Sonel MPU-1 User manual

OPERATING MANUAL
MPU-1
LEAKAGE CURRENT ALARM SIGNALLER
SONEL SA
ul. Wokulskiego 11
58-100 Świdnica, Poland
Version 1.5 27.04.2017

OPERATING MANUAL MPU-1 version 1.5
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OPERATING MANUAL MPU-1 version 1.5
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CONTENTS
1PREFACE................................................................................................................5
2INTRODUCTION...................................................................................................6
3SAFETY...................................................................................................................6
4DESCRIPTION AND FEATURES .......................................................................7
4.1 CHARACTERISTICS OF MPU-1.................................................................................7
4.2 ARRANGEMENT OF SOCKETS AND BUTTONS............................................................7
4.2.1 Keyboard......................................................................................................8
4.2.2 Sockets..........................................................................................................9
4.3 GRAPHIC DISPLAY (LCD) .....................................................................................10
4.4 ACOUSTIC/VISUAL SIGNALS. .................................................................................10
4.5 MEASURING CLAMPS............................................................................................10
5STARTING THE OPERATION..........................................................................11
6OPERATION.........................................................................................................11
6.1 PREPARING MPU-1 FOR OPERATION.....................................................................11
6.2 MONITORING THE POWER SUPPLY VOLTAGE (RECHARGEABLE BATTERY).............12
6.3 CONNECTING THE DEVICE.....................................................................................12
6.4 OPERATING THE INTERFACE..................................................................................13
6.4.1 Monitoring the leakage current with “Alarm on” mode ............................14
6.4.2 Leakage current measurement in "Alarm off" mode, with displaying the
measured value on the screen.....................................................................16
6.4.3 Changing the frequency of the monitored network.....................................17
6.4.4 DEMO function. .........................................................................................18
6.4.5 Function for informing about the operational status of the device.............19
6.4.6 Changing the language...............................................................................20
6.4.7 Reset function. ............................................................................................21
7TROUBLESHOOTING........................................................................................23
7.1 WARNINGS AND INFORMATION DISPLAYED BY THE DEVICE..................................23
8POWER SUPPLY OF THE DEVICE.................................................................24
8.1 MONITORING THE POWER SUPPLY VOLTAGE .........................................................24
8.2 REPLACING RECHARGEABLE BATTERIES ...............................................................24
8.3 CHARGING RECHARGEABLE BATTERY...................................................................24
8.4 GENERAL PRINCIPLES FOR USING NI-MH RECHARGEABLE BATTERIES..................25
9CLEANING AND MAINTENANCE ..................................................................26
10 STORAGE .............................................................................................................26
11 DISMANTLING AND DISPOSAL .....................................................................26
12 TECHNICAL SPECIFICATIONS......................................................................26

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12.1 BASIC DATA .......................................................................................................26
12.2 OTHER TECHNICAL SPECIFICATIONS...................................................................27
13 ACCESSORIES .....................................................................................................27
13.1 BASIC ACCESSORIES...........................................................................................27
13.2 OPTIONAL ACCESSORIES ....................................................................................27
14 MANUFACTURER...............................................................................................28

