Gossen MetraWatt MAVOWATT 4 User manual

3-348-721-02
5/4.17
Operating Instructions
MAVOWATT 4
Multifunction Power Meter
®

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A V
1
2
3
4
5
6
Figure 1

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Operating controls
1 Connection terminals Current I* (1), I (3)
Voltage L1 (2), L2 (5), L3 (8)
2 Mirror scale
3 Mechnical zero adjuster
4 Selector switch for voltage ranges 50 V / 100 V / 250 V / 500 V
5 Selector switch for current ranges 0.25 A /1 A /5 A / 25 A
6 Function switch
Symbols
The position of the function switch is marked by symbols. Where:
Meter in the "OFF" position
–1 Battery test for the voltage path of the meter
–2 Battery test for the current path of the meter
Measurement of the active power on a three-wire,
three-phase systems, balanced load
Measurement of the active power on a DC and single-phase AC system
U Measurement of AC voltage
I Measurement of AC current
U Measurement of DC voltage
I Measurement of DC current
cos ind Measurement of the power factor, inductive
cos cap Measurement of the power factor, capacitive
Phase sequence indication
Danger warning
((Caution: Note documentation)
Further symbols
Indicates EC conformity
This device may not be disposed of with the trash. Further informa-
tion regarding the WEEE mark can be accessed on the Internet at
www.gossenmetrawatt.com by entering the search term ’WEEE’.
L1L2L3
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Contents
1 Safety precautions .....................................................................5
2 Application .................................................................................6
3 Getting started ...........................................................................7
3.1 Description of the operating controls ..........................................................7
3.2 Installing the batteries ...............................................................................7
3.3 Mechanical zero check ..............................................................................7
3.4 Battery test ...............................................................................................8
4 Measurement .............................................................................8
4.1 Notes on measurements ...........................................................................8
4.2 Connection circuitries ..............................................................................10
4.3 Measured results ....................................................................................13
4.4 Internal consumption of the power meter and its influence on the accuracy 15
4.5 Voltage and current measurement ...........................................................16
4.5.1 Voltage measurement .............................................................................16
4.5.2 Current measurement .............................................................................17
4.5.3 Phase sequence indication ......................................................................17
5 Specifications ..........................................................................18
6 Maintenance ............................................................................22
6.1 Battery and Fuse Replacement ................................................................22
7 Repair and Replacement Parts Service
Calibration Center and Rental Instrument Service ..................24
8 Product Support .......................................................................24

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1 Safety precautions
This instrument fulfills the requirements of the applicable EU guidelines
and national regulations. We confirm this with the CE marking. The
relevant declaration of conformity can be obtained from GMC-I
Messtechnik GmbH.
The multi-function power meter MAVOWATT 4 is constructed and
tested in compliance with the safety rules of DIN VDE 0410 /IEC 414
and VDE 0411-1/EN 61010-1/IEC 61010-1.
When properly used, the safety of both the user and the meter is
assured. Their safety is not assured, however, if the meter is misused
or carelessly handled.
To maintain the technically safe and proper condition and to ensure
safe operation, it is absolutely necessary to carefully and completely
read these operating instructions before using the meter, and to follow
them in all respects.
Please note the following safety precautions:
• The meter must only be operated by persons who understand the
danger of shock hazards and know how to apply safety precau-
tions. Shock hazards exist wherever voltages of more than 50 V
can appear.
• When making measurements where shock hazards exist, do not
work alone. A second person must be present.
• The maximum permissible voltage between any of the connectors
and ground is 650 V.
• Take into account that unexpected voltages can appear on
devices under test, capacitors may be charged dangerously, for
instance.
• Verify that the test leads are in good condition, e.g. no cracked
insulation, no open circuits etc.
• This meter must not be used for measurements on circuits with
corona discharge (high voltage).
• Measurements under moist environmental conditions are not per-
mitted.
• Absolutely verify that overloading of the nominal voltage and nom-
inal current ranges does not exceed the permissible limits. See
chapter 5 „Specifications“ for limits.

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Repair, replacement of parts and calibration
When opening the meter, live parts may be exposed. Therefore, the
meter must be disconnected from all voltage sources prior to opening
its case for repair, replacement of parts or calibration. If repair or cali-
bration can then not be avoided unless the meter is open and live, this
work must only be performed by a qualified person who understands
the danger involved.
Faults and extraordinary stress
When it must be assumed that safe operation is no longer possible,
take the meter out of service and secure it against accidental use. It
must be assumed that safe operation is no longer possible,
• when the meter shows obvious signs of damage,
• when the meter no longer functions correctly,
• after prolonged storage under adverse conditions.
2 Application
The electronic multi-function power meter MAVOWATT 4 permits
direct power measurements on DC systems as well as active power
measurements on single-phase AC systems and on three-wire, three-
phase systems of balanced load.
In addition, the MAVOWATT 4 power meter can be used to directly
measure current and voltage on DC and single-phase AC systems.
Under consideration of correction factors, it is also possible to use the
meter for reactive power measurements on three-phase systems of
balanced load and also for interlinked voltages.
The MAVOWATT 4 power meter is particularly suited for industrial
measurements, for service and mounting. Also in the laboratory and in
the test room, diversified measuring tasks can be solved quickly and
without problems.

