-19
high voltage event has occurred the Teleflex M changes over to the Stop mode.
Single Difference
Continuous:
A measurement is taken each time a high voltage event occurs or a reference trace is taken. For quitting this mode press this key one more time.
Stop:
The trace which has just been measured is 'frozen'. A high voltage event occurring later will not trigger another test.
To toggle between alternating display of reference and fault traces and display of their difference. When the differnce is displayed the reference trace is deducted from the fault traces, the fault is thus depicted as a negative reflection in the difference trace.
4-20
4.3.12.
Menu Current Decoupling Press key 'Current Decoupling' in the main menu to navigate to menu 'Current Decoupling'. This menu is only available when the optional feature "3-phase current decoupling" has been installed in the test van.
Current decoupling
3-phased current decoupling: Return Connection of exactly 2 phases required !
Y gain 0 dB
X shift 0.00 m
X range 800 m
memory
Single Continuous
Cursor 0.00 m
Teleflex menu
Return
To return to the main menu
Y gain
To adjust gain
X Range Cursor Teleflex menu
To adjust the range displayed on screen by means of the soft knob To shift the cursor and set the marker by means of the soft knob To call the Teleflex menu for adjusting additional parameters required for testing such as v/2. You can toggle between the menus while a test is running.
X Shift
To determine the fault distance by means of the shifting technique
Memory
To call the Memory menu for storing or downloading test results.
Single
Toggle key for selecting the test mode. Pressing the key several times will toggle between modes single test, continuous testing, and stop.
Continuous
The selected mode is displayed in inverted representation. . The device is in the stop mode when there is no inverted text. Teleflex M
4-21
4-22
Single:
After a one-time high voltage event has occurred the Teleflex M changes over to the stop mode.
Continuous:
A measurement is taken each time a high voltage event occurs. For quitting this mode press this key one more time.
Stop:
The trace which has just been measured is 'frozen'. A high voltage event occurring later will not trigger another test.
4.3.13.
How to Use the Memory - The Memory Menu The memory contains 35 memory positions in which measured traces can be stored. Stored traces can be recalled and displayed again on the screen. The memory positions are labelled M1, M2 to M35. Memory position M1 is accessible in the Basic Memory menu for quickly storing a trace. Any other memory position is accessible in the submenus. Press key 'Store' to call the Basic Memory menu: 800.0 m
reflection measurement
808.80 m 100 ns
Return
97.8 m/µs
Select memory operation
Save trace
M1 → Trace 1
Delete display
M1 → Trace 2
L1 → M1
M1 → Trace 3
Load trace
Delete trace
Press key 'L1 → M1' to make the screen charge over to mode stop. The status field reads out the values of the measurement taken last. Return
To return to the previous menu
M1 → Trace1
The content of fast memory M1 is displayed on screen as trace 1.
M1 → Trace 2
The content of fast memory M1 is displayed on screen as trace 2.
M1 → Trace 3
The content of fast memory M1 is displayed on screen as trace 3.
This key is made available only when a printer has been configured in the Setup menu. The reflectogram(s) is (are) printed out by the printer.
Save Trace
Teleflex M
To save a trace displayed on the screen.
4-23
Delete display
To delete a trace displayed on the screen.
L1 → M1
To store the active trace in fast memory M1
Load Trace
To load a stored trace on the screen
Delete trace
To delete a trace stored in a storage position
Only those keys are displayed in the menus which are functional in the respective status of the system. E.g., 'Load Trace' is only displayed when at least one memory position is occupied. How to Use the Fast Memory Memory position ‘M1’ is used for the fast memory. (This means that a loading operation such as ”M1 → Trace 2” can only be executed when 'M1' is occupied.) You cannot select a trace for storing in the fast memory. It is always the "active trace" that is stored. An "active trace" is existing when exactly one of the traces on display is a current test result. E.g., when the content of ‘M7’ is displayed as trace 1 and the result of a reflection test on L2 is displayed as trace 2, then trace 2 (test result of L2) is the active trace. When a complete ARM test has been performed, the fault trace will be the active trace. When a trace is stored in the fast memory, the former content of ‘M1’ will be overwritten. How to Store a Trace: -
Press key 'Store Trace' in the Basic Memory menu.
