Sonel MPI-525 User manual

USER MANUAL
METER FOR ELECTRICAL INSTALLATION
PARAMETERS
MPI-525
SONEL S.A.
Wokulskiego 11
58-100 Świdnica
Version 2.908.07.2020

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The MPI-525 meter is a modern, easy in use and safe measuring device. Please acquaint yourself with
the present manual in order to avoid measuring errors and prevent possible problems related to opera-
tion of the meter.

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CONTENTS
1Safety ................................................................................................................5
2Menu..................................................................................................................6
2.1 Wireless transmission ..............................................................................................6
2.2 Settings of measurements........................................................................................ 6
2.2.1 Network voltage and frequency......................................................................................7
2.2.2 Additional results in insulation resistance measurement.................................................7
2.2.3 Main result of short circuit loop impedance measurement..............................................8
2.2.4 Measurement settings....................................................................................................8
2.2.5 Cell autoincrementing ....................................................................................................8
2.3 Settings of the meter................................................................................................9
2.3.1 LCD contrast..................................................................................................................9
2.3.2 LCD backlight time.......................................................................................................10
2.3.3 Auto-OFF settings........................................................................................................10
2.3.4 Date and time ..............................................................................................................10
2.3.5 Factory (default) settings..............................................................................................11
2.3.6 Program update...........................................................................................................11
2.4 Language selection................................................................................................ 11
2.5 Information about manufacturer............................................................................. 11
3Measurements................................................................................................12
3.1 Measurement of alternating voltage and frequency ............................................... 12
3.2 Checking correctness of PE (protective earth) connections................................... 12
3.3 Measurement of short circuit loop parameters....................................................... 13
3.3.1 Measurement of short circuit loop parameters in L-N and L-L circuit ............................13
3.3.2 Measurement of short circuit loop parameters in L-PE circuit.......................................16
3.3.3 Measurement of short circuit loop impedance in L-PE circuit protected with residual
current device (RCD) ...................................................................................................18
3.3.4 Prospective short-circuit current...................................................................................19
3.4 Measurement of resistance-to-earth ...................................................................... 20
3.5 Measurement of RCD parameters ......................................................................... 23
3.5.1 Measurement of RCD trip current.................................................................................23
3.5.2 Measurement of RCD trip time.....................................................................................25
3.5.3 Automatic measurement of RCD parameters...............................................................27
3.6 Measurement of insulation resistance.................................................................... 31
3.6.1 Double-lead measurement...........................................................................................31
3.6.2 Measurements with AutoISO-2500 adapter..................................................................33
3.7 Low-voltage measurement of resistance................................................................ 36
3.7.1 Measurement of resistance of protective conductors and equipotential bonding with
±200 mA current ..........................................................................................................36
3.7.2 Measurement of resistance..........................................................................................38
3.7.3 Calibration of test leads................................................................................................39
3.8 Checking sequence of phases............................................................................... 41
4Memory of measurement result data...........................................................42
4.1 Recording measurement result data in the memory............................................... 42
4.2 Viewing memory data............................................................................................. 44
4.3 Deleting memory data............................................................................................ 46
5Data transmission..........................................................................................48
5.1 Computer connection accessories......................................................................... 48

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5.2 Data transmission with USB................................................................................... 48
5.3 Data transmission with OR-1 radio module............................................................ 48
6Power supply..................................................................................................50
6.1 Monitoring of the power supply voltage.................................................................. 50
6.2 Replacement of batteries (accumulators)............................................................... 50
6.3 Charging of accumulators ...................................................................................... 51
6.4 General principles regarding using Ni-MH accumulators ....................................... 52
7Cleaning and maintenance ...........................................................................53
8Storage............................................................................................................53
9Dismantling and utilisation...........................................................................53
10 Technical data................................................................................................54
10.1 Basic data .............................................................................................................. 54
10.2 Additional data ....................................................................................................... 61
10.2.1 Additional uncertainties according to IEC 61557-2 (RISO)..............................................61
10.2.2 Additional uncertainties according to IEC 61557-3 (Z)..................................................61
10.2.3 Additional uncertainties according to IEC 61557-4 (R ±200 mA) ..................................61
10.2.4 Additional uncertainties according to IEC 61557-5 (RE)................................................61
10.2.5 Additional uncertainties according to IEC 61557-6 (RCD)............................................62
11 Accessories....................................................................................................63
11.1 Standard accessories............................................................................................. 63
11.2 Optional accessories.............................................................................................. 64
12 Positions of the meter’s cover .....................................................................66
13 Manufacturer ..................................................................................................66
14 Laboratory services.......................................................................................67

