Megger KMK 8 User manual

Mess
- und Ortungstechnik
Measuring and Locating Technologies
Elektrizitätsnetze
Power Networks
Kommunikationsnetze
Communication Networks
Rohrleitungsnetze
Water Networks
Abwassernetze
Sewer Systems
Leitungsortung
Line Locating
User Manual
Issue: 1 (08/2011) -
EN
Cable Fault Locator
KMK 8

CONSULTATION WITH MEGGER
The present system manual has been designed as an operating guide
and for reference. It is meant to answer your questions and solve your
problems in as fast and easy a way as possible. Please start with
referring to this manual should any trouble occur.
In doing so, make use of the table of contents and read the relevant
paragraph with great attention. Furthermore, check all terminals and
connections of the instruments involved.
Should any question remain unanswered, please contact:
Megger Limited
Seba Dynatronic
Mess- und Ortungstechnik GmbH
Archcliffe Road
Kent CT17 9EN
T: [phone]
F: [phone]
E: uks[email protected]om
Dr.-Herbert-Iann-Str. 6
D - 96148 Baunach
T: [phone] – 0
F: [phone]
E: [e-mail]
Hagenuk KMT
Kabelmesstechnik GmbH
Megger USA
Röderaue 41
D - 01471 Radeburg / Dresden
T: [phone] – 0
F: [phone]
E: [e-mail]
Valley Forge Corporate Centre
2621 Van Buren Avenue
Norristown, PA 19403 USA
T: [phone]
F: [phone]
Megger
All rights reserved. No part of this handbook may be copied by photographic or other means
unless Megger have before-hand declared their consent in writing. The content of this
handbook is subject to change without notice. Megger cannot be made liable for technical or
printing errors or shortcomings of this handbook. Megger also disclaims all responsibility for
damage resulting directly or indirectly from the delivery, supply, or use of this matter.

TERMS OF WARRANTY
Megger will accept a warranty claim brought forward by a customer for a
product sold by Megger under the terms stated below.
Megger guarantees that at the time of delivery Megger products are free
from faults in material and 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 Megger 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 Megger.
All warranty claims versus Megger expire after a period of 12 months
from the date of delivery. Each component supplied by Megger in the
context of warranty will also be covered by this warranty for the remaining
period of time, but at least for 90 days.
Each measure to remedy a warranty claim must be carried out
exclusively by Megger or one of their authorised service stations.
It is a precondition for accepting a warranty claim that the customer com-
plains about the fault, in a 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 which are not in accordance with this specification,
by storing, transporting or using it improperly, or having it serviced or in-
stalled by a workshop not authorised by Megger. No claim will be ac-
cepted in case of wear and tear, will of God, or connection to foreign
components.
For any damage resulting from a violation of their duty to repair or re-
supply items, Megger can be made liable only in case of severe
negligence or intention. Any liability for slight negligence is disclaimed.

CONTENTS
1INTRODUCTION .......................................................................1-1
1.1 Application .................................................................................1-1
1.2 Application Guide for Fault Location..........................................1-4
1.2.1 Active Bridge .........................................................................1-5
1.2.2 Passive Wheatstone-Bridge ..................................................1-5
1.2.3 End to End Synchronic Measuring Method...........................1-5
1.3 General Features.......................................................................1-6
2KEYBOARD, SOCKETS AND LEDS .......................................2-1
2.1 Connectors & Balance Controls.................................................2-4
3OPERATING INSTRUCTIONS .................................................3-5
3.1 Start up and general rules .........................................................3-5
3.2 Calibration..................................................................................3-6
3.3 Storage and Recall of Measuring Results .................................3-8
3.4 Provided Special Actions after Measurements..........................3-9
4TDR MEASUREMENTS............................................................4-1
4.1 Principles of Operation ..............................................................4-1
4.2 Settings before Measurement....................................................4-3
4.3 Test of a Single Pair...................................................................4-6
4.4 Waveform Evaluation.................................................................4-7
4.5 Location of Cross Talk Points ....................................................4-8
4.6 Comparison of Two Pairs ..........................................................4-8
4.7 Comparison to Stored Result.....................................................4-9
4.8 Application Guide (General Hints for TDR) .............................4-10
4.9 Typical Waveforms ..................................................................4-11
4.10 Obtaining the Missing V/2 ...................................................4-15
5ACTIVE BRIDGE.......................................................................5-1
5.1 Interference Voltage Measurement (AC and DC)......................5-1
5.2 Resistance Measurements ........................................................5-2
5.2.1 Loop Resistance Measurement (2 WIRE).............................5-2
5.2.2 Loop Resistance Measurement (2-WIRE & GND) ................5-4
5.2.3 Resistance Difference Measurement ....................................5-5
5.2.4 Insulation Resistance Measurement .....................................5-6
5.3 Capacitance Measurements ......................................................5-8
5.3.1 Capacitance Measurement (2 WIRE)....................................5-9
5.3.2 Capacitance Measurement (2 WIRE&GND) .......................5-10
5.3.3 Capacitive Balance Measurement.......................................5-12
5.4 DC Fault Location with MURRAY Method...............................5-13
5.5 DC Fault Location with Küpfmüller Method .............................5-15
5.6 DC Fault Location with 3 Point Method ...................................5-18