The screen displays the Trace menu:
4-24
reflection measurement
Return
Select trace to be saved
Trace L1
Trace L2
Trace L3
Press the respective key to select a trace for storage. The screen will display the Memory menu: reflection measurement
Return
Select trace to be loaded Use soft-knob to select trace
Selection done ARM reference trace 100 ns 7 dB 48,5 Ω 14. 01. 98 / 13:03:32
REF
ARM fault trace FAULT 100 ns 7 dB 48,5 Ω 14. 01. 98 / 13:03:38 ARM reference trace 100 ns 7 dB 48,5 Ω 14. 01. 98 / 13:03:32
REF
The entire memory consists of 7 memory pages with 5 memory positions each. The operating window of the screen reads out the parameters of those traces stored in the 5 memory positions of the memory page which is on display. Use the soft knob to scroll the memory pages up or down. Within a memory page the number of memory place is selected with the cursor.
Teleflex M
4-25
Press the soft knob or press key 'Select Memory' to store a trace in the select memory position. The memory position will be overwritten, the old content cannot be restored by any means. How to Erase a Trace: -
Press key ‘Delete Trace' in the Basic Memory menu.
-
The screen will display the Trace menu.
-
Erase the selected trace by pressing the key allocated to the trace. There will not be any safeguarding query. The old content cannot be restored.
How to display a stored trace on the screen: -
Press key ‘Load Trace' in the Basic Memory menu.
-
The screen will display the Memory menu.
-
Select the trace to be displayed by scrolling to the corresponding memory page and selecting the respective memory by means of the soft knob.
-
Uploading the content of the memory position by pressing the soft knob or pressing key 'Select Memory'.
-
The screen will display the Trace menu.
-
Press the key of the respective trace to select whether the trace shall be displayed as trace 1, trace 2, or trace 3.
-
The trace is displayed in the operating window of the screen. It is retained in its storage position.
-
The most important parameters of the trace are displayed in the message box after the trace has been loaded.
How to erase a stored trace: -
Press key ‘Delete Memory' in the Basic Memory menu.
-
The screen will display the Memory menu.
-
Select the storage position to be erased by navigating to the respective store page and activating this storage position.
-
Press the soft knob or press key 'Select memory' to erase the storage position. The store will be erased without any safeguarding query. The old content cannot be restored.
4.4.
How to Operate the 3-Phase Current Decoupling Unit 4-26
The 3-phase Current Decoupling Unit is an optional feature of the test van. It is controlled through the Teleflex M. 3-phase current decoupling facilitates the location of a fault in a widely ramified network. Locating the fault is made much easier by concurrently picking up a reference trace and a fault trace on different conductors and by deducting the signals from one another. The 3-phase Current Decoupling Unit consists of four measuring pick-ups and an affiliated multplexer unit installed in the test van. Switching and connecting a conducter to the high voltage is controlled by the test van. The selection of a decoupling coil is from the Teleflex M. After key 'Current decoupling' has been pressed in the main menu and the test van has been set accordingly, the device will display the following menu which corresponds to the menu of mode 'HV Prelocation'. For the details of operation please refer to paragraphs 4.3.9 and 5.3.1.: Current decoupling
3-phased current decoupling: Return
Connection of exactly 2 phases required !
Y gain 0 dB
X shift 0.00 m
X range 800 m
memory
Cursor 0.00 m
Single Continuous
Teleflex menu
Use the phase selection keys L1, L2, and L3 of the Teleflex M to select the decoupling coils. This mode of testing always requires exactly 2 conductors to be connected to the high voltage circuitry. After these connections have been made, the corresponding signal LEDs of the Teleflex M will flash. If this does not happen, the Teleflex M will read out a message. You can actuate only those keys the LEDs of which are flashing. The selection of the mode of current decoupling is by pressing the respective key. The LED will signal the present status: 2 LEDs flashing
The summation current is decoupled
1 LED lighting permanently
The current of the conductor is decoupled the LED of which is lighting
2 LEDs lighting permanently
The difference current is decoupled
Teleflex M
4-27
4-28
5.
HOW TO CARRY OUT A TEST
5.1.
