Landis+Gyr E650 Series 4 User manual

Electricity Meters IEC/MID
Industrial and Commercial
ZMD400AT/CT, ZFD400AT/CT
E650 Series 4
User Manual
Date: 11.09.2017
File name: D000062026 E650 ZxD400xT Series 4 User Manual en a.docx
© Landis+Gyr
D000062026 en a

2/96 Revision history
© Landis+Gyr D000062026 en a –E650 Series 4 –ZMD400AT/CT, ZFD400AT/CT –User Manual
Revision history
Version
Date
Comments
a
11.09.2017
Updated to hardware Series 4 (firmware version B40) based on Series 3 document
D000030110:
Added section 1.5 “Safety-related meter data”.
Added section 2.2 “Standards”.
Updated section 2.4 “Type designation” with additional functions.
Updated section 2.6.3 “Measured quantities”.
Updated section 2.6.4 “Formation of measured quantities”.
Updated section 2.7.3 “Event log”.
Deleted section 2.9.2 “Terminal cover detection”.
Updated section 2.10 “Anti-tampering features”.
Updated section 3.2 “Faceplates”.
Updated section 3.4 “Connection diagrams (examples)” by adding extension board
421x and deleting 046x.
Added section 4.3.3 “Maximum current of auxiliary current outputs”.
Added section 4.3.4 “Connection of active inputs”.
Deleted section 4.6 “Installation of terminal cover detection”.
Updated section 5.1 “Operation with auxiliary power supply”.
Although the information contained within this document are presented in good faith and believed to be correct, Landis+Gyr (including its
affiliates, agents and employees) disclaim any and all liability for any errors, inaccuracies or incompleteness relating to the product.
Landis+Gyr makes no warranty, representation or guarantee regarding the performance, quality, durability or suitability of the products for
any particular purpose. To the fullest extent permitted by law Landis+Gyr disclaims (1) any and all liability arising out of the use of the
product, (2) any and all liability, including, but without limitation to, special, consequential and indirect damages and losses, and (3) any and
all implied warranties, including, but without limitation to, fitness for purpose and merchantability.
The information contained in this document is strictly confidential and is intended for the addressee only. The unauthorised use, disclosure,
copying, alteration or distribution of this document or the contents thereof is strictly prohibited and may be unlawful.
All product information are subject to change without notice.

Table of contents 3/96
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Table of contents
Revision history ...................................................................................................................................2
Table of contents .................................................................................................................................3
About this document............................................................................................................................5
1Safety...........................................................................................................................................6
1.1 Safety information...................................................................................................................6
1.2 Responsibilities.......................................................................................................................6
1.3 Safety regulations ...................................................................................................................7
1.4 Radio interference...................................................................................................................7
1.5 Safety-related meter data........................................................................................................8
2Device description......................................................................................................................9
2.1 Field of application..................................................................................................................9
2.2 Standards..............................................................................................................................10
2.3 Characteristics ......................................................................................................................11
2.4 Type designation...................................................................................................................13
2.5 Block schematic diagram ......................................................................................................14
2.6 Measuring system.................................................................................................................17
2.6.1 Input signals ....................................................................................................................17
2.6.2 Signal processor..............................................................................................................18
2.6.3 Measured quantities ........................................................................................................20
2.6.4 Formation of measured quantities....................................................................................21
2.6.5 Summation channels.......................................................................................................27
2.7 Data profile............................................................................................................................27
2.7.1 Stored value profile..........................................................................................................27
2.7.2 Load profile 1 and load profile 2 (option)..........................................................................27
2.7.3 Event log..........................................................................................................................28
2.8 Communication.....................................................................................................................31
2.8.1 Optical interface...............................................................................................................31
2.8.2 Communication units .......................................................................................................31
2.9 MAP software tools...............................................................................................................33
2.10 Anti-tampering features.........................................................................................................34
2.10.1 DC magnet detection.......................................................................................................34
3Mechanical construction..........................................................................................................35
3.1 Housing.................................................................................................................................35
3.2 Faceplates ............................................................................................................................39
3.3 Connections..........................................................................................................................40
3.4 Connection diagrams (examples)..........................................................................................42
3.5 Dimensions...........................................................................................................................46
4Installation and uninstallation .................................................................................................47
4.1 Basic information for connecting the meter............................................................................47
4.1.1 Connection to low voltage with current transformers........................................................47
4.1.2 Connection to medium and high voltage (Aron circuit).....................................................48
4.1.3 Connection to medium and high voltage (three-phase four-wire circuit)...........................49
4.2 Mounting the meter...............................................................................................................50
4.3 Connecting the meter............................................................................................................52
4.3.1 Connecting the phase connection lines............................................................................53
4.3.2 Connecting the signal inputs and outputs ........................................................................54
4.3.3 Maximum current of auxiliary current outputs...................................................................55
4.3.4 Connection of active inputs..............................................................................................56
4.3.5 Connecting the RS485 interface......................................................................................56