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1 Safety
MPI-525 meter is designed for performing check tests of protection against electric shock in mains
systems. The meter is used for making the measurements the results of which determine safety of
electrical installations. Therefore, in order to provide conditions for correct operation and the correctness
of the obtained results, the following recommendations must be observed:
Before you proceed to operate the meter, acquaint yourself thoroughly with the present manual and
observe the safety regulations and specifications determined by the producer.
The MPI-525 meter has been designed for the purpose of measurements of short-circuit loop im-
pedance, earth connection and equipotential bonding resistance, RCDs parameters as well as in-
sulation resistance measurements. Any application that differs from those specified in the present
manual may result in a damage to the device and constitute a source of danger for the user.
The device must be operatedsolely by appropriately qualified personnel with relevant certificates to
realise measurements of electric installation. Operation of the meter realised by unauthorised per-
sonnel may result in damage to the device and constitute a source of danger for the user.
Using this manual does not exclude the need to comply with occupational health and safety regula-
tions and with other relevant fire regulations required during the performance of a particular type of
work. Before starting the work with the device in special environments, e.g. potentially fire-risk/ex-
plosive environment, it is necessary to consult it with the person responsible for health and safety.
It is unacceptable to operate the following:
A damaged meter which is completely or partially out of order,
A meter with damaged test leads insulation,
A meter stored for an excessive period of time in disadvantageous conditions (e.g. excessive
humidity). If the meter has been transferred from a cool to a warm environment of a high level
of relative humidity, do not realise measurements until the meter has been warmed up to the
ambient temperature (approximately 30 minutes).
It should be remembered that BAT message appearing on the display indicates that supply voltage
of the meter is too low. This message signals also that the batteries must be replaced or the accu-
mulator charged. Measurements performed by means of the meter whose supply voltage is too low
are burdened with additional errors that are impossible to be estimated by the user. Such measure-
ments must not be relied on in order to state correctness of protection of a network tested.
Battery spill and damage to the meter may occur if discharged batteries are left in the meter.
Before measurements may commence, make sure the test leads are connected to the appropriate
measurement sockets.
Do not operate a meter with an open or incorrectly closed battery (accumulator) compartment or
power it from other sources than those specified in the present manual.
The RISO inputs of the meter are protected electronically from overload (e.g. due to having been
connected to a live circuit) up to 440V rms for 60 seconds.
Repairs may be realised solely by an authorised service point.
ATTENTION!
Only standard and additional accessories for a given device should be used, as listed in the "Equip-
ment" section. Use of different accessories can lead to errors in the test connection and can intro-
duce additional measurement uncertainties.
Attention:
Due to continuous development of the meter’s software, the actual appearance of the display, in case
of some of the functions, may slightly differ from the display presented in this operating manual.
Note:
An attempt to install drivers in 64-bit Windows 8 may result in displaying "Installation failed" mes-
sage.
Cause: Windows 8 by default blocks drivers without a digital signature.
Solution: Disable the driver signature enforcement in Windows.

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2 Menu
The Menu is accessible in each position of the rotary switch.
Press MENU push-button.
Select a proper item by means of ,
push-buttons. Enter a selected
option by pressing ENTER.
2.1 Wireless transmission
See chapter 5.3.
2.2 Settings of measurements
Select a proper item by means of ,
push-buttons. Enter a selected
option by pressing ENTER.

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2.2.1 Network voltage and frequency
Before measurements a nominal network voltage Un(110/190V, 115/200V, 127/220V, 220/380V,
230/400V or 240/415V) should be selected that is valid in the area where measurements are made. This
voltage value is used for calculating the values of prospective short-circuit current.
Determination of network frequency, that is the source of potential interferences, is necessary
in order to select a proper measuring signal frequency in resistance-to-earth measurements. Only the
measurement conducted with a properly selected frequency of measuring signal will ensure optimum
filtration of interferences. The meter is designed for filtration of interferences that originate from 50 Hz
and 60 Hz networks.
By means of , push-buttons se-
lect a parameter to be changed, by
means of , select network volt-
age and frequency. Confirm a choice
made by means of ENTER push-but-
ton.
2.2.2 Additional results in insulation resistance measurement
Choose the calculated absorption coefficients. The coefficients’ change cause automatic setting of in-
sulation resistance measurement time periods to the following values:
AB1, AB2 –t1= 15 s, t2= 60 s,
DAR, PI –t1= 30 s, t2= 60 s.
By means of , select names
of the additional results of insulation
resistance measurement.
Confirm a choice made by means of
ENTER push-button.