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1 Preface
Thank you for purchasing leakage current alarm signaller. MPU-1 is a modern, easy and safe in
use signalling device. Please acquaint yourself with this manual in order to avoid measuring errors and
prevent possible problems in operation of the device.
This manual contains three types of warnings. They are presented as a framed text describing the
possible risks for the user and the device. Texts starting with word ‘WARNING:’ describe situations,
which may endanger user's life or health, when instructions are not followed. Word ‘CAUTION!’ begins
a description of a situation, which may result in device damage, when instructions are not followed.
Indication of possible problems is preceded by word ‘Note:’.
WARNING:
Before operating the device, read thoroughly this manual and observe the safety regulations
and guidelines provided by the producer.
WARNING:
MPU-1 is not the only device required to ensure 100% safety of works with electricity. Moreo-
ver, the user's alarm response time he must be taken into account MPU-1 is designed to pro-
vide additional protection againstelectric shock in the workplace, therefore using MPU-1 must
not substitute any other protection measure in the workplace and/or personal protection
equipment used by employees. Appropriate occupational health and safety regulations must
be observed along with other instructions, rules and basic safety measures, in accordance
with local or national regulations.
WARNING:
Leakage current alarm signaller is designed for monitoring (measuring) the leakage current in
LV and MV networks. 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.
WARNING:
MPU-1 signallers may be used only by qualified persons, certified to perform measurements
on LV and MV live networks. Operating the device by unauthorised personnel may result in
damage to the device and constitute a source of danger for the user.
WARNING:
Using this manual does not exclude the need to comply with occupational health and safety
regulations and with other relevant fire regulations required during the performance of a par-
ticular 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 re-
sponsible for health and safety.

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2 Introduction
This manual describes the operation of MPU-1 leakage current alarm signaller. We recommend
reading the manual thoroughly in order to avoid errors that may result in danger to the user or an incor-
rect assessment of the tested network. For more information on safety during measurements -see
Chapter 3–Safety. Before first use of the device, be sure to read Chapter 5–Starting the operation.
For additional information related to interpreting the warnings and information displayed by the device,
it is recommended to read Chapter 7 –Troubleshooting. All information on operating the device may
be found in Chapter 6 –Operation.
3 Safety
Sonel has made every effort to ensure that our product MPU-1 is reliable and of the highest quality.
Remember that MPU-1 is not the only device required to ensure 100% safety of works with electricity.
Moreover, the user's alarm response time he must be taken into account MPU-1 is designed to provide
additional protection against electric shock in the workplace, therefore using MPU-1 must not substi-
tute any other protection measure in the workplace and/or personal protection equipment used by em-
ployees. Appropriate occupational health and safety regulations must be observed along with other
instructions, rules and basic safety measures.
MPU-1 is designed for monitoring (measuring) the leakage current in LV and MV AC power
systems; it is used for measurements that provide results required for assessing safety of the
monitored network in terms of leakage current. The device allows its users to set a threshold of
leakage current flowing through a network, above which a visual/acoustic alarm will be trig-
gered. Therefore, in order to provide conditions for correct operation and accuracy of obtained
results, the following recommendations must be observed:
before using the device read carefully this manual,
the meter should be operated only by qualified persons that have passed health and safety training,
It is unacceptable to operate the following:
a damaged device, which is completely or partially out of order,
a device with damaged insulation of test leads,
a device stored for an excessive period of time in disadvantageous conditions (e.g. excessive
humidity).
before using the device, make sure the leads are connected to the appropriate measurement sock-
ets.
repairs may be performed only by an authorised service point.
In addition, please note that:
discharged battery symbol appears on the display when the supply voltage is too low and indicates
the need to recharge the batteries,
when the power supply voltage istoo low, themeasurements performed with thedevice may include
additional errors undetected by the user and they may not be used to confirm that the tested cir-
cuit/network are properly protected.
using MPU-1 must not substitute any other protection measure in the workplace and/or personal
protection equipment used by employees. Appropriate occupational health and safety regulations
must be observed along with other instructions, rules and basic safety measures, in accordance
with local or national regulations. Avoid working alone.
Caution is required for AC voltages with RMS value exceeding 30 V or when their peak value ex-
ceeds 42 V. Be also careful when DC voltages exceeding 60 V. Such voltages generate a risk of
electric shock.