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4.4 Check of connections ........................................................................................................... 56
4.5 Commissioning, functional check and sealing....................................................................... 57
4.6 Uninstallation........................................................................................................................ 59
5Operation.................................................................................................................................. 61
5.1 Operation with auxiliary power supply................................................................................... 61
5.2 Control elements .................................................................................................................. 61
5.2.1 Display buttons................................................................................................................ 62
5.2.2 Control of display via optical interface............................................................................. 62
5.2.3 Reset button.................................................................................................................... 62
5.3 Display.................................................................................................................................. 63
5.3.1 Introduction..................................................................................................................... 63
5.3.2 Basic layout..................................................................................................................... 63
5.3.3 Index system................................................................................................................... 64
5.4 Types of display.................................................................................................................... 65
5.4.1 Operating display............................................................................................................ 65
5.4.2 Display menu .................................................................................................................. 66
5.4.3 Service menu.................................................................................................................. 69
5.5 Alarm LED............................................................................................................................ 70
5.6 Optical test output................................................................................................................. 70
5.7 Data readout......................................................................................................................... 71
5.7.1 Readout to IEC 62056-21................................................................................................ 72
5.7.2 Readout to DLMS............................................................................................................ 74
5.8 Input of formatted commands ............................................................................................... 75
5.9 Set time and date, ID numbers, battery time......................................................................... 76
6Service...................................................................................................................................... 77
6.1 Operating faults.................................................................................................................... 77
6.2 Error messages.................................................................................................................... 77
6.2.1 Structure of an error message......................................................................................... 78
6.2.2 Error groups.................................................................................................................... 78
6.3 Repairing meters.................................................................................................................. 83
7Maintenance............................................................................................................................. 84
7.1 Meter testing......................................................................................................................... 84
7.1.1 Test mode....................................................................................................................... 84
7.1.2 Measuring times.............................................................................................................. 85
7.1.3 Optical test output ........................................................................................................... 85
7.1.4 No-load test..................................................................................................................... 87
7.1.5 Starting test active part.................................................................................................... 87
7.1.6 Starting test reactive part................................................................................................. 87
7.2 Changing the battery ............................................................................................................ 88
8Disposal.................................................................................................................................... 90
9Index ......................................................................................................................................... 91
Appendix 1 OBIS code ............................................................................................................... 94

About this document 5/96
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About this document
The present user manual applies to the meters specified on the title page.
The user manual contains all the information required for metering
applications for the intended purpose. This includes:
Provision of knowledge concerning the characteristics, construction and
function of the meters
Information about potential dangers, their consequences and measures
to prevent any danger
Details about the performance of all activities throughout the service life
of the meters (parameterisation, installation, commissioning, operation,
maintenance, decommissioning and disposal)
The content of this user manual is intended for technically qualified
personnel of utilities (energy supply companies), responsible for system
planning, installation and commissioning, operation, maintenance,
decommissioning and disposal of meters.
The following documents provide further information related to the subject
of this document:
D000062002 "E650 ZxD400xT Series 4 Technical Data"
D000062040 "E650 ZxD/S650 SxA Series 4 Functional Description"
The structure and significance of meter type designations are described in
section 2.4 "Type designation". The following conventions are employed in
this user manual for representing type designations:
The lower case letter "x" can be used as an unknown to indicate
different versions (e.g. ZxD400 for the ZMD400 and ZFD400 meters or
ZMD410xT for the ZMD410AT and ZMD410CT meters).
The digit pair "00" can be used to indicate accuracy data (e.g. ZxD400
for the ZxD405 and ZxD410 meters).
The abbreviated type designation ZMD or ZFD meters can be used
when all three-phase four-wire meters or three-phase three-wire meters
are meant.
The following collective terms are also sometimes used instead of the
type designation:
–"Active energy meters" for the E650 ZxD400AT meters
–"Combimeters" for the E650 ZxD400CT meters
Range of validity
Purpose
Target group
Reference documents
Conventions

