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.