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4 Description and Features
4.1 Characteristics of MPU-1
MPU-1 is designed for monitoring (measuring) the leakage current in LV and MV AC power
systems; it is used for measurements in grounding systems to provide results required for as-
sessing safety of the monitored network in terms of leakage current. The device allows its users
to set a threshold of leakage current flowing through a network, above which a visual/acoustic
alarm will be triggered.
The most important features of MPU-1 include:
constant monitoring of current flowing through the grounding of poles, in the range of 0.1 ... 299A,
in LV and MV 50Hz or 60Hz networks (after proper configuration in MENU), automatic selection of
the measuring range
measurement with oneor two clamps at thesame time; with double-clamp measurement the current
is summed, providing the opportunity to cover the twin poles (vortex), independent clamps for each
component pole,
triggering alarm when the current flow exceeds the alarm threshold (default setting at 1A), acoustic
and visual alarm (a speaker built-in within the housing),
no measurement for direct currents,
measurement with Sonel flexible clamps of F series (Rogowski coil), the option of changing the
diameter of clamps without the need to re-calibrate the device,
monitoring the battery charge status, LED indicator for operation mode,
ergonomic operation,
IP 67.
4.2 Arrangement of sockets and buttons
Fig.1. Arrangement of LEDs and buttons (front panel).
1
2
3
4
5
6

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4.2.1 Keyboard
1 ON/OFF button
Turning the device ON/OFF.
2 MENU button
Selecting the measurement function:
Alarm –setting the alarm on or off;
Curr –setting the alarm threshold for current flow;
Demo –simulation of an alarm condition;
Freq –setting the rated frequency of the network (50Hz or 60Hz);
Info –activation of information about the operation of the device;
Lang –selection of the user interface language;
Reset –restoring factory (default) settings.
3 ENTER button
Approving entered settings, exiting to menu.
4 LED indicating the operational status of the device
Measuring Mode:
- LED is illuminated in green –the device is in operational mode,
- LED is illuminated in red –device error (additional error code is displayed, as described
below),
- LED flashes red –low battery charge level,
Battery charging mode"
- LED flashes red –low battery charge level,
- LED flashes green –charging the battery,
- LED is illuminated in green –battery fully charged,
5 Buttons and
A set of cursors with auto-repetition for choosing MENU options and changing setting values
6 Alarm LEDs
A set of red alarm LEDs arranged in two rows on the front panel (5 LEDs in each row), and in two
rows at the sides of the device (5 LEDs on each side). Their operation is described in the next
sections.

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4.2.2 Sockets
Fig.2. Arrangement of sockets in MPU-1.
CAUTION!
MPU-1 signaller is designed to measure the current flowing through the clamps with phase
voltages up to 1000V.
Connecting voltage higher than 25V, between any of the test terminals may damage the
device.
7 Measuring socket [Clamp (1) / Charger]
The socket forconnecting Sonelmeasuring clamps of F-Series (Rogowski coil), used formeasurements
with single clamps or for connecting the battery charger. Unused socket should be secured with a flex-
ible socket plug.
8 Measuring [Clamp (2)]
The socket forconnecting Sonelmeasuring clamps of F-Series (Rogowski coil), used formeasurements
with double clamps. Unused socket should be secured with a flexible socket plug.
The device sums up current values from the two sockets, it is the mathematical sum (it does not
take into account the phase shifts).
7
8

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4.3 Graphic display (LCD)
Fig.2. The view of the screen when alarm is off.
Fig.3. The view of the screen during the measurement of LV network.
4.4 Acoustic/visual signals.
Warning signals:
Continuous two-tone beep with flashing alarm LEDs (mode: "Alarm on"):
ALARM status, the current flowing through the clamps exceeded the set threshold. The beep lasts
for 30 seconds, then it is muted - when the alarm status continues, then it is indicated by flashing
alarm LEDs.
Two long beeps with illuminated alarm LEDs, repeated every 15 seconds.
low level of battery charge, the device should be switched off or it will turn off automatically in a
short time, more information on discharged batteries - see Chapter 8 "Power supply of the de-
vice".
Short, two acoustic signals [beeps] (with active Info option):
the signal indicating the device operation, working when you turn Info function, the signal is re-
peated approx. every 60 seconds.
4.5 Measuring Clamps
MPU-1 is calibrated in the factory, taking into account the parameters of original Sonel clamps of
F-Series, The examples of clamp models compatible with MPU-1 are listed in Chapter 13 "Acces-
sories".
WARNING:
Connecting wrong or damaged clamps may cause electric shock (dangerous voltage).
The value of measured
Current flowing through
the clamps.
Device operation
mode / value of the set
alarm threshold.
Indication of the bat-
tery charge status,
The value of measured
current flowing
through the clamps.
Device operation
mode.
Indication of the bat-
tery charge status,