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1 Safety This section describes the safety information used in this manual, outlines
the responsibilities and lists the safety regulations to be observed.
1.1 Safety information
The following symbols are used to draw your attention to the relevant
danger level, i.e. the severity and probability of any danger, in the individual
sections of this document.
Warning
Used to indicate a dangerous situation that could cause bodily injury or
death.
Caution
Used to indicate a situation/ action that could result in material damage or
loss of data.

Note
Used to indicate general guidelines and other useful information.
In addition to the danger level, safety information also describes the type
and source of the danger, its possible consequences and measures for
avoiding the danger.
1.2 Responsibilities
The owner of the meters –usually the utility company –is responsible for
ensuring that all persons working with meters:
Have read and understood the relevant sections of the user manual.
Are appropriately qualified for the work to be performed.
Strictly observe the safety regulations (laid down in section 1.3) and the
operating instructions as specified in the individual sections.
In particular, the owner of the meters bears responsibility for the protection
of persons, prevention of material damage and the training of personnel.
For this purpose, Landis+Gyr provides training on a variety of products and
solutions. Contact your local Landis+Gyr representative if interested.

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1.3 Safety regulations
The following safety regulations must be observed at all times:
The meter connections must be disconnected from all voltage sources
during installation or when opening.
Contact with live parts can be fatal. The relevant supply fuses should,
therefore, be removed and kept in a safe place until the work is
completed so that other persons cannot replace them unnoticed.
Local safety regulations must be observed. Only technically qualified
and appropriately trained personnel are authorised to install the meters.
Only appropriate tools shall be used for the job. This means, e.g. that
the screwdriver must be of the correct size for the screws, and the
handle of the screwdriver must be insulated.
Secondary circuits of current transformers must be short-circuited (at
the test terminal block) without fail before opening. The high voltage
produced by an interrupted current transformer circuit is dangerous to
life and destroys the transformer.
Transformers in medium or high voltage systems must be earthed on
one side or at the neutral point on the secondary side. Otherwise they
can be statically charged to a voltage which exceeds the insulation
strength of the meter and is also dangerous to life.
The meters must be held securely during installation. They can cause
injuries if dropped.
Meters that have been dropped must not be installed, even if no
damage is apparent, but must be returned to the service and repair
department (or the manufacturer) for testing. Internal damage may
result in malfunctions or short-circuits.
The meters must never be cleaned under running water or with
compressed air. Water ingress can cause short-circuits.
1.4 Radio interference

Possible radio interference in residential environments
This meter is normally a class B product. In combination with some
communication modules it can become a class A product. In a domestic
environment, this may then cause radio interference, in which case the user
may be required to take adequate measures.

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1.5 Safety-related meter data
Item
Standard
Value
Protection class
IEC 62052-11
II
Rated impulse
voltage
IEC 62052-31
6 kV
Overvoltage category
IEC 60364-4-44:2007
OVC III
Usage
Indoor use
Operating altitude
IEC 62052-31
Up to 2000 m
Pollution degree
IEC 62052-31
2
Environmental
conditions
IEC 62052-31
Normal
environmental
conditions
Ingress protection
IEC 60529
IP51
For nominal reference voltage and current, see the nameplate of the meter.
The same applies to the current range.
For maximum currents of auxiliary terminals, see section 4.3.3 “Maximum
current of auxiliary current outputs”.