General Information The Teleflex M resembles a Radar device in that it works by the pulse echo technique. To this end appropriately shaped test pulses are transmitted into the cable under test. The pulses travel along the cable at a speed which depends on the characteristics of the test object. In all places where there is a change in these characteristics, a fraction of the transmitter pulse is reflected. This reflected component returns to the connected Teleflex M and is displayed on its screen with a delay which directly corresponds to the travel time of the pulse. A change in the electrical characteristics of a cable may be caused by a possible fault and/or by local conditions such as a ramification, sleeve, or the end of the cable.
5.1.1.
Fault Display on the Screen
1
2
1 Transmitter pulse;
3 2 Fault;
3 End of cable
Fig 5-1 Typical Reflection Trace
Teleflex M
5-1
Assumption:
A positive-going pulse is transmitted into the cable
Result:
positive reflections in all places where the characteristic impedance of the cable changes from its nominal value to higher values (see Fig 5-1, mark 3 ). negative reflections in all places where the characteristic impedance of the cable changes from its nominal value to lower values.
The greater the deviation from the nominal value of the characteristic impedance, the more pronounced the representation of the fault. The most outstanding reflections are caused by ruptures (characteristic impedance Z → ∞) and short-circuits (characteristic impedance Z = 0 â„Ś ) A capacitive fault results in an oscillating trace, e.g.
Reflection traces of cables with sections having different characteristic impedances When the characteristic impedance of the following cable section is higher than the previous one, the place of transition will be marked by a positive reflection in the trace of the cable on screen. When the characteristic impedance of the following section is lower, a negative reflection is displayed.
5.1.2.
Optimum Pulse Width and Range of Measurement Due the attenuation and dispersion characteristics of the cable which depend on frequency, every signal is changed in amplitude and shape. This applies to the transmitter pulse and each reflection. As a result, narrow transmitter pulses which have a greater proportion of high frequencies than longer pulses will deformed more heavily. This fact has to be taken into account when selecting a combination of pulse width and range of measurement. It means that short pulses are only suited for tests at short distance. On the one hand, they provide for a very good local resolution, but at long distances they are heavily attenuated and widened, on the other. Long pulses are attenuated much less, clear echoes can so be received even over long distances. At short distance, however, they are inferior to shorter pulses due to their limited local resolution.
5-2
The following ranges of measurement are allocated to the pulse widths that can be selected: Pulse width
Time measuring range
Distance measuring range (at v/2 = 80 m/µs)
50 ns
20 µs
1,6 km
100 ns
40 µs
3,2 km
200 ns
80 µs
6,4 km
500 ns
200 µs
16 km
1 µs
400 µs
32 km
2 µs
800 µs
64 km
5 µs
2 ms
160 km
Note:
The distance measuring range depends on the setting of v/2.
Fig 5-2 demonstrates the effect of pulse width on the shape of the reflection trace. cable without fault
connecting sleeve
narrow transmitter pulse
1st reflection
long transmitter pulse
1st reflection
MWG_42.DRW
cable without fault
2nd reflection
2nd reflection not detectable, is merged with 1st reflection
Fig 5-2 Effect of Pulse Width on the Reflection Trace
5.1.3.
Compensation of the Transmitter Pulse The Teleflex M has an internal compensating facility allowing the transmitter pulse to be eliminated from the picked-up signal and its display on screen. This way any overload of the amplifier can be excluded, so measurements can be taken without any dead zone and, therefore, faults can be located at close range, too. Even when the transmitter pulse has always the same polarity when fed into the cable, its trace may look quite different dependent on how compensation has been adjusted:
Teleflex M
5-3
a ) Poor compensation of transmitter pulse short circuit
rupture transmitter pulse
echo
transmitter pulse
echo
b ) Negative compensation of transmitter pulse short circuit
rupture transmitter pulse
echo
transmitter pulse
echo
c ) Good compensation of transmitter pulse short circuit
rupture transmitter pulse
5-4
echo
transmitter pulse
echo
5.1.4.
How to Determine the Location of the Fault The physical principle of this technique is to determine the fault distance by measuring the travelling time of the pulse from the moment of emission to the point in time when the fault reflection arrives at the instrument. In doing so, the propagation speed specific for the cable under test is taken into account. The points in Fig 5-3 marked 1, 2, and 3 are the bases of reflections.
1
2
1 Transmitter pulse;
3 2 Fault;
3 End of cable
Fig 5-3 Examples of Reflections and their Bases Every pulse is more and more severely deformed with growing distance. This means that the longer the distance, the more difficult the precise determination where the base of the reflection is located. 5.1.4.1.
