Megger SMART THUMP ST25-30 User manual

ST25-30-UG-EN-V03
User Manual
Portable / Vehicle Mounted
Fault Locating System
SMART THUMP ST25-30
covering units with and without
MULTI SHOT Capability
Read this entire manual before operating.
M
Valley Forge Corporate Center
2621 Van Buren Avenue
Norristown, PA 19403-2329
U.S.A.
610-676-8500
www.megger.com

Portable / Vehicle Mounted Fault Locating System
SMART THUMP ST25-30

Copyright© 2019 by 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.
The information presented in this manual is believed to be adequate for the intended use of the
product. If the product or its individual instruments are used for purposes other than those
specified herein, confirmation of their validity and suitability must be obtained from Megger.
Refer to the warranty information below. Specifications are subject to change without notice.
WARRANTY
Products supplied by Megger are warranted against defects in material and workmanship for a
period of one year following shipment. Our liability is specifically limited to replacing or
repairing, at our option, defective equipment. Equipment returned for repair must be shipped
prepaid and insured. Contact your local MEGGER representative for instructions and a return
authorization (RA) number. Please indicate all pertinent information, including problem
symptoms. Also specify the serial number and the catalog number of the unit. This warranty does
not include batteries, lamps or other expendable items, where the original manufacturer’s
warranty shall apply. We make no other warranty. The warranty is void in the event of abuse
(failure to follow recommended operating procedures) or failure by the customer to perform
specific maintenance as indicated in this manual.

Local Megger Offices
Australia
Canada
France
Megger Pty Limited
Unit 1, 11-21 Underwood Road
Homebush
NSW 2140
T: [phone]
F:[phone]
110 Milner Avenue Unit 1
Scarborough Ontario
M1S 3R2 Canada
T: 1 416 298 6770
F: 416 298 0848
9 rue Michael Faraday
78180 Montigny-le-Bretonneux
T: 01 30 16 08 90
F: 01 34 61 23 77
Germany
India
Kingdom of Bahrain
Megger Germany
Dr. Herbert Iann Str. 6
96148 Baunach / Germany
T: [phone]
F: [phone]
Megger (India) Pvt Limited
501 Crystal Paradise Mall
Off. Veera Desai Road
Andheri (W)
Mumbai 400053
T: [phone]
F: [phone]
P.O. Box 15777
Office 81, Building 298
Road 3306, Block 333
Manama
Kingdom of Bahrain.
T: [phone]
F: + 973 177 20 975
[e-mail]
Kingdom of Saudi Arabia
South Africa
Sweden
PO Box 1168
Khobar 31952
T: [phone]
F: [phone]
[e-mail]
PO Box 22300
Glen Ashley 4022
Durban
South Africa
T: [phone]
F:[phone]
Megger Sweden AB
Eldarvägen 4
Box 2970
SE-187 29 TÄBY
SWEDEN
T: [phone]
F: [phone]
Switzerland
United Kingdom (Dover)
Megger Schweiz AG
Ob. Haselweg 630
5727 Oberkulm
Aargau
T: [phone]
F: [phone]
Megger Limited
Archcliffe Road
Dover CT17 9EN
T: 01304 502101
F: 01304 207342
United States
(Dallas)
United States
(Valley Forge)
United States
(College Station)
4545 W Davis St.,
Dallas, Texas 75211 USA
T: 1-800-723-2861
F: 1-214-331-7399
Valley Forge Corporate Center
2621 Van Buren Avenue
Norristown, PA 19403 USA
T: 610-676-8500
F: 610-676-8610
4064 State Highway 6 South
College Station, TX 77845 USA
T: 979-690-7925
F: 979-690-0276

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Table of Contents
1 SAFETY...................................................................................................................................... 1
Precautions .................................................................................................................................. 1
Warning and Caution Notices..................................................................................................... 1
Working with the Product .......................................................................................................... 3
Operating Personnel ................................................................................................................... 3
Repair and Maintenance.............................................................................................................. 3
General Cautions and Warnings ................................................................................................. 3
Intended Application............................................................................................................... 3
What to Do if Equipment Malfunctions ................................................................................. 4
Five Safety Rules ..................................................................................................................... 4
Important Safety Advisory Note - When Working With Hv Surge Generator / Thumper ... 5
Requirements for Safe High Voltage Work Environment ...................................................... 5
2 TECHNICAL DESCRIPTION ................................................................................................. 8
System Description ..................................................................................................................... 8
Functional Description............................................................................................................ 8
Product Models ....................................................................................................................... 8
Features ................................................................................................................................... 9
Scope of Delivery ...................................................................................................................10
Available Accessories..............................................................................................................10
Technical Data ...........................................................................................................................11
Control Elements, Indicators and Connectors...........................................................................14
Power Supply .............................................................................................................................16
Battery Operation ..................................................................................................................16
Introduction .......................................................................................................................16
Battery Status and Automatic Shutoff ................................................................................16
Backup Battery / DC Power Supply ..................................................................................17
Charging .............................................................................................................................17
120/230V AC Line Operation................................................................................................17
3 SETTING UP THE SYSTEM...................................................................................................19
Connection Diagram..................................................................................................................20
Connection Sequence .................................................................................................................20
4 OPERATING INSTRUCTIONS.............................................................................................22
Power on the System..................................................................................................................22
Basics of Operation ....................................................................................................................22
Operation with Rotary Knob.................................................................................................22
High Voltage Control ............................................................................................................23
Safety Circuit .............................................................................................................................23
Introduction ...........................................................................................................................23
Conditions of the Safety Circuit ............................................................................................24
User Modes ................................................................................................................................24
System Settings .......................................................................................................................25
5 HOW TO PERFORM A TEST................................................................................................31
Detecting and Locating a Cable Fault in a Shielded Medium Voltage Power Cable ..................31

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Locating a Faulty Cable Segment (Sectionalizing)..................................................................31
Introduction .......................................................................................................................31
How to Determine the Faulty Section ...............................................................................32
How to Verify Whether it is Actually a Bad Section .........................................................34
Locating a Cable Fault (shielded MV power cable) ................................................................35
How to Test the Dielectric Strength of the Cable..............................................................35
How to Pre-Locate the Fault..................................................................................................37
Arc Reflection Method (ARM) ..........................................................................................37
Current Decoupling (ICE) .................................................................................................40
How to Pinpoint a High Resistance (Flash-over) Fault..........................................................41
Detecting a Sheath Fault in a shielded Medium Voltage Cable or a Ground Fault in an
Unshielded, Low Voltage Cable (both must be directly buried)................................................42
How to Pinpoint a Sheath Fault in a Shielded Medium Voltage cable or a Ground Fault in an
Unshielded Low Voltage Cable (both must be directly buried).................................................45
6 CUSTOMIZE TDR FEATURES (applicable to TDR and ARM Mode)..................................46
Introduction...............................................................................................................................46
Customized TDR Features ........................................................................................................48
Completing the Operation.........................................................................................................50
7 ADVANCED SYSTEM SETTINGS ........................................................................................51
How to Edit the Cable List........................................................................................................51
Introduction ...........................................................................................................................51
XML Structure of a Cable List File........................................................................................51
How to Edit the Cable List....................................................................................................52
How to Setup Customer-Specific TDR Features .......................................................................53
How to Use EasyPROT Software to Plot DC HIPOT/Sheath Test Data................................55
8 CARE and MAINTENANCE ..................................................................................................56
Maintenance ...............................................................................................................................56
Storage........................................................................................................................................56
APPENDIX 1................................................................................................................................58
Overview of TDR Features........................................................................................................59

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Receiving Instructions
1. Check the equipment received against the packing list to ensure that all
materials are present. Notify Megger of any shortage. Email your local Service
Representative or send to VFCustomerSu[email protected].
2. Examine the equipment for damage received in transit. If damage is discovered,
file a claim with the carrier at once and notify Megger, giving a detailed
description of the damage.
3. Prior to operation, check for loosened hardware or damage incurred during
transit. If these conditions are found, a safety hazard is likely,
DO NOT attempt to operate equipment.
Please contact Megger as soon as possible.
Please check your delivery against:
a) your order
b) our advice note
c) the item delivered, and
d) the parts list
any shortages must be reported immediately.
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:
VFCustomerSu[email protected]
or
phone: [phone] (USA)

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1
SAFETY
Precautions
This manual contains basic instructions on commissioning and operating
the SMART THUMP ST25-30 system. For this reason, it is important to
ensure that the manual is available at all times to authorised and trained
personnel. Any personnel who will be using the devices shall read and
understand the manual thoroughly. The manufacturer will not be held
liable for any injury or damage to personnel or property through failure
to observe the safety precautions contained in this handbook.
Applicable local regulations have to be observed.
Warning and Caution Notices
Warning and caution notices are used throughout this manual where
applicable. These notices appear in the format shown below and are defined
as follows:
F
WARNING!
Warning, as used in this manual, is defined as a condition or
practice which could result in personal injury or loss of life.
G
CAUTION
Caution, as used in this manual, is defined as a condition or
practice which could result in damage to or destruction of the
equipment or apparatus under test. The user must consult the
User Guide when this symbol marked on the instrument.
u
PROTECTIVE EARTH TERMINAL
NOTE: The notes contain important information and useful tips for
using the system. Failure to observe them can render the
measuring results useless.

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SAFETY
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Working with the Product
It is important to observe the general electrical regulations of the country
in which the device will be installed and operated, as well as the current
national accident prevention regulations and internal company rules (work,
operating and safety regulations).
After working with the equipment, make sure to de-energise, protect
against re-energising; discharge, earth and short-circuit the equipment and
installations that have been worked on.
Use genuine accessories to ensure system safety and reliable operation. The
use of other parts is not permitted and invalidates the warranty.
Operating Personnel
This system and its peripheral equipment may only be operated by trained
or instructed personnel. Anyone else must be kept away.
The system may only be installed by a trained or authorized electrician. In
Germany DIN VDE 0104 (EN 50191), DIN VDE 0105 (EN 50110) and the
German accident prevention regulations (UVV) define an electrician as
someone whose knowledge, experience and familiarity with the applicable
regulations enables him to recognize potential hazards.
Repair and Maintenance
Repairs and service must only be done by Megger or Megger authorized
service departments. Megger recommends having the equipment serviced
and checked once per year at a Megger service location.
Megger also offers direct on-site support. Please contact our service office
for more information
General Cautions and Warnings
Intended Application
Safe operation is only warranted if using the equipment for its intended
purpose. Using the equipment for other purposes may result in bodily harm
or death of the operator and damage the equipment itself and that of the
involved test site.

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The limits described under technical data may not be exceeded. Operating
Megger products in environments, which feature high humidity in combi-
nation with condensation, may lead to flash-over, creepage, danger and
damage. The instruments should only be operated under tempered condi-
tions. It is not allowed to operate Megger products in direct contact with
humidity, water or near aggressive chemicals nor explosive gases and fumes.
What to Do if Equipment Malfunctions
The equipment shall only be used when working properly. If irregularities
or malfunctions appear which cannot be solved consulting this manual, the
equipment must immediately be put out of operation and marked as not
functional. In this case inform the person in charge who should inform the
Megger service to resolve the problem. The equipment shall only be
operated after the malfunction is resolved.
Five Safety Rules
The five safety rules must always be followed when working with HV
(High Voltage):
1. De-energize
2. Protect against re-energizing
3. Confirm absence of voltage
4. Ground and short-circuit
5. Cover close by energized components
Using cardiac pacemaker
Physical processes during operation of high voltage may endanger
persons wearing a cardiac pacemaker when near these high voltage
facilities
Fire fighting in electrical installations
According to regulations, Carbon Dioxide (CO2) is required to be used
as extinguishing agent for fighting fire in electrical installations.
Carbon Dioxide is electrically non conductive and does not leave
residues. It is safe to be used in energized facilities as long as the
minimum distances are maintained. A Carbon Dioxide fire extinguisher
must be always available within electrical installations.
If, contrary to the regulations, any other extinguishing agent is used for fire
fighting, this may lead to damage at the electrical installation. Megger
disclaims any liability for consequential damage. Furthermore, when using
a powder extinguisher near high-voltage installations, there is a danger

SAFETY
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that the operator of the fire extinguisher will get an electrical shock from an
ARC FLASH (voltage arc-over created by the powder dust cloud).
It is essential to observe the safety instruction on the extinguishing agent.
Applicable is DIN VDE 0132 in Germany
F
WARNING
Dangers when working with HV
Special attention and safety awareness are needed when operating HV equipment
and especially non-stationary equipment. The regulations VDE 0104 about setting
up and operation of electric test equipment, i.e. the corresponding EN 50191 as
well as country-specific regulations and standards must be observed.
The system generates a dangerous voltage of up to 20 kV during operation.
This is supplied via a HV cable to the test object.
The system may not be operated without supervision.
Safety installations may not be by-passed nor deactivated.
All metallic parts in proximity of the test equipment must be grounded in order to
avoid the build-up of hazardous electric surface charges.
F
WARNING
Not paying attention or correcting unsafe conditions can lead to personal injury
and potential death
IMPORTANT SAFETY ADVISORY NOTE -
WHEN WORKING WITH HV SURGE GENERATOR / THUMPER
REQUIREMENTS FOR SAFE WORK ENVIRONMENT WHEN PERFORMING MV or LV
POWER CABLE FAULT LOCATING BY DISCHARGING A HIGH VOLTAGE CAPACITOR
(Surge generator /Thumper)
Requirements for safe High Voltage work environment
(schematic on next page)
1. Safety Ground lead of unit is connected to system grounding point of power
device, ①, e.g. transformer, switchgear etc., via proper clamp,
no alligator clips.
2. High Voltage Return (= shield of test lead) ②is connected via clamp to
concentric neutral (shield) of power cable to be tested or to the grounded
second faulty core in case of belted MV cables or to the second faulty core of a
LV cable.
3. High Voltage lead ③is connected via clamp or other proper means to the
conductor of the power cable to be tested, no alligator clips.

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4. The Concentric Neutral (shield of the cable to be tested) of the power cable, or
the second faulty core of the cable to be tested must be bonded to the system
grounding point of the power device (see also 1).
5. The resistance of the system grounding point of the power device to earth ground
must be 5 Ohms or less when measured with an earth ground meter.
6. If a 5 Ωor less condition cannot be attained, the operator must follow the
specific work procedures and instructions, applicable to a
“hot”/“energized”/“live” work site; in Europe EN 50110-1 is mandatory.

