Sonel MPI-502 User manual

OPERATING MANUAL
ELECTRICAL INSTALLATION METER
MPI-502
SONEL S. A.
ul. Wokulskiego 11
58-100 Świdnica
Version 1.16 22.01.2016

MPI-502 OPERATING MANUAL, version 1.16
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The MPI-502 is a modern, state-of-the art measuring instrument, easy to operate and safe. Read this
manual to avoid mistakes during the measurements and prevent operational problems.

MPI-502 OPERATING MANUAL, version 1.16
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CONTENTS
1SAFETY....................................................................................................................5
2MEASUREMENTS..................................................................................................6
2.1 SWITCHING ON AND OFF,DISPLAY BACKLIGHT ......................................................6
2.2 SELECTING GENERAL MEASUREMENT PARAMETERS..............................................6
2.3 REMEMBERING THE LAST MEASUREMENT RESULT ................................................8
2.4 ALTERNATING VOLTAGE MEASUREMENT ..............................................................8
2.5 VOLTAGE AND FREQUENCY MEASUREMENT..........................................................8
2.6 VERIFYING THE PROTECTIVE CONDUCTOR CONNECTION CORRECTNESS................8
2.7 MEASUREMENTS OF FAULT LOOP PARAMETERS ....................................................9
2.7.1 Selecting the lead length................................................................................9
2.7.2 Prospective short-circuit current.................................................................10
2.7.3 Measurement of fault loop parameters in the L-N and L-L systems............11
2.7.4 Measurement of fault loop parameters in the L-PE system.........................13
2.7.5 Measurement of fault loop impedance in the L-PE system protected by an
RCD.............................................................................................................15
2.8 MEASUREMENT OF RESISTANCE TO EARTH..........................................................17
2.9 MEASUREMENT OF THE RESIDUAL CURRENT DEVICE PARAMETERS.....................18
2.9.1 Measurement of the RCD tripping current ..................................................18
2.9.2 Measurement of the RCD tripping time.......................................................20
2.9.3 Automatic RCD parameters measurement...................................................22
2.10 LOW-VOLTAGE RESISTANCE MEASUREMENT.......................................................28
2.10.1 Continuity measurements of protective conductors and equipotential
bonding (with the  200mA current).............................................................28
2.10.2 Low-current resistance measurement..........................................................29
2.10.3 Test leads resistance compensation –auto-zeroing.....................................31
3MEMORY OF MEASUREMENT RESULTS.....................................................32
3.1 ENTERING THE MEASUREMENT RESULTS TO TE MEMORY....................................32
3.2 CHANGING THE CELL AND BANK NUMBER...........................................................34
3.3 BROWSING THE MEMORY....................................................................................34
3.4 CLEARING THE MEMORY.....................................................................................36
3.4.1 Clearing the bank ........................................................................................36
3.4.2 Clearing the whole memory.........................................................................37
3.5 COMMUNICATION WITH COMPUTER ....................................................................38
3.5.1 Package for cooperation with computer......................................................38
3.5.2 Data transmission........................................................................................38
4TROUBLESHOOTING.........................................................................................39
5POWER SUPPLY ..................................................................................................40
5.1 MONITORING THE POWER SUPPLY VOLTAGE........................................................40

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5.2 REPLACING THE BATTERIES.................................................................................41
5.3 GENERAL RULES OF USING THE NICKEL METAL HYDRIDE (NI-MH) BATTERIES..41
6CLEANING AND MAINTENANCE....................................................................42
7STORAGE ..............................................................................................................42
8DISMANTLING AND DISPOSAL.......................................................................43
9TECHNICAL SPECIFICATION .........................................................................43
9.1 BASIC INFORMATION...........................................................................................43
9.2 ADDITIONAL INFORMATION.................................................................................48
9.2.1 Additional uncertainty according to IEC 61557-3 (Z) ................................48
9.2.2 Additional uncertainty according to IEC 61557-4 (R ±200mA)..................48
9.2.3 Additional uncertainty according to IEC 61557-6 (RCD)...........................48
10 EQUIPMENT .........................................................................................................49
10.1 STANDARD EQUIPMENT.......................................................................................49
10.2 OPTIONAL EQUIPMENT ........................................................................................49
11 MANUFACTURER ...............................................................................................51