How to Measure the Fault Distance The Teleflex M provides two ways for measuring the fault distance which can be employed alternatively depending on the test procedure used or the user's preference. Either method can be applied to any test method:
Teleflex M
5-5
-
Cursor and Marker When this method is used, use the soft knob to shift the cursor to the base of the reflection caused by the transition from the connecting line to the test object or to the transmitter pulse, respectively. Press the soft knob to set a marker. Shift the cursor to the base of the fault reflection. The distance between cursor and marker read out on screen is the fault distance. The default setting of the Teleflex M is such that the end of the connecting cable corresponds to cursor position 0 m. Please take this fact into consideration when using a different mode of connection.
-
Shifting Technique When the shifting technique is used, the fault distance is measured by shifting the trace relative to itself or some other trace. Use the soft knob to make the fault reflection coincide with the reflection at the transition to the connecting line or with the transmitter pulse, respectively. The shift corresponds to the fault distance, its value is read out on screen in field ‘X shift’. This method is very useful for all tests involving high voltage (e.g. decay).
5.1.4.2.
The Cursor and Marker Technique The marker can be used to define a point of reference on the cable and take measurements in relation to this point by means of the cursor. Using the marker may be useful in the following cases: • to determine the length of cable sections (in an environment where a cable is composed of sections with differing v/2 values), • when an additional connecting line is used, • to take a measurement relative to a known point of reference (this may be a way to reduce measuring uncertainty) and • to determine the v/2 value of a cable section with known length. Press the soft knob to set or erase a marker. Before that make sure that mode ”Cursor” has been selected. • Pressing the soft knob for the first time sets the marker at the current cursor position • The status line indicates the current distance between the marker and the cursor. The value is continuously updated when the cursor is moved. • Pressing the soft knob one more time erases the marker. This technique can also be used to eliminate the length of an additional connecting line when determining a fault distance. To this end, set the marker on the reflection caused by the transition of the connecting line to the cable proper. The distance read out on screen now relates to the beginning of the cable.
5-6
The following example of a reflection test shows the transmitter pulse without compensation, a fault reflection, and the end-of-cable reflection.
reflection measurement
Return
Reflection Difference
Y gain 4 dB
L → N L → L
X range 1.2 km
memory
cursor 838.38 m
Active Stop
Teleflex menu
TDR-mode
If, for instance, the length of the cable shall be determined, press key ‘Cursor’ and move the cursor to the base of the uncompensated transmitter pulse. Select a small display range, in order to position the cursor/marker precisely on the base of the transmitter pulse. Then press the soft knob to set a marker. After that select a display range, which again covers the open end or the reflection searched for, respectively. The cursor is moved to the base of the end-of-cable reflection. Select now a display range as small as possible in order to position the cursor precisely. The status field will now read out the length of the cable. In order to determine the fault distance, first set the marker as mentioned before and then move the cursor to the base of the fault reflection. The status field will now read out the fault distance. In order to determine the distance between the cable fault and the end of the cable, move the cursor to the end-of-cable reflection, press the soft knob to set a marker in this place, and move the cursor to the base of the fault reflection. The screen will now read out the distance.
Teleflex M
5-7
5.1.4.3.
The Shifting Technique The shifting technique is an alternative to the cursor-marker technique and can preferably be used to enhance the evaluation of measured traces when high voltage is involved. Access to this method is by pressing key ‘X Shift’. Single-trace representation means that a trace is copied to form a second trace and this second trace is shifted in relation to the first one. The copied trace is erased automatically as soon as another measurement is taken. In multiple-trace representation, one trace is retained for reference and the other trace(s) is (are) shifted in relation to the first one. We recommend to take a measured curve for reference and use trace 1 as the reference trace. ”X-Shift” is reset to ‘0’ automatically as soon as another measurement is taken. The following example shows the result of a surge prelocation.
HV-Prelocation
Return
Y gain -24 dB
X shift 280.00 m
X range 1.6 km
memory
cursor 1.29 km
Single Continuous
Teleflex menu
This figure shows the first reflection and the other ones following it. To determine the fault location, press key X Shift in the Trace selection menu. The trace is then duplicated automatically and can be shifted by means of the soft knob. Make the bases of two reflections coincide on the screen. The key 'X Shift' will now indicate the fault distance. Note: In order to preclude any possible measuring uncertainty caused by a delay in firing we suggest not to use the first reflection for determining the fault location but to use the second one at the earliest.
