EurotestCOMBO
MI 3125
MI 3125 BT
Instruction manual
Version 2.3.2, Code no. 20 751 484
Source document version: Version 2.3, Code no. 20 751 484
2
Distributor:
Mark on your equipment certifies that this equipment meets the requirements of the EU
(European Union) concerning safety and electromagnetic compatibility regulations
Manufacturer:
METREL d.d.
Ljubljanska cesta 77
1354 Horjul
Slovenia
web site: http://www.metrel.si
e-mail: metrel@metrel.si
© 2019 METREL
The trade names Metrel, Smartec, Eurotest, Autosequence are trademarks registered or pending in
Europe and other countries.
No part of this publication may be reproduced or utilized in any form or by any means
without permission in writing from METREL.
3
MI 3125 / BT EurotestCOMBO Table of contents
Table of contents
1 Preface .................................................................................................................... 7
2 Safety and operational considerations ................................................................. 8
2.1 Warnings and notes .......................................................................................... 8
2.2 Battery and charging ....................................................................................... 11
2.2.1 New battery cells or cells unused for a longer period ............................................. 12
2.3 Standards applied ........................................................................................... 13
3 Instrument description ......................................................................................... 14
3.1 Front panel ...................................................................................................... 14
3.2 Connector panel .............................................................................................. 16
3.3 Back side ......................................................................................................... 17
3.4 Display organization ........................................................................................ 18
3.4.1 Terminal voltage monitor ....................................................................................... 18
3.4.2 Battery indication ................................................................................................... 18
3.4.3 Message field ........................................................................................................ 18
3.4.4 Result field ............................................................................................................ 19
3.4.5 Sound warnings ..................................................................................................... 19
3.4.6 Help screens ................................................................ ......................................... 19
3.4.7 Backlight and contrast adjustments ....................................................................... 20
3.5 Instrument set and accessories ....................................................................... 21
3.5.1 Standard set MI 3125 ............................................................................................ 21
3.5.2 Standard set MI 3125 BT ....................................................................................... 21
3.5.3 Optional accessories ............................................................................................. 21
4 Instrument operation ............................................................................................ 22
4.1 Function selection ........................................................................................... 22
4.2 Settings ........................................................................................................... 23
4.2.1 Memory (model MI 3125 BT) ................................................................................. 23
4.2.2 Language .............................................................................................................. 24
4.2.3 Date and time (model MI 3125 BT) ........................................................................ 24
4.2.4 RCD testing ........................................................................................................... 24
4.2.5 Isc factor................................................................................................................ 26
4.2.6 Commander support .............................................................................................. 26
4.2.7 Initial settings ........................................................................................................ 27
5 Measurements ...................................................................................................... 29
5.1 Voltage, frequency and phase sequence ........................................................ 29
5.2 Insulation resistance ........................................................................................ 31
5.3 Resistance of earth connection and equipotential bonding ............................. 33
5.3.1 R LOWΩ, 200 mA resistance measurement .......................................................... 34
5.3.2 Continuous resistance measurement with low current ................................ ........... 35
5.3.3 Compensation of test leads resistance .................................................................. 36
5.4 Testing RCDs .................................................................................................. 37
5.4.1 Contact voltage (RCD Uc) ..................................................................................... 38
5.4.2 Trip-out time (RCDt) .............................................................................................. 39
5.4.3 Trip-out current (RCD I) ......................................................................................... 40
5.4.4 RCD Autotest ........................................................................................................ 41
5.5 Fault loop impedance and prospective fault current ........................................ 44
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MI 3125 / BT EurotestCOMBO Table of contents
5.6 Line impedance and prospective short-circuit current / Voltage drop .............. 46
5.6.1 Voltage drop .......................................................................................................... 48
5.7 Earth resistance .............................................................................................. 50
5.8 PE test terminal ............................................................................................... 51
6 Data handling (model MI 3125 BT) ...................................................................... 53
6.1 Memory organization ....................................................................................... 53
6.2 Data structure .................................................................................................. 53
6.3 Storing test results ........................................................................................... 55
6.4 Recalling test results ....................................................................................... 56
6.5 Clearing stored data ........................................................................................ 57
6.5.1 Clearing complete memory content ....................................................................... 57
6.5.2 Clearing measurement(s) in selected location ....................................................... 57
6.5.3 Clearing individual measurements ......................................................................... 58
6.5.4 Renaming installation structure elements (upload from PC) .................................. 59
6.5.5 Renaming installation structure elements with serial barcode reader or RFID reader
59
6.6 Communication (model MI 3125 BT) ............................................................... 61
6.6.1 USB and RS232 communication ........................................................................... 61
6.6.2 Bluetooth communication ...................................................................................... 62
7 Upgrading the instrument ................................................................ .................... 63
8 Maintenance .......................................................................................................... 64
8.1 Fuse replacement ............................................................................................ 64
8.2 Cleaning .......................................................................................................... 64
8.3 Periodic calibration .......................................................................................... 64
8.4 Service ............................................................................................................ 64
9 Technical specifications ...................................................................................... 65
9.1 Insulation resistance ........................................................................................ 65
9.2 Continuity ........................................................................................................ 66
9.2.1 Resistance R LOW ............................................................................................. 66
9.2.2 Resistance CONTINUITY ...................................................................................... 66
9.3 RCD testing ..................................................................................................... 66
9.3.1 General data ......................................................................................................... 66
9.3.2 Contact voltage RCD-Uc ....................................................................................... 67
9.3.3 Trip-out time .......................................................................................................... 67
9.3.4 Trip-out current ...................................................................................................... 68
9.4 Fault loop impedance and prospective fault current ........................................ 68
9.4.1 No disconnecting device or FUSE selected ........................................................... 68
9.4.2 RCD selected ........................................................................................................ 69
9.5 Line impedance and prospective short-circuit current / Voltage drop .............. 69
9.6 Resistance to earth ......................................................................................... 70
9.7 Voltage, frequency, and phase rotation ........................................................... 70
9.7.1 Phase rotation ....................................................................................................... 70
9.7.2 Voltage .................................................................................................................. 71
9.7.3 Frequency ............................................................................................................. 71
9.7.4 Online terminal voltage monitor ............................................................................. 71
9.8 General data .................................................................................................... 71
A Appendix A - Fuse table ....................................................................................... 73
A.1 Fuse table - IPSC ............................................................................................ 73
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MI 3125 / BT EurotestCOMBO Table of contents
A.2 Fuse table – Impedances at 230 V a.c. (AS/NZS 3017) .................................. 76
B Appendix B - Accessories for specific measurements ..................................... 77
C Appendix C – Country notes ............................................................................... 78
C.1 List of country modifications ............................................................................ 78
C.2 Modification issues .......................................................................................... 78
C.2.1 HUN modification – gR fuse types ..................................................................... 78
C.2.2 AT modification - G type RCD............................................................................ 79
C.2.3 NO, DK, SW modification – IT supply system .................................................... 80
C.2.4 AUS / NZ modification – Fuse types according to AS/NZS 3017 ....................... 81
D Appendix D - IT supply systems ......................................................................... 84
D.1 Standard references ........................................................................................ 84
D.2 Fundamentals .................................................................................................. 84
D.3 Measurement guides ....................................................................................... 84
E Appendix E – Commanders (A 1314, A 1401) ..................................................... 87
E.1 Warnings related to safety............................................................................. 87
E.2 Battery ................................................................................................................. 87
E.3 Description of commanders ................................................................................. 87
E.4 Operation of commanders ................................................................................... 88
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MI 3125 / BT EurotestCOMBO Preface
1 Preface
Congratulations on your purchase of the Eurotest instrument and its accessories from
METREL. The instrument was designed on a basis of rich experience, acquired through
many years of dealing with electric installation test equipment.
The Eurotest instrument is professional, multifunctional, hand-held test instrument
intended to perform all the measurements required in order for a total inspection of
electrical installations in buildings. The following measurements and tests can be
performed:
Voltage and frequency,
Continuity tests,
Insulation resistance tests,
Earthing resistance tests,
RCD testing,
Fault loop / RCD trip-lock impedance measurements,
Line impedance / Voltage drop,
Phase sequence.
The graphic display with backlight offers easy reading of results, indications,
measurement parameters and messages. Two LED Pass/Fail indicators are placed at
the sides of the LCD.
The operation of the instrument is designed to be as simple and clear as possible and
no special training (except for the reading this instruction manual) is required in order to
begin using the instrument.
In order for operator to be familiar enough with performing measurements in general
and their typical applications it is advisable to read Metrel handbook Guide for testing
and verification of low voltage installations.
The model MI 3125 BT has inbuilt Bluetooth interface for easy communication with PC
and Android devices.
The instrument is equipped with the entire necessary accessory for comfortable testing.
Note:
For some national specific instrument implementations some details in the below
description can differ from the actual instrument implementation. Check the national
specific notes in Appendix C or ask your local dealer.
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MI 3125 / BT EurotestCOMBO Safety and operational considerations
2 Safety and operational considerations
2.1 Warnings and notes
In order to maintain the highest level of operator safety while carrying out various tests
and measurements, Metrel recommends keeping your Eurotest instruments in good
condition and undamaged. When using the instrument, consider the following general
warnings:
The symbol on the instrument means »Read the Instruction manual
with special care for safe operation«. The symbol requires an action!
If the test equipment is used in a manner not specified in this user manual,
the protection provided by the equipment could be impaired!
Read this user manual carefully, otherwise the use of the instrument may
be dangerous for the operator, the instrument or for the equipment under
test!
Do not use the instrument or any of the accessories if any damage is
noticed!
If a fuse blows in the instrument, follow the instructions in this manual in
order to replace it!
Consider all generally known precautions in order to avoid risk of electric
shock while dealing with hazardous voltages!
Do not use the instrument in supply systems with voltages higher than
550 V!
Service intervention or adjustment is only allowed to be carried out by a
competent authorized personnel!
Use only standard or optional test accessories supplied by your
distributor!
Consider that protection category of some accessories is lower than of the
instrument. Test tips and Tip commander have removable caps. If they are
removed the protection falls to CAT II. Check markings on accessories!
(cap off, 18 mm tip)…CAT II up to 1000 V
(cap on, 4 mm tip)… CAT II 1000 V / CAT III 600 V / CAT IV 300 V
The instrument comes supplied with rechargeable Ni-Cd or Ni-MH battery
cells. The cells should only be replaced with the same type as defined on
the battery compartment label or as described in this manual. Do not use
standard alkaline battery cells while the power supply adapter is
connected, otherwise they may explode!
Hazardous voltages exist inside the instrument. Disconnect all test leads,
remove the power supply cable and switch off the instrument before
removing the battery compartment cover.
All normal safety precautions must be taken in order to avoid risk of
electric shock while working on electrical installations!
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MI 3125 / BT EurotestCOMBO Safety and operational considerations
Warnings related to measurement functions:
Insulation resistance
Insulation resistance measurement should only be performed on de-energized
objects!
Do not touch the test object during the measurement or before it is fully
discharged! Risk of electric shock!
When an insulation resistance measurement has been performed on a capacitive
object, automatic discharge may not be done immediately! The warning message
and the actual voltage is displayed during discharge until voltage drops below
10 V.
Do not connect test terminals to external voltage higher than 600 V (AC or DC) in
order not to damage the test instrument!
Continuity functions
Continuity measurements should only be performed on de-energized objects!
Parallel impedances or transient currents may influence test results.
Testing PE terminal
If phase voltage is detected on the tested PE terminal, stop all measurements
immediately and ensure the cause of the fault is eliminated before proceeding
with any activity!
Notes related to measurement functions:
General
The indicator means that the selected measurement cannot be performed
because of irregular conditions on input terminals.
Insulation resistance, continuity functions and earth resistance measurements
can only be performed on de-energized objects.
PASS / FAIL indication is enabled when limit is set. Apply appropriate limit value
for evaluation of measurement results.
In the case that only two of the three wires are connected to the electrical
installation under test, only voltage indication between these two wires is valid.
Insulation resistance
If voltages of higher than 10 V (AC or DC) is detected between test terminals, the
insulation resistance measurement will not be performed. If voltages of higher
than 10 V (AC or DC) is detected between test terminals, the insulation
resistance measurement will not be performed.
The instrument automatically discharge tested object after finished
measurement.
A double click of TEST key starts a continuous measurement.
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MI 3125 / BT EurotestCOMBO Safety and operational considerations
Continuity functions
If voltages of higher than 10 V (AC or DC) is detected between test terminals, the
continuity resistance test will not be performed.
Before performing a continuity measurement, where necessary, compensate test
lead resistance.
RCD functions
Parameters set in one function are also kept for other RCD functions!
The measurement of contact voltage does not normally trip an RCD. However,
the trip limit of the RCD may be exceeded as a result of leakage current flowing
to the PE protective conductor or a capacitive connection between L and PE
conductors.
The RCD trip-lock sub-function (function selector switch in LOOP position) takes
longer to complete but offers much better accuracy of fault loop resistance (in
comparison to the RL sub-result in Contact voltage function).
RCD trip-out time and RCD trip-out current measurements will only be performed
if the contact voltage in the pre-test at nominal differential current is lower than
the set contact voltage limit!
The autotest sequence (RCD AUTO function) stops when trip-out time is out of
allowable time period.
Z-LOOP
The low limit prospective short-circuit current value depends on fuse type, fuse
current rating, fuse trip-out time and impedance scaling factor.
The specified accuracy of tested parameters is valid only if the mains voltage is
stable during the measurement.
The measuring accuracy and immunity against noise are higher if parameter in
Zs rcd is set to standard “Std”.