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2 Device description
This section provides you with a brief overview of the design and function of
the ZxD400xT meters.
2.1 Field of application
ZxD400xT meters can be used for transformer connection at all three
voltage levels, namely on low, medium and high voltage. They are primarily
used by medium and large consumers and in the field of energy generation
and exchange.
The ZMD400xT meter is especially suitable for applications at the low
voltage level, while the ZFD400xT meter is generally used more at the
medium and high voltage levels.
ZxD400xT meters have a comprehensive tariff structure. This extends from
seasonal tariffs to multiple energy and demand tariff rates.
The ZMD400xT and ZFD400xT meters are designed for connection to
current transformers with 5 A or 1 A rated current or as a special version for
both applications (5//1).
The ZMD400CT and ZFD400CT combimeters record active and reactive
energy consumption, the ZMD400AT and ZFD400AT active energy meters
only the active energy in three-phase four-wire or three-phase three-wire
networks (low, medium and high voltage) and from this determine the
required electrical measured quantities. For this purpose they are
connected to the measuring point via current transformers and possibly
also voltage transformers:
Low voltage: ZMD400xT with current transformers
Medium voltage: ZFD400xT (sometimes also ZMD400xT) with current
and voltage transformers
High voltage: ZMD400xT (sometimes also ZFD400xT) with current and
voltage transformers
The data determined are displayed (LCD) and are also available at the
optical interface for data acquisition, with an appropriate communication
unit also as required via CS, RS232, RS485, modem, etc.
When equipped with transmitting contacts, the meters can also be used as
transmitting meters for telemetering. The tariff rates can be controlled
internally or externally.
With a communication unit, the meters can also be used for recording
counter pulses for other physical media (e.g. water or gas volumes).

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2.2 Standards
The meter complies with the following standards and directives.
IEC standards:
IEC 62052 Electricity metering equipment (a.c.) –General
requirements, tests and test conditions
–IEC 62052-11 (Part 11: Metering equipment)
–IEC 62052-31 (Part 31: Product safety requirements and tests)
IEC 62053 Electricity metering equipment (a.c.) –Particular
requirements
–IEC 62053-22 (Part 22: Static meters for reactive energy (classes
0.2 S and 0.5 S))
–IEC 62053-23 (Part 23: Static meters for reactive energy (classes 2
and 3))
–IEC 62053-24 (Part 24: Static meters for reactive energy at
fundamental frequency (classes 0.5 S, 1 S and 1))
IEC 62056 Electricity metering –Data exchange for meter reading, tariff
and load control
–IEC 62056-21 (Electricity metering –Data exchange for meter
reading, tariff and load control –Part 21: Direct local data exchange)
–IEC 62056-53 (Electricity metering –Data exchange for meter
reading, tariff and load control –Part 53: COSEM application layer)
–IEC 62056-61 (Electricity metering –Data exchange for meter
reading, tariff and load control –Part 61: Object identification
system (OBIS))
–IEC 62056-62 (Electricity metering –Data exchange for meter
reading, tariff and load control –Part 62: Interface classes)
EN standards:
EN 50470-1 (Electricity metering equipment –General requirements,
tests and test conditions –Metering equipment class indexes A, B, and
C)
EN 50470-3 (Electricity metering equipment –Particular requirements –
Static meters for active energy class indexes A, B and C)
EN standards corresponding to the IEC standards listed above
Directives:
MID (Directive 2014/32/EU of the European parliament and of the
council 26 February 2014 on the harmonisation of the laws of the
Member States relating to the making available on the market of
measuring instruments)
EMCD (2014/30/EU Electromagnetic Compatibility Directive)
RED (Radio Equipment Directive 2014/53/EU)
RoHS2 –Directive on the Restriction of the Use of Certain Hazardous
Substances in Electrical and Electronic Equipment 2011/65/EU