5-8
5.1.5.
Determination of v/2 from a Known Cable Length If the length of a cable is known, the Teleflex M can be used to determine the propagation speed v/2 specific for the cable either by the cursor-and-marker technique or the shifting technique. Cursor-Marker Technique Set a marker at the first reflection of the cable and move the cursor to the end-ofcable reflection. In order to determine the v/2 value of the cable, press key ‘v/2’ in menu ‘Teleflex’ and change the setting such that the distance between cursor and marker is in agreement with the actual length of the cable. The value of v/2 can directly be read off the message box of key ‘v/2’. Shifting Technique In this case use mode ‘X Shift’ in menu ‘Teleflex’ to make the end-of-cable reflection coincide with the first reflection. In order to determine v/2 of the cable, press key ‘v/2’ in menu ‘Teleflex’ and change the setting such that the distance indicated by key 'X Shift' is in agreement with the actual length of the cable. The value of v/2 can directly be read off the message box of key ‘v/2’.
5.2.
Teleflex Reflection Test (TDR) A reflection test can be carried out on three phases simultaneously. Use the conductor selection keys L1, L2, and L3 of the Teleflex M to select a conductor. This is a simple way to compare the test results of up to three conductors and to display their difference. Use key ‘Reflection / Difference’ to make your choice whether the pulse echo test shall be performed in relation to the internal balancing network or a second cable which does not have any fault. Reflection Test A reflection test is carried out to determine the places of faults on a cable. The screen will show every deviation of the cable from the internal balancing network. This way not only the fault to be detected is displayed but also every sleeve and ramification etc.. These points may give additional assistance in pinpointing the exact location of the fault.
Teleflex M
5-9
Differential Test When a differential test is carried out, the internal balancing network is replaced with a second cable with identical characteristics. This method provides for enhanced sensitivity as compared with reflection testing. The differential method has the following advantages: -
Cable inhomogeneities such as sleeves etc. are suppressed. The trace is displayed more clearly and cable faults can be detected more easily.
-
For a long pulse duration the transmitter pulse can be suppressed still more efficiently when a second cable is used for balancing.
Key ”L → N / L → L” is for selecting whether a measurement shall be taken between two conductors or between conductor and shield. L → L Test In this configuration a measurement is taken between two conductors to detect any conductor-to-conductor fault.
Teleflex M
L1 L2 L3 N
L3
L1
L2
L3
comparison L3 L1 L2 L3 difference (L3 -> L1) – (L2 -> L3)
5-10
faulty conductor faultless conductor
L → N Test In this configuration a measurement is taken between one conductor and the shield. This method is suited, e.g., for the location of line-to-earth faults.
L1 L2
Teleflex M
L3 N
L1
N
faulty conductor
L3
N
faultless conductor
comparison L1 / L3
N
difference L3 – L1
N
The following configurations or methods of testing can be selected: Reflection test (L → N)
Reflection test (L → L)
Differential test
L1 → GND
L1 → L2
(L1 - L2) → GND
L2 → GND
L2 → L3
(L2 - L3) → GND
L3 → GND
L3 → L1
(L3 - L1) → GND
In a cable laid out directly between two stations, i.e. without any ramification, the determination of the reflection pattern will not be difficult. The beginning and the end of the cable, all the sleeves, and possible faults can be detected easily (see Fig 5-4).
Teleflex M
5-11
faultless cable
change in type of cable
Teleflex M
Teleflex M
shunt resistance
Z = 50 Ohm
Z = 25 Ohm
change in type of cable RF
short circuit
Z = 25 Ohm
Z = 50 Ohm
connecting sleeve RF
series resistance RF
joint sleeve
rupture RF
Fig 5-4 Idealised Reflection Traces The situation is far more complicated in a low-voltage system. The great number of ramifications and branch lines results in a reflection trace pattern which is difficult to analyse when common reflection testing is carried out, so this method is not well suited for locating faults (see Fig 5-5). There is quite a different situation, however, when a comparative test with a faultless conductor or a differential test is carried out. faultless cable
VERZWG.DRW
Fig 5-5
5-12
Reflection Trace Pattern of a Cable with a Number of Ramifications and Branch Lines
5.2.1.
How to Carry Out a Teleflex Test -
Refer to chapter 3 for getting the system started.
-
Connect the object of testing to the test van.
-
Press key ‘TDR internally’ in the main menu.
After that the following TDR menu is displayed:
reflection measurement
Return
Reflection Difference
Y gain 0 dB
L → N L → L
X range 800 m
memory
cursor 0.00 m
Active Stop
Teleflex menu
TDR-mode
-
Select the conductors to be tested and the mode of testing by pressing keys ‘L1’, ‘L2’, and ‘L3’, ‘Reflection / Difference’ and ‘L → L / L → N’.
-
Adjust your desired parameter setup in this menu and in the Teleflex menu.
-
Select Mode (Single, Continuous, Averaging) in menu 'Mode'.
-
Press key ‘Active / Stop’ to stop a test and restart it. When single testing has been selected, press the key twice to start another test.
-
You may change over between the TDR menu and the Teleflex menu any time. This allows you to change your parameter setup even when a test is running.
-
Follow the instructions in paragraph 5.1.4. to determine the fault distance. You may use either the Cursor-marker technique or the Shifting technique.
Teleflex M
5-13
reflection measurement
Return
Reflection Difference
Y gain 4 dB
L → N L → L
X range 1.2 km
memory
cursor 838.38 m
Active Stop
Teleflex menu
TDR-mode
This figure shows the result of a reflection test of L1 versus N. The marker has been placed on the uncompensated transmitter pulse and the cursor has been moved to the open end of the cable. The distance from the open end id read out in the status field. The location of a low-resistance fault can be detected easily.
5-14
5.3.
Tests Involving High Voltage The connecting and control units of the test van take on the connection of the test object and the selection of the conductor to be tested. Press key 'HV Methods' to make the Teleflex M change over automatically to the mode selected in the test van.
5.3.1.
Surge Prelocation -
Refer to chapter 3 to get the system started.
-
Connect the object of testing to the test van.
-
Press key ‘HV methods’ in the main menu.
-
The following menu will now appear provided that the test van has beforehand been set to mode ”Surging”:
HV-Prelocation
Return
Y gain 0 dB
X range 800 0 m
memory
cursor 0.00 m
Single Continuous
Teleflex menu
Symbol is shown as an indicator that the Teleflex M is waiting for a trigger event such as a high-voltage flash-over. -
Select your desired parameters, e.g. v/2 in menu ‘Teleflex’.
-
Adjust the high voltage generated by the test van such that a flash-over occurs.
-
Press key 'Single/Continuous' to set the Teleflex M to continuous testing.
-
Adjust the gain such that the Teleflex M starts taking measurements.
-
Select the range such that the reflectogram can be analysed.
-
Press key ‘Single / Continuous’ to select mode Single or Continuous testing and the mode of display. We recommend to change over to mode Stop or Single testing when a test result shall be evaluated or stored.
Teleflex M
5-15
When the system is switched to 'Single', the next flash-over will still trigger a measurement. After that the Teleflex M changes over to the Stop mode. -
Follow paragraph 5.1.4. to determine the fault distance. We suggest to use the shifting technique. HV-Prelocation
Return
Y gain -24 dB
X shift 280.00 m
X range 1.6 km
memory
cursor 1.29 km
Single Continuous
Teleflex menu
NOTE:
5-16
In order to preclude any possible measuring uncertainty caused by a delay in firing we suggest not to use the first reflection for determining the fault location but to use the second one at the earliest.
5.3.2.
Decay (Voltage Decoupling) -
Refer to chapter 3 to get the system started.
-
Connect the object of testing to the test van.
-
Press key ‘HV methods’ in the main menu.
-
The following menu will now appear provided that the test van has beforehand been set to mode ”Decay”:
HV-Prelocation
Return
Y gain 0 dB
X range 800 0 m
memory
cursor 0.00 m
Single Continuous
Teleflex menu
-
Select your desired parameters, e.g. v/2 in menu ‘Teleflex’.
-
Adjust the high voltage generated by the test van such that a flash-over occurs.
-
Press key 'Single/Continuous' to set the Teleflex M to continuous testing.
-
Adjust the gain such that the Teleflex M starts taking measurements.