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1 Safety
The MPI-502 meter is designed for testing the protection against electric shock in the mains sys-
tems. The meter is used to make measurements which results determine the electrical installation
safety level. Consequently, in order to ensure safe operation and correct measurement results, ob-
serve the following recommendations:
Before you proceed to operate the meter, acquaint yourself thoroughly with the present manual
and observe the safety regulations and recommendations of the manufacturer.
Any application that differs from those specified in the present manual may cause damage of the
instrument and a serious hazard to its user.
The MPI-502 meters must be operated solely by appropriately qualified personnel with relevant
certificates to perform measurements of electric installation. Operation of the instrument by unau-
thorized personnel may result in damage to the device and constitute a hazard to the user.
Using this manual does not exclude the need to comply with occupational health and safety regu-
lations 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/explosive 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,
leads with damaged insulation,
a meter which ahs been stored to long in unsuitable conditions (for example is wet). When the
meter is transferred from cold environment to warm and humid one, do not make measure-
ments until the meter warms up to the ambient temperature (about 30 minutes).
Remember that the message on the display means that the power supply voltage is too low
and indicates the need to replace/ charge the batteries. The measurements performed with the
meter with insufficient supply voltage have additional measuring errors which are impossible to be
evaluated by the user and cannot be the basis to determine the correct protection of the tested in-
stallation.
Do not leave the discharged batteries in the meter as they can leak and damage the instrument.
Before starting the measurement, check if the leads are connected to correct measuring termi-
nals.
Never use the meters with open or only partially closed battery compartment cover and use only
the power supplies specified in this manual.
Repairs may be performed solely by an authorized service outlet.
NOTE
Use only standard and optional accessories intended for a given instrument which are
listed in the “Equipment” section. Using other accessories may cause damage of the
measuring terminal and additional measuring errors.
Note:
Due to continuous development of the meter software, the display view for some functions
may be a bit different from the view shown in this manual.

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Note:
An attempt to install drivers in 64-bit Windows 8 may result in displaying "Installation
failed" message.
Cause: Windows 8 by default blocks drivers without a digital signature.
Solution: Disable the driver signature enforcement in Windows.
2 Measurements
WARNING:
During the measurements (fault loop impedance, RCD) never touch the earthed and ac-
cessible parts in the tested electrical installation.
WARNING:
During the measurement do not switch the range selector as this may cause damage of
the meter and hazard for the user.
2.1 Switching on and off, display backlight
To switch on the meter, briefly press the button. To switch off, press the same button
longer (the message appears). To switch on/off the display and keypad backlight during the meter
operation, briefly press the button.
2.2 Selecting general measurement parameters
Keeping the SET/SEL button de-
pressed, switch on the meter and wait
for the parameter selection screen to
appear.
Use the and buttons to go to next pa-
rameter.
Use the and buttons to change the pa-
rameter value. The value or symbol to be
changed is flashing.
The symbol indicates an active parameter,
the symbol indicates an inactive one.
Set the parameters according to the following algorithm:

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Parameter
Mains
voltage
Voltage for
calculating
IK: rated/
measured
RCD-
AUTO
parameters
Auto-
OFF
Change
PIN
Supply
source
selection
Buzzer
Software
updating
Symbol(s)
?
Parameter
symbol(s)
...
Press ENTER to save the changes and go to the
measurement function.
or
Press ESC to go the measurement function with-
out saving the changes.
Notes:
- Before the first measurements, set the mains rated voltage Un(220/380V, 230/400V or 240/415V)
which is applicable in the test location. The voltage is used to calculate the prospective short-circuit
current, if this option was chosen from the main menu.
- The symbol means the positive phase or polarization, the symbol –a negative one.
- The symbol in the time to auto-off settings, indicates absence of such time.
- The RCD Auto mode settings are described in section 2.7.3.
- PIN settings –see section 3.5.2 Data transmission.
- Use OR-1 receiver (section 3.5.1) to update the software. New software may be downloaded from
www.sonel.pl.