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2.3 Characteristics
ZxD400xT meters have the following basic characteristics:
Recording of active, reactive and apparent energy in all four quadrants
(ZxD400CT) or recording of imported and exported active energy
(ZxD 400AT)
Tariff system with energy and demand tariff rates, stored values, load
profiles, etc.
Extended functions such as monitoring functions, sliding maximum
demand, etc. (for ZxD400CT additionally power factor cosφ)
Tariff control
–External
- via control inputs (ZxD400xT21 and ZxD400xT41)
- via communication interfaces using formatted commands
–Internal
- by integral time switch (ZxD400xT24 and ZxD400xT44)
- by event signals based on monitored values, such as voltage,
current and demand.
Display of data on a liquid crystal display (LCD)
Active and reactive power per phase and true RMS values of voltages
and currents by means of digital signal processing (DSP) chips
Accuracy: Compliance with IEC class 1 or 0.5 S and with MID accuracy
class B or C for active energy consumption (ZxD400xT) and IEC class 1
S for reactive energy (ZxD400CT).
Exception: ZxD402CT –IEC class 0.2 S for active energy and IEC
class 0.5 S for reactive energy.
Flexible measuring system through parameterisation (definition of
different variables by software)
Correct measurement even with failure of individual phases or when
used in two- or single-phase networks
Wide range of measurement from starting current to maximum current
Optical interface according to IEC 62056-21 and DLMS
–for direct readout of meter data
–for service functions of the meter, extension board and
communication unit (e.g. parameterisation)
Inputs for recording fixed valency pulses (communication unit)
Output contacts (solid-state relays) for fixed valency pulses, control
signals and status messages
Output contacts (relays) for control and status messages
Input contact for alarm monitoring and sending SMS messages, if
suitable optional communication unit selected
Installation aids
–Indication of phase voltages, phase angles, rotating field and
direction of energy

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Storage of event information, e.g. voltage failures, exceeding of
thresholds or error messages. Event information can be read out via the
available interfaces. Important events can be communicated to the
energy supply company as operational messages (sending of SMS
messages, control of an arrow in the display, drive for an output
contact, etc.).
Interfaces such as CS, RS232, RS485, modem, etc. for remote
transmission of data (communication unit)
Auxiliary power supply for communication with the meter if no
measuring voltage is present

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2.4 Type designation
ZMD
4
10
C
T
44
4207
S4
Network type
ZFD
ZMD
3-phase, 3-wire network (F-circuit)
3-phase, 4-wire network (M-circuit)
Connection type
4
Transformer operated
Accuracy class
10
05
02
Active energy class 1 (IEC), B (MID)
Active energy class 0.5 S (IEC), C (MID)
Active energy class 0.2 S (IEC)
Measured quantities
C
A
Active and reactive energy
Active energy
Construction
T
With exchangeable communication units
Tariffication
21
24
41
44
Energy rates, external rate control via control inputs
Energy rates, internal rate control via time switch
(additionally possible via control inputs)
Energy and demand rates, external rate control via control inputs
Energy and demand rates, internal rate control via time switch
(additionally possible via control inputs)
All versions with 3 control inputs and 2 output contacts
Additional functions
000x
060x
240x
326x
420x
421x
045x
047x
No extension board
6 outputs
2 control inputs, 4 outputs
3 control inputs. 2 relay outputs, auxiliary power supply 12–24 VDC
4 control inputs, 2 outputs
4 active inputs, 2 relay outputs 8 A
4 outputs, auxiliary power supply 100–240 VAC/VDC
4 outputs, auxiliary power supply 12–48 VDC
xxx0
xxx2
xxx7
xxx9
No additional functions
DC magnet detection
Load profile
DC magnet detection and load profile (integrated terminal cover switch option only available
in this configuration)
Series 4
As the communication unit is a device on its own, it is not part of the meter’s
type designation. The customer can exchange it at any time without opening
the certification seal. Each communication unit has its own user manual.
The hardware version is defined with a series designation.
The type designation on the nameplate ends with the series designation S4
for the fourth hardware generation (Series 4). An attached suffix points out
that the meter is equipped with certain non-standard features, e.g. S4s
represents a Series 4 meter with symmetrical terminal layout.
Series designation