Fault loop impedance measurements will trip an RCD.
The measurement of fault loop impedance using trip-lock function does not
normally trip an RCD. However, the trip limit may be exceeded as a result of
leakage current flowing to the PE protective conductor or a capacitive connection
between L and PE conductors. In this case setting parameter in measuring
function Zs rcd to “Low” can help.
Z-LINE / VOLTAGE DROP
In case of measurement of Z
Line-Line
with the instrument test leads PE and N
connected together the instrument will display a warning of dangerous PE
voltage. The measurement will be performed anyway.
Specified accuracy of tested parameters is valid only if mains voltage is stable
during the measurement.
L and N test terminals are reversed automatically according to detected terminal
voltage (except in UK version).
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MI 3125 / BT EurotestCOMBO Safety and operational considerations
+
-
Symbols:
Indication of battery charging
Figure 2.3: Charging indication
2.2 Battery and charging
The instrument uses six AA size alkaline or rechargeable Ni-Cd or Ni-MH battery cells.
Nominal operating time is declared for cells with nominal capacity of 2100 mAh.
Battery condition is always displayed in the lower right display part.
In case the battery is too weak the instrument indicates this as shown in figure 2.1. This
indication appears for a few seconds and then the instrument turns itself off.
Figure 2.1: Discharged battery indication
The battery is charged whenever the power supply adapter is connected to the
instrument. The power supply socket polarity is shown in figure 2.2.Internal circuit
controls charging and assures maximum battery lifetime.
Figure 2.2: Power supply socket polarity
The instrument automatically recognizes the connected power supply adapter and
begins charging.
When connected to an installation, the instruments battery compartment can
contain hazardous voltage inside! When replacing battery cells or before
opening the battery/fuse compartment cover, disconnect any measuring
accessory connected to the instrument and turn off the instrument,
Ensure that the battery cells are inserted correctly otherwise the instrument will
not operate and the batteries could be discharged.
If the instrument is not to be used for a long period of time, remove all batteries
from the battery compartment.
Alkaline or rechargeable Ni-Cd or Ni-MH batteries (size AA) can be used. Metrel
recommends only using rechargeable batteries with a capacity of 2100 mAh or
above.
Do not recharge alkaline battery cells!
Use only power supply adapter delivered from the manufacturer or distributor of
the test equipment to avoid possible fire or electric shock!
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MI 3125 / BT EurotestCOMBO Safety and operational considerations
Procedure
Notes
Completely charge the battery.
At least 14 h with in-built charger.
Completely discharge the battery.
This can be performed by using the
instrument normally until the instrument is
fully discharged.
Repeat the charge / discharge cycle
at least 2-4 times.
Four cycles are recommended in order to
restore the batteries to their normal
capacity.
2.2.1 New battery cells or cells unused for a longer period
Unpredictable chemical processes can occur during the charging of new battery cells or
cells that have been left unused for a longer period (more than 3 months). Ni-MH and
Ni-Cd cells can be subjected to these chemical effects (sometimes called the memory
effect). As a result the instrument operation time can be significantly reduced during the
initial charging/discharging cycles of the batteries.
In this situation, Metrel recommend the following procedure to improve the battery
lifetime:
Notes:
The charger in the instrument is a pack cell charger. This means that the battery
cells are connected in series during the charging. The battery cells have to be
equivalent (same charge condition, same type and age).
One different battery cell can cause an improper charging and incorrect
discharging during normal usage of the entire battery pack (it results in heating of
the battery pack, significantly decreased operation time, reversed polarity of
defective cell,…).
If no improvement is achieved after several charge / discharge cycles, then each
battery cell should be checked (by comparing battery voltages, testing them in a
cell charger, etc). It is very likely that only some of the battery cells are
deteriorated.
The effects described above should not be confused with the normal decrease of
battery capacity over time. Battery also loses some capacity when it is repeatedly
charged / discharged. Actual decreasing of capacity, versus number of charging
cycles, depends on battery type. This information is provided in the technical
specification from battery manufacturer.
12
MI 3125 / BT EurotestCOMBO Safety and operational considerations
Electromagnetic compatibility (EMC)
EN 61326
Electrical equipment for measurement, control and laboratory use –
EMC requirements
Class B (Hand-held equipment used in controlled EM environments)
Safety (LVD)
EN 61010-1
Safety requirements for electrical equipment for measurement, control
and laboratory use – Part 1: General requirements
EN 61010-031
Safety requirements for hand-held probe assemblies for electrical
measurement and test
EN 61010-2-030
Safety requirements for electrical equipment for measurement,
control, and laboratory use - Part 2-030: Particular requirements for
testing and measuring circuits.
Functionality
EN 61557
Electrical safety in low voltage distribution systems up to 1000 VAC
and 1500 VAC – Equipment for testing, measuring or monitoring of
protective measures
Part 1: General requirements
Part 2: Insulation resistance
Part 3: Loop resistance
Part 4: Resistance of earth connection and equipotential bonding
Part 5: Resistance to earth
Part 6: Residual current devices (RCDs) in TT and TN systems
Part 7: Phase sequence
Part 10: Combined measuring equipment
Other reference standards for testing RCDs
EN 61008
Residual current operated circuit-breakers without integral overcurrent
protection for household and similar uses
EN 61009
Residual current operated circuit-breakers with integral overcurrent
protection for household and similar uses
EN 60364-4-41
Electrical installations of buildings Part 4-41 Protection for safety –
protection against electric shock
IEC 60364-5-52
Low-voltage electrical installations – Part 5-52: Selection and erection
of electrical equipment – Wiring systems
BS 7671
IEE Wiring Regulations (17th edition)
AS / NZ 3760
In-service safety inspection and testing of electrical equipment
2.3 Standards applied
The Eurotest instruments are manufactured and tested in accordance with the following
regulations:
Note about EN and IEC standards:
Text of this manual contains references to European standards. All standards of
EN 6XXXX (e.g. EN 61010) series are equivalent to IEC standards with the same
number (e.g. IEC 61010) and differ only in amended parts required by European
harmonization procedure.
13
MI 3125 / BT EurotestCOMBO Instrument description
2
3
4
5
6
7
8
9
10
1
11
12
1
LCD
128 x 64 dots matrix display with backlight.
2
TEST
TEST
Starts measurements.
Acts also as the PE touching electrode.
3
UP
Modifies selected parameter.
4
DOWN
5*
MEM
Store / recall / clear tests in memory of instrument.
5**
CAL
Calibrates test leads in Continuity functions.
Starts Z
REF
measurement in Voltage drop sub-function.
6
Function selectors
Selects test function.
7
Backlight,
Contrast
Changes backlight level and contrast.
8
ON / OFF
Switches the instrument power on or off.
The instrument automatically turns off 15 minutes after the
last key was pressed.
3 Instrument description
3.1 Front panel
Legend:
* Model MI 3125 BT
** Model MI 3125
Figure 3.1: Front panel (picture of MI 3125 BT)
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MI 3125 / BT EurotestCOMBO Instrument description
9*
HELP / CAL
Accesses help menus.
In RCD Auto toggles between top and bottom parts of results
field.
Calibrates test leads in Continuity functions.
Starts Z
REF
measurement in Voltage drop sub-function.
9**
HELP
Accesses help menus.
In RCD Auto toggles between top and bottom parts of results
field.
10
TAB
Selects the parameters in selected function.
11
PASS
Green indicator
Indicates PASS/ FAIL of result.
12
FAIL
Red indicator
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MI 3125 / BT EurotestCOMBO Instrument description
1
Test connector
Measuring inputs / outputs
2
Protection cover
3 Charger socket
4*
USB connector
Communication with PC USB (1.1) port.
5*
PS/2 connector
Communication with PC serial port and connection to optional
accessories.
5**
PS/2 connector
Serial port for upgrading the instrument.
3.2 Connector panel
Figure 3.2: Connector panel (picture of MI 3125 BT)
Legend:
* Model MI 3125 BT
** Model MI 3125
Warnings!
Maximum allowed voltage between any test terminal and ground is 600 V!
Maximum allowed voltage between test terminals is 600 V!
Maximum short-term voltage of external power supply adapter is 14 V!
16
MI 3125 / BT EurotestCOMBO Instrument description
1
Side belt
2
Battery compartment cover
3
Fixing screw for battery compartment cover
4
Back panel information label
5
Holder for inclined position of the instrument
6
Magnet for fixing instrument close to tested item (optional)
1
Battery cells
Size AA, alkaline or rechargeable NiMH / NiCd
2
Serial number label
3 Fuse
M 0.315 A, 250 V
3.3 Back side
Figure 3.3: Back side
Legend:
Figure 3.4: Battery compartment
Legend:
17
MI 3125 / BT EurotestCOMBO Instrument description
Figure 3.5: Typical function
display
Function name
Result field
Test parameter field
Message field
Terminal voltage
monitor
Battery indication
Online voltages are displayed together with test terminal indication. All
three test terminals are used for selected measurement.
Online voltages are displayed together with test terminal indication. L
and N test terminals are used for selected measurement.
L and PE are active test terminals; N terminal should also be connected
for correct input voltage condition.
Battery capacity indication.
Low battery.
Battery is too weak to guarantee correct result. Replace or
recharge the battery cells.
Recharging in progress (if power supply adapter is connected).
Measurement is running, consider displayed warnings.
Conditions on the input terminals allow starting the measurement;
consider other displayed warnings and messages.
Conditions on the input terminals do not allow starting the
measurement, consider displayed warnings and messages.
3.4 Display organization
3.4.1 Terminal voltage monitor
The terminal voltage monitor displays on-line the voltages on the test terminals and
information about active test terminals.
3.4.2 Battery indication
The indication indicates the charge condition of battery and connection of external
charger.
3.4.3 Message field
In the message field warnings and messages are displayed.
18
MI 3125 / BT EurotestCOMBO Instrument description
RCD tripped-out during the measurement (in RCD functions).
Instrument is overheated. The measurement is prohibited until the
temperature decreases under the allowed limit.
Result(s) can be stored. (model MI 3125 BT)
High electrical noise was detected during measurement. Results may
be impaired.
L and N are changed.
Warning! High voltage is applied to the test terminals.
Warning! Dangerous voltage on the PE terminal! Stop the activity
immediately and eliminate the fault / connection problem before
proceeding with any activity!
Test leads resistance in Continuity measurement is not compensated.
Test leads resistance in Continuity measurement is compensated.
High resistance to earth of test probes. Results may be impaired.
Fuse F1 is broken.
Measurement result is inside pre-set limits (PASS).
Measurement result is out of pre-set limits (FAIL).
Measurement is aborted. Consider displayed warnings and messages.
Continuous sound
Warning! Dangerous voltage on the PE terminal is detected.
HELP
Opens help screen.
UP / DOWN
Selects next / previous help screen.
HELP
Scrolls through help screens.
Function selectors / TEST
Exits help menu.
3.4.4 Result field
3.4.5 Sound warnings
3.4.6 Help screens
Help menus are available in all functions. The Help menu contains schematic diagrams
for illustrating how to properly connect the instrument to electric installation. After
selecting the measurement you want to perform, press the HELP key in order to view
the associated Help menu.
Keys in help menu:
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MI 3125 / BT EurotestCOMBO Instrument description
Click
Toggles backlight intensity level.
Keep pressed for 1 s
Locks high intensity backlight level until power is turned off or the
key is pressed again.
Keep pressed for 2 s
Bargraph for LCD contrast adjustment is displayed.
DOWN
Reduces contrast.
UP
Increases contrast.
TEST
Accepts new contrast.
Function selectors
Exits without changes.
Figure 3.6: Examples of help screens
3.4.7 Backlight and contrast adjustments
With the BACKLIGHT key backlight and contrast can be adjusted.
Figure 3.7: Contrast adjustment menu
Keys for contrast adjustment:
20
MI 3125 / BT EurotestCOMBO Instrument description
3.5 Instrument set and accessories
3.5.1 Standard set MI 3125
Instrument
Short instruction manual
Calibration Certificate
Mains measuring cable
Test lead.,3 x 1.5 m
Test probe, 3 pcs
Crocodile clip, 3 pcs
Set of NiMH battery cells
Power supply adapter
CD with instruction manual, and “Guide for testing and verification of low voltage
installations” handbook
Set of carrying straps
3.5.2 Standard set MI 3125 BT
Instrument
Short instruction manual
Calibration Certificate
Mains measuring cable
Test lead, 3 x 1.5 m
Test probe, 3 pcs
Crocodile clip, 3 pcs
Set of NiMH battery cells
Power supply adapter
CD with instruction manual, and “Guide for testing and verification of low voltage
installations” handbook and PC software EuroLink PRO
Set of carrying straps
RS232 - PS/2 cable
USB cable
3.5.3 Optional accessories
See the attached sheet for a list of optional accessories that are available on request
from your distributor.
21
MI 3125 / BT EurotestCOMBO Instrument operation
FUNCTION
SELECTOR
Select test / measurement function:
<VOLTAGE TRMS> Voltage and frequency and phase sequence.
<R ISO> Insulation resistance.
<R LOWΩ> Resistance of earth connections and bondings.
<Zline> Line impedance
<Zloop> Fault loop impedance.
<RCD> RCD testing.
<EARTH RE> Resistance to earth
<SETTINGS> General instrument settings.
UP/DOWN
Selects sub-function in selected measurement function.
TAB
Selects the test parameter to be set or modified.
TEST
Runs selected test / measurement function.
MEM
Stores measured results / recalls stored results (model MI 3125 BT).