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2.3 Remembering the last measurement result
The result of the last measurement is remembered until the next measurement is activated, the
measurement parameters are changed or the measuring function is changed with the dial switch. Use
the ESC button to go to the starting screen of a given function and press ENTER to display the last
measurement result. Use the same procedure to display the last measurement result after the meter
has been switched off (applies to the measurements of Z, RCD and RCONT).
2.4 Alternating voltage measurement
The meter measures and displays the mains alternating voltage in all measurement functions
with the exception of R. The voltage is measured for the 45..65Hz frequency range. The test leads
should be connected as for a given measuring function.
2.5 Voltage and frequency measurement
Set the dial switch to the U,f posi-
tion.
Read the measure-
ment result: voltage in
the auxiliary display
field, frequency in the
main field.
2.6 Verifying the protective conductor connection correctness
or
PE
Connect the meters as shown in the figure, touch
the contact electrode with your finger and wait
about 1 second. When the voltage on the PE
conductor is detected, the instrument displays the
message (error in the installation, the PE con-
ductor is connected to the phase conductor) and
generates a continuous audio signal. This option
is available for all measurement functions related
to the RCD’s and fault loop, except for ZL-N,L-L.

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Notes:
WARNING:
When dangerous voltage on the protective conductor PE is detected, discontinue the
measurements immediately and repair the electrical installation.
- Make sure that during the measurements you are not standing on an uninsulated floor as this may
cause erroneous results.
- The threshold value, which triggers the signal of exceeded allowable voltage on PE conduit, is ap-
proximately 50 V.
2.7 Measurements of fault loop parameters
If the tested mains includes residual current devices, for the duration of measurement they
should be omitted by bypassing. Remember however that bypassing changes the tested
circuit and the results may very slightly differ from the actual values.
After the measurement, restore the mains to its original state and check operation of the
residual current device.
This note does not apply to the earth loop impedance measurements with the
ZL-PE RCD function.
Measurements of fault loop impedance performed downstream of inverters are ineffective
and their results are unreliable. This is due to the instability of internal impedance in in-
verter circuits during its operation. The measurements of fault loop impedance should not
be performed directly downstream of inverters.
2.7.1 Selecting the lead length
Set the dial switch to one of the
fault loop impedance measure-
ment ranges.
Set the parameters according to the following algorithm and
the rules for setting the general parameters.
NOTE: The WS-05 and WS-01 leads are detected by the
meter and you cannot select their length (the symbol is
displayed). When you are using the leads with banana
plugs, before you start the measurements set the correct
phase conductor length complying with the test leads
length.

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Notes:
Using original leads and selecting correct length is a guarantee of keeping the declared
measuring accuracy.
2.7.2 Prospective short-circuit current
The meter always measures the impedance, and the displayed short-circuit current is calculat-
ed according to the following formula:
S
n
kZ
U
I
where: Un–rated voltage of the tested mains, ZS–measured impedance.
Based on the rated voltage Unselected in the general settings (section 2.1), the meter automat-
ically detects the measurement with phase-to-neutral or phase-to-phase voltage and includes this in
the calculations.
If the tested mains voltage is out of tolerance range, the meter will not be able to determine the
correct rated voltage for calculation of short-circuit current. In such case, horizontal lines will be dis-
played instead of the short-circuit current. The figure below shows the voltage ranges for which the
short-circuit current is calculated.
230 400 440 U [V]
U voltage ranges for which the
short-circuit current is calculated
L-N
Voltage range for which the impedance is measured
207 253 360
220 380 418
198 242 342
373 415 440 216 240 264
440 U [V]
U [V]
U =220V
n
U =230V
n
U =240V
n
U voltage ranges for which the
short-circuit current is calculated
L-L

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2.7.3 Measurement of fault loop parameters in the L-N and L-L systems
Switch on the meter.
Set the dial switch to
the ZL-L ZL-N position.
Select the leads length as described in 2.6.1 according to the needs.
or
N L N L
a) b)
Connect the test
leads as shown
in the figure
a) for meas-
urement in the
L-N circuit or
b) measurement
in the L-L circuit
The meter is ready for
measurement.
Phase conductor
length or the sym-
bol.
UL-N or UL-L voltage
Press START to perform the measure-
ment.

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Read the main result:
the fault loop imped-
ance ZSand the mains
voltage during the
measurement.
Press to read additional results.
IK
short-circuit
current.
R
fault loop
resistance
XL
fault loop
reactance

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Note:
- Save the result in the memory (see sections 3.1 and 3.2) or press ESC to return to the voltage
measurement.
- Making a large number of tests over a short time causes the meter to emit a lot of heat. As a result
the casing may become warm. This is normal, and the meter has an overheat protection.
- The minimum time between successive measurements is 5 seconds. This value is controlled by the
meter which displays the message when you can make the next measurement.
Additional information displayed by the meter
Meter ready for measurement
Voltage on the meter Land Nterminals is out of range for
which the measurement can be made.
Voltage on the meter Land PE terminals is out of range for
which the measurement can be made.
Measurement error
Measurement error –loss of voltage after the measurement.
Damage of the meter short circuit.
N conductor not connected.
Message (displayed after the measurement) indicates signif-
icant disturbances in the mains during measurement. The
measurement result may include a large, unspecified error.
Temperature inside the meter has exceeded the allowed lim-
it. The measurement is blocked.
The L and N conductors are switched (voltage between the
PE and N conductors).
2.7.4 Measurement of fault loop parameters in the L-PE system
Switch on the meter.
Set the dial switch to
the ZL-PE position.
Select the leads length as described in 2.6.1 according to the
needs.

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or
N LPE
Connect the test
leads as shown
in one of the
figures.
PE L
0
a)
b)
Checking the effectiveness of protection against electric shock of the equipment casing for: a) TN
mains b) TT mains.
The meter is ready
for measurement.
Phase conductor
length or the
symbol.
UL-PE voltage
Press START to perform the measurement.
The remaining measurement issues are analogous to the ones described for the measurements
in the L-N or L-L systems.

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Notes:
- A double-lead measurement is possible when selecting the test lead other than with the socket
adapter.
Additional information displayed by the meter
Information and error messages are the same as in case of L-N and L-L.
2.7.5 Measurement of fault loop impedance in the L-PE system protected by
an RCD
The MPI-502 allows the fault loop impedance measurements without making changes in the
mains with the residual current devices with rated current of minimum 30mA.
Switch on the meter.
Set the dial switch to
the ZL-PE
RCD
position.
Select the leads length as described in 2.6.1 according to the
needs.
Connect the test leads as shown in one of the figures.

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The remaining measurement issues are analogous to the ones described for the measurements
in the L-N or L-L systems.
Notes:
- The measurement takes maximum about 32 seconds. You can discontinue the measurement by
pressing the ESC button.
- In the electrical installations with the 30mA residual current devices the sum of the installation leak-
age currents and the test current may trip the RCD. In such case, try to reduce the leakage current of
the tested installation (i.e. by disconnecting the loads).
Additional information displayed by the meter
Information and error messages are the same as in case of L-N and L-L.

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2.8 Measurement of resistance to earth
The MPI-502 instrument can be used for approximate measurements of resistance to earth For
this purpose, the phase conductor is used as secondary source of voltage which generates test cur-
rent. Connection diagram for the instrument for such measurement in the TN-C, TN-S and TT sys-
tems is shown in the figure below, the dial switch must be set to the ZL-PE position.
L
PE
N(PEN)
Ru
Rr
During the measurement check the connections of the measured earth electrode with the electri-
cal installation. For correct measurement, the tested earthing system should be disconnected from
the electrical installation (N and PE conductors). If you want to measure the earth electrode, for in-
stance in the TN-C-S system and simultaneously use the phase of the same system as an auxiliary
source of current, disconnect the PE and N conductors from the measured earth electrode (see figure
below). Otherwise, the meter will measure an incorrect value (the test current will flow not only
through the measured earthing system.
L
PE
N
Ru
Rr
L1L1
L2
L3
PE
Disconnect
Note:
WARNING:
Disconnection of protective conductors is serous life hazard for the staff performing the
measurements and also third parties. When the measurements are completed, the protec-
tive and neutral conductors MUST be reconnected.
- If it is not possible to disconnect the conductors, use an earth resistance meter from the MRU range.
- As the measurement result is the sum of impedances of the measured earth electrode, operational
earthing system, source and phase conductor, it contains a positive error. However, if such error does
not exceed a limit value for the tested earthing system, it can be concluded that the earthing has been
made correctly and and there is no need for a more accurate measurement methods.

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2.9 Measurement of the residual current device parameters
2.9.1 Measurement of the RCD tripping current
Switch on the meter.
Set the dial switch to
the IAposition.
Set the parameters according to the following algorithm and the rules
for setting the general parameters.
Parameter
In
Current
waveform
RCD type
UL
Measurement
mode
or
N LPE
Connect the test
leads as shown
in the figure.