-
Select the range such that the reflectogram can be analysed.
-
Press key ‘Single / Continuous’ to select mode Single or Continuous testing and the mode of display. We recommend to change over to mode Stop or Single testing when a test result shall be evaluated or stored. When the system is switched to 'Single', the next flash-over will still trigger a measurement. After that the Teleflex M changes over to the Stop mode.
Teleflex M
5-17
HV-Prelocation
Return
Y gain 4 dB
X shift 600.00 m
X range 4.0 km
memory
cursor 1.61 km
Single Continuous
Teleflex menu
-
Follow paragraph 5.1.4. to determine the fault distance. We suggest to use the shifting technique. There are two ways to evaluate the fault distance: 1st possibility ”Use the shifting technique to make the rising and falling slopes coincide” 2nd possibility ” Use the shifting technique to make two rising slopes coincide”
NOTE: The true fault distance is half the distance read out since two oscillations have been taken into account.
5-18
5.3.3.
Arc Reflection Method (ARM) The location of faults by the Arc Reflection Method (ARM) requires that a reference trace and a fault trace be taken and, thereafter, be compared with one another. The course of operations to be performed to this purpose is controlled by the Teleflex M in a largely automated way. How to Take a Reference Trace -
Refer to chapter 3 to get the system started.
-
Connect the object of testing to the test van.
-
Press key ‘HV methods’ in the main menu.
-
The following menu will now appear provided that the test van has beforehand been set to mode ”ARM”:
ARM reference trace
Return
Y gain 0 dB
Reference Fault
X range 800.0 m
memory
cursor 0.00 m
Single Continuous
Teleflex menu
-
Press key ‘Single / Continuous’ to start measuring the reference trace.
-
Select your desired parameters, e.g. v/2 in menu ‘Teleflex’.
-
Select the Y gain and range as well as pulse width such that the reflectogram can be analysed.
-
Adjust compensation.
The following figure shows the result of a reference test:
Teleflex M
5-19
ARM reference trace
Return
Y gain 7 dB
Reference Fault
X range 1.2 km
memory
cursor 310.20 m
Single Continuous
Teleflex menu
How to Take a Fault Trace -
Press key ‘Reference trace / Fault trace’ in order to change over to taking the fault trace.
-
The Teleflex M will now wait for a high-voltage event. Symbol displayed to signal this state.
-
Adjust the high voltage such that a flash-over takes place.
-
The Teleflex M is triggered by this flash-over and displays both the reference trace and the fault trace.
-
Due to physical phenomena taking place in the arc it may happen that the measured trace deviates from the ideal course before the reflection is reached. In this case please take another fault measurement.
-
Follow paragraph 5.1.4. to determine the fault distance.
is
In order to facilitate the detection of the reflection (place of fault) the Teleflex M has a key ‘Fault - Ref / Fault & Ref’ that allows the user to choose between the display of both traces and the display of their difference.
5-20
The following figure shows a reference trace and a fault trace: ARM fault trace
Return
Reference Fault
X range 1.2 km
memory
cursor 310.20 m
Single Continuous
Teleflex menu
Single Difference
Changing Gain or Pulse Width As this method of testing requires the reference and the fault traces to be taken with identical parameter settings, both traces have to be measured one again after the setting of gain or pulse width has been changed.
Teleflex M
5-21
5.3.4.
Arc Burning -
Refer to chapter 3 to get the system started.
-
Connect the object of testing to the test van.
-
Press key ‘HV methods’ in the main menu.
-
The following menu will now appear provided that the test van has beforehand been set to mode ”Arc Burning”:
ARM burning
Return
Y gain 4 dB
X range 1.2 km
memory
cursor 838.38 m
Active Stop
Teleflex menu
-
Select your desired parameters, e.g. v/2 in menu ‘Teleflex’.
-
Select gain and range as well as pulse width such that the reflectogram can be analysed.
-
Adjust compensation.
-
Adjust the high voltage such that a flash-over takes place.
The following figure shows the result of a test:
5-22
ARM burning
Return
Y gain 4 dB
X range 1.2 km
memory
cursor 838.38 m
Active Stop
Teleflex menu
-
Use key ‘Active / Stop’ to stop the test and freeze the result currently on display. This facilitates the evaluation and storage.