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2
TECHNICAL DESCRIPTION
System Description
Functional Description
The SMART THUMP ST25-30 is a compact fault location system typically
to be used for fault locating of medium voltage power cables. It offers 2
or 3 power sources to be operated from, depending whether it is a vehicle
mounted or portable version. The 3 power sources are AC line voltage,
internal battery or external battery. When connected to the AC line, the
portable ST25-30 will operate and if equipped with an internal battery, its
74 Ah internal battery gets simultaneously charged.
The ST25-30 is ideally suited for use in both URD systems as well as for fee-
der cables and small and medium size network type systems. The
12/5/25kV surge and 30kV DC Hipot rating, in combination with the
ARM Multishot fea- ture qualify the ST25-30 for all type of cable insulation
materials, XLPE, EPR and also PILC. The main advantages of the ST25-30
are its solid HV perfor- mance, simple operation, automated fault locating
process, capable of ope- ration in rainy conditions, weight, ergonomics and
being self-contained.
Beside proven pre-location technique, like inductive ARM, current
decoupling ICE, the SMART THUMP provides sectionalizing capability
(trouble shooting in URD loop systems, North America), acoustic
pinpointing with the integra- ted 1600 J surge generator as well as HV DC
for insulation breakdown detec- tion, indication of insulation resistance
and LV cable Ground fault locating/ sheath testing / sheath fault locating
(sheath locating requires optional recei- ver ESG-NT).
Product Models
There are 7 configurations available for the ST25-30, 3 portable versions
mounted on an integrated hand truck with large air tires and 4 vehicle
mount versions with either an integrated or a remote control head.

TECHNICAL DESCRIPTION
ST25-30-UG-EN-V03
9
The portable versions can be selected with 1- (AC Only with internal
Isolation Transformer), 2- (AC with internal Isolation Transformer plus
external DC/ Internal Inverter) or 3power options (AC, External DC,
Internal Battery /Inverter, no Internal isolation transformer).
The vehicle mounted versions ST25-30 can be powered by AC (internal
isolation transformer) from the vehicle (via customer provided inverter) or
a generator system or by AC and external DC depending on the customer’s
specification
When installed into a vehicle, the ST25-30 also offers either an integrated or
remotely operated control head with a separation of up to 12ft between the
control head and the HV unit. The remote control head is installed in a
Pelicase style instrument enclosure.
This manual covers all models of the SMART THUMP ST25-30. If
necessary, any differences are noted in the text.
Features
The SMART THUMP ST25-30system combines the following features and
functions as a fully integrated device:
Quick Steps, Expert Mode and Manual Mode, allows to address 3 levels of
user skill; the Manual Mode is available in all units that are equipped with the
optional Multishot feature; if set to this mode all TDR features are always
available on the user interface and must be selected / adjusted by the user; the
automatic adjustments known from Quick-Steps and Expert mode are disabled in
Manual Mode. This mode caters to the group of users who prefer to set the TDR
up according to their own experience and expertise.
Quick Steps and Expert Mode provide Automatic fault Prelocation and
localization with regard to the 2 closest transformers (Sectionalizing software for
MV circuits, optional)
Quick Steps and Expert Mode provide Automatic cable end and fault
detection and localization
DC test up to 30kV with automatic breakdown detection and insulation
resistance measurement
Pinpointing of high resistance faults in surge mode (0-12.5 or 0-25kV)

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Ground Fault (Sheath) test with automatic breakdown detection (5kV
max.)
Ground Fault (Sheath Fault)) pinpointing (requires optional receiver
ESG-NT) (5kV max.)
Integrated safety circuit for user’s safety (F-OHM for verification of
correct connections of Safety Ground and HV Return)
Optional external remotely operated safety device to shut off HV and
ground system (remote Emergency Off function)
Operation from internal battery / inverter or from an external AC or
external DC source (e.g. external battery)
Sturdy and dust /weatherproof enclosure for outdoor use, IP53
Scope of Delivery
The scope of delivery of the ST25-30 system comprises of the following
components:
HV output cable hard wired
Safety Grounding cable
AC Power cord
Owner’s manual
Available Accessories
The following accessories* can be ordered from Megger, if required:
Accessories Description Item number
Elbow adaptor with 14 mm
female MC connector, fits
T1 terminations
(NAFTA market)
Used to connect HV output
cable
865000100100000 (15 kV)
865000200100000 (25 kV)
865000300100000 (35 kV)
External safety device Safety device with signal
lamps, key switch and
EMERGENCY OFF switch
893024147 and 890024896
*see also separate Data Sheet for optional accessories and cable reels CFL_ACCESS_DS_US_V04