UP/DOWN
Changes the selected parameter.
TAB
Selects the next measuring parameter.
FUNCTION SELECTOR
Toggles between the main functions.
MEM
Stores measured results / recalls stored results
(model MI 3125 BT).
Parameter
OFF
No limit values, indication: _ _ _.
ON
Value(s) – results will be marked as PASS or FAIL in
accordance with selected limit.
4 Instrument operation
4.1 Function selection
For selecting test function the FUNCTION SELECTOR shall be used.
Keys:
Keys in test parameter field:
General rule regarding enabling parameters for evaluation of measurement / test result:
See Chapter 5 for more information about the operation of the instrument test functions.
22
MI 3125 / BT EurotestCOMBO Instrument operation
All models:
Selection of language,
Setting the instrument to initial
values,
Selection of reference standard for
RCD test,
Entering Isc factor,
Commander support.
Model MI 3125 BT:
Recalling and clearing stored results,
Setting the date and time
Figure 4.1: Options in Settings menu
UP / DOWN
Selects appropriate option.
TEST
Enters selected option.
Function selectors
Exits back to main function menu.
In this menu the stored data can be recalled
and deleted. See chapter 6 Data handling for
more information.
Figure 4.2: Memory options
UP / DOWN
Selects option.
TEST
Enters selected option.
Function selectors
Exits back to main function menu.
4.2 Settings
Different instrument options can be set in the SETTINGS menu.
Keys:
4.2.1 Memory (model MI 3125 BT)
Keys:
23
MI 3125 / BT EurotestCOMBO Instrument operation
In this menu the language can be set.
Figure 4.3: Language selection
UP / DOWN
Selects language.
TEST
Confirms selected language and exits to settings menu.
Function selectors
Exits back to main function menu.
In this menu date and time can be set.
Figure 4.4: Setting date and time
TAB
Selects the field to be changed.
UP / DOWN
Modifies selected field.
TEST
Confirms new setup and exits.
Function selectors
Exits back to main function menu.
In this menu the used standard for RCD
tests can be set.
Figure 4.5: Selection of RCD test
standard
4.2.2 Language
Keys:
4.2.3 Date and time (model MI 3125 BT)
Keys:
Warning:
If the batteries are removed for more than 1 minute the set time and date will be
lost.
4.2.4 RCD testing
24
MI 3125 / BT EurotestCOMBO Instrument operation
UP / DOWN
Selects standard.
TEST
Confirms selected standard.
Function selectors
Exits back to main function menu.
½I
N
*)
I
N
2I
N
5I
N
General RCDs
(non-delayed)
t > 300 ms
t < 300 ms
t < 150 ms
t < 40 ms
Selective RCDs
(time-delayed)
t > 500 ms
130 ms < t < 500 ms
60 ms < t < 200 ms
50 ms < t < 150 ms
½I
N
*)
I
N
2I
N
5I
N
General RCDs
(non-delayed)
t > 999 ms
t < 999 ms
t < 150 ms
t < 40 ms
Selective RCDs
(time-delayed)
t > 999 ms
130 ms < t < 999 ms
60 ms < t < 200 ms
50 ms < t < 150 ms
½I
N
*)
I
N
2I
N
5I
N
General RCDs
(non-delayed)
t > 1999 ms
t < 300 ms
t < 150 ms
t < 40 ms
Selective RCDs
(time-delayed)
t > 1999 ms
130 ms < t < 500 ms
60 ms < t < 200 ms
50 ms < t < 150 ms
½I
N
*)
I
N
2I
N
5I
N
RCD type
IN [mA]
t
t
t
t
Note
I
10
> 999 ms
40 ms
40 ms
40 ms
Maximum break time
II
> 10 30
300 ms
150 ms
40 ms
III
> 30
300 ms
150 ms
40 ms
IV
S
> 30
> 999 ms
500 ms
200 ms
150 ms
130 ms
60 ms
50 ms
Minimum non-actuating time
Standard
½I
N
I
N
2I
N
5I
N
EN 61008 / EN 61009
300 ms
300 ms
150 ms
40 ms
IEC 60364-4-41
1000 ms
1000 ms
150 ms
40 ms
BS 7671
2000 ms
300 ms
150 ms
40 ms
AS/NZS 3017 (I, II, III)
1000 ms
1000 ms
150 ms
40 ms
Keys:
Maximum RCD disconnection times differ in various standards.
The trip-out times defined in individual standards are listed below.
Trip-out times according to EN 61008 / EN 61009:
Trip-out times according to IEC 60364-4-41:
Trip-out times according to BS 7671:
Trip-out times according to AS/NZS 3017
*)
Minimum test period for current of ½IN, RCD shall not trip-out.
**)
Test current and measurement accuracy correspond to AS/NZS 3017 requirements.
**)
:
Maximum test times related to selected test current for general (non-delayed) RCD
Maximum test times related to selected test current for selective (time-delayed) RCD
25
MI 3125 / BT EurotestCOMBO Instrument operation
Standard
½I
N
I
N
2I
N
5I
N
EN 61008 / EN 61009
500 ms
500 ms
200 ms
150 ms
IEC 60364-4-41
1000 ms
1000 ms
200 ms
150 ms
BS 7671
2000 ms
500 ms
200 ms
150 ms
AS/NZS 3017 (IV)
1000 ms
1000 ms
200 ms
150 ms
In this menu the Isc factor for calculation of
short circuit current in Z-LINE and Z-LOOP
measurements can be set.
Figure 4.6: Selection of Isc factor
UP / DOWN
Sets Isc value.
TEST
Confirms Isc value.
Function selectors
Exits back to main function menu.
UP / DOWN
Selects commander model. Disables commander support.
TEST
Confirms selected option.
Function
selectors
Exits back to main function menu.
4.2.5 Isc factor
Keys:
Short circuit current Isc in the supply system is important for selection or verification of
protective circuit breakers (fuses, over-current breaking devices, RCDs).
The default value of Isc factor (ksc) is 1.00. The value should be set according to local
regulative.
Range for adjustment of the Isc factor is 0.20 3.00.
4.2.6 Commander support
The support for commanders can be set in this menu.
Figure 4.7: Selection of commander support
Keys:
26
MI 3125 / BT EurotestCOMBO Instrument operation
In this menu the instrument settings and
measurement parameters and limits can be
set to initial (factory) values.
Internal Bluetooth module is initialized. (MI
3125 BT only)
Figure 4.8: Initial settings dialogue
TEST
Restores default settings (YES must be selected with
/ keys).
Function selectors
Exits back to main function menu without changes.
Instrument setting
Default value
Contrast
As defined and stored by adjustment procedure
Isc factor
1.00
RCD standards
EN 61008 / EN 61009
Language
English
Commander
A1314, A1401
Internal bluetooth
Initialization of internal Bluetooth module.
(MI 3125 BT only)
Function
Parameters / limit value
Sub-function
EARTH RE
No limit
Commander models
A1314, A1401: new commanders (more information can be found in Appendix E)
Note:
Commander disabled is intended to disable the commander’s remote keys. In the
case of high EM interfering noise the operation of the commander’s key can be
irregular.
4.2.7 Initial settings
Keys:
Warnings:
Customized settings will be lost when this option is used!
If the batteries are removed for more than 1 minute the custom made settings will
be lost.
The default setup is listed below:
27
MI 3125 / BT EurotestCOMBO Instrument operation
R ISO
No limit
Utest = 500 V
Low Ohm Resistance
R LOW
No limit
CONTINUITY
No limit
Z - LINE
Fuse type: none selected
VOLTAGE DROP
ΔU: 4.0 %
Z
REF
: 0.00 Ω
Z - LOOP
Fuse type: none selected
Zs rcd
Test current: standard
Fuse type: none selected
RCD
RCD t
Nominal differential current: IN=30 mA
RCD type: AC
non-delayed
Test current starting polarity: (0)
Limit contact voltage: 50 V
Current multiplier: 1
Note:
Initial settings (reset of the instrument) can be recalled also if the TAB key is
pressed while the instrument is switched on.
28
MI 3125 / BT EurotestCOMBO Measurements
See chapter 4.1 Function selection for instructions on
key functionality.
Figure 5.1: Voltage in single
phase system
5 Measurements
5.1 Voltage, frequency and phase sequence
Voltage and frequency measurement is always active in the terminal voltage monitor. In
the special VOLTAGE TRMS menu the measured voltage, frequency and information
about detected three-phase connection can be stored. Phase sequence measurement
conforms to the EN 61557-7 standard.
Test parameters for voltage measurement
There are no parameters to set.
Connections for voltage measurement
Figure 5.2: Connection of 3-wire test lead and optional adapter in three-phase system
Figure 5.3: Connection of plug commander and 3-wire test lead in single-phase system
29
MI 3125 / BT EurotestCOMBO Measurements
Select the VOLTAGE TRMS function using the function selector switch.
Connect test cable to the instrument.
Connect test leads to the item to be tested (see figures 5.2 and 5.3).
Store voltage measurement result by pressing the MEM key (optional)*.
Voltage measurement procedure
* model MI 3125 BT
Measurement runs immediately after selection of VOLTAGE TRMS function.
Figure 5.4: Examples of voltage measurement in three-phase system
Displayed results for single phase system:
Uln ........... Voltage between phase and neutral conductors,
Ulpe ......... Voltage between phase and protective conductors,
Unpe ........ Voltage between neutral and protective conductors,
f ............... frequency.
Displayed results for three-phase system:
U12 .......... Voltage between phases L1 and L2,
U13 .......... Voltage between phases L1 and L3,
U23 .......... Voltage between phases L2 and L3,
1.2.3 ........ Correct connection – CW rotation sequence,
3.2.1 ........ Invalid connection – CCW rotation sequence,
f ............... frequency.
30
MI 3125 / BT EurotestCOMBO Measurements
See chapter 4.1 Function selection for instructions on
key functionality.
Figure 5.5: Insulation resistance
Uiso
Test voltage [50 V, 100 V, 250 V, 500 V, 1000 V]
Limit
Minimum insulation resistance [OFF, 0.01 M ÷ 200 M]
5.2 Insulation resistance
The Insulation resistance measurement is performed in order to ensure safety against
electric shock through insulation. It is covered by the EN 61557-2 standard. Typical
applications are:
Insulation resistance between conductors of installation,
Insulation resistance of non-conductive rooms (walls and floors),
Insulation resistance of ground cables,
Resistance of semi-conductive (antistatic) floors.
Test parameters for insulation resistance measurement
Test circuits for insulation resistance
Figure 5.6: Connections for insulation measurement
31
MI 3125 / BT EurotestCOMBO Measurements
Select the INS function using the function selector switch.
Set the required test voltage.
Enable and set limit value (optional).
Disconnect tested installation from mains supply (and discharge insulation as
required).
Connect test cable to the instrument and to the item to be tested (see figure 5.6).
Press the TEST key to perform the measurement (double click for continuous
measurement and later press to stop the measurement).
After the measurement is finished wait until tested item is fully discharged.
Store the result by pressing the MEM key (optional)*.
Insulation resistance measuring procedure
* model MI 3125 BT
Figure 5.7: Example of insulation resistance measurement result
Displayed results:
R.........................Insulation resistance
Um......................Test voltage – actual value.
32
MI 3125 / BT EurotestCOMBO Measurements
See chapter 4.1 Function selection for instructions on
key functionality.
Figure 5.8: 200 mA RLOW Ω
TEST
Resistance measurement sub-function [R LOWΩ, CONTINUITY]
Limit
Maximum resistance [OFF, 0.1 ÷ 20.0 ]
5.3 Resistance of earth connection and equipotential bonding
The resistance measurement is performed in order to ensure that the protective
measures against electric shock through earth connections and bondings are effective.
Two sub-functions are available:
R LOWΩ - Earth bond resistance measurement according to EN 61557-4
(200 mA),
CONTINUITY - Continuous resistance measurement performed with 7 mA.
Test parameters for resistance measurement
33
MI 3125 / BT EurotestCOMBO Measurements
Select continuity function using the function selector switch.
Set sub-function to R LOWΩ.
Enable and set limit (optional).
Connect test cable to the instrument.
Compensate the test leads resistance (if necessary, see section 5.3.3).
Disconnect from mains supply and discharge installation to be tested.
Connect the test leads to the appropriate PE wiring (see figure 5.9).
Press the TEST key to perform the measurement.
After the measurement is finished store the result by pressing the MEM button
(optional)*.
5.3.1 R LOWΩ, 200 mA resistance measurement
The resistance measurement is performed with automatic polarity reversal of the test
voltage.
Test circuit for R LOWΩ measurement
Figure 5.9: Connection of 3-wire test lead plus optional extension lead
Resistance to earth connection and equipotential bonding measurement procedure
* model MI 3125 BT
Figure 5.10: Example of RLOW result
34
MI 3125 / BT EurotestCOMBO Measurements
Select continuity function using the function selector switch.
Set sub-function CONTINUITY.
Enable and set the limit (optional).
Enable sound (optional).
Connect test cable to the instrument.
Compensate test leads resistance (if necessary, see section 5.3.3).
Disconnect from mains supply and discharge the object to be tested.
Connect test leads to the tested object (see figure 5.11).
Press the TEST key to begin performing a continuous measurement.
Press the TEST key to stop measurement.
After the measurement is finished, store the result (optional)*.
Displayed result:
R................R LOWΩ resistance.
R+..............Result at positive polarity
R-...............Result at negative test polarity
5.3.2 Continuous resistance measurement with low current
In general, this function serves as standard -meter with a low testing current. The
measurement is performed continuously without polarity reversal. The function can also
be applied for testing continuity of inductive components.