5.7 DC Fault Location with repeated KÜPFMÜLLER method.......5-20
5.8 AC Fault Location with Interruption Measurement ..................5-23
5.9 AC Fault Location with repeated KÜPFMÜLLER method .......5-24
6PASSIVE BRIDGE ....................................................................6-1
6.1 Principles of Operation ..............................................................6-1
6.2 Loop Resistance Measurement.................................................6-2
6.3 Insulation Resistance Measurement .........................................6-3
6.4 Resistance Difference Measurement ........................................ 6-5
6.5 DC Fault Location with MURRAY Method................................. 6-7
6.6 DC Fault Location with 3 Point Method ...................................6-10
6.7 DC Fault Location with Küpfmüller Method .............................6-14
6.8 AC Fault Location with Küpfmüller Method .............................6-18
6.9 Capacitive Balance Measurement...........................................6-22
7END TO END SYNCHRONOUS MEASUREMENT..................7-1
8PRE MEASUREMENTS............................................................8-1
8.1 Survey of Pair Condition............................................................8-1
8.2 AC DC Voltage Measurement ...................................................8-3
8.3 Loop Resistance Measurement.................................................8-4
8.4 Insulation Resistance Measurement .........................................8-5
8.5 DC Current Measurement ......................................................... 8-6
8.6 Cable Temperature Measurement............................................. 8-7
9AUTOMATIC TEST SEQUENCES ........................................... 9-1
9.1 Automatic Quick Test.................................................................9-1
9.2 Automatic Quality Test...............................................................9-2
10 BATTERY MANAGER ............................................................10-1
10.1 Battery Capacity Indication..................................................10-1
10.2 Normal Charging .................................................................10-1
10.3 Fast Charging......................................................................10-2
10.4 Regenerating Charge Process............................................10-2
10.5 Initial Charging ....................................................................10-2
10.6 Automatic Battery Switch-Off ..............................................10-3
10.7 Battery Life Expectancy.......................................................10-3
10.8 Charging During Measurement ...........................................10-3
11 USB PORTS............................................................................11-1
11.1 Result Transfer from KMK 8 to USB flash drive..................11-2
11.2 Result Transfer from USB flash drive to KMK 8..................11-3
12 STATUS & OPTIONS..............................................................12-1
13 UPGRADE (KMK8U.EXE) ......................................................13-1

14 DEMOPROGRAMM (KMK8D.EXE)........................................14-1
15 SETTINGS ...............................................................................15-1
16 LOOP CLOSING DEVICE KLC 8 ...........................................16-1
17 INTELLIGENT SLAVE KMK 80S (OPTIONAL) .....................17-1
18 SPECIFICATIONS...................................................................18-3
18.1 General Specifications.........................................................18-3
18.2 TDR .....................................................................................18-5
18.3 Active Bridge .......................................................................18-7
18.4 Passive Bridge...................................................................18-11
18.5 Pre Measurements ............................................................18-15
18.6 Quick Test .........................................................................18-19
18.7 Quality Test .......................................................................18-20
19 SCOPE OF DELIVERY AND OPTIONAL ACCESSORIES ...19-1