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3 Getting started
3.1 Description of the operating controls
There are five connection terminals (1, figure 1), arranged on the front
of the power meter, two for current connection with the markings I* (1)
and I (3) and three for voltage connection with the markings L1 (2), L2
(5) and L3 (8). They are contact-protected.
The operating panel of the power meter consists of:
One selector switch for the voltage ranges (4, figure 1), with the four
ranges 50 V, 100 V, 250 V and 500 V.
One selector switch for the current ranges (5, figure 1), which can be
switched in four ranges 0.25 A, 1 A, 5 A and 25 A. One function switch
(6, figure 1) featuring 12 positions.
3.2 Installing the batteries
Caution: Make an all-pole disconnection of the meter from the
measuring circuits before you open the battery
compartment on the bottom!
➭Undo the slotted screw of the battery compartment cover using an
adequate tool or a coin, and remove the cover.
➭Install two 9-V flat cell batteries 6F22, 6LF22 or 6LR61 according to
IEC 86-2 in the two compartments.
Caution: Except for the specified 9-V flat cell batteries, no other voltage
souces must be connected to the battery connection contacts.
The connection contacts must not be connected with each other!
➭Replace the cover and screw-tighten it.
3.3 Mechanical zero check
➭Check that the meter is switched off.
➭Place the meter in a horizontal position.
➭Check the mechanical zero position of the pointer.
➭If required, correct the zero position with the adjuster " " on
the front panel.
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3.4 Battery test
➭To test the battery for the voltage path and the battery for the cur-
rent path, set the function switch to the positions " 1" and "
2", one after another. When, at a time, the pointer is within the bat-
tery section marked " " on the scale, the battery voltages are
within the permissible range.
It is assured that the error limits according to the data given in
chapter 5 „Specifications“ are maintained.
4 Measurement
4.1 Notes on measurements
➭Prior to connecting the meter, check according to which of the cir-
cuitries shown in the following section the MAVOWATT 4 is to be
connected.
➭Find out whether direct connection of current path and voltage
path is possible on the basis of the system on which the measure-
ments are to be made and with respect to the power to be mea-
sured.
Caution: In systems having a voltage of more than 600 V,
measurements must, on principle, only be made via
current and voltage transformers!
The nominal currents and nominal voltages of the meters correspond
to those of commercial current transformers with secondary currents
of 1 A and 5 A, and the standardized voltage transformers with sec-
ondary voltages of 100 V or 110 V.
➭When using current transformers, consider the secondary load.
Particularly with longer connection leads and with a transformer
having a secondary current of 5 A, the power loss on the lines is
often remarkable.
➭Set up the current path mechanically solid and secure it against
accidental opening. Lay out the cross sections of the leads and the
connection points in such a way that they will not heat-up unper-
missibly. For currents above 5 A, the connections must always be
made as screw connections (e.g. with cable lugs), but not as plug
connections.
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➭Prior to measuring, always set the selector switch for the current
ranges and that for the voltage ranges to the highest range. Make
sure that the set nominal values are never exceeded by more than
1.2 times.
➭For power measurements on DC and single-phase AC systems,
set the function switch to the " " position, for power measure-
ments on three-wire, three-phase systems of balanced load to the
" " position.
➭To measure the power factor (cos ), set the function switch to
"cos ind" with inductive load, with capacitive load to "cos cap".
The connection circuitries for active power and power factor mea-
surements (cos ) are identical and are shown later.
➭Switch the meter off after the measurement to avoid unnecessary
load on the batteries (function switch set to position " ").
The symbols used in the equations of the connection circuitries have
the following meaning:
P = Active power in W
Q = Reactive power in var
I = Load current of a phase in A
U = Interlinked generator voltage with three-phase connection in V
cos = Power factor
a = Readout of the pointer deflection on the corresponding
instrument scale in W, V or A
a= Readout of the pointer deflection on the cos scale
c ,c = Scale factor for power measurement
cI,cU= Scale constant for current and voltage measurement
üI,üU= Scale constant for current and voltage measurement

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4.2 Connection circuitries
Current and voltage input takes place on the meter via connectors
which are suited for both plugging (banana plugs) and as terminals
(e.g. cable lugs). The current path is run to the two connectors I* (1)
and I (3), the voltage path to connectors L1 (2), L2 (5) and L3 (8).
For DC current and for single-phase AC systems, the voltage must be
applied to L1 (2) and L2 (5), for three-wire, three-phase systems (with-
out neutral conductor) to L1 (2), L2 (5) and L3 (8).
Following is a presentation of the wiring diagrams. The most important
diagrams are also affixed to the rear of the meter.
Power measurement on DC systems
M
P (W) = I · U = · c
L-
L1
(2)
L2
(5)
L3
(8)
I
(3)
I*
(1)
L+
M
L1
(2)
L2
(5)
L3
(8)
I
(3)
I*
(1)