Test circuit for continuous resistance measurement
Figure 5.11: 3-wire test lead application
Continuous resistance measurement procedure
* model MI 3125 BT
Figure 5.12: Example of continuous resistance measurement
35
MI 3125 / BT EurotestCOMBO Measurements
Select R LOWΩ or CONTINUITY function.
Connect test cable to the instrument and short the test leads together (see figure
5.13).
Press TEST to perform resistance measurement.
Press the CAL key to compensate leads resistance.
Figure 5.14: Results with old calibration
values
Figure 5.15: Results with new calibration
values
Displayed result:
R............Resistance
Notes:
Continuous buzzer sound indicates that measured resistance PASS the limit.
There is no sound if the limit is disabled (---).
5.3.3 Compensation of test leads resistance
This chapter describes how to compensate the test leads resistance in both continuity
functions, R LOWΩ and CONTINUITY. Compensation is required to eliminate the
influence of test leads resistance and the internal resistances of the instrument on the
measured resistance. The lead compensation is therefore a very important feature to
obtain correct result.
R LOWΩ and CONTINUITY has common compensation. symbol is displayed if the
compensation was carried out successfully.
Circuits for compensating the resistance of test leads
Figure 5.13: Shorted test leads
Compensation of test leads resistance procedure
Note:
The highest value for lead compensation is 5 . If the resistance is higher the
compensation value is set back to default value.
is displayed if no calibration value is stored.
36
MI 3125 / BT EurotestCOMBO Measurements
See chapter 4.1 Function selection for instructions on
key functionality.
Figure 5.16: RCD test
TEST
RCD sub-function test [RCDt, RCD I, AUTO, Uc].
IN
Rated RCD residual current sensitivity IN [10 mA, 30 mA, 100 mA, 300 mA,
500 mA, 1000 mA].
type
RCD type AC, A, F, B*, B+*, starting polarity [ , , , ,
*, *
],
selective
S
or general characteristic.
MUL
Multiplication factor for test current [½, 1, 2, 5 IN].
Ulim
Conventional touch voltage limit [25 V, 50 V].
5.4 Testing RCDs
Various test and measurements are required for verification of RCD(s) in RCD protected
installations. Measurements are based on the EN 61557-6 standard.
The following measurements and tests (sub-functions) can be performed:
Contact voltage,
Trip-out time,
Trip-out current,
RCD autotest.
Test parameters for RCD test and measurement
* Model MI 3125 BT
Notes:
Ulim can be selected in the Uc sub-function only.
Selective (time delayed) RCDs have delayed response characteristics. As the
contact voltage pre-test or other RCD tests influence the time delayed RCD it
takes a certain period to recover into normal state. Therefore a time delay of 30 s
is inserted before performing trip-out test by default.
37
MI 3125 / BT EurotestCOMBO Measurements
Select the RCD function using the function selector switch.
Set sub-function Uc.
Set test parameters (if necessary).
Connect test cable to the instrument.
Connect test leads to the item to be tested (see figure 5.17).
Press the TEST key to perform the measurement.
Store the result by pressing the MEM key (optional)*.
Connections for testing RCD
Figure 5.17: Connecting the plug commander and the 3-wire test lead
5.4.1 Contact voltage (RCD Uc)
A current flowing into the PE terminal causes a voltage drop on earth resistance, i.e.
voltage difference between PE equipotential bonding circuit and earth. This voltage
difference is called contact voltage and is present on all accessible conductive parts
connected to the PE. It shall always be lower than the conventional safety limit voltage.
The contact voltage is measured with a test current lower than ½ I
the RCD and then normalized to the rated IN.
Contact voltage measurement procedure
* model MI 3125 BT
to avoid trip-out of
N
The contact voltage result relates to the rated nominal residual current of the RCD and
is multiplied by an appropriate factor (depending on RCD type and type of test current).
The 1.05 factor is applied to avoid negative tolerance of result. See table 5.1 for detailed
contact voltage calculation factors.
38
MI 3125 / BT EurotestCOMBO Measurements
RCD type
Contact voltage Uc
proportional to
Rated IN
AC
1.05IN
any
All models
AC
S
21.05IN
A, F
1.41.05IN
30 mA
A, F
S
21.41.05IN
A, F
21.05IN
< 30 mA
A, F
S
221.05IN
B, B+
21.05IN
any
Model MI 3125 BT
B, B+
S
221.05IN
N
C
L
I
U
R
Select the RCD function using the function selector switch.
Set sub-function RCDt.
Set test parameters (if necessary).
Connect test cable to the instrument.
Connect test leads to the item to be tested (see figure 5.17).
Press the TEST key to perform the measurement.
Store the result by pressing the MEM key (optional)*.
Table 5.1: Relationship between Uc and I
N
Loop resistance is indicative and calculated from Uc result (without additional
proportional factors) according to:
.
Figure 5.18: Example of contact voltage measurement results
Displayed results:
Uc ........ Contact voltage.
Rl ......... Fault loop resistance.
5.4.2 Trip-out time (RCDt)
Trip-out time measurement verifies the sensitivity of the RCD at different residual
currents.
Trip-out time measurement procedure
* model MI 3125 BT
39
MI 3125 / BT EurotestCOMBO Measurements
RCD type
Slope range
Waveform
Note
Start value
End value
AC
0.2IN
1.1IN
Sine
All models
A, F (IN 30 mA)
0.2IN
1.5IN
Pulsed
A, F (IN = 10 mA)
0.2IN
2.2IN
B, B+
0.2IN
2.2IN
DC
Model MI 3125 BT
Select the RCD function using the function selector switch.
Set sub-function RCD I.
Set test parameters (if necessary).
Connect test cable to the instrument.
Connect test leads to the item to be tested (see figure 5.17).
Press the TEST key to perform the measurement.
Store the result by pressing the MEM key (optional)*.
Trip-out
After the RCD is turned on again
Figure 5.19: Example of trip-out time measurement results
Displayed results:
t ........... Trip-out time,
Uc ........ Contact voltage for rated IN.
5.4.3 Trip-out current (RCD I)
A continuously rising residual current is intended for testing the threshold sensitivity for
RCD trip-out. The instrument increases the test current in small steps through
appropriate range as follows:
Maximum test current is I (trip-out current) or end value in case the RCD didn’t trip-out.
Trip-out current measurement procedure
* model MI 3125 BT
Figure 5.20: Trip-out current measurement result example
40
MI 3125 / BT EurotestCOMBO Measurements
HELP / DISPLAY
Toggles between top and bottom part of results field.
RCD Autotest steps
Notes
Select the RCD function using the function selector switch.
Set sub-function AUTO.
Set test parameters (if necessary).
Connect test cable to the instrument.
Connect test leads to the item to be tested (see figure
5.17).
Press the TEST key to perform the test.
Start of test
Test with I
N
, 0 (step 1).
RCD should trip-out
Re-activate RCD.
Test with I
N
, 180 (step 2).
RCD should trip-out
Re-activate RCD.
Test with 5I
N
, 0 (step 3).
RCD should trip-out
Re-activate RCD.
Test with 5I
N
, 180 (step 4).
RCD should trip-out
Re-activate RCD.
Test with ½IN, 0 (step 5).
RCD should not tripout
Test with ½IN, 180 (step 6).
RCD should not tripout
Trip-out current test, 0 (step 7).
RCD should trip-out
Re-activate RCD.
Trip-out current test, 180 (step 8).
RCD should trip-out
Re-activate RCD.
Store the result by pressing the MEM key (optional)*.
End of test
Displayed results:
I ........... Trip-out current,
Uci Contact voltage at trip-out current I or end value in case the RCD didn’t
trip,
t ........... Trip-out time.
5.4.4 RCD Autotest
RCD autotest function is intended to perform a complete RCD test (trip-out time at
different residual currents, trip-out current and contact voltage) in one set of automatic
tests, guided by the instrument.
Additional key:
RCD autotest procedure
* model MI 3125 BT
41
MI 3125 / BT EurotestCOMBO Measurements
Step 1
Step 2
Step 3
Step 4
Step 5
Step 6
Step 7
Step 8
Figure 5.21: Individual steps in RCD autotest
Top
Bottom
Figure 5.22: Two parts of result field in RCD autotest
Result examples:
42
MI 3125 / BT EurotestCOMBO Measurements
Displayed results:
x1 ........ Step 1 trip-out time ( , IN, 0º),
x1 ........ Step 2 trip-out time ( , IN, 180º),
x5 ........ Step 3 trip-out time ( , 5IN, 0º),
x5 ........ Step 4 trip-out time ( , 5IN, 180º),
x½ ....... Step 5 trip-out time ( , ½IN, 0º),
x½ ....... Step 6 trip-out time ( , ½IN, 180º),
I ......... Step 7 trip-out current (0º),
I ......... Step 8 trip-out current (180º),
Uc ........ Contact voltage for rated IN.
Notes:
The autotest sequence is immediately stopped if any incorrect condition is
detected, e.g. excessive Uc or trip-out time out of bounds.
Auto test is finished without x5 tests in case of testing the RCD types A, F with
rated residual currents of In = 300 mA, 500 mA, and 1000 mA. In this case auto
test result passes if all other results pass, and indications for x5 are omitted.
Tests for sensitivity (I
, steps 7 and 8) are omitted for selective type RCD.
43
MI 3125 / BT EurotestCOMBO Measurements
See chapter 4.1 Function selection for
instructions on key functionality.
Figure 5.23: Fault loop impedance
Test
Selection of fault loop impedance sub-function [Zloop, Zs rcd]
I test*
Selection of test current [Std, Low]
Fuse type
Selection of fuse type [---, NV, gG, B, C, K, D]
Fuse I
Rated current of selected fuse
Fuse T
Maximum breaking time of selected fuse
Lim
Minimum short circuit current for selected fuse.
5.5 Fault loop impedance and prospective fault current
Fault loop is a loop comprised by mains source, line wiring and PE return path to the
mains source. The instrument measures the impedance of the loop and calculates the
short circuit current. The measurement is covered by requirements of the EN 61557-3
standard.
Test parameters for fault loop impedance measurement
*Applicable only in Zs rcd (some models)
See Appendix A for reference fuse data.
Circuits for measurement of fault loop impedance
Figure 5.24: Connection of plug commander and 3-wire test lead
44
MI 3125 / BT EurotestCOMBO Measurements
Select the Zloop or Zs rcd sub-function using the function selector switch and
/ keys
Select test parameters (optional).
Connect test cable to the Eurotest Combo.
Connect test leads to the item to be tested (see figure 5.24 and 5.17).
Press the TEST key to perform the measurement.
Store the result by pressing the MEM key (optional)*.
Z
kUn
I
SC
SC
Un
Input voltage range (L-PE)
110 V
(93 V U
L-PE
134 V)
230 V
(185 V U
L-PE
266 V)
Fault loop impedance measurement procedure
* model MI 3125 BT
Figure 5.25: Examples of loop impedance measurement result
Displayed results:
Z .............. Fault loop impedance,
ISC ............ Prospective fault current,
Lim .......... Low limit prospective fault loop current value or high limit fault loop
impedance value for the UK version.
Prospective fault current ISC is calculated from measured impedance as follows:
where:
Un ........ Nominal U
voltage (see table below),
L-PE
ksc ....... Correction factor for Isc (see chapter 4.2.5).
Notes:
High fluctuations of mains voltage can influence the measurement results (the
noise sign is displayed in the message field). In this case it is recommended
to repeat few measurements to check if the readings are stable.
This measurement will trip-out the RCD in RCD-protected electrical installation if
test Zloop is selected.
Select Zs rcd to prevent trip-out of RCD in RCD protected installation.
45
MI 3125 / BT EurotestCOMBO Measurements
See chapter 4.1 Function selection for instructions on
key functionality.
Figure 5.26: Line impedance
Figure 5.27: Voltage drop
Test
Selection of line impedance [Zline] or voltage drop [ΔU] sub-function
FUSE type
Selection of fuse type [---, NV, gG, B, C, K, D]
FUSE I
Rated current of selected fuse
FUSE T
Maximum breaking time of selected fuse
Lim
Minimum short circuit current for selected fuse.
ΔU
MAX
Maximum voltage drop [3.0 % ÷ 9.0 %].
5.6 Line impedance and prospective short-circuit current / Voltage drop
Line impedance is measured in loop comprising of mains voltage source and line wiring.
Line impedance is covered by the requirements of the EN 61557-3 standard.
The Voltage drop sub-function is intended to check that a voltage in the installation
stays above acceptable levels if the highest current is flowing in the circuit. The highest
current is defined as the nominal current of the circuit's fuse. The limit values are
described in the standard IEC 60364-5-52.
Sub-functions:
Z LINE- Line impedance measurement according to EN 61557-3,
ΔU – Voltage drop measurement.
Test parameters for line impedance measurement
See Appendix A for reference fuse data.
Additional test parameters for voltage drop measurement
46
MI 3125 / BT EurotestCOMBO Measurements
Select the Z-LINE sub-function.
Select test parameters (optional).
Connect test cable to the instrument.
Connect test leads to the item to be tested (see figure 5.28).
Press the TEST key to perform the measurement.
Store the result by pressing the MEM key (optional)*.
Line to neutral
Line to line
Z
kUn
I
SC
SC
Line impedance and prospective short circuit current
Circuits for measurement of line impedance
Figure 5.28: Phase-neutral or phase-phase line impedance measurement – connection
of plug commander and 3-wire test lead
Line impedance measurement procedure
* model MI 3125 BT
Figure 5.29: Examples of line impedance measurement result
Displayed results:
Z .............. Line impedance,
ISC ............ Prospective short-circuit current,
Lim .......... Low limit prospective short-circuit current value.