1-1
1 INTRODUCTION
This Operating Manual is intended to help the user in operating
Cable Fault Locator KMK 8 explaining the operation rules. While following
the instructions as given below, it is recommended to use the demo
program found on the CD inside the carrying case. Running the demo
under WINDOWS will show you the front panel of the instrument with
display and keyboard. By clicking with the mouse on the keyboard, the
“virtual” KMK 8 will behave as the real instrument, helping the user to
carry out complete measuring procedures, but of course only “virtually”.
1.1 Application
KMK 8 hand-held small size instrument is intended to test the quality of
telecom cables during installation and to locate cable faults. That
combined instrument provides the followings:
•Time Domain Reflectometer (TDR)
•Active bridge for comfortable automatic, and accurate DC, AC
fault location and resistance, capacitance measurements on lines
with only small interference voltages
•Passive Wheatstone bridge for DC, AC fault location and
resistance, capacitive measurements on lines with heavy interfer-
ence voltages
•A voltage measurement module for measurements of AC and DC
interference voltages at cable systems.
•Voltage meter module to measure the DC and AC interference
voltages on the line
•Warning and information-systems continuously informing the user
about interference voltages to ensure the best measurement
accuracy.
•Remote control system for the far end loop closing device

1-2
In TDR mode KMK 8 can be used, to locate…
•Open ends
•Shorted conductors
•Water damage
•Screen faults (interruption)
•Loose connectors
•Crimp faults
•Simple or double split
•Branches
•Capacitance networks
•Unwanted loading coils
•Change of cable type
In active bridge mode KMK 8 provides:
DC fault location methods like:
•Murray,
•3 Point
•Küpfmüller
•Repeated Küpfmüller
AC fault location methods like:
•Line break
•Repeated Küpfmüller
The measurement of parameters like:
•Loop resistance
•Resistance difference
•Insulation resistance
•Cable capacity
•Capacitive unbalance
•AC, DC voltage
In passive bridge mode KMK 8 provides:
DC fault location methods like:
•Murray,
•Küpfmüller
•3 Point
AC fault location methods like:
•Küpfmüller
•Capacitive unbalance

1-3
End to End synchronous current measurement with
•Graaf method using the DC interference voltages for fault location
The measurement of parameters like:
•Loop resistance
•Resistance difference
•Insulation resistance
KMK 8 provides remote control for far end devices like:
•KLC 8 loop closing device to close or open the loop during the
measurement (e.g fault location with Küpfmüller method).
•KMK 80S slave unit to measure the current at the far end in case
of fault location with Graaf method

1-4
1.2 Application Guide for Fault Location
We are talking about cable fault when the insulation resistance of one or
more pairs (between wire and wire or between wire and ground)
becomes too low.
That usually occurs after strong rains wetting the insulation material in
discrete points (typically not along the whole cable).
During the trouble shooting the first task is to locate that points. The
name of this process is “DC Fault Location”.
Performing calculations KMK 8 always supposes that there is only one
faulty point on the tested cable.
In the opposite case the cable should be split into sections containing
only one faulty point so as to measure them one by one.
The fault location can be disturbed when the fault resistance
interconnects the faulty wire with a DC voltage source (e.g. an active pair
using DC voltage).
The applicable fault location method depends on the characteristics of
cable fault. In PRE MEASUREMENT,S/PAIR CONDITION survey mode
KMK 8 provides an extremely useful help for the user to find the best
method.
From the point of view of interference voltages the cable faults can be
included into three groups:
•The AC interference voltages are low and the DC voltage isn’t
intermittent
•The AC interference voltages are high but the DC voltage isn’t
intermittent
•The AC and DC interference voltages are extremely high and
intermittent
KMK 8 offers three fault location methods for the above mentioned three
groups:
•Active bridge - when the interference voltages are low
•Passive Wheatstone bridge - when the interference voltages are
high but moderately intermittent
•End to End synchronic measurement - when the interference
voltages are extremely high and intermittent (Graaf method)