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S4 represents the newest hardware generation.
The meter’s firmware version, which determines certain meter
characteristics, can be displayed on the LCD, e.g. as part of the rolling
display (depending on parameterisation) and can be read out in the
following two ways:
meter data readout (depending on parameterisation)
meter identification readout (see section 5.7 "Data readout")
Some executions of ZMD400CT/CR meters are available with accuracy
class 0.2 S. These meters fulfil the IEC accuracy class 0.2 S for active
energy and class 0.5 S for reactive energy. For details, see the
corresponding datasheet.
2.5 Block schematic diagram
This section provides an overview of the function of ZxD400xT meters
based on a block schematic diagram.
Figure 1. Block schematic diagram ZMD400xT
ZxD400AT active energy meters record the imported and exported active
energy consumption, while the ZxD400CT combimeters record the active
and reactive energy consumption in all four quadrants.
ZxD400xT meters can be fitted with modular communication interfaces in a
communication unit, which can be exchanged or used in the field as
required.
The main meter inputs are:
Connections of phase voltages (U1, U2, U3), phase currents (I1, I2, I3)
and neutral conductor N
–for processing in the measuring system
–for the three-phase power supply to the meter and voltage monitor
Control inputs Ut(3 fixed, plus up to 4 others on extension board) for:
Firmware version
Class 0.2 S
Inputs

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–Changeover of energy and demand tariff rates
–Resetting
–Demand inhibition
–Synchronising
Optocouplers protect the internal circuitry from interference, which
could otherwise enter via the control inputs.
Buttons
–for display control (display buttons, optical interface)
–for resetting or service functions (reset button)
Pulse inputs for connection of external pulse transmitters (only for
meters equipped with a communication unit)
The meter has the following outputs:
LCD display with display buttons for local reading of billing data (single
8-digit display with additional information, such as energy direction, type
of energy, presence of phase voltages and identification number)
Optical test outputs (red), 1 in active energy meters, 2 in combimeters)
Optional alarm LED (red) to indicate alarms on the front face of the
meter
Static relay with freely parameterised signal assignment (2 fixed, plus
up to 6 others on the extension board)
Relay outputs with limited parameterised signal assignment due to
limited life expectancy (up to 2 on the extension board)
Optical interface for automatic local data acquisition by a suitable
acquisition unit (PDA)
Communication interfaces of various kinds in the communication unit
(also see section 2.8 "Communication")
The input circuits (voltage dividers and current transformers) record voltage
and current in the individual phases. Analogue-digital converters digitise
these values and feed them as instantaneous digital values via calibration
stages to a signal processor.
The signal processor determines the following measured quantities from
the instantaneous digital values of voltage and current for each phase and
forms their mean value over one second:
Active power per phase
Reactive power per phase (ZxD400CT combimeters only)
Phase voltages
Phase currents
Network (mains) frequency
Phase angles
Outputs
Measuring system
Signal processing

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For signal utilisation in the various registers, the microprocessor scans the
measured quantities every second to determine the following values:
Active energy (sum and individual phases, separated according to
energy direction, if required in the ZxD400CT combimeters also
assigned to the 4 quadrants)
Reactive energy (only for ZxD400CT combimeters, sum and individual
phases, separated according to energy direction, assigned to the 4
quadrants)
Apparent energy (only for ZxD400CT combimeters, sum and individual
phases, separated according to energy direction)
Power factor cosφ (only for ZxD400CT combimeters, individual phases
and mean value)
Phase voltages
Phase currents and neutral current
Active and reactive power
Direction of rotating field
Total harmonic distortions of active energy, voltage and current
Energy losses (line losses and transformer losses)
Tariff control is performed:
Externally via control inputs (3 fixed, plus up to 4 others on the
extension board)
Externally via communication interfaces using formatted commands
Internally by time switch and calendar clock
By event signals based on threshold values of the monitoring functions
The following registers are available for evaluation of the individual
measured values:
32 for energy rates
27 for total energy
10 for running mean demand values
24 for demand rates
2 for power factors cosφ (ZxD400CT combimeters only)
up to 41 diagnostic registers
others for values of voltage and current, network frequency and phase
angles
A non-volatile flash memory serves to record data profiles and contains the
configuration and parameterisation data of the meter and secures the
billing data against loss due to voltage failures.
The supply voltages for the meter electronics are obtained from the three-
phase network, whereby the phase voltage can vary over the entire voltage
Signal utilisation
Tariff control
Data preparation for
billing
Memory
Power supply