Prospective short circuit current is calculated as follows:
where:
Un ........ Nominal L-N or L1-L2 voltage (see table below),
ksc ....... Correction factor for Isc (see chapter 4.2.5).
47
MI 3125 / BT EurotestCOMBO Measurements
Un
Input voltage range (L-N or L1-L2)
110 V
(93 V U
L-N
134 V)
230 V
(185 V U
L-N
266 V)
400 V
(321 V U
L-L
485 V)
Select the ΔU sub-function using the function selector switch and / keys.
Select test parameters (optional).
Connect test cable to the instrument.
Connect the test leads to the origin of electrical installation (see figure 5.30).
Press the CAL key to perform the measurement.
Select the ΔU sub-function using the function selector switch and / keys.
Select test parameters (Fuse type must be selected).
Connect test cable or plug commander to the instrument.
Connect the test leads to the tested points (see figure 5.30).
Press the TEST key to perform the measurement.
Store the result by pressing the MEM key (optional)*.
Note:
High fluctuations of mains voltage can influence the measurement results (the
noise sign is displayed in the message field). In this case it is recommended
to repeat few measurements to check if the readings are stable.
5.6.1 Voltage drop
The voltage drop is calculated based on the difference of line impedance at connection
points (sockets) and the line impedance at the reference point (usually the impedance
at the switchboard).
Circuits for measurement for voltage drop
Figure 5.30: Phase-neutral or phase-phase voltage drop measurement – connection of
plug commander and 3-wire test lead
Voltage drop measurement procedure
Step 1: Measuring the impedance Zref at origin
Step 2: Measuring the voltage drop
* model MI 3125 BT
48
MI 3125 / BT EurotestCOMBO Measurements
Step 1 - Zref
Step 2 - Voltage drop
100
)(
%
N
NREF
U
IZZ
U
Un
Input voltage range (L-N or L1-L2)
110 V
(93 V U
L-N
134 V)
230 V
(185 V U
L-N
266 V)
400 V
(321 V U
L-L
485 V)
Figure 5.31: Examples of voltage drop measurement result
Displayed results:
ΔU ........... Voltage drop,
ISC ............ Prospective short-circuit current,
Z .............. Line impedance at measured point,
Zref .......... Reference impedance
Voltage drop is calculated as follows:
where:
ΔU ........ calculated voltage drop
Z………impedance at test point
Z
…...impedance at reference point
REF
IN………rated current of selected fuse
UN…….nominal voltage (see table below)
Note:
If the reference impedance is not set the value of Z
The Z
is cleared (set to 0.00 Ω) if pressing CAL key while instrument is not
REF
is considered as 0.00 Ω.
REF
connected to a voltage source.
I
is calculated as described in chapter 5.6.1 Line impedance and prospective
SC
short circuit current.
If the measured voltage is outside the ranges described in the table above the
ΔU result will not be calculated.
High fluctuations of mains voltage can influence the measurement results (the
noise sign is displayed in the message field). In this case it is recommended
to repeat few measurements to check if the readings are stable.
49
MI 3125 / BT EurotestCOMBO Measurements
See chapter 4.1 Function selection for instructions on
key functionality.
Figure 5.32: Earth resistance
Limit
Maximum resistance OFF, 1 ÷ 5 k
5.7 Earth resistance
Earth resistance is one of the most important parameters for protection against electric
shock. Main earthing arrangements, lightning systems, local earthings, etc can be
verified with the earthing resistance test. The measurement conforms to the EN 615575 standard.
Test parameters for earth resistance measurement
Connections for earth resistance measurement
Figure 5.33: Resistance to earth, measurement of main installation earthing
Figure 5.34: Resistance to earth, measurement of a lightning protection system
50
MI 3125 / BT EurotestCOMBO Measurements
Select EARTH function using the function selector switch.
Enable and set limit value (optional).
Connect test leads to the instrument
Connect the item to be tested (see Figure 5.33 and Figure 5.34).
Press the TEST key to perform the measurement.
Store the result by pressing the MEM key (optional)*.
Earth resistance measurements, common measurement procedure
* model MI 3125 BT
Figure 5.35: Example of earth resistance measurement result
Displayed results for earth resistance measurement:
R.............. Earth resistance,
Rp............ Resistance of S (potential) probe,
Rc ............ Resistance of H (current) probe.
Notes:
High resistance of S and H probes could influence the measurement results. In
this case, “Rp” and “Rc” warnings are displayed. There is no pass / fail indication
in this case.
High noise currents and voltages in earth could influence the measurement
results. The tester displays the “noise” warning in this case.
Probes must be placed at sufficient distance from the measured object.
5.8 PE test terminal
It can happen that a dangerous voltage is applied to the PE wire or other accessible
metal parts. This is a very dangerous situation since the PE wire and MPEs are
considered to be earthed. An often reason for this fault is incorrect wiring (see examples
below).
When touching the TEST key in all functions that require mains supply the user
automatically performs this test.
51
MI 3125 / BT EurotestCOMBO Measurements
Connect test cable to the instrument.
Connect test leads to the item to be tested (see Figure 5.36 and Figure 5.37).
Touch PE test probe (the TEST key) for at least one second.
If PE terminal is connected to phase voltage the warning message is displayed,
instrument buzzer is activated, and further measurements are disabled in ZLOOP and RCD functions.
Examples for application of PE test terminal
Figure 5.36: Reversed L and PE conductors (application of plug commander)
Figure 5.37: Reversed L and PE conductors (application of 3-wire test lead)
Reversed phase and protection conductors! The most dangerous situation!
PE terminal test procedure
Warning:
If dangerous voltage is detected on the tested PE terminal, immediately stop all
measurements, find and remove the fault!
Notes:
In the SETTINGS and VOLTAGE TRMS menus the PE terminal is not tested.
PE test terminal does not operate in case the operator’s body is completely
insulated from floor or walls!
52
MI 3125 / BT EurotestCOMBO Data handling
6 Data handling (model MI 3125 BT)
6.1 Memory organization
Measurement results together with all relevant parameters can be stored in the
instrument’s memory. After the measurement is completed, results can be stored to the
flash memory of the instrument, together with the sub-results and function parameters.
6.2 Data structure
The instrument’s memory place is divided into 4 levels each containing 199 locations.
The number of measurements that can be stored into one location is not limited.
The data structure field describes the location of the measurement (which object,
block, fuse, connection) and where can be accessed.
In the measurement field there is information about type and number of measurements
that belong to the selected structure element (object and block and fuse and
connection).
The main advantages of this system are:
Test results can be organized and grouped in a structured manner that reflects
the structure of typical electrical installations.
Customized names of data structure elements can be uploaded from
EurolinkPRO PCSW.
Simple browsing through structure and results.
Test reports can be created with no or little modifications after downloading
results to a PC.
Figure 6.1: Data structure and measurement fields
53
MI 3125 / BT EurotestCOMBO Data handling
Memory operation menu
Data structure field
1
st
level:
OBJECT: Default location name (object and its
successive number).
004: No. of selected element.
2
nd
level:
BLOCK: Default location name (block and its
successive number).
001: No. of selected element.
3
rd
level:
FUSE: Default location name (fuse and its successive
number).
002: No. of selected element.
4
th
level:
CONNECTION: Default location name (connection
and its successive number).
003: No. of selected element.
No. of measurements in selected location
[No. of measurements in selected location and its sublocations].
Type of stored measurement in the selected location.
No. of selected test result / No. of all stored test results in
selected location.
Data structure field
Measurement field
54
MI 3125 / BT EurotestCOMBO Data handling
Figure 6.2: Save test menu
Memory available for storing results.
TAB
Selects the location element (Object / Block / Fuse /
Connection).
UP / DOWN
Selects number of selected location element (1 to 199).
MEM
Saves test results to the selected location and returns to the
measuring menu.
Function selector /
TEST
Exits back to main function menu.
6.3 Storing test results
After the completion of a test the results and parameters are ready for storing ( icon
is displayed in the information field). By pressing the MEM key, the user can store the
results.
Keys in save test menu - data structure field:
Notes:
The instrument offers to store the result to the last selected location by default.
If the measurement is to be stored to the same location as the previous one just
press the MEM key twice
55
MI 3125 / BT EurotestCOMBO Data handling
Figure 6.3: Recall menu - installation
structure field selected
Figure 6.4: Recall menu - measurements
field selected
TAB
Selects the location element (Object / Block / Fuse /
Connection).
UP / DOWN
Selects number of selected location element (1 to 199).
Function selector /
TEST
Exits back to main function menu.
MEM
Enters measurements field.
UP / DOWN
Selects the stored measurement.
TAB
Returns to installation structure field.
Function selector /
TEST
Exits back to main function menu.
MEM
View selected measurement results.
Figure 6.5: Example of recalled measurement result
UP / DOWN
Displays measurement results stored in selected location.
MEM
Returns to measurements field.
Function selector /
TEST
Exits back to main function menu.
6.4 Recalling test results
Press the MEM key in a main function menu when there is no result available for storing
or select MEMORY in the SETTINGS menu.
Keys in recall memory menu (installation structure field selected):
Keys in recall memory menu (measurements field):
Keys in recall memory menu (measurement results are displayed)
56
MI 3125 / BT EurotestCOMBO Data handling
TEST
Confirms clearing of complete memory content.
Function selector
Exits back to main function menu without changes.
TAB
Selects the location element (Object / Block / Fuse /
Connection).
UP / DOWN
Selects number of selected location element (1 to 199).
Function selector /
TEST
Exits back to main function menu.
HELP
Enters dialog box for deleting all measurements in selected
location and its sub-locations.
6.5 Clearing stored data
6.5.1 Clearing complete memory content
Select CLEAR ALL MEMORY in MEMORY menu. A warning will be displayed.
Figure 6.6: Clear all memory
Keys in clear all memory menu
Figure 6.7: Clearing memory in progress
6.5.2 Clearing measurement(s) in selected location
Select DELETE RESULTS in MEMORY menu.
Figure 6.8: Clear measurements menu (data structure field selected)
Keys in delete results menu (installation structure field selected):
57
MI 3125 / BT EurotestCOMBO Data handling
HELP
Deletes all results in selected location.
TAB / MEM
Exits back to delete results menu without changes.
Function selector /
TEST
Exits back to main function menu without changes.
TAB
Selects the location element (Object / Block / Fuse /
Connection).
UP / DOWN
Selects number of selected location element (1 to 199).
Function selector /
TEST
Exits back to main function menu.
MEM
Enters measurements field for deleting individual
measurements.
UP / DOWN
Selects measurement.
HELP
Opens dialog box for confirmation to clear selected
measurement.
TAB
Returns to installation structure field.
Function selector /
TEST
Exits back to main function menu without changes.
HELP
Deletes selected measurement result.
MEM / TAB
Exits back to measurements field without changes.
Function selector /
TEST
Exits back to main function menu without changes.
Keys in dialog for confirmation to clear results in selected location:
6.5.3 Clearing individual measurements
Select DELETE RESULTS in MEMORY menu.
Figure 6.9: Menu for clearing individual measurement (installation structure field
selected)
Keys in delete results menu (installation structure field selected):
Keys in delete results menu (measurements field selected):
Keys in dialog for confirmation to clear selected result(s):
58
MI 3125 / BT EurotestCOMBO Data handling
Figure 6.10: Dialog for confirmation
Figure 6.11: Display after measurement
was cleared
Figure 6.12: Example of menu with customized installation structure names
Figure 6.13: Connection of the barcode reader and RFID reader
6.5.4 Renaming installation structure elements (upload from PC)
Default installation structure elements are “Object”, “Block”, “Fuse” and “Connection”.
In the PCSW package Eurolink-PRO default names can be changed with customized
names that corresponds the installation under test. Refer to PCSW Eurolink-PRO
HELP for information how to upload customized installation names to the instrument.
6.5.5 Renaming installation structure elements with serial barcode
reader or RFID reader
Default installation structure elements are “Object”, “Block”, “Fuse” and “Connection”.
When the instrument is in the Save results menu location ID can be scanned from a
barcode label with the barcode reader or can be read from a RFID tag with the RFID
reader.
59
MI 3125 / BT EurotestCOMBO Data handling
Connect the barcode reader or RFID reader to the instrument.
In Save menu select memory location to be renamed.
A new location name (scanned from a barcode label or a RFID tag) will be
accepted by the instrument. A successful receive of the barcode or RFID tag is
confirmed by two short confirmation beeps.
How to change the name of memory location
Note:
Use only barcode readers and RFID readers delivered by Metrel or authorized
distributor.
60
MI 3125 / BT EurotestCOMBO Data handling
RS-232 communication: connect a PC COM port to the instrument PS/2
connector using the PS/2 - RS232 serial communication cable;
USB communication: connect a PC USB port to the instrument USB connector
using the USB interface cable.
Switch on the PC and the instrument.
Run the EurolinkPRO program.
The PC and the instrument will automatically recognize each other.
The instrument is prepared to communicate with the PC.
6.6 Communication (model MI 3125 BT)
Stored results can be transferred to a PC. A special communication program on the PC
automatically identifies the instrument and enables data transfer between the instrument
and the PC.
There are three communication interfaces available: USB, RS 232 and Bluetooth.
6.6.1 USB and RS232 communication
The instrument automatically selects the communication mode according to detected
interface. USB interface has priority.