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2.2.3 Main result of short circuit loop impedance measurement
By means of , push-buttons se-
lect main result in the form of imped-
ance ZS or prospective short-circuit
current IK; confirm a choice made by
means of ENTER push-button.
2.2.4 Measurement settings
The setting enables activation/deactivation of the field displaying measurement settings. Show
or hide the field with measurement settings by means of and push-buttons, press ENTER push-
button.
2.2.5 Cell autoincrementing

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By means of , push-buttons se-
lect the option of automatic incre-
menting of field number after its stor-
ing in the memory or the manual in-
crementing option (automatic incre-
menting is deactivated); confirm a
choice made by means of ENTER
push-button.
2.3 Settings of the meter
Select a suitable item by means of
, push-buttons; enter the edition of
a selected option by means of
ENTER push-button.
2.3.1 LCD contrast
Select contrast value by means of
, push-buttons; confirm a choice
made by means of ENTER push-but-
ton.

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2.3.2 LCD backlight time
User can turn the LCD backlight on at any time by pushing button. The LCD backlight setting
defines the period, after which the backlight is automatically turned off. When “Always” option is chosen,
to turn the backlight off user will need to push button again.
Select LCD backlight time by means
of , push-buttons; confirm a
choice made by means of ENTER
push-button.
2.3.3 Auto-OFF settings
The setting defines time till automatic shutdown of idle meter.
Set the time or deactivate Auto-OFF
by means of , push-buttons;
confirm a choice made by means of
ENTER push-button.
2.3.4 Date and time
By means of , push-buttons select the value to be changed (day, month, year, hour, minute).
Set a required value by means of , push-buttons.When required settings are made, press ENTER
push-button.

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2.3.5 Factory (default) settings
In order to introduce factory (default) settings, highlight YES by means of , push-buttons and
press ENTER push-button.
2.3.6 Program update
ATTENTION!
This function may be used only by the users who are fluent in operation of com-
puter equipment.
The guarantee does not cover defective operation of the device resulting from
wrong use of this function.
ATTENTION!
A new package of batteries should be installed before programming or the accu-
mulator should be charged.
During programming themeter must not be switched off as well as the transmission
cable must not be disconnected.
Before updating the program, download the program that is use for programming the meter from the
manufacturer’s website (www.sonel.pl), install this program on your computer and connect the meter to
the computer.
Select Software upgrade in the MENU and follow the instructions displayed by the program.
2.4 Language selection
By means of and push-buttons choose **Language choice** in the main MENU; press
ENTER push-button.
Select a required language by means of and push-buttons; press ENTER push-button.
2.5 Information about manufacturer
By means of and push-buttons choose Manufacturer info in themain MENU; press ENTER
push-button.

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3 Measurements
Remarks:
- A progress bar is displayed during long measurements.
- The content of this chapter should be thoroughly familiarized with since it describes the meter circuits,
the methods of measurements and basic principles concerning interpretation of measurement results.
- Result of the latest measurement is remembered by the meter until a next measurement is started or
measurement settings are changed or the measuring function is changed by means of the rotary switch
or the meter is switched off. The result of the latest measurement is displayed on the screen for 20
seconds. It can be recalled by pressing ENTER push-button.
WARNING:
During measurements (short circuit loop, RCD), earthed parts and parts accessible in the
electrical installation being tested must not be touched.
WARNING:
During a measurement, switching of the range switch is forbidden because it may damage
the meter and pose a threat to the user.
3.1 Measurement of alternating voltage and frequency
The meter measures and displays alternating voltage and frequency of the network in all measuring
functions except RE, RX, R±200mA, RISO-conductor. For
L1
L2
L3
and RISO functions, only voltage
is displayed. This voltage is measured for the frequencies within the range of 45..65 Hz as True RMS.
If a frequency measured is outside the specified range, a proper message is displayed instead of the
frequency value: f<45 Hz or f>65 Hz. Voltage is displayed as the main result only for UL-N,L-L, ZL-N,L-L, UL-
PE ZL-PE and UL-PE ZL-PE RCD. The test leads should be connected as for a given measuring function.
3.2 Checking correctness of PE (protective earth) connections
When the meter is connected according to the drawing, touch the touch electrode with a finger and
wait for about 1 second. When voltage if found on PE, the device displays PE! message (error in the
installation; PE lead is connected to the phase lead) and generates a continuous audio signal. This
possibility is available for all measuring functions that apply to residual current devices (RCD) and short
circuit loop.