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range without the supply voltage having to be adjusted. A voltage monitor
ensures correct operation and reliable data recovery in the event of a
power failure and correct restarting when the voltage is restored.
For medium or high-voltage applications in particular, the measuring
voltage can be switched off. Since the meter normally obtains its supply
from the measuring voltage, it is also switched off and cannot be read. The
auxiliary power supply connected in parallel with the normal power supply
ensures operation of the meter free from interruption, so that it can be read
at any time. The auxiliary power supply is situated on an extension board.
The extension board is fitted inside the meter and is secured by the
certification seals. It cannot be exchanged. It can have the following
components:
up to 4 control inputs in combination with
up to 6 output contacts (solid-state relays)
up to 2 relays outputs
an auxiliary power supply
The communication unit for fitting only in the ZxD400xT meters is a
complete unit in its own case. If present, it is situated behind the front door,
and is therefore secured by a utility seal and can be exchanged or inserted
in the field, if necessary. It contains:
Communication interfaces as required for remote readout of the meter
(e.g. CS, RS232, RS485, modem)
2 signal inputs (S0 interfaces) for processing external pulse transmitters
2.6 Measuring system
Figure 2. Block schematic diagram of measuring system
2.6.1 Input signals
The meter has the analogue current values I1, I2 and I3 and analogue
voltage values U1, U2 and U3 available as input signals.
Figure 3. Type of measurement ZMD400xT
Since the ZMD400xT measures the individual phases mutually
independently with one measuring element each, it can record the sum of
the three phases, the individual phases themselves, the phase angle
between voltage and current as well as the angle between voltages U1–U2
and U1–U3.
Auxiliary power
supply
Extension board
Communication unit
ZMD400xT

18/96 Device description
© Landis+Gyr D000062026 en a –E650 Series 4 –ZMD400AT/CT, ZFD400AT/CT –User Manual
Figure 4. Type of measurement ZFD400xT
The ZFD400xT with Aron circuit records the phase currents I1 or I3,
together with the corresponding voltage U12 or U32, with its two measuring
elements. It cannot therefore construct any actual single-phase values. In
addition, the phase angles between voltage and current always have an
additional angle of 30° and are therefore not representative.
High resistance voltage dividers reduce the voltages U1, U2 and U3 (58 to
240 V) applied to the meter to a proportionate amount of a few mV (UU) for
further processing.
Internal current transformers reduce the input currents I1, I2 and I3 to the
meter (0 to 10 A) for further processing. The secondary currents of these
current transformers develop voltages proportional to the input currents
across resistors, also of a few mV (UI).
2.6.2 Signal processor
Figure 5. Principle of signal processor
ZxD400AT active energy meters do not measure reactive energy.
The analogue signals Ux and Ix are digitised in Sigma-Delta converters
(analogue-digital converters with highest resolution) with a sample rate of
1.6 kHz and then filtered. A following calibration stage compensates for the
natural errors of the voltage divider or current transformer, so that no
further adjustment is necessary in the subsequent processing.
Calibrated digital instantaneous values of voltage (u) and current (i) for all
three phases are then available as intermediate values for the formation of
the required values in the signal processor.
The instantaneous value of active power p is produced by multiplying the
instantaneous values of voltage u and current i (the active component
corresponds to the product of voltage component with the current
component parallel to the voltage). Thereby the harmonics up to 1 kHz are
measured correctly.
ZFD400xT
Voltage input
Current input
Digitising
Calculation of active
power