Figure 6.14: Interface connection for data transfer over PC COM port
How to establish an USB or RS232 link:
The program EurolinkPRO is a PC software running on Windows XP, Windows Vista,
Windows 7, and Windows 8. Read the file README_EuroLink.txt on CD for instructions
about installing and running the program.
Note:
USB drivers should be installed on PC before using the USB interface. Refer to
USB installation instructions available on installation CD.
61
MI 3125 / BT EurotestCOMBO Data handling
Switch On the instrument.
On PC configure a Standard Serial Port to enable communication over Bluetooth
link between instrument and PC. No code for pairing the devices is needed.
Run the EurolinkPRO program.
The PC and the instrument will automatically recognize each other.
The instrument is prepared to communicate with the PC.
Switch On the instrument.
Some Android applications automatically carry out the setup of a Bluetooth
connection. It is preferred to use this option if it exists.
This option is supported by Metrel's Android applications.
If this option is not supported by the selected Android application then configure
a Bluetooth link via Android device’s Bluetooth configuration tool. No code for
pairing the devices is needed.
The instrument and Android device are ready to communicate.
6.6.2 Bluetooth communication
The internal Bluetooth module enables easy communication via Bluetooth with PC and
Android devices.
How to configure a Bluetooth link between instrument and PC
How to configure a Bluetooth link between instrument and Android device
Notes:
Sometimes there will be a demand from the PC or Android device to enter the
code. Enter code ‘NNNN’ to correctly configure the Bluetooth link.
The name of correctly configured Bluetooth device must consist of the instrument
type plus serial number, eg. MI 3125 BT-12240429I. If the Bluetooth module got
another name, the configuration must be repeated.
Model MI 3125 BT doesn’t support operation with Bluetooth dongle A 1436.
In case of serious troubles with the Bluetooth communication it is possible to
reinitialize the internal Bluetooth module. The initialization is carried out during
the Initial settings procedure. In case of a successful initialization “INTERNAL
BLUETOOTH SEARCHING OK!” is displayed at the end of the procedure. See
chapter 4.2.7 Initial settings.
62
MI 3125 / BT EurotestCOMBO Upgrading the instrument
7 Upgrading the instrument
The instrument can be upgraded from a PC via the RS232 communication port. This
enables to keep the instrument up to date even if the standards or regulations change.
The upgrade can be carried with help of a special upgrading software and the
communication cable as shown on Figure 6.14. Please contact your dealer for more
information.
63
MI 3125 / BT EurotestCOMBO Maintenance
8 Maintenance
Unauthorized persons are not allowed to open the Eurotest Combo instrument. There
are no user replaceable components inside the instrument, except the battery and fuse
under rear cover.
8.1 Fuse replacement
There is a fuse under back cover of the Eurotest Combo instrument.
F1
M 0.315 A / 250 V, 205 mm
This fuse protects internal circuitry for continuity functions if test probes are
connected to the mains supply voltage by mistake during measurement.
Warnings:
Disconnect all measuring accessory and switch off the instrument
before opening battery / fuse compartment cover, hazardous voltage
inside!
Replace blown fuse with original type only, otherwise the instrument may
be damaged and/or operator’s safety impaired!
Position of fuse can be seen in Figure 3.4 in chapter 3.3 Back side.
8.2 Cleaning
No special maintenance is required for the housing. To clean the surface of the
instrument use a soft cloth slightly moistened with soapy water or alcohol. Then leave
the instrument to dry totally before use.
Warnings:
Do not use liquids based on petrol or hydrocarbons!
Do not spill cleaning liquid over the instrument!
8.3 Periodic calibration
It is essential that the test instrument is regularly calibrated in order that the technical
specification listed in this manual is guaranteed. We recommend an annual calibration.
Only an authorized technical person can do the calibration. Please contact your dealer
for further information.
8.4 Service
For repairs under warranty, or at any other time, please contact your distributor.
64
MI 3125 / BT EurotestCOMBO Technical specifications
Measuring range (M)
Resolution (M)
Accuracy
0.00 19.99
0.01
(5 % of reading + 3 digits)
20.0 99.9
0.1
(10 % of reading)
100.0 199.9
(20 % of reading)
Measuring range (M)
Resolution (M)
Accuracy
0.00 19.99
0.01
(5 % of reading + 3 digits)
20.0 199.9
0.1
(5 % of reading)
200 999
1
(10 % of reading)
Measuring range (V)
Resolution (V)
Accuracy
0 1200
1
(3 % of reading + 3 digits)
9 Technical specifications
9.1 Insulation resistance
Insulation resistance (nominal voltages 50 VDC, 100 V
Measuring range according to EN61557 is 0.15 M 199.9 M.
Insulation resistance (nominal voltages 500 VDC and 1000 VDC)
Measuring range according to EN61557 is 0.15 M 1 G.
and 250 VDC)
DC
Voltage
Nominal voltages ............................... 50 VDC, 100 VDC, 250 VDC, 500 VDC, 1000 VDC
Open circuit voltage ........................... -0 % / +20 % of nominal voltage
Measuring current .............................. min. 1 mA at RN=UN1 k/V
Short circuit current ........................... max. 3 mA
The number of possible tests ............ > 1200, with a fully charged battery
Auto discharge after test.
Specified accuracy is valid if 3-wire test lead is used while it is valid up to 100 M if tip
commander is used.
Specified accuracy is valid up to 100 M if relative humidity > 85 %.
In case the instrument gets moistened, the results could be impaired. In such case, it is
recommended to dry the instrument and accessories for at least 24 hours.
The error in operating conditions could be at most the error for reference conditions
(specified in the manual for each function) 5 % of measured value.
65
MI 3125 / BT EurotestCOMBO Technical specifications
Measuring range R ()
Resolution ()
Accuracy
0.00 19.99
0.01
(3 % of reading + 3 digits)
20.0 199.9
0.1
(5 % of reading)
200 999
1
1000 1999
1
(10 % of reading)
Measuring range ()
Resolution ()
Accuracy
0.0 19.9
0.1
(5 % of reading + 3 digits)
20 1999
1
9.2 Continuity
9.2.1 Resistance R LOW
Measuring range according to EN61557 is 0.16 1999 .
Open-circuit voltage ........................... 6.5 VDC 9 VDC
Measuring current .............................. min. 200 mA into load resistance of 2
Test lead compensation ..................... up to 5
The number of possible tests ............ > 2000, with a fully charged battery
Automatic polarity reversal of the test voltage.
9.2.2 Resistance CONTINUITY
Open-circuit voltage ........................... 6.5 VDC 9 VDC
Short-circuit current ........................... max. 8.5 mA
Test lead compensation ..................... up to 5
9.3 RCD testing
Note:
All data (marked with “*”) regarding B and B+ type RCDs is valid for model MI 3125 BT
only.
9.3.1 General data
Nominal residual current (A, F,AC) .... 10 mA, 30 mA, 100 mA, 300 mA, 500 mA,
1000 mA
Nominal residual current accuracy ..... -0 / +0.1I; I = IN, 2IN, 5IN
-0.1I / +0; I = 0.5IN
AS / NZ selected: ± 5 %
Test current shape…………………...Sine-wave (AC), pulsed (A, F), smooth DC (B, B+)*
DC offset for pulsed test current ........ 6 mA (typical)
RCD type ........................................... (non-delayed), S (time-delayed)
Test current starting polarity ............. 0 º or 180 º
Voltage range .................................... 93 V 134 V (45 Hz 65 Hz)
185 V 266 V (45 Hz 65 Hz)
66
MI 3125 / BT EurotestCOMBO Technical specifications
IN × 1/2
IN × 1
IN × 2
IN × 5
RCD I
IN
(mA)
AC
A,F
B,B+*
AC
A,F
B,B+*
AC
A,F
B,B+*
AC
A,F
B,B+*
AC
A,F
B,B+*
10 5 3.5 5 10
20
20
20
40
40
50
100
100
30
15
10.5
15
30
42
60
60
84
120
150
212
300
100
50
35
50
100
141
200
200
282
400
500
707
1000
300
150
105
150
300
424
600
600
848
n.a.
1500
n.a.
n.a.
500
250
175
250
500
707
1000
1000
1410
n.a.
2500
n.a.
n.a.
1000
500
350
500
1000
1410
n.a.
2000
n.a.
n.a.
n.a.
n.a.
n.a.
n.a.
Measuring range (V)
Resolution (V)
Accuracy
0.0 19.9
0.1
(-0 % / +15 %) of reading ± 10 digits
20.0 99.9
(-0 % / +15 %) of reading
Measuring range (ms)
Resolution (ms)
Accuracy
0.0 40.0
0.1
1 ms
0.0 max. time *
0.1
3 ms
n.a. ..................................................... not applicable
AC type .............................................. sine wave test current
A, F types…… ................................... pulsed current
B*, B+* types ..................................... smooth DC current
9.3.2 Contact voltage RCD-Uc
Measuring range according to EN61557 is 20.0 V 31.0V for limit contact voltage 25V
Measuring range according to EN61557 is 20.0 V 62.0V for limit contact voltage 50V
The accuracy is valid if mains voltage is stabile during the measurement and PE
terminal is free of interfering voltages.
Test current ...................................... max. 0.5IN
Limit contact voltage ......................... 25 V, 50 V
Specified accuracy is valid for complete operating range.
9.3.3 Trip-out time
Complete measurement range corresponds to EN 61557 requirements.
Maximum measuring times set according to selected reference for RCD testing.
* For max. time see normative references in 4.2.4 – this specification applies to max.
time >40 ms.
Test current ...................................... ½IN, IN, 2IN, 5I
5IN is not available for IN=1000 mA (RCD type AC) or I
N
300 mA (RCD types A, F,
N
B*, B+*).
2IN is not available for IN=1000 mA (RCD types A, F) or I
300 mA (RCD types B,
N
B+)*.
1IN is not available for IN=1000 mA (RCD types B, B+)*.
Specified accuracy is valid for complete operating range.
67
MI 3125 / BT EurotestCOMBO Technical specifications
Measuring range I
Resolution I
Accuracy
0.2IN 1.1IN (AC type)
0.05IN
0.1IN
0.2IN 1.5IN (A, F types, IN ≥30 mA)
0.05IN
0.1IN
0.2IN 2.2IN (A, F types, IN <30 mA)
0.05IN
0.1IN
0.2IN 2.2IN (B, B+ types)*
0.05IN
0.1IN
Measuring range (ms)
Resolution (ms)
Accuracy
0 300
1
3 ms
Measuring range (V)
Resolution (V)
Accuracy
0.0 19.9
0.1
(-0 % / +15 %) of reading 10 digits
20.0 99.9
0.1
(-0 % / +15 %) of reading
Measuring range ()
Resolution ()
Accuracy
0.00 9.99
0.01
(5 % of reading + 5 digits)
10.0 99.9
0.1
100 999
1
10 % of reading
1.00k 9.99k
10
Measuring range (A)
Resolution (A)
Accuracy
0.00 9.99
0.01
Consider accuracy of fault
loop resistance
measurement
10.0 99.9
0.1
100 999
1
1.00k 9.99k
10
10.0k 23.0k
100
9.3.4 Trip-out current
Trip-out current
Complete measurement range corresponds to EN 61557 requirements.
Trip-out time
Contact voltage
The accuracy is valid if mains voltage is stabile during the measurement and PE
terminal is free of interfering voltages.
Trip-out measurement is not available for IN=1000 mA (RCD types B, B+)*.
Specified accuracy is valid for complete operating range.
9.4 Fault loop impedance and prospective fault current
9.4.1 No disconnecting device or FUSE selected
Fault loop impedance
Measuring range according to EN61557 is 0.25 9.99k.
Prospective fault current (calculated value)
The accuracy is valid if mains voltage is stabile during the measurement.
Test current (at 230 V) ...................... 6.5 A (10 ms)
Nominal voltage range ....................... 93 V 134 V (45 Hz 65 Hz)
185 V 266 V (45 Hz 65 Hz)
68
MI 3125 / BT EurotestCOMBO Technical specifications
Measuring range
()
Resolution
()
Accuracy
I test = “Std”
Accuracy
I test = “Low”
0.00 9.99
0.01
(5 % of reading + 10
digits)
(5 % of reading + 12
digits)
10.0 99.9
0.1
100 999
1
10 % of reading
10 % of reading
1.00k 9.99k
10
Measuring range (A)
Resolution (A)
Accuracy
0.00 9.99
0.01
Consider accuracy of fault
loop resistance
measurement
10.0 99.9
0.1
100 999
1
1.00k 9.99k
10
10.0k 23.0k
100
Measuring range ()
Resolution ()
Accuracy
0.00 9.99
0.01
(5 % of reading + 5 digits)
10.0 99.9
0.1
100 999
1
10 % of reading
1.00k 9.99k
10
Measuring range (A)
Resolution (A)
Accuracy
0.00 0.99
0.01
Consider accuracy of line
resistance measurement
1.0 99.9
0.1
100 999
1
1.00k 99.99k
10
100k 199k
1000
9.4.2 RCD selected
Fault loop impedance
Measuring range according to EN61557 is 0.46 9.99 k for I test = “Std” and 0.48 Ω
9.99 kΩ for I test = “Low”.
Accuracy may be impaired in case of heavy noise on mains voltage.
Prospective fault current (calculated value)
Nominal voltage range ....................... 93 V 134 V (45 Hz 65 Hz)
185 V 266 V (45 Hz 65 Hz)
No trip out of RCD.
9.5 Line impedance and prospective short-circuit current / Voltage
drop
Line impedance
Measuring range according to EN61557 is 0.25 9.99k.