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Remarks:
WARNING:
When phase voltage is detected on PE lead, measurements must be immediately
stopped and a fault in the installation must be removed.
- The person making ameasurementmust ensure that he/she is standing on a non-insulated floor during
the measurement; otherwise the result of the measurement may be incorrect.
- The threshold value, which triggers the signal of exceeded allowable voltage on PE conduit, is approx-
imately 50 V.
3.3 Measurement of short circuit loop parameters
If there are residual current devices in the network tested, theyshould be bypassed
by bridging for the period of impedance measurement. However,
it should be remembered that the circuit tested is modified in this way and the
results obtained may slightly differ from the actual results.
Each time after completion of measurements, modifications introduced to the in-
stallation for the period of measurements should be removed and operation
of the residual current device should be checked.
The above remark does not apply to measurements of short circuit loop impedance
with the use of ZL-PE RCD function.
Measurements of fault loop impedance performed downstream of inverters are in-
effective and their results are unreliable. This is due to the instability of internal
impedance ininverter circuits duringits operation. The measurements of fault loop
impedance should not be performed directly downstream of inverters.
3.3.1 Measurement of short circuit loop parameters in L-N and L-L circuit
Set the rotary switch of function se-
lection at ZL-N,L-L/UL-N,L-L position.
Press F1 push-button if lead
length L needs to be selected.
Select lead length by means
of and push-buttons
and press ENTER push-but-
ton.

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In order to select the voltage
for calculating the prospective
short circuit current Ik- nominal
or measured - press F2
.
Use , to select desired
voltage and press ENTER.
Connect test leads according to the drawing
a) for measurement in L-N circuit or
b) for measurement in L-L circuit
The meter is
ready for meas-
urement.
Make measurement by pressing START
push-button
or

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Read out the re-
sult.
The result is displayed on the screen for 20s.
The result can be recalled by pressing ENTER push-button.
Remarks:
- The result can be stored in the memory (see point 4.1).
- When many measurements are made in short time intervals, the meter may emit a large amount
of heat. As a result of this, the housing of the device may become hot. This is a normal phenomenon
and the meter is equipped with the protection against excessive temperature. After approximately 15
consecutive measurements of short circuit loop, wait until the instrument cools down. This limitation
results from the high current measurement and multi-functionality of the meter.
- Minimum interval between successive measurements is 5 seconds.This minimum interval requirement
is controlled by the meter. A next measurement can be made only when READY! message appears on
the screen.
Additional information displayed by the meter
READY!
The meter is ready for measurement.
L-N!
UL-N voltage is incorrect for making a measurement.
L-PE!
UL-PE voltage is incorrect for making a measurement.
N-PE!
UN-PE voltage exceeds allowable value of 50V.
Phase connected to N terminal instead of L terminal (for ex-
ample, exchange of L and N in the mains socket.
Temperature exceeded.
f!
Network frequency is outside the range of 45...65 Hz.
Error during meas-
ure
A correct result can not be displayed.
Loop circuit mal-
function!
The meter should be serviced.
No UL-N!
Lack of UL-N voltage before the principal measurement.
U>500 V! and con-
tinuous audio signal
Before measurement, voltage at test terminals exceeds 500
V.

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3.3.2 Measurement of short circuit loop parameters in L-PE circuit
Set the rotary switch of function se-
lection at ZL-PE/UL-PE position.
Press F1 push-button if L lead
length needs to be selected.
Select a lead length by
means of and push-
buttons and press ENTER
push-button.
Connect test leads according to one of the drawings.
Checking effectiveness of protection against electric shock of the device hous-
ing in case of: a) TN network b) TT network

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The meter is
ready for meas-
urement.
Make measurement by pressing START
push-button.
Read out the re-
sult.
The result is displayed on the screen for 20s.
The result can be recalled by pressing ENTER push-button.
Remarks:
- Double lead measurement is possible when a test lead other that the lead with a mains socket is
selected.
- Remaining issues connected with the measurements as well as the messages displayed are the same
as those described for measurements in L-N circuit or L-L circuit.

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3.3.3 Measurement of short circuit loop impedance in L-PE circuit protected
with residual current device (RCD)
Set the rotary switch of function se-
lection at ZL-PE RCD position.
Press F1 push-button if L lead
length needs to be selected.
Select a lead length by
means of and push-
buttons and press ENTER
push-button.
Connect test leads according to one of the drawings.
Remarks:
- Maximum measurement time is about 32 seconds. The measurement can be aborted by pressing ESC
push-button.
- In the electrical installations in which 30 mA - rated residual current devices are used, it may happen
that the sum of leakage currents of the installation and the test current will trigger RCD. In such
a situation, one should try to reduce leakage current of the network being tested (for example, by dis-
connecting load points).
- Remaining issues connected with the measurements as well as the messages displayed are the same
as those described for measurements L-PE circuit.
- The function works for residual current devices of nominal current ≥30 mA.
or
or