-
Follow paragraph 5.1.4. to determine the fault distance. You have the choice of using the cursor-and-marker technique or the shifting technique for evaluating the traces.
NOTE: In any case where there are only small changes in the displayed reflectogram, detectability can be enhanced to a large degree by comparing the trace taken with high voltage with a trace taken without high voltage. To this end take a measurement without high voltage, store it in the memory, and reload it, e.g., as trace 2. Use mode 'Trace comparison' in menu ‘Teleflex’ to display either both traces or their difference.
Teleflex M
5-23
5-24
6.
HOW TO STORE AND PRINT THE RESULTS
6.1.
Using the Memory Please refer to paragraph 4.3.13. to learn the details on how to use the memory.
6.2.
Printing The Teleflex M allows the test results to be printed out by a standard printer. The printer can be connected through a socket on the operator's panel of the test van or on the rear of the instrument, respectively. The following printers and their compatibles are supported: -
IBM Proprinter (8-needles printer) Epson 24-needles printer Printer specification language PCL 3, e.g. HP Deskjet
Almost every common printer is able to emulate at least one of these three printer languages. The test results of the Teleflex M can be printed out by a printer. Configuration of the Printer: To this end call menu ‘Printer Selection’ in the Setup menu. Enable the print function to the selected printer by selecting ‘Parallel Port’ and select the appropriate type of printer. Press key 'Save Setup' in the system menu to store your settings and retain them even when the instrument is switched off. Printing Press key 'Print' in the Memory menu to trigger printing. This key is made available only when a printer has been configured in the Setup menu. After printing has started you may call the print status menu which will indicate the percentage of progress. Press key 'Cancel' if you want to abort printing. Structure of a Printout Page Each page printed out will show the traces displayed on the screen of the Teleflex M at that time. Below the diagram the most vital test parameters are printed in up to three columns. The left-hand column shows the parameters of trace 1, the centre one those of trace 2, and the right-hand one those of trace 3. Below right in the diagram a message is read out which mode of display (e.g., the differential mode) of the Teleflex M is active. When for instance ‘K1-K2’ is read Teleflex M
6-1
out, this message indicates that the trace printed out is the difference of traces 1 and 2 the parameters of which are printed out in the left-hand and the centre colums. Printing Out the System Information: In mode ‘System Info’ of the System menu, a hardcopy can be printed out, too. In this case an information about the version used as well as the calibration values for the measurement of current and voltage will be printed out.
6-2
7.
CLEANING, MAINTENANCE, REPAIR
7.1.
Cleaning Use only soft detergents for plastics when cleansing the surface of the case and the front panel from soiling. Chemical agents such as gasoline, acetone, acids, or lyes may damage the instrument, interfere with its proper function, or result in a total breakdown.
7.2.
Maintenance Teleflex M portable Check the connecting cables and the earth terminal of the Teleflex M portable in regular intervals according to the relevant national and international regulations. Always keep all terminals in a clean condition. Teleflex M in a test van Built into a test van, the device Teleflex M is subject to the specific care and maintenance operations that apply to the test van.
7.3.
Repair Whenever some trouble or breakdown occurs while you operate your instrument, always contact certified expert staff or submit your instrument to your customer service workshop or to Hagenuk KMT Kabelmesstechnik GmbH for repair. (For the addresses and Phone/Fax numbers, please refer to paragraph 1 of this manual.)
Teleflex M
7-1
7-2
8.
ANNEX Table of v/2 of Common Cables Insulator
v/2 (m/Âľs)
Type of cable
PVC
70 -
78
low-voltage cable
rubber
65 -
75
cables on cranes and elevators
oil-impregnated cable
80 -
86
77 -
82
low-voltage and 10/15 kV medium voltage cables
77 -
80
PEX cable for 10 kV networks
86 -
90
PEX cables for higher voltages
70 -
90
heating cable
cross-linked PE (VPE)
impregnated glass fabric or cotton
silk
massive PE
90 - 100
signal and aerial cables
foamed PE
115 - 130
signal and aerial cables
ca. 86
signal and telecommunication cables
ca. 98
signal and telecommunication cables
paper / air
110 - 120
signal and service lines
PE disk / air
141 - 144
disk-insulated coax cable, longdistance cables
insulators / air
146 - 148
open-wire lines
Teleflex M
8-1