1-5
1.2.1 Active Bridge
The active bridge provides quick, comfortable, very accurate and
automatic measurements. There are two measuring modes to select:
•Sensitive mode providing extremely accurate test results even if
the measured fault resistances are very high. But high AC
interference voltages may overload the bridge indicator.
•Protected mode providing accurate test result even in the
presence of medium level interference voltages (if the fault
resistances are not higher than 3 to 5 MOhm)
It is recommended to start the measurement with sensitive mode. When
the interference voltages overload the indicator a warning appears
informing the user that the result can be inaccurate. In that case the
measurement should be repeated in protected mode.
1.2.2 Passive Wheatstone-Bridge
The passive bridge is not sensitive for external AC interference voltages
but its usage is not as comfortable as that of the active bridge. Measuring
methods like Küpfmüller or Three-point methods require two or three
consecutive measurements. Measuring error may occur if the level of DC
interference voltage changes between the measurements.
1.2.3 End to End Synchronic Measuring Method
In the worst case due to high and intermittent AC and DC interference
voltages neither the active nor the passive bridge can provide satisfactory
result.
In that case the best tool is the improved version of Graaf method using
the interference voltages for the measurement. (No other measuring
voltage is added to it).
KMK 8 performs current measurements at the two ends of the tested
cable at the same time and calculates the location of fault of the rate of
currents. That means:
The higher is the interference voltage the easier to locate a fault!
The only drawback is: two instruments are necessary working in Master-
Slave mode. In that mode KMK 8 can communicate with another KMK 8
or with an intelligent slave device like the KMK 80S.

1-6
1.3 General Features
KMK 8 has a graphic display an easy to use menu system and a many-
sided help system providing extremely simple operation for the user.
The displayed test results can be stored in the internal memory of the
instrument and transferred to PC:
KMK 8 has two USB ports for the transfer of test results:
•USB A host-port for USB flash drive (indirect transfer)
•USB B device-port for PC connection (direct transfer)
The indirect transfer is advantageous for the users who are not allowed to
install special drivers to their PCs.
IMPORTANT NOTE
For the time of measurements the PC should be disconnected!
High voltages on the line may interference the measurements or in
the worst case destroy the instrument or the PC!
KMK 8 calculates the cable length and the distance to fault by means of
the pre-programmed or user defined cable parameters and the preset
temperature.
KMK 8 is equipped with an internal rechargeable NiMH battery and a
processor controlled automatic charger-discharger circuit providing the
following functions:
•Battery capacity indication
•Charging process control
•Normal charging
•Fast charging
•Battery regeneration
•Battery initialization
•Protection against deep discharging
The battery can be charged from mains or from 12V car-battery or using
a 100 … 240 V AC charger.

2-1
2 KEYBOARD, SOCKETS AND LEDS
Controls
Switches the KMK 8 on and off. The instrument has an
automatic switch-off feature to save battery life: switch-off
takes place automatically 10 minutes after the latest
keystroke. (see section 15.1).
F1

F6
The function of the six Function keys depends on the active
measuring mode.
Starts or stops the selected measurement,
sequence or process.
This key is intended to acknowledge a selected measurement
mode or a new parameter, or to carry out other changes.

2-2
These keys are intended to select the required measuring
mode or to change a parameter.
These keys are intended to select the required option and to
adjust the position of vertical line cursor.
This key is intended to enter a minus sign or to set a vertical
maker in TDR mode
This key can be used to cancel something.
This key is intended to call the help function.
This key can be used for LCD contrast adjustment.
This key can be used for the control of back light..
This key enters ’0' (or a space pressing it twice) and
in TDR mode activates the SMOOTH function
This key enters '1'.