Device description 19/96
D000062026 en a –E650 Series 4 –ZMD400AT/CT, ZFD400AT/CT –User Manual © Landis+Gyr
U
I
IP
IQ
P = U I cosj
..
Calculation per phase of
j
Figure 6. Active power calculation
If the meter is parameterised to calculate instantaneous power as signed
values, the following values of power are available:
Active P: + in QI and QIV, - in QII and QIII
Reactive P: + in QI and QII, - in QIII and QIV
There are two possibilities to calculate the instantaneous value of reactive
power (ZxD400Cx combimeters only):
Measured:
For the instantaneous value of reactive power q the instantaneous value of
voltage u must be rotated by 90° before multiplication (the reactive
component is the product of the voltage component with the current
component vertical to the voltage). Thereby no harmonics are measured
since only the fundamental wave is rotated through 90°.
U
I
IP
IQ
Q = U I sinj
..
Calculation per phase of
j
Figure 7. Reactive power calculation (method: measured)
Calculated vectorial (not recommended):
The instantaneous value of reactive power is calculated using the values of
active power and apparent power.
The reactive power is the square root of the square value of apparent
power minus the square value of active power. This method includes the
harmonics.
𝑄 = √𝑆2− 𝑃2
The square values of voltage and current are obtained by multiplying the
instantaneous values of voltage and current by themselves. From these
values the signal processor forms the corresponding single-phase RMS
values URMS and IRMS.
The network frequency can be calculated from the time measured between
two zero passages (change from negative to positive value of voltage U1).
The times between zero passage of the phase voltage U1 and those of the
other phase voltages U2 and U3 serves to determine the phase angle
between the voltages and of the rotating field.
Instantaneous power
with sign
Calculation of reactive
power
URMS, IRMS calculation
Time measurement

20/96 Device description
© Landis+Gyr D000062026 en a –E650 Series 4 –ZMD400AT/CT, ZFD400AT/CT –User Manual
U1 U2 U3
1 : TU1-U2
2 : TU1-U3
3 : T (fn)
123
Time measurement
for rotating field,
frequency, phase angle
U1-U1
Figure 8. Time measurement
The phase angle between voltage and current is determined by the times
between zero passage of the phase voltage U1 and those of the phase
currents I1, I2 and I3.
For further processing of the individual signal the signal processor
generates mean values over one second, which the following
microprocessor scans at intervals of one second.
2.6.3 Measured quantities
Measured quantity
ZMD400
ZFD400
Active energy in quadrant I
A (QI)
Sum / Phases
Sum
Active energy in quadrant II
A (QII)
Sum / Phases
Sum
Active energy in quadrant III
A (QIII)
Sum / Phases
Sum
Active energy in quadrant IV
A (QIV)
Sum / Phases
Sum
Active energy import
+A (QI+QIV)
Sum / Phases
Sum
Active energy export
–A (QII+QIII)
Sum / Phases
Sum
Active energy, absolute value
+A+-A
Sum / Phases
Sum
Active energy, absolute value
+A--A
Sum / Phases
Sum
Active energy import summation
Σ +A
Sum
Sum
Active energy export summation
Σ -A
Sum
Sum
Active energy by single quantity
Σ ALx
Sum
Sum
Reactive energy in quadrant I
R (QI)
Sum / Phases
Sum
Reactive energy in quadrant II
R (QII)
Sum / Phases
Sum
Reactive energy in quadrant III
R (QIII)
Sum / Phases
Sum
Reactive energy in quadrant IV
R (QIV)
Sum / Phases
Sum
Reactive energy import
+R (QI+QII)
Sum / Phases
Sum
Reactive energy export
–R (QIII+QIV)
Sum / Phases
Sum
Reactive energy import
+R (QI+QIV)
Sum / Phases
Sum
Reactive energy export
–R (QII+QIII)
Sum / Phases
Sum
Reactive energy, combined
R (QI+QIII)
Sum / Phases
Sum
Reactive energy, combined
R (QII+QIV)
Sum / Phases
Sum
Reactive energy, absolute value
+R+-R
Sum / Phases
Sum
Reactive energy, absolute value
+R--R
Sum / Phases
Sum
Reactive energy import summation
Σ +R
Sum
Sum
Reactive energy export summation
Σ -R
Sum
Sum
Mean value formation