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Note:
The manufacturer guarantees the accuracy of device readings, only when it is used with
measuring clamps supplied with the device or purchased from manufacturer's authorized
source. Using extension cords or other modifications and aftermarket clamps may be a
source of additional errors.
Note:
"CAT III 1000V" marking on accessories is equivalent to "CAT IV 600V" marking.
5 Starting the operation
Before starting the operation of the device:
check the contents of the package
check and modify (if needed) the settings of the device (displaying results, operating mode, alarm
threshold, etc.)
6 Operation
Read thoroughly this chapter, as it describes metering circuits, measurement methods, settings and
other important issues.
6.1 Preparing MPU-1 for operation
Before performing the measurement:
make sure that the battery level is sufficient for measurements,
check the device and accessories for damage
check the proper connection of clamps and adequate fixing of the device in its workplace.
WARNING:
Connecting wrong or damaged clamps may cause electric shock (dangerous voltage).
WARNING:
Do not use the device with a damaged housing and do not power it from sources other than
those listed in this manual.
WARNING:
Do not leave unattended device connected to the tested circuit.
Do not touch the equipment connected to the tested circuit/network.
WARNING:
Do not use the device if it was stored for an excessive period of time in disadvantageous
conditions (e.g. excessive humidity)

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Note:
Do not use the device if its display is completely unreadable.
Note:
Using accessories other than those specified by the manufacturer is prohibited and may
result in a danger to the user or damage to the device.
6.2 Monitoring the power supply voltage (rechargeable battery)
It is important that MPU-1 has properly charged batteries before using it. The charge level of the
rechargeable battery is indicated by the symbol in the right upper corner of the display on a current
basis.
Fig. 7. Monitoring the battery charge status
In order to get more information on power supply of the device, read Chapter 8 "Power supply of
the device".
6.3 Connecting the device.
CAUTION!
Pay attention to the correct connection of plugs of the clamps, as the accuracy of the meas-
urements depends on the connection quality. They must ensure good contact and provide
uninterrupted measurement current flow. Using extension cords or other modifications and
aftermarket clamps is unacceptable.
CAUTION!
Connecting voltage higher than 25 V, between any of the test terminals may damage the
device.
The device is connected to the tested power network or to the tested device, as shown in the draw-
ings below:
Indication of the bat-
tery charge status,

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Fig.9. Operating the device with single clamps
Fig.10. Operating the device with double clamps
6.4 Operating the interface.
Additional information:
Pressing MENU button when viewing
the MENU options results in exiting the
current MENU option without approv-
ing the selected value(s). Its function is
equal to BACK /CANCEL button.
Any changes / selected options are ap-
proved by pressing ENTER.

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6.4.1 Monitoring the leakage current with “Alarm on” mode
CAUTION!
Connecting voltage higher than 25 V, between any of the test terminals may damage the
device.
“Alarm on” mode is a standard operation mode of MPU-1. After switching off and restarting the
device, it is always activated in alarm on mode (it remembers the settings entered before switching off).
In order to monitor the leakage current flowing through the clamps in this mode proceed as follows:
Connect clamps to the socket: 7 "Clamp (1)" to perform single-clamps measurement or to sockets
"Clamp (1)" 7 and "Clamp (2)" 8 to perform double-clamps measurement.
Then:
Press MENU button.
,
Use , buttons to select Alarm.
Confirm your choice by pressing
ENTER button.
,
Use , buttons to select Alarm
on. Confirm your choice by pressing
ENTER button.