2-3
ABC
2
This key enters '2' or A B C letters when required
This key enters '3' or D E F letters when required.
This key enters '4' or G H I letters when required.
This key enters '5' or J K L letters when required.
This key enters '6' or M N O letters when required.
This key enters '7' or P Q R S letters when required.
This key enters '8' or T U V letters when required.
This key enters '9' or W X Y Z letters when required.
LEDs
Mains indicator
Charge indicator
Measurement indicator
Remote control indicator

2-4
2.1 Connectors & Balance Controls
1
Anti-theft protection
2
TDR balance
3
Socket to connect wire D in bridge modes, and L2 in TDR mode
4
Socket to connect wire C in bridge modes, and L2 in TDR mode
5
Socket to connect wire B in bridge modes, and L1 in TDR mode
6
Socket to connect wire A in bridge modes, and L1 in TDR mode
7
GND
8
Bridge balance M
9
2.1/5.5 mm coaxial connector for mains or 12 V car adapter
10
USB connector for connecting a PC
11
USB connector for connecting an USB flash drive
.

3-5
3 OPERATING INSTRUCTIONS
3.1 Start up and general rules
•Switch the instrument on.
•First the opening display appears showing the name and e-mail
address of the manufacturer .
•After the percentage of the BATTERY LEVEL will be shown.
•2 seconds later, self-test indication and the MAIN MENUappears.
Basically, the user should follow the instructions appearing at the bottom
of each display in all measurement modes.
•In most cases, the measuring, setting and editing modes are
selected by the menu-driven operation system. For selection use
the vertical cursor keys and then press ENTER.
•The various cable and test parameters can be selected with the
function keys: F1 to F6. To facilitate and speed up operation,
some of the measuring modes can be selected directly with them
too.
•The measurements can be started or stopped with the
START/STOP key. To return back to the previous display, press
ESC.

3-6
3.2 Calibration
Pressing the CAL (F6) key the CALIBRATION menu appears providing
two options:
•Calibration of test leads
•Self-calibration
Calibration of Test Leads
In that mode not only the resistance of test leads A, B, and Ebut also the
relay resistances of the input switch field will be measured, stored and
during the measurements compensated as well.
During the manufacturing process the actual resistance values were
stored but before the measurement of very low resistances or resistance
differences a repeated calibration is recommended.
Before calibration short the far ends of the three test leads and after:
•Select the CAL OF TEST LEADS option of CALIBRATION menu
•Press ENTER
When the calibration is completed three resistance values are displayed
containing the test lead and relay resistances.
These resistances will be taken into consideration at the following
measuring modes:
•Resistance 2-wire
•Resistance 2-wire&gnd
•Resistance difference
•Fault location Murray-Method
•Fault location 3 Point-Method
•Fault location Küpfmüller- Methods

3-7
Self calibration
•Select the SELF CALIBRATION option of CALIBRATION menu
•Press ENTER
Doing so the calibration parameters of active and passive bridges are
measured
The accuracy of the active bridge is based on the measurement of a built
in normal resistor of high preciosity. The result of that measurement is
stored as a reference value.
The accuracy of the passive bridge is based on the measurement of a
built in reference voltage source of high preciosity. The result of that
measurement is stored as a reference value.
During the calibration process the offset voltages of amplifiers are
measured and stored as well.

3-8
3.3 Storage and Recall of Measuring Results
When a test is completed the result can be saved in each measuring
mode under a user given object name There are four identifiers of each
stored results:
•OBJECT (user given name)
•DATE (automatically added)
•TIME (automatically added)
•MODE (automatically added)
The automatically added identifiers are very comfortable for the user,
as the time is different for each test result, the same object name can
be used repeatedly
Note:
The name of operator should be given before starting a measurement.
•Select SETTINGS/OPERATOR’S NAME
•Type the name in as it is usual at mobile phones
•Press ENTER
Saving of test results:
Having the test finished:
•Press the SAVE (F1) key
•Type an object name and press ENTER
Recall of test results.
•Enter the MAIN MENU/STORED RESULTS option
•Select the required result and press ENTER
Deleting a test result
•Enter the MAIN MENU/STORED RESULTS option
•Select the result to be deleted and press DELETE (F3)
•If you are sure press YES (F2)
Deleting all of the test results
•Enter the MAIN MENU/STORED RESULTS option
•Enter the group to be deleted and press EMPTY (F1)
•If you are sure press YES (F2)