Prospective short-circuit current (calculated value)
Test current (at 230 V) ...................... 6.5 A (10 ms)
Nominal voltage range ....................... 93 V 134 V (45 Hz 65 Hz)
185 V 266 V (45 Hz 65 Hz)
69
MI 3125 / BT EurotestCOMBO Technical specifications
Measuring range (%)
Resolution (%)
Accuracy
0.0 99.9
0.1
Consider accuracy of line
impedance
measurement(s)*
Measuring range ()
Resolution ()
Accuracy
0.00 19.99
0.01
(5% of reading + 5 digits)
20.0 199.9
0.1
200 9999
1
321 V 266 V (45 Hz 65 Hz)
Voltage drop (calculated value)
Z
measuring range……………………… 0.00 Ω 20.0 Ω
REF
*See chapter 5.6.2 Voltage drop for more information about calculation of voltage drop
result.
9.6 Resistance to earth
Measuring range according to EN61557-5 is 2.00 9999 .
Max. auxiliary earth electrode resistance RC ... 100RE or 50 k (whichever is lower)
Max. probe resistance RP ................................ 100RE or 50 k (whichever is lower)
Additional probe resistance error at R
Cmax
or R
(10 % of reading + 10 digits)
Pmax.
Additional error
at 3 V voltage noise (50 Hz) ............................ (5 % of reading + 10 digits)
Open circuit voltage ......................................... < 15 VAC
Short circuit current .......................................... < 30 mA
Test voltage frequency .................................... 125 Hz
Test voltage shape .......................................... sinusoidal
Noise voltage indication threshold ................... 1 V (< 50 , worst case)
Automatic measurement of auxiliary electrode resistance and probe resistance.
Automatic measurement of voltage noise.
9.7 Voltage, frequency, and phase rotation
9.7.1 Phase rotation
Nominal system voltage range ......... 100 VAC 550 VAC
Nominal frequency range .................. 14 Hz 500 Hz
Result displayed ............................... 1.2.3 or 3.2.1
70
MI 3125 / BT EurotestCOMBO Technical specifications
Measuring range (V)
Resolution (V)
Accuracy
0 550
1
(2 % of reading + 2 digits)
Measuring range (Hz)
Resolution (Hz)
Accuracy
0.00 9.99
0.01
(0.2 % of reading + 1 digit)
10.0 499.9
0.1
Measuring range (V)
Resolution (V)
Accuracy
10 550
1
(2 % of reading + 2 digits)
9.7.2 Voltage
Result type ........................................ True r.m.s. (trms)
Nominal frequency range .................. 0 Hz, 14 Hz 500 Hz
9.7.3 Frequency
Nominal voltage range ...................... 10 V 550 V
9.7.4 Online terminal voltage monitor
9.8 General data
Models MI 3125 and MI 3125 BT:
Power supply voltage ........................ 9 VDC (61.5 V battery or accu, size AA)
Operation .......................................... typical 20 h
Charger socket input voltage ............ 12 V 10 %
Charger socket input current ............ 400 mA max.
Battery charging current ................... 250 mA (internally regulated)
Overvoltage category ........................ 600 V CAT III / 300 V CAT IV
Plug commander
overvoltage category ................ 300 V CAT II
Protection classification .................... double insulation
Pollution degree ................................ 2
Protection degree ............................. IP 40
Display ............................................ 128x64 dots matrix display with backlight
Dimensions (w h d) ..................... 14 cm 8 cm 23 cm
Weight ............................................ 1.0 kg, without battery cells
Reference conditions
Reference temperature range ........... 10 C 30 C
Reference humidity range ................. 40 %RH 70 %RH
Operation conditions
Working temperature range .............. 0 C 40 C
71
MI 3125 / BT EurotestCOMBO Technical specifications
Maximum relative humidity ............... 95 %RH (0 C 40 C), non-condensing
Storage conditions
Temperature range ........................... -10 C +70 C
Maximum relative humidity ............... 90 %RH (-10 C +40 C)
80 %RH (40 C 60 C)
Model MI 3125 BT:
Communication transfer speed
RS 232.. ............................................ 115200 baud
USB…... ............................................ 256000 baud
Memory size......................................1700 results
Bluetooth module: Class 2
The error in operating conditions could be at most the error for reference conditions
(specified in the manual for each function) +1 % of measured value + 1 digit, unless
otherwise specified in the manual for particular function.
72
MI 3125 / BT EurotestCOMBO Appendix A
Rated
current
(A)
Disconnection time [s]
35m
0.1
0.2
0.4 5 Min. prospective short- circuit current (A)
2
32.5
22.3
18.7
15.9
9.1
4
65.6
46.4
38.8
31.9
18.7
6
102.8
70
56.5
46.4
26.7
10
165.8
115.3
96.5
80.7
46.4
16
206.9
150.8
126.1
107.4
66.3
20
276.8
204.2
170.8
145.5
86.7
25
361.3
257.5
215.4
180.2
109.3
35
618.1
453.2
374
308.7
169.5
50
919.2
640
545
464.2
266.9
63
1217.2
821.7
663.3
545
319.1
80
1567.2
1133.1
964.9
836.5
447.9
100
2075.3
1429
1195.4
1018
585.4
125
2826.3
2006
1708.3
1454.8
765.1
160
3538.2
2485.1
2042.1
1678.1
947.9
200
4555.5
3488.5
2970.8
2529.9
1354.5
250
6032.4
4399.6
3615.3
2918.2
1590.6
315
7766.8
6066.6
4985.1
4096.4
2272.9
400
10577.7
7929.1
6632.9
5450.5
2766.1
500
13619
10933.5
8825.4
7515.7
3952.7
630
19619.3
14037.4
11534.9
9310.9
4985.1
710
19712.3
17766.9
14341.3
11996.9
6423.2
800
25260.3
20059.8
16192.1
13545.1
7252.1
1000
34402.1
23555.5
19356.3
16192.1
9146.2
1250
45555.1
36152.6
29182.1
24411.6
13070.1
Rated
current
(A)
Disconnection time [s]
35m
0.1
0.2
0.4 5 Min. prospective short- circuit current (A)
2
32.5
22.3
18.7
15.9
9.1
4
65.6
46.4
38.8
31.9
18.7
6
102.8
70
56.5
46.4
26.7
10
165.8
115.3
96.5
80.7
46.4
13
193.1
144.8
117.9
100
56.2
16
206.9
150.8
126.1
107.4
66.3
20
276.8
204.2
170.8
145.5
86.7
25
361.3
257.5
215.4
180.2
109.3
32
539.1
361.5
307.9
271.7
159.1
35
618.1
453.2
374
308.7
169.5
40
694.2
464.2
381.4
319.1
190.1
A Appendix A - Fuse table
A.1 Fuse table - IPSC
Fuse type NV
Fuse type gG
73
MI 3125 / BT EurotestCOMBO Appendix A
50
919.2
640
545
464.2
266.9
63
1217.2
821.7
663.3
545
319.1
80
1567.2
1133.1
964.9
836.5
447.9
100
2075.3
1429
1195.4
1018
585.4
Rated
current
(A)
Disconnection time [s]
35m
0.1
0.2
0.4 5 Min. prospective short- circuit current (A)
6
30
30
30
30
30
10
50
50
50
50
50
13
65
65
65
65
65
15
75
75
75
75
75
16
80
80
80
80
80
20
100
100
100
100
100
25
125
125
125
125
125
32
160
160
160
160
160
40
200
200
200
200
200
50
250
250
250
250
250
63
315
315
315
315
315
Rated
current
(A)
Disconnection time [s]
35m
0.1
0.2
0.4 5 Min. prospective short- circuit current (A)
0.5 5 5 5 5
2.7
1
10
10
10
10
5.4
1.6
16
16
16
16
8.6
2
20
20
20
20
10.8
4
40
40
40
40
21.6
6
60
60
60
60
32.4
10
100
100
100
100
54
13
130
130
130
130
70.2
15
150
150
150
150
83
16
160
160
160
160
86.4
20
200
200
200
200
108
25
250
250
250
250
135
32
320
320
320
320
172.8
40
400
400
400
400
216
50
500
500
500
500
270
63
630
630
630
630
340.2
Rated
current
(A)
Disconnection time [s]
35m
0.1
0.2
0.4
Min. prospective short- circuit current (A)
0.5
7.5
7.5
7.5
7.5
1
15
15
15
15
Fuse type B
Fuse type C
Fuse type K
74
MI 3125 / BT EurotestCOMBO Appendix A
1.6
24
24
24
24 2
30
30
30
30 4
60
60
60
60 6
90
90
90
90 10
150
150
150
150 13
195
195
195
195
15
225
225
225
225
16
240
240
240
240 20
300
300
300
300 25
375
375
375
375 32
480
480
480
480
Rated
current
(A)
Disconnection time [s]
35m
0.1
0.2
0.4
5
Min. prospective short- circuit current (A)
0.5
10
10
10
10
2.7
1
20
20
20
20
5.4
1.6
32
32
32
32
8.6
2
40
40
40
40
10.8
4
80
80
80
80
21.6
6
120
120
120
120
32.4
10
200
200
200
200
54
13
260
260
260
260
70.2
15
300
300
300
300
81
16
320
320
320
320
86.4
20
400
400
400
400
108
25
500
500
500
500
135
32
640
640
640
640
172.8
Fuse type D
75
MI 3125 / BT EurotestCOMBO Appendix A
Type B
Type C
Rated
current
(A)
Disconnection time [s]
Rated
current
(A)
Disconnection time [s]
0.4
0.4
Max. loop impedance ()
Max. loop impedance ()
6 9.58 6 5.11
10 5.75 10 3.07
16 3.59 16 1.92
20 2.88 20 1.53
25 2.30 25 1.23
32 1.80 32 0.96
40 1.44 40 0.77
50 1.15 50 0.61
63 0.91 63 0.49
80 0.72 80 0.38
100 0.58
100 0.31
125 0.46
125 0.25
160 0.36
160 0.19
200 0.29
200 0.15
Type D
Fuse
Rated
current
(A)
Disconnection time [s]
Rated
current
(A)
Disconnection time [s]
0.4
0.4 5 Max. loop impedance ()
Max. loop impedance ()
6 3.07 6
11.50
15.33
10 1.84 10
6.39
9.20
16 1.15 16
3.07
5.00
20 0.92 20
2.09
3.59
25 0.74 25
1.64
2.71
32 0.58 32
1.28
2.19
40 0.46 40
0.96
1.64
50 0.37 50
0.72
1.28
63 0.29 63
0.55
0.94
80 0.23 80
0.38
0.68
100 0.18 100
0.27
0.48
125 0.15 125
0.21
0.43
160 0.12 160
0.16
0.30
200 0.09 200
0.13
0.23
A.2 Fuse table – Impedances at 230 V a.c. (AS/NZS 3017)
All impedances are scaled with factor 1.00.
76
MI 3125 / BT EurotestCOMBO Appendix B
Function
Suitable accessories (Optional with ordering code A….)
Insulation resistance
Test lead, 3 x 1.5 m
Tip commander (A 1401)
R LOWΩ resistance
Test lead, 3 x 1.5 m
Tip commander (A 1401)
Test lead, 4 m (A 1154)
Continuous resistance
measurement
Test lead, 3 x 1.5 m
Tip commander (A 1401)
Test lead, 4 m (A 1154)
Line impedance
Test lead, 3 x 1.5 m
Mains measuring cable
Plug commander (A 1314)
Tip commander (A 1401)
Three-phase adapter (A 1110)
Three-phase adapter with switch (A 1111)
Fault loop impedance
Test lead, 3 x 1.5 m
Mains measuring cable
Plug commander (A 1314)
Tip commander (A 1401)
Three-phase adapter (A 1110)
Three-phase adapter with switch (A 1111)
RCD testing
Test lead, 3 x 1.5 m
Mains measuring cable
Plug commander (A 1314)
Three-phase adapter (A 1110)
Three-phase adapter with switch (A 1111)
Earth resistance
Test lead, 3 x 1.5 m
Earth test set, 3-wire, 20 m (S 2026)
Earth test set, 3-wire, 50 m (S 2027)
Phase sequence
Test lead, 3 x 1.5 m
Three-phase adapter (A 1110)
Three-phase adapter with switch (A 1111)
Voltage, frequency
Test lead, 3 x 1.5 m
Mains measuring cable
Plug commander (A 1314)
Tip commander (A 1401)
B Appendix B - Accessories for specific
measurements
The table below presents standard and optional accessories required for specific
measurement. The accessories marked as optional may also be standard ones in some
sets. Please see attached list of standard accessories for your set or contact your
distributor for further information.
77
MI 3125 / BT EurotestCOMBO Appendix C
Country
Related chapters
Modification type
Note
HUN
5.5, 5.6, C.2.1
Appendix A
Appended
Added gR fuse type
AT
5.4, 9.3, C.2.2
Appended
Special G type RCD
NO, DK, SW
4.2, C.2.3
Appended
IT supply system
AUS / NZ
4.2, 4.2.5, 4.2.8,
5.5, 5.6,
Appendix A
Appended
AUS / NZ fuse table added
Test
Selection of fault loop impedance sub-function [Zloop, Zs rcd]
Fuse type
Selection of fuse type [---, gR, NV, gG, B, C, K, D]
Fuse I
Rated current of selected fuse
Fuse T
Maximum breaking time of selected fuse
Lim
Minimum short circuit current for selected fuse.
Test
Selection of line impedance [Zline] or voltage drop [ΔU] sub-function
FUSE type
Selection of fuse type [---, gR, NV, gG, B, C, K, D]
FUSE I
Rated current of selected fuse
FUSE T
Maximum breaking time of selected fuse
Lim
Minimum short circuit current for selected fuse.
C Appendix C – Country notes
This appendix C contains collection of minor modifications related to particular country
requirements. Some of the modifications mean modified listed function characteristics
related to main chapters and others are additional functions. Some minor modifications
are related also to different requirements of the same market that are covered by
various suppliers.
C.1 List of country modifications
The following table contains current list of applied modifications.
C.2 Modification issues
C.2.1 HUN modification – gR fuse types
Modifications of the chapter 5.5
Test parameters for fault loop impedance measurement
See Appendix A and Appendix C for reference fuse data.
Modifications of the chapter 5.6
Test parameters for line impedance measurement
See Appendix A and Appendix C for reference fuse data.
78
MI 3125 / BT EurotestCOMBO Appendix C
Rated
current
(A)
Disconnection time [s]
35m
0.1
0.2
0.4 5 Min. prospective short- circuit current (A)
2
31.4
14
10
8
5
4
62.8
28
20
16
10
6
94.2
42
30
24
15
10
157
70
50
40
25
13
204
91
65
52
32.5
16
251
112
80
64
40
20
314
140
100
80
50
25
393
175
125
100
62.5
32
502
224
160
128
80
35
550
245
175
140
87.5
40
628
280
200
160
100
50
785
350
250
200
125
63
989
441
315
252
157.5
80
1256
560
400
320
200
100
1570
700
500
400
250
125
1963
875
625
500
313
160
2510
1120
800
640
400
200
3140
1400
1000
800
500
250
3930
1750
1250
1000
625
315
4950
2210
1575
1260
788
400
6280
2800
2000
1600
1000
500
7850
3500
2500
2000
1250
630
9890
4410
3150
2520
1575
710
11150
4970
3550
2840
1775
800
12560
5600
4000
3200
2000
1000
15700
7000
5000
4000
2500
1250
19630
8750
6250
5000
3130
C.2.1.1 Modification of Appendix A
In addition to fuse data given in Appendix A gR fuses are added.
Fuse type gR
C.2.2 AT modification - G type RCD
Modified is the following related to the mentioned in the chapter 5.4:
- Added G type RCD,
- Time limits are the same as for general type RCD,
- Contact voltage is calculated the same as for general type RCD.
Modifications of the chapter 5.4
79
MI 3125 / BT EurotestCOMBO Appendix C
TEST
RCD sub-function test [RCDt, RCD I, AUTO, Uc].
IN
Rated RCD residual current sensitivity IN [10 mA, 30 mA, 100 mA, 300
mA, 500 mA, 1000 mA].
type
RCD type AC, A, F, B*, B+* starting polarity [ , , , ,
*, *
],
selective
S
,
general , delayed
G
characteristic.
MUL
Multiplication factor for test current [½, 1, 2, 5 IN].
Ulim
Conventional touch voltage limit [25 V, 50 V].
RCD type
Contact voltage Uc
proportional to
Rated IN
AC
, G
1.05IN
any
All models
AC
S
21.05IN
A,F
, G
1.41.05IN
30 mA
A,F
S
21.41.05IN
A,F
, G
21.05IN
< 30 mA
A,F
S
221.05IN
B, B+
21.05IN
any
Model MI 3125 BT
B, B+
S
221.05IN
Test parameters for RCD test and measurement
* Model MI 3125 BT
Notes:
Ulim can be selected in the Uc sub-function only.
Selective (time delayed) RCDs and RCDs with (G) - time delayed characteristic
demonstrate delayed response characteristics. They contain residual current
integrating mechanism for generation of delayed trip out. However, contact
voltage pre-test in the measuring procedure also influences the RCD and it takes
a period to recover into idle state. Time delay of 30 s is inserted before
performing trip-out test to recover S type RCD after pre-tests and time delay of
5 s is inserted for the same purpose for G type RCD.
Modification of the chapter 5.4.1
Table C.1: Relationship between Uc and I
N
Technical specifications remain the same.
C.2.3 NO, DK, SW modification – IT supply system
C.2.3.1 Modification of chapter 4.2
Different instrument options can be set in the SETTINGS menu, additional option is
added:
Selection of power supply system.
80
MI 3125 / BT EurotestCOMBO Appendix C
In this menu the tested supply system can be
selected.
Figure 4.9: Selection of supply system
UP / DOWN
Selects distribution supply system.
TEST
Confirms selected system and exits to settings menu.
Function selector
Exits back to main function menu.
I
SC
factor is replaced with Z factor.
Figure 4.1: Options in
Settings menu
In this menu the Z factor can be set.
Figure 4.6: Selection of Z
factor
C.2.3.2 New chapter
For selection of proper supply system, the chapter 4.2.9 is added.
4.2.9. Supply earthing system
Keys:
C.2.3.3 New appendix D for IT supply system
C.2.4 AUS / NZ modification – Fuse types according to AS/NZS 3017
Modifications of the chapter 4.2
Modifications of the chapter 4.2.5
C.2.4.1 Z Factor
81
MI 3125 / BT EurotestCOMBO Appendix C
UP / DOWN
Sets Z value.
TEST
Confirms Z value.
Function selectors
Exits back to main function menu.
Instrument setting
Default value
Z factor
1.00
RCD standards
AS/NZS 3017
Fuse type
Selection of fuse type [---, FUSE, B, C, D]
Lim
High limit fault loop impedance value for selected fuse.
factorscalingZ
U
I
PEL
N
PFC
_
Keys:
The impedance limit values for different overcurrent protective devices depend on
nominal voltage and are calculated using the Z factor. Z factor 1.00 is used for nominal
voltage 230 V and Z factor 1.04 is used for nominal voltage 240 V.
Modifications of the chapter 4.2.8
The default setup is listed below:
Modifications of the chapter 5.5
Modified test parameters for fault loop impedance measurement
See Appendix A.2 for reference fuse data.
Figure 5.25: Examples of loop impedance measurement result
Displayed results:
Z fault loop impedance
Isc ........... prospective fault current,
Lim .......... high limit fault loop impedance value.
Prospective fault current I
is calculated from measured impedance as follows:
PFC
where:
Un Nominal U
voltage (see table below),
L-PE
82
MI 3125 / BT EurotestCOMBO Appendix C
Un
Input voltage range (L-PE)
110 V
(93 V U
L-PE
134 V)
230 V
(185 V U
L-PE
266 V)
Fuse type
Selection of fuse type [---, FUSE, B, C, D]
Lim
High limit line impedance value for selected fuse.
Line to neutral
Line to line
factorscalingZ
U
I
LNL
N
PFC
_
)(
Un
Input voltage range (L-N or L1-L2)
110 V
(93 V U
L-N
134 V)
230 V
(185 V U
L-N
266 V)
400 V
(321 V U
L-L
485 V)
scalling_factor ...... Correction factor for Isc (set to 1.00).
Modifications of the chapter 5.6
Modified test parameters for line impedance measurement
See Appendix A.2 for reference fuse data.
Figure 5.29: Examples of line impedance measurement result
Displayed results:
Z line impedance
Isc ........... prospective short-circuit current
Lim .......... high limit line impedance value.
Prospective short circuit current I
is calculated from measured impedance as follows:
PFC
where:
Un Nominal U
L-N
or U
voltage (see table below),
L1-L2
Scalling factor ...... Correction factor for Isc (set to 1.00).
83
MI 3125 / BT EurotestCOMBO Appendix D
133 V
133 V
L1
L2
230 V
133 V
L3
230 V
230 V
Optional
high
impedance
N (Optional) IMD
Figure D.1: General IT supply system with reference designations
Three phase star connection, optional delta connection.
Optional neutral line.
Single-phase connection is also possible.
Various system voltages possible.
One faulty connection of any line to PE is treated as first fault and is regular but it has to
be repaired as soon as possible.
D Appendix D - IT supply systems
In order for operator to be familiar enough with measurements in and their typical
applications in IT supply system it is advisable to read Metrel handbook Measurements
on IT power supply systems.
D.1 Standard references
EN 60364-4-41, EN 60364-6, EN 60364-7-710, BS 7671
D.2 Fundamentals
In IT systems live parts are insulated from earth or connected to earth through
sufficiently high impedance.
Testing of IT supply system is slightly different to standard tests in TN / TT system.
D.3 Measurement guides
The user has to select the IT supply system in the instrument before testing it. The
procedure for selecting the IT supply system is defined in chapter 4.2.9 Supply earthing
system. Once the IT system is selected the instrument can be used immediately. The
instrument keeps selected IT system when it is turned off. Displayed designations
correspond to IT system, see figure D.1.
84
MI 3125 / BT EurotestCOMBO Appendix D
IT system functions
Note
Voltage
Voltage
Symbols modified for IT system, see figure D.2.
Phase rotation
For three phase system only, automatic detection.
RCD functions Partially applicable.
RCD - Uc
Not applicable.
RCD - Trip out Time t
Applicable with bypassing the test current.
RCD - Tripping Current
RCD – Automatic test
Loop functions Not applicable.
Fault Loop Impedance
Fault Loop Prospective
Short-circuit Current
Line functions
Line Impedance
Impedance Z
L1-L2
.
Line Prospective
Short-circuit Current
ISC for rated U
L1-L2
.
Continuity functions
Independent of selected supply system.
Insulation Resistance
Independent of selected supply system.
Earth resistance
Independent of selected supply system.
PE test probe
Active, but does not inhibit selected test if voltage is
detected.
MI 3125 / MI 3125 BT test functions and IT systems
The table below contains functions of the instrument including compatibility notes
related to the IT system.
Voltage measurements
Figure D.2: Voltage measurements
Displayed results for single phase system:
U21 .......... Voltage between line conductors,
U1pe ........ Voltage between line 1 and protective conductor,
U2pe ........ Voltage between line 2 and protective conductor.
Line impedance
See chapter 5.6, the measurement is the same; only terminal voltage monitor indication
corresponds to IT system.
85
MI 3125 / BT EurotestCOMBO Appendix D
RCD testing
RCD testing is performed in the same way as in TN/TT system (See chapter 5.4), with
the following exception:
- UC measurement is relevant only in case of first fault.
Test circuit with bypassing principle should correspond to that on figure D.3.
Figure D.3: RCD testing in IT system with bypassing RC
86
MI 3125 / BT EurotestCOMBO Appendix E
Figure E.1: Front side tip commander (A 1401)
E Appendix E – Commanders (A 1314, A 1401)
E.1 Warnings related to safety
Measuring category of commanders:
Plug commander A 1314 ………… 300 V CAT II
Tip commander A 1401
(cap off, 18 mm tip) 1000 V CAT II / 600 V CAT II / 300 V CAT II
(cap on, 4 mm tip)…1000 V CAT II / 600 V CAT III / 300 V CAT IV
Measuring category of commanders can be lower than protection category
of the instrument.
If dangerous voltage is detected on the tested PE terminal, immediately
stop all measurements, find and remove the fault!
When replacing battery cells or before opening the battery compartment
cover, disconnect the measuring accessory from the instrument and
installation.
Service, repairs or adjustment of instruments and accessories is only
allowed to be carried out by a competent authorized personnel!
E.2 Battery
The commander uses two AAA size alkaline or rechargeable Ni-MH battery cells.
Nominal operating time is at least 40 h and is declared for cells with nominal capacity of
850 mAh.
Notes:
If the commander is not used for a long period of time, remove all batteries from
the battery compartment.
Alkaline or rechargeable Ni-MH batteries (size AA) can be used. Metrel
recommends only using rechargeable batteries with a capacity of 800 mAh or
above.
Ensure that the battery cells are inserted correctly otherwise the commander will
not operate and the batteries could be discharged.
E.3 Description of commanders
MI 3125 / BT EurotestCOMBO Appendix E
Figure E.2: Front side plug commander (A 1314)
Figure E.3: Back side
1
TEST
TEST
Starts measurements.
Acts also as the PE touching electrode.
2
LED
Left status RGB LED
3
LED
Right status RGB LED
4
LEDs
Lamp LEDs (Tip commander)
5
Function selector
Selects test function.
6
MEM
Store / recall / clear tests in memory of instrument.
7
BL
Switches On / Off backlight on instrument
8
Lamp key
Switches On / Off lamp (Tip commander)
9
Battery cells
Size AAA, alkaline / rechargeable NiMH
10
Battery cover
Battery compartment cover
11
Cap
Removable CAT IV cap (Tip commander)
Both LED yellow
Warning! Dangerous voltage on the commander’s PE
terminal!
Right LED red
Fail indication
Right LED green
Pass indication
Left LED blinks blue
Commander is monitoring the input voltage
Legend:
E.4 Operation of commanders
88
MI 3125 / BT EurotestCOMBO Appendix E
Left LED orange
Voltage between any test terminals is higher than 50 V
Both LEDs blink red
Low battery
Both LEDs red and switch off
Battery voltage too low for operation of commander
Connect commander to the instrument.
Connect commander to the item to be tested (see figure E.4 and E.5).
Touch PE test probe (the TEST key) on commander for at least one second.
If PE terminal is connected to phase voltage both LEDs will light yellow, the
warning message on the instrument is displayed, instrument’s buzzer is
activated, and further measurements are disabled in Zloop and RCD functions.
PE terminal test procedure
Figure E.4: Reversed L and PE conductors (application of plug commander)
Figure E.5: Reversed L and PE conductors (application of tip commander)
Reversed phase and protection conductors! The most dangerous situation!
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