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
The device is in operating mode with alarm on. The top line of the display indicates the measured
value of the current flowing through the clamps, the bottom line alternately displays: the mode in which
the device operates (Alarm on) and the values set as alarm threshold values (limit). Depending on the
value of the measured current, the symbol shown in the bottom line indicates whether the measured
current is: lower (I <), equal (I =) or higher (I>) from the set limit.
The device monitors/measures alternating current with rated frequency of 50Hz or 60Hz depending on
user settings. When the measured current exceeds the set alarm threshold, acoustic and visual alarm
will be triggered. The beep lasts for 30 seconds, then it is muted - when the alarm status continues,
then it is indicated by flashing alarm LEDs.
To set the alarm threshold (limit) for the current flowing through the clamps, proceed as follows:
Press MENU button.
,
Use , buttons to select Current.
Confirm your choice by pressing
ENTER button.
,
Use , buttons to select the cur-
rent value above which the alarm will
be triggered. Confirm your choice by
pressing ENTER button.

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
After pressing ENTER the device automatically display screen of "Alarm on" mode and begins to
monitor the current flowing through the clamps.
The set Limit is saved and remembered by the device even after it is turned OFF and ON again.
CAUTION: In "Alarm on" mode - in order to reduce energy consumption, the display goes blank
after 5 min. from switching the device ON or from the last pressing of any button. Pressing any button
will re-activate the display.
WARNING:
Do not leave unattended device connected to the tested circuit.
Do not touch the equipment connected to the tested circuit/network.
6.4.2 Leakage current measurement in "Alarm off" mode, with displaying the
measured value on the screen.
Remember that after switching off and restarting the device, it is always activated in “Alarm on”
mode, even when before switching off, it operated in “Alarm off”.
In order to measure the leakage current flowing through the clamps in “Alarm off” mode proceed as
follows:
Connect clamps to the socket: "Clamp (1)" 7 to perform single-clamps measurement; or to sock-
ets "Clamp (1)" 7 and "Clamp (2)" 8 to perform double-clamps measurement.Then:
Press MENU button.
,
Use , buttons to select Alarm.
Confirm your choice by pressing
ENTER button.

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,
Use , buttons to select Alarm
off. Confirm your choice by pressing
ENTER button.
After pressing ENTER the device automatically displays screen of “Alarm off” mode. The signaller
in “Alarm off” mode, displays in real-time the measured value of the current flowing through the clamps.
The device monitors/measures alternating current with rated frequency of 50Hz or 60Hz depending on
user settings.
Additional information:
Pressing MENU button when viewing the MENU op-
tions results in exiting the current MENU option with-
out approving the selected value(s). Its function is
equal to BACK/CANCEL button.
WARNING:
Do not leave unattended device connected to the tested circuit.
Do not touch the equipment connected to the tested circuit/network.
6.4.3 Changing the frequency of the monitored network.
In order to measure the leakage current flowing through the clamps - both in "Alarm on" mode
and in "Alarm off" mode, set the rated frequency of tested network as 50Hz or 60Hz.
In order to introduce a change or to check frequency settings, proceed as follows:
Press MENU button.

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,
Use , buttons to select Fre-
quency. Confirm your choice by
pressing ENTER button.
,
Use , buttons to select 50Hz or
60Hz. Confirm your choice by pressing
ENTER button.
After pressing ENTER the device automatically displays screen of monitoring/measurement mode.
The device is in the operational mode in which it was before the user entered MENU to change the
frequency.
The set frequency of the network is saved and remembered by the device even after it is turned
OFF and ON again.
6.4.4 DEMO function.
As the device is designed to protect employees working with electricity (including those that did not
read the manual), we have introduced DEMO function, which may be used to show its operation - after
selecting DEMOfunction the device enters alarm mode for 5 sec. (as in when threshold of the monitored
current is exceeded in "Alarm on" mode). This allows to demonstrate the alarm signal to users.
To start DEMO mode: