Mega MEg31, MEg 30, MEg33, MEg32 User Manual

MEg 30 - portable version
for LV networks

MEg 31 - portable version
for MV networks

1. Charakteristics

PQ monitor is a multi-function measuring instrument to be used for the measure

­ment and a long-term recording of up to four voltages and four currents, of active
and reactive power and energy in three-phase four-conductor and five-conductor
LV networks, as well as in MV and HV networks. Complying with the EN 50160
standard and with methods of the international standard IEC 61000-4-30, the PQ
monitor analyses all parameters of the voltage quality on voltage inputs U1, U2
and U3.

It registers theevents(voltage dips, swells and interruptions) on all the four volt

­ages and it records not only the characteristics of events on voltages as defined by
the standard but also the shapes of all the four voltages and currents at the begin­ning and at the end of each event – the so-called initial and final details. The initial
detail of an event also comprises the section of time prior to the event while the final
detail also includes the section of time following after this event.

Basing on the measured shapes of currents the PQ monitor enables to assess the
direction of the origination of an event as well as of flicker. By its ability to measure
even small voltages the PQ monitor is also ready for monitoring the voltages be­tween the neutral conductor and ground. On its fourth current input the PQ moni­tor enables to carry out the measurement and harmonics analysis of the current of
the neutral conductor. Variably, when using a corresponding sensor the fourth cur­rent input canalsobeusedforthemeasurement of other physical quantities, e. g. for
the measurement of temperature.

PQ monitor is provided with a galvanicly separated synchronizing input SYNC.
Its change ofstate can be registered as anevent, too. This makes possible an external
synchronization of the record of shapes of all voltages and of all currents, as well as
a mutual synchronization of a set of severalPQ monitors. ThePQ monitor has, on its
output, a change-over contact of the polarized relay with a programmable assigna

-

tion of the meaning of the signalization.

PQ monitor enables to measure therelationship between the voltage quality and
the power and/or energy. When the preset parameters of voltage quality have been
overpassed, it is possible to switch an external two-state electricitymeter or – for op

­erational purposes – to initialize the internal function of the measurement of
“non-quality energy”.

PQ monitor has been designed in the following versions:

MEg 30 – PQ monitor in portable version for LV networks
MEg 31 – PQ monitor in portable version for MV networks

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MEgA Měřicí Energetické Aparáty

MEg 32 – PQ monitor in version for fixed mounting in LV networks
MEg 33 – PQ monitor in version for fixed mounting in MV networks

The following instruments have beendesignedfor PQ monitors in portable version:

–

current sensor AMOS PQ (30 A, 100 A, 300 A, 1000 A)

–

instrument current transformers MT PQ (1 A, 5 A, 30 A, 150 A).

PQ monitors in version intended for fixed mounting are manufactured with cur

­rent inputs 5 A, 1A or with a special current input. The versions with current inputs
5 A or 1 A are especially suitable for precise measurements of electric energy. So
that the PQ monitor may be additionally installed for permanent utilization in
substations being already under operation, it is advantageous to use current trans­formers with split cores MEg MT manufactured complying with Patent Nr. 286255.
Fixed version of PQ monitors with flexible current sensors AMOS can also be deliv­ered as option.

All versions of PQ monitors for the measurement in LV networks have a
three-phase supply from voltages being measured U1, U2 and U3. In order to pre­vent the degradation of accuracyand credibility of voltage qualityparameters being
measured, a single-phase external supply is used in PQ monitors intended for mea­surements in MV networks with heterogeneous instrument voltage transformers.

Each version of the PQ monitor is provided with an internal back-up battery
which enables the monitor to be operated during up to 5 minutes without the exter­nal supply.

The measuring ranges of phase voltages of PQ monitors for LV networks are
from 0 V

ef

to 480 Vefand of those for MV networks from 0 Vefto 140 Vef.

Phase-to-phase voltages can be registered and analysed by calculation as well.

The basis of all version of PQ monitors is a signal processor with a high-capacity
non-destructive data memory which enables a really long-term (more than 1 year)
antonomous performance. The parallel and continuous performance of all measur

-

ing, visualization and communication functions represents a substational character

­istic of the PQ monitor. A high accuracy and independence on operational
conditions is ensured by a high-quality A/D converter with a minimized extent of
analog circuits and with a correction of errors of the whole measuring string made
by calculation.

By means of communication interfaces the PQ monitor can also be used as an in

­telligent peripheral unit of large SCADA systems and energy systems of industrial
enterprises and agglomerations.

Like all other measuring instruments MEg being manufactured till now, the PQ

monitor enables not only the teleparametrization of measuring functions but also

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PQ monitor – MEg30, MEg31, MEg32, MEg33

the telereprogramming of their structure according to user’s requirements and/or
the teleprogramming of newly developed functions.

2. Principle of measurement and of data processing, organization
of the data memory

The measurement of four voltages and of four currents is based on sampling them
with frequency 5120 Hz. The total number of 1024 values with resolution of 14 bits
are always sampled in 200 ms long intervals, following one after another without
timeouts. After transformation into the frequency area, 512 complex harmonic com­ponents with step 5 Hz (i. e. 51harmonic components regarding the multiple 50 Hz)
and 461 interharmonic componentsare then calculatedfrom these values. The mag­nitudes of voltages U1 to U4, currents I1 to I4 and “control signals” (ripple control)
are calculated from the absolute values of the complete spectrum. Active and reac­tive power of individual components as well as the unbalance are calculated from
complex components.

The data from channels U1, U2 and U3 for evaluating the events and flicker on

voltages are processed in the time area. The square of the TRMS value for the
elapsed period (20 ms) is calculated after every 10 ms. Frequency is calculated from
the data of channel U1.

Corrections ofDC components,corrections of strengtheningthe current sensors,

of voltage and current measuring channels and frequency characteristics including
corrections of a possible phase shift between individual measuring channels are
made during the calculations. The tables of calibration constants are a part of the
configuration. None upto 100 various tables of calibration constants can be stored in
the memory of the firmware depending on the set of the whole measuring string
(measuring converter + measuring channels).

The non-destructive data memory, type FLASH with capacity of 2 MB (4 MB as

option) is divided into five circularly organized areas. The first area shall be used for
recording the development in time of RMS values of measured voltages, currents
and power in a complex form. Detailed data on voltage quality in the elapsed week
shall be stored in the second area. The third data area includes unified data with a
list of events according to methodology of ČSN EN 50160 and the fourth data area
includes a detailed record of the development of RMS values of the half-periods of
voltages U1, U2, U3, U4 and currents I1, I2, I3, I4. The fifth data area includes com

­pressed weekly data on quality. The ratios of ranges of individual areas of the data
memories can be mutually changed respecting the user’s requirements.

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MEgA Měřicí Energetické Aparáty

The basicsetting of ranges of the circular areas of the 2 MB memory has been chosen
as follows:

–

recording of average RMS values of four voltages, four currents and three real
and three imaginary components of the power; the data memory will be suffi

-

cient for recording during 30 days when the records are made with step 1 min

–

recording of the list of events with capacity of more than 910 events

–

recording of a detailed development of events for more than 180 last events

–

recording of compressed weekly data for the period longer than 52 weeks.

When extending the data memory to 4 MB it is possible to extend anyone of the
above-mentioned data areas, e. g. the area of recording the average values and the
area of recording the list of events.

3. Description of measuring functions and of input/output
functions of the PQ monitor

3.1 Function of monitoring (time recorder, type MDS)

Average RMS values from all periods within the chosen step are being recorded
when the monitor operates in this function. Average values of up to four voltages,
four currents and three active and reactive powers (U1, I1), (U2, I2), (U3, I3) are
being recorded according to setting. Basing on these recorded data, real power fac­tors and energies are then calculated in the higher SW. When a suitable sensor is
installed, another physical quality, e. g. the temperature can be recorded instead of
the current I4.

3.2 Function of voltage quality (monitor, type QN)

The following ten-minute data can be recorded here:

–

average frequency, maximum and minimum 10 s frequency derived from U1,

–

numbers of overpassing the 10 s values of frequency of four limits defined by
ČSN EN 50160,

–

values of voltage unbalance calculated from the negative-sequence and the pos

-

itive-sequence voltage component as well as from phase-to-phase voltages,

–

average and maximum RMS values of voltages U1 to U4 and currents I1 to I4,
minimum values of voltages U1 to U4 from the 0.2 s long intervals,

–

average values of five selected harmonic components of voltages U1 to U4 and
currents I1 to I4 in the range of the 2

nd

to 51stharmonic,

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PQ monitor – MEg30, MEg31, MEg32, MEg33

–

average values of the basic harmonic of voltages U1 to U4 and current I1 to I4,

–

values Umax95 and Umin95 of voltages U1 to U3,

–

values Umax and Umin (0.2 s) of voltages U1 to U3,

–

values of flicker Pst of voltages U1 to U3,

–

magnitude of THD of voltages U1 to U3 in relation to the harmonics and to all
interharmonic components,

–

magnitudes of ripple control signals on voltages U1 to U3,

–

total duration of dips, swells and interruptions of voltages U1 to U3.

The function of voltage quality can also be used in case of a single-phase or
two-phase measurement. The recorded data enable to obtain a detailed survey of
voltage quality parameters for the elapsed week and to evaluate the quality under
changed requirements of the standards.

3.3 Function of recording the events (statistic voltmeter of events)

The function of recording the events operates over the quantities U1 to U3 and I1 to
I3. Every new event is recorded into the list of events and into a detailed record.

Beside the parameters of events unifiedby standard ČSN EN 50160, i. e.the time
of originating and ending of an event with resolution to 10 ms, the list of events in­cludes the values of maximum deviations of voltages U1 to U3 from the nominal
value.

Adetailed record ofevents includes the developments ofRMS valuescalculated
for voltages U1 to U3 and currents I1 to I3 after every 10 ms for the elapsed 20 ms.
The total duration of the record of the initial detail of an event makes 0.6 s from
which the interval of 0.2 s is being recorded prior to the origination of an event. The
total duration of the record of the final detail of an event makes 0.6 s from which an
interval of 0.2 s is being recorded after the ending of an event. The length of these
intervals can be changed programmably.

3.4 Function of compressing the weekly voltage quality data

This function serves for a long-term archiving of weekly quality parameters of volt

-

ages U1 to U3 complyingwith ČSN EN 50160. Thefollowing data can be recorded:

–

number of 10 s intervals when the frequency overpassed the preset limits 47 Hz,

49.5 Hz, 50.5 Hz and 52 Hz,

–

number of 10 s intervals in which the mean value of the voltage lied outside the

tolerances 90% U

nom

to 106% U

nom

and 110% U

nom

,

–

order of two-hour intervals in which the Plt value was ³ 1.0,

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MEgA Měřicí Energetické Aparáty

–

number of ten-minute intervals in which average value of the 2ndto 25thhar

-

monic was higher than the value defined by the standard,

–

number of ten-minute intervals in which the THD for the 2ndto 40thharmonic
was higher than the value defined by the standard,

–

number of ten-minute intervals in which the average value of unbalance was
higher than the limit defined by the standard,

–

the number of 3 s mean values of voltage components with frequency of the rip

­ple control signal, which overpassed the limit defined by the standard, is being
recorded for each day of a compressed week.

3.5 Function of oscilloscopic measurements

The function of oscilloscopic measurements serves for checking the correct connec­tion of the set the PQ monitor, the correct choice of measuring ranges and the correct
orientation of current sensors. A notebook with a series interface USBII is used for
displaying the shapes of voltages U1 to U4 and currents I1to I4. The recording with
duration of 2 periods (40 ms) can be started case by case or repeatedly.

3.6 Communication function

The basic communication interface of the PQ monitor is a series interface USBII with
the data transmission rate up to 460.8 kbit/s. This enables to read out the content of
the 2 MB data memory during about 2 minutes. It is also possible to choose another
transmission rate (921.6 kbit/s).

Alternatively, the PQ monitors for fixed mounting can be ordered with interface

RS 232 or with another series interface according to the customer’s requirement
(RS485, …).

3.7 External input

The external input is a two-value one and it enables to connect DC and AC voltages
in the range of 24 V to 230 V. The decision making level is at 15 V. The external input
can generate an event without recording the detail of the event. The front edge or
the trailing edge of the voltage of the external input may be active depending on
programming.

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PQ monitor – MEg30, MEg31, MEg32, MEg33

3.8 Relay output

The relay output is made by a change-over contact of the polarized relay and one or
more of the following meanings can be assigned to it by the program:

–

voltage U1 to U4 outside the chosen tolerances,

–

frequency outside the chosen tolerances,

–

flicker Pst higher than 1.0,

–

any harmonic component overpassed the chosen limit,

–

THD overpassed the chosen limit,

–

unbalance overpassed the chosen limit,

–

the average RMS value of the current for 10periods overpassed the chosen limit,

–

conversion to supply from internal battery,

–

change of state of the contact in case of the change of the voltage on the external
input enables a mutual synchronization of more PQ monitors installed in one
substation.

3.9 Signalization by LEDs

The indication of state of the PQ monitor is signalized by the diode OPERATION
(PROVOZ) which is lighting permanently at the external supply (supply from mea­suring inputs orexternal supply)and intermittently with frequency5 Hzat the sup­ply from the internal battery. The lighting of this diode can be assigned to the
indication of state of the relay output by program.

In a preset tolerance band (90% U

nom

to 106% U

nom

) the LED diodes U1, U2 and
U3 indicate the state of voltages U1, U2, U3 by permanent lighting and by intermit­tent lighting withf=1Hzthey signalize that the respective voltage is outside the
preset tolerance band.

3.10 State of battery charge

Under reference conditions and at its full charge the internal battery ensures the
supply of the PQ monitor during 5 minutes. Complying with the recommendation
IEC 61000-4-30 and in accordance with the meaning of data measured in the course
of failures in the distribution networks, the supply from the internal battery shall be
automatically switched-off after any interruption of the external supply lasting
more than 1 minute. The discharging of energy of the battery at the interruption of
the external supply with duration ofmore than 5 minutes is thus prevented and– af

­ter a restored supply and its subsequent interruption due to e. g. switching-in into
short-circuit – the instrument is able to remain in operation for a further 1 minute.

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MEgA Měřicí Energetické Aparáty

In order to savethe energy of the internal battery, it is recommendedto suppress
the unnecessary (in this case) one-minute back-up supply of the monitor before
each planned disconnection of measuring conductors from the supply voltage. This
shall be done by using the notebook with the started program of the PQ monitor
where the item Uspat shall be updated in menu Measuring instrument.

4. Technical data

4.1 Measurement of voltages

U

nom

of phase voltages U1, U2, U3, U4: 230 V

Range of measurement of phase voltages: 0 to 2 U

nom

Highest permissible phase voltage: 480 V

ef

Accuracy of voltage measurement:

± 0.1% of the measured value ± 0.1% U

nom

at 0.8 U

nom

to 1.2 U

nom

± 0.2% of the measured value ± 0.2% U

nom

outside 0.8 U

nom

to 1.2 U

nom

Resolution: 0.1% U

nom

or better

Temperature coefficient: better than 0.2% U

nom

/10°C

4.2 Measurement of currents

Accuracy of measurement:

± 0.2% of the measured value and 0.2% I

nom

at 0.1 I

nom

to 1.2 I

nom

± 0.5% of the measured value at 1.2 I

nom

to 2 I

nom

Resolution: 0.1% I

nom

or better

Temperature coefficient: better than 0.2% I

nom

/10°C

Highest permissible current loading: 5 × I

nom

during 1 s

Measuring string AMOS PQ - MEg30

I

nom

at shape coefficient K = 1.11: 30 A, 100 A, 300 A, 1000 A

Range of measurement: 0 to 1.2 I

nom

Accuracy of measurement: 0.1% I

nom

Linearity of measurement: better than 0.5% I

nom

Change of the measured value with the

change of position: 1% I

nom

Measuring string MT PQ - MEg30

I

nom

at shape coefficient K = 1.11: 1 A, 5 A, 30 A, 150 A

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PQ monitor – MEg30, MEg31, MEg32, MEg33

Maximum size of the conductor being
clamped: 10 mm × 20 mm
Range of measurement: 0 to 1.2 I

nom

Accuracy of measurement: 0.5% I

nom

+ 0.2% of the measured

value at f = 50 Hz

Frequency range: 40 Hz to 2 kHz

4.3 Measurement of frequency

Nominal value: f

nom

= 50.0 Hz
Range of measurement: 45.0 Hz to 55.0 Hz
Accuracy of measurement: better than 10 mHz in range 48 Hz

to 52 Hz

Resolution: 1 mHz

4.4 Measurement of power factor

Range of measurement: 0 to 1.0 in all four quadrants
Accuracy of measurement: better than 0.5% at U

nom

and I

nom

4.5 Measurement of power

Accuracy of measurement: 0.5% P

nom

at f = 50 Hz,

0.8 U

nom

to 1.2 U

nom

0.1 I

nom

to 1.2 I

nom

4.6 Measurement of voltage unbalance

resolution 0.01

4.7 Measurement of Pst

resolution 0.01

4.8 Measurement of THD

resolution 0.01

4.9 Measurement of Uharm

resolution 0.01% U

nom

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MEgA Měřicí Energetické Aparáty

4.10 Reference ambient conditions

Ambient temperature: 20°C ± 2°C
Relative humidity: 40% to 60%
Air pressure: 86 kPa to 105 kPa
Without hoarfrost, bedewing, rain and sunshine

4.11 Ambient conditions

Operating temperature: –20°C to +60°C
Operation: in indoor space
Relative humidity: 20% to 90%
Altitude: up to 2000 m
Operating position: arbitrary
Protection: IP40
Category of measurement: IV (ČSN EN 61010-1)
Degree of contamination: 2
Protection under condition of one failure is ensured by protective impedance
with a combination of component parts.

4.12 Supply

Supply from any measuring input U1, U2, U3
Range of input power: 5 VA
Back-up supply: battery SANYO N-50AAA L 1×5,

in average during up to five
intervals of 1 minute at reference

ambient conditions
Replacement of the battery shall be carried out by the manufacturer basing on
order.
Mean time between battery replacements makes 2 years.

4.13 External connection

Terminals S1, S2 of signal SYNC

U0: 0 V to 5 V DC and AC
U1: 20 V to 200 V DC and AC
The terminals are galvanicly separated by an optoelectronic element with
insulation strength 5 kV

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PQ monitor – MEg30, MEg31, MEg32, MEg33

Terminals K1, K2, K3 of the change-over contact of the polarized relay

Maximum DC/AC voltage: 125 V/150 V
Maximum switched/permanent current: 1 A
Maximum switched power: 30 W/60 VA
Electric strength between the coil and the contact of the relay:

2.5 kV

4.14 Dimensions and weight

Length × height × width: 170 × 130 × 42 mm
Weight: 0.75 kg

5. Design

As far as constructional design is concerned, the PQ monitor in its MEg30 version is
a portable measuring instrument emphasizing the requirements on minimum di­mensions and on the flexibility of current sensors.

Its application even in modern, space-saving, compact switchboards is thus
made possible. A unit of PQ monitors in its MEg30 version is placed in a plastic,
all-insulated, self-extinguishing case with dimensions 170 × 120 × 42 mm, provided
with firmly connected voltage cables, with four connectors for connecting current
sensors or sensors of other physical quantities (I1, I2, I3, 14/T), with a signalizing
LED diode OPERATION (PROVOZ) and three LED diodes signalizing the magni­tude of connected voltages being measured. The case of MEg30 includes a two-pole
terminal board with a removable plug of the signal SYNC and a three-pole terminal
board with a removable plug of the change-overcontact of the polarized relay. Max

-

imum cross-section of the connected conductor is 2.5 mm

2

.

Version MEg30 has five firmly connected double-insulated voltage cables with
length 1.5 m, ended with safety modular banana plugs. These cables maintain a
high flexibility even at negative temperatures. The measuring cables are marked
with U1, U2, U3, U4 and N at their ends. The measuring cables U1, U2, U3 and N
serve for a three-phase supply of MEg30 at thesame time.The measuring cables U1,
U2, U3 and U4 are red, the measuring cable N is black. As need be, either safety alli

­gator clips or measuring grips with an integrated fuse type 10 133 01, manufacturer
Legrand, 1A/500 V (10 × 38 mm) shall be installed on banana plugs of the measur

­ing cables. Red alligator clips shall be connected to cables U1, U2 and U3, a blue alli

­gator clip to cable U4 and a black one to the measuring cable N. For voltage

13

MEgA Měřicí Energetické Aparáty

measurements and supply in single-phase LV networks we can use a LV adapter
which shall be inserted into a LV mains socket. Modular banana plugs of measuring
cables U1 and N of the MEg30 unit shall be connected into its safety jacks.

In case of the MEg30 version, active flexible measuring sensors AMOS PQ with
increased accuracy of measurement are intended to be used for the measurement of
AC currents. The loop of these sensors is 16 mm. The loop has two insulation layers
distinguished in colour. The minimum permitted radius of curvature of the loop is
30 mm. The loop is provided with a plastic closure. The supply cable between the
loop and the converter unit is 150 cm long. The converter unit comprises a four-po

-

sition switch of the nominal current (30 A, 100 A, 300 A, 1000 A) and a signalizing di

­ode RUN which – by its intermittent lighting – signalizes the supplying from MEg30
via the connector used for the connection of the current sensor.

Clamp instrument transformers MT PQ with the maximum size of the conduc-

tor being clamped 10 × 20 mm shall be used for a precise measurement of small cur

­rents with MEg30. The nominal current of transformers MT PQ can be set by means
of a four-position switch. The length of supply cables is 150 cm. The direction of the
current flowing through the current sensors AMOS PQ and MT PQ is indicated by
an arrow with an integrated marking of the current being measured I1, I2, I3 and I4.
The serial numbers of current sensors AMOS PQ and of instrument transformers
MT PQ shall agree with the serial number of the MEg30 unit, forming a measuring
set with it. This set can be delivered in a textile bag or in a leatherette case.

Acontact thermometer T-PQ with aswinging, electrically insulated temperature
sensor can be used with MEg30. This thermometer shall be connected into connec­tor 14/T of the MEg30 unit by using a 150 cm long cable.

6. Installation

First of all, suitable current sensors, i. e. either AMOS PQ or MT PQ shall be chosen.
The same type of the current sensor shall be usually chosen for the measurement of
currents I1 to I3. A suitable value of I

nom

shall be set on the current sensors accord

­ing to the expected magnitude of the current. When the current sensors AMOS PQ
and/or MT PQ are being installed the arrows on their sensing parts shall indicate a
positive direction of the current being measured. Agreement between serial num

­bers of the current sensors and that ofthe MEg30 unit shall be checkedwhen install

­ing the current sensors. The current sensors shall be connected into a current
connector I1, I2, I3 and 14/T with identical marking.

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PQ monitor – MEg30, MEg31, MEg32, MEg33

According to the place of measurement, either safety alligator clips or grips with
an integrated fuse shall be inserted onto modular banana plugs of the measuring
conductors U1, U2, U3, U4, complying with the category of measurement IV. Grips
with an integrated fuse shall be used for measurements in unprotected circuits. Red
alligator clips shall beconnected to measuring conductorsU1, U2 andU3,a blue alli

­gator clipto conductor N and a black one to conductor N. The measuring conductor
N shall be first connected to the neutral conductor of the measuring point and only
then measuring conductors U1, U2, U3 and/or U4 shall be connected. In case of a
single-phase or a two-phase measurement the conductors which are not being used
shall be connected to conductor N. The supply for MEg30 shall be switched-on by
connecting the first one ofthe measuring conductors U1, U2 orU3 to the phase volt

­age higher than 100 V

ef

.

After the supply has been connected, the LED diode OPERATION (PROVOZ)
will be lighting permanently and, at a possible disconnection of the external supply
during the following 1 minute interval, the PQ monitor continues to measure while
being supplied with energy from the built-in battery. The LED diode OPERATION
(PROVOZ) is lighting intermittently with frequency 5 Hz during this period. After 1
minute the PQ monitor stops the measurement and the LED diode OPERATION
(PROVOZ) will not be lighting any more.

A switched-on notebook with the started program PQ-monitor shall be con­nected – at the place of measurement – to the monitor being supplied, using the ca­ble of a series communication interface USBII. The item Setting of measurement
shall be chosen and a correct choice of the nominal value of the current on the cur­rent sensors, a correct order of connected voltages and a correct orientation of the
current sensors shall be checked.By usingthe procedure described in the user guide
for the program PQ-monitor, the measuring protocol shall then be specified accord

-

ing to which the PQ monitor in version MEg30 will measure.

The portable version MEg30 of the PQ monitor can also be programmed in ad

­vance in the laboratory and at the place of measurement the monitor shall only be
connected into measuring and supply circuits. However, a correct connection and a
suitable choice of the range of currents being measured is not possible here.

The portable version MEg30 of the PQ monitor can be connected to telecommu

­nication devices via a series interface USBII in a standard way.

In order to savethe energy of the internal battery, it is recommendedto suppress

the unnecessary (in this case) one-minute back-up supply of the monitor when dis

­connecting it from the supply. This shall be done by using the notebook with the
started program of the PQ monitor where the item Uspat shall be updated in menu
Measuring instrument.

15

MEgA Měřicí Energetické Aparáty

6.1 Basic steps when installing the monitor

–

choice of type of current sensors

–

checking the agreement between the serial number of MEg30 and those of cur

-

rent sensors

–

choice of the range of current measurement

–

installation of current sensors in a correct direction

–

installation of contact elements on voltage measuring cables

–

installation of a common conductor and then of measuring conductors

–

checking the lighting of the LED diode OPERATION (PROVOZ) and of LEDs
U1, U2 and U3

–

communication connection of MEg30 with the notebook (program Control of
PQ monitor)

–

checking the correct installation and the ranges of measurement by means of the
program



The utilization of the PQ monitor in version MEg30 in another way than in
that for which it is intended may result in impairing the protection provided
by the equipment.

7. Demands on maintenance

The MEg30 monitor has no requirements on forced ventilation, it contains no mov­able control elements and –beside the usual cleaning of its surface – it has no special
demands on maintenance. Soft materials and non-aggressive solutions, preferably
water with detergent, shall be used for cleaning the surface.

Preventive inspection of portable PQ monitors in version MEg30 includes:

–

checking the undamaged state of insulation of measuring conductors, of alli

-

gator clips, current sensors and temperature sensors,

–

checking the legibility of the marking of measuring elements,

–

checking the undamaged mechanical state of the monitor unit and of all mea

-

suring accessories,

–

checking whether water has not got into the monitor or into its accessories.

It is recommended to carry out preventive inspections before each installing – not
later than after everythree months. The periodicity of checking the accuracy of mea

-

16

PQ monitor – MEg30, MEg31, MEg32, MEg33

surement shall be chosen by the user of the monitor according to the significance
and properties of the place of its installation. In case of theportable versionMEg30 it
is recommended to check the accuracy of measurement every 2 years in average.
The battery of the internal back-up supply type SANYO N-50AAA L 1×5 shall al

­ways be replaced during the checking of the accuracy of measurement.

It is not permitted to remove the cover of the monitor unit at installed or con

­nected monitors and their accessories. The removal of the cover is dangerous for
life.

8. Content of the set of MEg30 monitor

•

Unit of PQ monitor MEg30

• User guide for PQ monitor

• Program on CD

• Optional parts of the set:

• Set of flexible current sensor AMOS-PQ (3 or 4 pcs)

• Set of clamp transformers MT-PQ (3 or 4 pcs)

• Contact thermometer T-PQ

• Set of safety alligator clips (3 pcs red, 1 pc blue, 1 pc black)

• Set of grips (3 pcs red, 1 pc black) with fuse 10 133 01, manufacturer Le-

grand, 1 A/500 V with dimensions 10 × 38 mm

• Adapter for single-phase measurement of PQ

• Communication cable USB-PQ/1.5 m or 5 m

•

Textile bag with sling

•

Leatherette case, dimensions 50 × 33 ×17 cm

9. Delivery

The place of delivery is the address of the manufacturer’s seat if not otherwise
started. The portable set of the PQ monitor in version MEg30 is usually delivered ei

­ther in a textile bag or in a leatherette case with lockable closures. Delivery protocol
and certificate of guarantee with the marked date of sale are parts of the delivery.

17

MEgA Měřicí Energetické Aparáty

10. Guarantee

It is not permitted to open the PQ monitor unit and its accessories during the guar

-

antee period.

A guarantee in the length of two years since the date of sale is provided for the

PQ monitor in version MEg30. Defects originating during this period as a demon

­strable result of defective design, manufacturing or using unproper material will be
repaired free of change by the manufacturer. The place of repair is the manufac

­turer’s seat.

The guarantee becomes invalid if the user damages the seals or carries out

unpermitted modifications or changes on themonitor or on its accessories, ifhe con

­nects the instrument incorrectly or if the monitor or its accessories were operated
out of keeping with technical conditions.

The defects on the monitor and its accessories originating during the guarantee
period shall be claimed by the userto the manufacturer of thePQ monitor. The claim
without the attached certificate of guarantee will not be accepted.
The manufacturer bears in any case no responsibility for subsequent damages
caused by using the MEg30 monitor and its accessories. No responsibility which
would exceed the price of the PQ monitor follows for the manufacturer from this
guarantee.

11. Manufacturer

MEgA – Měřicí Energetické Aparáty, s.r.o.

621 00 Brno, Letovická 1412/4

Office:

MEgA – Měřicí Energetické Aparáty, s.r.o.

638 00 Brno, Okružní 794/29a

phone/fax : [phone]

e-mail: [e-mail]

web: www.e-mega.cz

18

PQ monitor – MEg30, MEg31, MEg32, MEg33

MEg 30

AMOS PQ

AMOS M

Měřicí Energetické Aparáty, s.r.o. • Letovická 1412/4 • 621 00 Brno • tel/fax [phone] • [e-mail] • www.e-mega.cz

MEg 33
for fixed mounting
in LV networks

MEg 33 s nasazeným
plombovacím krytem
a bez něj