METREL MI 3295 User manual

Step Contact Voltage
Measuring System
MI 3295
Instruction manual
Version 2.1.1, Code no. 20 752 071

2
Distributor:
Manufacturer:
METREL d.d.
Ljubljanska cesta 77
1354 Horjul
Slovenia
web site: http://www.metrel.si
e-mail: [email protected]
Mark on your equipment certifies that it meets requirements of all subjected EU regulations
© 2017 METREL
The trade names Metrel®, Smartec®, Eurotest®, Auto Sequence®are trademarks registered 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.

MI 3295 Step Contact Voltage Measuring System Table of contents
3
Table of content
1Preface.......................................................................................................................5
2Safety and operational considerations....................................................................6
2.1 Warnings and notes..............................................................................................6
2.2 Battery and charging of MI 3295M........................................................................6
2.2.1 New battery cells or cells unused for a longer period .....................................................8
2.3 Standards applied ................................................................................................8
3Instrument description MI 3295M Meter ................................................................10
3.1 Front panel.........................................................................................................10
3.2 Connector panel.................................................................................................11
3.3 Back panel .........................................................................................................11
4Instrument description MI 3295S Station...............................................................13
4.1 Front panel.........................................................................................................13
4.2 Instrument set and accessories..........................................................................14
4.2.1 Standard set...................................................................................................................14
4.2.2 Optional accessories......................................................................................................14
5MI 3295M Meter operation.......................................................................................15
5.1 Organization of display.......................................................................................15
5.1.1 Battery indication............................................................................................................15
5.1.2 Warnings and messages ...............................................................................................15
5.2 Backlight and contrast adjustments ....................................................................16
5.3 Function selection ..............................................................................................16
5.4 Settings..............................................................................................................16
5.4.1 Language .......................................................................................................................17
5.4.2 Help screens ..................................................................................................................17
5.4.3 Initial settings..................................................................................................................17
5.4.4 Date and time.................................................................................................................18
5.4.5 Synchronization..............................................................................................................18
6MI 3295S Station operation.....................................................................................20
6.1 Organization of displays .....................................................................................20
6.2 Warnings and messages....................................................................................20
6.3 Help screens ......................................................................................................21
6.4 Contrast adjustments..........................................................................................21
6.5 Function selection ..............................................................................................21
6.6 Settings..............................................................................................................22
6.6.1 Language .......................................................................................................................22
6.6.2 Initial settings..................................................................................................................22
6.6.3 Date and time.................................................................................................................23
6.6.4 Output power range .......................................................................................................23
6.6.5 Alarm..............................................................................................................................23
7Measurements.........................................................................................................24
7.1 Theory of measurements....................................................................................24
7.1.1 General on earthing .......................................................................................................24
7.1.2 General on specific earth resistance .............................................................................25
7.1.3 Measurement .................................................................................................................25
7.2 Step voltage, Contact/Touch voltage and Potential ............................................28
7.2.1 Injection of test current...................................................................................................28

MI 3295 Step Contact Voltage Measuring System Table of contents
4
7.2.2 Synchronization before the test (recommended) ..........................................................29
7.2.3 Step voltage and Contact/Touch voltage measurements .............................................30
7.2.4 Potential..........................................................................................................................31
7.2.5 Synchronization after the test (recommended) .............................................................32
7.3 Current measurement.........................................................................................33
7.4 Earth resistance .................................................................................................34
7.4.1 Earth resistance measurement......................................................................................34
7.4.2 Specific earth resistance measurement ........................................................................35
7.4.3 Downloading Earth results to the Meter ........................................................................36
8Data handling ..........................................................................................................37
8.1 Memory..............................................................................................................37
8.1.1 Data structure.................................................................................................................37
8.1.2 Storing test results .........................................................................................................38
8.1.3 Recalling test results......................................................................................................38
8.1.4 Clearing stored data.......................................................................................................39
8.2 Current Logger...................................................................................................41
8.2.1 Clearing the logger content............................................................................................41
8.3 Communication ..................................................................................................42
9Maintenance ............................................................................................................43
9.1 Fuse replacement and range selection...............................................................43
9.2 Cleaning.............................................................................................................44
9.3 Periodic calibration.............................................................................................45
9.4 Service...............................................................................................................45
10 Technical specifications.........................................................................................46
10.1 Step voltage, Contact/Touch voltage (MI 3295M)...............................................46
10.2 Current (MI 3295S).............................................................................................46
10.3 Resistance to earth (MI 3295S)..........................................................................46
10.4 Specific earth resistance (MI 3295S)..................................................................47
10.5 Potential (MI 3295M)..........................................................................................47
10.6 Current (MI 3295M) ............................................................................................48
10.7 General data.......................................................................................................49

MI 3295 Step Contact Voltage Measuring System Preface
5
1 Preface
Congratulations on your purchase of the measuring system from METREL.
The Step Contact Voltage Measuring System consists of Station (MI 3295S) and Meter (MI
3295M) and is intended for the following tests and measurements:
Step voltage
Contact/Touch voltage
Potential
Earth resistance
Specific earth resistance
Current
The instrument is equipped with all the necessary accessory for comfortable testing. The
PC SW Metrel ES Manager enables uploading structure, downloading of results, storing of
results and making test reports.
Some measuring system highlights:
Graphic LCD displays on Meter and Station.
Autonomous Step / Contact/Touch Voltage Meter(s).
Potential measurement with adjustable step length (straight line method).
TRMS, 50 Hz, 55 Hz and 60 Hz clamp current measurement.
Over 1000 memory locations in data flash memory for storing test results &
parameters.
USB and RS232 ports on Meter for communication with PC.
Synchronization between Meter and Station.
Large test current of up to 50 A.
Stable and accurate results due to a DSP measuring system.
Fully compatible with new Metrel ES Manager PC software.

MI 3295 Step Contact Voltage Measuring System Safety and operational considerations
6
2 Safety and operational considerations
2.1 Warnings and notes
In order to reach high level of operator’s safety while carrying out various tests and
measurements using the Step Contact Voltage Measuring System, as well as to keep the
equipment undamaged, it is necessary to consider the following general warnings:
Warning on the instrument means »Read the Instruction manual with
special care to safety operation«. The symbol requires an action!
If the test equipment is used in a manner not specified in this Instruction
manual the protection provided by the equipment might be impaired!
Read this Instruction manual carefully, otherwise use of the instrument may be
dangerous for the operator or for the instrument!
All normal safety precautions have to be taken in order to avoid risk of electric
shock when working in the area of distribution systems!
Do not use the instrument and accessories if any damage is noticed!
Service intervention or adjustment and calibration procedure is allowed to be
carried out only by a competent authorized person!
Use only standard or optional test accessories supplied by your distributor!
Meter (MI 3295M)
Instrument contains rechargeable NiMh battery cells. The cells should only be
replaced with the same type as defined on the battery placement label or in
this manual. Do not use standard alkaline battery cells while power supply
adapter is connected, otherwise they may explode!
Do not connect any voltage source on clamp inputs. It is intended only for
connection of current clamps. Maximal input voltage is 3 V!
Disconnect all test leads, remove the power supply cable and switch off the
instrument before removing battery compartment cover.
The weight of each test probe is 25 kg. This weight may be harmful if the
probes are not lifted and carried appropriately.
Station (MI 3295S)
During instrument operation ventilation holes on casing should always stay
open to ensure sufficient air-flow for cooling.
Disconnect all test leads, switch off the instrument and remove the mains cord
before changing the fuse.
The weight of the MI 3295S is 29.5 kg. This weight may be harmful if the
instrument is not lifted and carried appropriately. It is recommended that the
instrument is transported by 2 persons.
2.2 Battery and charging of MI 3295M
The instrument MI 3295M 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.

MI 3295 Step Contact Voltage Measuring System Safety and operational considerations
7
Figure 2.1: Discharged battery indication
The battery is charged whenever the power supply adapter is connected to the instrument.
Internal circuit controls charging assuring maximum battery lifetime. The power supply
socket polarity is shown in Figure 2.2.
+
-
Figure 2.2: Power supply socket polarity
The instrument automatically recognizes the connected power supply adapter and begins
charging.
Symbols:
Indication of battery charging
Figure 2.3: Charging indication
Before opening battery compartment cover disconnect all measuring
accessories connected to the instrument and switch off the instrument.
Do not charge alkaline battery cells!
Insert cells correctly, otherwise the instrument will not operate and the batteries
could be damaged.
Remove all battery cells from the battery compartment if the instrument is not used
for a long period of time.
Take into account handling, maintenance and recycling requirements that are
defined by related regulations and manufacturers of alkaline or rechargeable
batteries!
Use only power supply adapter delivered from the manufacturer or distributor of the
test equipment to avoid possible fire or electric shock!

MI 3295 Step Contact Voltage Measuring System Safety and operational considerations
8
2.2.1 New battery cells or cells unused for a longer period
Unpredictable chemical processes can occur during charging of new battery cells or cells
that were unused for a longer period (more than 3 months). NiMH and NiCd battery cells
are affected to capacity degradation (sometimes called as memory effect). As a result the
instrument operation time can be significantly reduced.
Recommended procedure for recovering battery cells:
Procedure
Notes
Completely charge the battery.
At least 14 h with in-built charger.
Completely discharge the battery.
Use the instrument for normal testing until
the unit displays the “Bat” symbol on
screen.
Repeat the charge / discharge cycle for
at least twice.
Four cycles are recommended.
Complete discharge / charge cycle can be performed automatically for each cell using
external intelligent battery charger.
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. This information is provided in the technical specification from
battery manufacturer.
2.3 Standards applied
The Step Contact Voltage Measuring System (MI 3295) is manufactured and tested
according to the following regulations, listed below.
Electromagnetic compatibility (EMC)
IEC/ EN 61326-1
Electrical equipment for measurement, control and laboratory use -
EMC requirements - Part 1: General requirements
Class B (Hand held equipment used in controlled EM
environments)
IEC/EN 61326-2-2
Electrical equipment for measurement, control and laboratory use -
EMC requirements - Part 2-2: Particular requirements - Test
configurations, operational conditions and performance criteria for
portable test, measuring and monitoring equipment used in low-
voltage distribution systems

MI 3295 Step Contact Voltage Measuring System Safety and operational considerations
9
Safety (LVD)
IEC/ EN 61010-1
Safety requirements for electrical equipment for measurement,
control, and laboratory use –Part 1: General requirements
IEC/ 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
IEC/ EN 61010-031
Safety requirements for hand-held probe assemblies for electrical
measurement and test
IEC/ EN 61010-2-032
Safety requirements for electrical equipment for measurement,
control and laboratory use –Part 2-032: Particular requirements for
hand-held and hand-manipulated current sensors for electrical test
and measurement
Functionality
HD 637 S1
Power installations exceeding 1 kV a.c.
ANSI/IEEE Std 81
IEEE Guide for Measuring Earth Resistivity, Ground Impedance,
and Earth Surface Potentials of a Ground System
RAT 2008
Spain High Voltage regulation

MI 3295 Step Contact Voltage Measuring System Instrument description 3295 M Meter
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3 Instrument description MI 3295M Meter
3.1 Front panel
Figure 3.1: Front panel
Legend:
1
LCD
LCD display with backlight
2
ESC
Returns to previous menu
3
MEM
Handling with memory
4
Cursor and TEST keys
Cursors
Selects test parameters
TEST
Starts / stops measurement
5
BACKLIGHT, CONTRAST
Changes backlight level and contrast
6
ON / OFF
Switches the instrument power on or off
The instrument automatically turns off 15 minutes
after the last key was pressed
7,8
Function selector
Selects test function and settings

MI 3295 Step Contact Voltage Measuring System Instrument description 3295M Meter
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3.2 Connector panel
Figure 3.2: Connector panel
Legend:
1
Charger socket
2
USB communication port
Communication with PC USB (1.1) port
3
PS/2 communication port
RS232 serial communication port
4
Current clamp inputs
Warning! Maximum allowed voltage between clamp test terminals is 3 V!
5
Test connector
Warning! Maximal allowed voltage between test terminals and ground is 50 V!
Maximal allowed voltage between test terminals is 100 V!
6
Protection cover
3.3 Back panel
Figure 3.3: Back panel
Legend:
1
Battery compartment cover
2
Fixing screws for battery compartment cover
3
Information label

MI 3295 Step Contact Voltage Measuring System Instrument description 3295M Meter
12
Figure 3.4: Battery compartment
Legend:
1
Serial number label
2
Battery cells (size AA)

MI 3295 Step Contact Voltage Measuring System Instrument description 3295S Station
13
4 Instrument description MI 3295S Station
4.1 Front panel
Figure 4.1: Front panel
Legend:
1
Fuse and voltage
selector cover
Supply voltage range selector with mains fuses. See
chapter 9.1 Fuse replacement and range selection for
more information.
Voltage selector
2
Mains input
For connection to mains cord.
3
Power On/Off switch
4
RS232 connector
For connection to the Meter.
5
C1/H
Connection for auxiliary earthing probe.
6
S
Connection for voltage sense probe.
7
ES
Connection for second voltage sense probe.
8
C2/E
Connection for auxiliary earthing probe.
9
HELP
Help menus.
10,11
Function selector
Selects test function and settings.
12
LCD
LCD display with backlight.
13
CONTRAST
Changes contrast.
14
MEM
Handling with memory.
15
ESC
Returns to previous screen.
16
Cursor and TEST keys
Cursors:
Selects test parameters.
TEST:
Starts measurement.

MI 3295 Step Contact Voltage Measuring System Instrument description 3295S Station
14
4.2 Instrument set and accessories
4.2.1 Standard set
Instrument MI 3295S
1 pc
Instrument MI 3295M
1 pc
Mains cable
1 pc
Step voltage probe (25 kg) or Step voltage plates
2 pcs
Current earth spike
2 pcs
Potential earth spike
1 pc
Current test lead, 50 m, black, 10 mm2, with crocodile clip, on wheel
1 pc
Current test lead, 10 m, black, 10mm2, with crocodile clip
1 pc
Test lead, black, 2 x 3 m
1 pc
Test lead, green, 10 m
1 pc
Test lead, red, 50 m
1 pc
Connection lead with crocodile clip, red, 1 m
1 pc
Test lead, black, 1.5 m
1 pc
Crocodile clip
4 pcs
RS232 cable
1 pc
USB cable
1 pc
Soft carrying bag
2 pcs
Soft carrying neck belt
1 pc
NiMH battery, type AA
6 pcs
Power supply adapter
1 pc
CD with Instruction manual and PC SW Metrel ES Manager
1 pc
Instruction manual
1 pc
Calibration certificate
4.2.2 Optional accessories
See the attached sheet for a list of optional accessories that are available on request
from your distributor.

MI 3295 Step Contact Voltage Measuring System MI 3295M Meter operation
15
5 MI 3295M Meter operation
5.1 Organization of display
Figure 5.1: Typical function display
Function name
Result field
Test parameter field
Message field
5.1.1 Battery indication
The battery indication indicates the charge condition of battery and connection of external
charger.
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).
Warning:
If the batteries are removed for more than 1 minute:
- set time and date will be lost
- the instrument will return to Initial settings.
5.1.2 Warnings and messages
In the message field warnings and messages are displayed.
The Meter and Station are not synchronized.
Measurement is running; consider displayed warnings.
Result(s) can be stored.
Measurement result is inside pre-set limits (PASS).
Measurement result is out of pre-set limits (FAIL).

MI 3295 Step Contact Voltage Measuring System MI 3295M Meter operation
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5.2 Backlight and contrast adjustments
With the BACKLIGHT key backlight and
contrast can be adjusted.
Figure 5.2: Contrast adjustment menu
BACKLIGHT key:
Click
Toggle backlight intensity level.
Keep pressed for 1 s
Lock 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.
Keys for contrast adjustment:
Cursor LEFT / RIGHT
Sets contrast.
TEST
Confirms new contrast.
ESC
Exits without changes.
5.3 Function selection
For selecting function main menus the FUNCTION SELECTOR shall be used:
Function
selector
Selects test / measurement function:
<STEP VOLT> step voltage test
<U CONTACT/TOUCH> contact / touch voltage test
<POTENTIAL> potential measurement (straight line method)
<CURRENT> current measurement
<SETTINGS> settings / synchronization
5.4 Settings
Different instrument options can be set in the SETTINGS menu.
Options are:
Selection of language
Help screens
Synchronization with the Station
Setting the instrument to initial values
Recalling and clearing stored results
Setting date and time
Selection of length unit (m, ft)
Figure 5.3: Settings menu
Keys:
Cursor UP / DOWN
Selects appropriate option.
TEST
Enters selected option.

MI 3295 Step Contact Voltage Measuring System MI 3295M Meter operation
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5.4.1 Language
Language can be set in the SELECT
LANGUAGE menu.
Figure 5.4: Language selection
Keys:
Cursor UP / DOWN
Selects language.
TEST
Confirms selected language.
ESC
Returns to Settings main menu.
5.4.2 Help screens
The help screens contain basic schematic /
connection diagrams and information about
the instrument.
Figure 5.5: Example of help screen
Keys:
Cursor LEFT / RIGHT
Selects next / previous help screen.
ESC
Returns to Settings main menu.
5.4.3 Initial settings
The instrument settings and measurement
parameters and limits can be set to their
initial (factory) settings in this menu.
Figure 5.6: Initial settings screen
Keys:
Cursor LEFT / RIGHT
Selects Yes or No
TEST
Restores initial settings (if Yes is selected)
ESC
Exits back to Settings main menu without changes.
Initial settings are:
Instrument setting
Default value
Contrast
Default value
Language
English
Length units
m

MI 3295 Step Contact Voltage Measuring System MI 3295M Meter operation
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Function
Parameter
Limit
Default value
Contact/Touch Voltage
Step Voltage
Iset
Iflt
Rinp
Ulim
10.0 A
1.0 kA
1.0 kΩ
50V
Potential
Iset
Iflt
Step
Dir
10.0 A
10 A
1.0 m
0°
Current
Type
Mode
Lim
A 1018
55 Hz
Off
5.4.4 Date and time
Date and time can be set in this menu.
Figure 5.7: Setting date and time
Keys:
Cursor LEFT / RIGHT
Selects the item to be changed.
Cursor UP / DOWN
Modifies selected item.
TEST
Confirms new setup and exits.
ESC
Returns to Settings main menu.
5.4.5 Synchronization
Selecting SYNC. MI3295S will allow uploading different data from the Station to the Meter
and vice versa.
Options are:
Synchronization of date, time,
current and structure names
Uploading of test current results for
Step voltage, Contact/Touch voltage
and Potential calculation
Uploading of Earth resistance results
Figure 5.8: Synchronization menu
Keys:
Cursor UP / DOWN
Selects option.
TEST
Enters selected option.
ESC
Returns to Settings main menu.

MI 3295 Step Contact Voltage Measuring System MI 3295M Meter operation
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Synchronized data:
BEFORE TESTS
Station’s time and date will be uploaded to the Meter.
Value of generator current will be uploaded to the Meter (if current
generator is on).
Structure names from Meter will be uploaded to the Station.
AFTER TESTS
Values of logged generator currents IGEN will be uploaded to the
Meter for calculation of Step voltage, Contact/Touch voltage and
Potential.
EARTH RESULTS
Stored Earth resistance or Specific earth resistance results in the
Station will be uploaded to the Meter.
Note:
The main purpose of the Time/ Current synchronization is to enable a correction of
the step and contact voltage results after the test. During the test the Step and
Contact/Touch voltage results and Potential results are calculated on base on the
set ISET in the Meter. After the test the results made with the Meter can be updated
with the real generator currents IGEN that were measured at the same time with the
Station. The stored USTEP, UCONTACT and Potential result values are then corrected
according to the following formula:
SET
generatedactuallyGEN
STEPoldSTEPnew I
I
UU )_( 
SET
generatedactuallyGEN
CONToldCONTnew I
I
UU )_( 
SET
generatedactuallyGEN
ldPOTENTIALoewPOTENTIALn I
I
UU )_( 
The synchronization is active for 24 h.
If the date / time are changed at the Meter or the Station the synchronization of time
and data will be lost. The Current logger must be cleared before it can be
proceeded with the measurements. Before clearing it the content can be
downloaded to the Meter.
If there is no synchronization between both units the icon is displayed in the
Meter measuring screen.

MI 3295 Step Contact Voltage Measuring System MI 3295S Station operation
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6 MI 3295S Station operation
6.1 Organization of displays
Figure 6.1: Typical display in earth
resistance function
Function name
Result & Sub-result field
Message field
Figure 6.2: Typical display in
specific earth resistance function
Function name
2.4m
Test parameter field
Result & Sub-result field
Message field
Figure 6.3: Typical display in
current function
Function name
Result field
Message field
Remained place in current logger
6.2 Warnings and messages
Before and during the measurement the instrument performs different tests to ensure
safety and to prevent from damaging it. These safety tests include checking for any
external voltage or improper loading of test terminals. If a problem is detected, an
appropriate warning message will be displayed. Warnings and protective measures are
described in this chapter.
Voltage between test terminals C1/H and C2/E is higher than
allowed (>10 V). Disconnect the test leads and check why an
external voltage was detected!
Output was overloaded or test current abruptly fall down.
Overload can be caused by high spurious earth current. In this
case it is recommended to decrease the output power. See
chapter 6.6.4 Output power range for more information.
Output current is too low. A too low current can be caused
because of bad connection or high probe resistance.