Iskra WM3M4 User manual

User’s Manual
1
Three-phase electrical energy meters for
charging stations
WM3M4 & WM3M4C
October 2020 • Version 1.07

THREE-PHASE ELECTRICAL ENERGY METERS FOR CHARGING STATIONS
ii
User’s Manual WM3M4 &WM3M4C
Three-phase electrical energy meters for charging
stations
WM3M4 & WM3M4C
User and Installation manual

SECURITY ADVICES AND WARNINGS
User’s Manual WM3M4 &WM3M4C
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Security Advices and Warnings
Please read this chapter carefully and examine the equipment carefully for potential damages which might
arise during transport and to become familiar with it before continue to install, energize and work with
the WM3M4 & WM3M4C three-phase energy meters.
This chapter deals with important information and warnings that should be considered for safe installation
and handling with a device in order to assure its correct use and continuous operation.
Everyone using the product should become familiar with the contents of chapter »Security Advices and
Warnings«.
If equipment is used in a manner not specified by the manufacturer, the protection provided by the
equipment may be impaired.
PLEASE NOTE
This booklet contains instructions for installation and use of a three-phase energy meters
WM3M4 & WM3M4C. Installation and use of a device also includes handling with dangerous
currents and voltages therefore should be installed, operated, serviced and maintained by
qualified personnel only. ISKRA Company assumes no responsibility in connection with
installation and use of the product. If there is any doubt regarding installation and use of the
system in which the device is used for measuring or supervision, please contact a person who is
responsible for installation of such system.
Before installing
Check the following before installing:
Nominal voltage.
Terminals integrity.
Protection fuse for voltage inputs (recommended maximum external fuse size is 40 A).
External switch or circuit breaker must be included in the installation for disconnection of the
devices’ power supply. It must be suitably located and properly marked for reliable
disconnection of the device when needed.
Proper connection of communication terminals.

USED SYMBOLS ON DEVICES’HOUSING AND LABELS
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User’s Manual WM3M4 &WM3M4C
Used symbols on devices’ housing
and labels
SYMBOL
EXPLANATION
DANGER
Indicates proximity of hazardous high voltage, which might result in serious injury or
death if not handled with care.
WARNING
Indicates situations where careful reading of this manual is required and following
requested steps to avoid potential injury is advised.
Compliance of the product with directive 2002/96/EC, as first priority, the prevention
of waste electrical and electronic equipment (WEEE), and in addition, the reuse,
recycling and other forms of recovery of such wastes so as to reduce the disposal of
waste. It also seeks to improve the environmental performance of all operators
involved in the life cycle of electrical and electronic equipment.
Compliance of the product with European CE directives.
Disposal
It is strongly recommended that electrical and electronic equipment (WEEE) is not deposit as
municipal waste. The manufacturer or provider shall take waste electrical and electronic equipment
free of charge. The complete procedure after lifetime should comply with the Directive 2002/96/EC
about restriction on the use of certain hazardous substances in electrical and electronic equipment.

User’s Manual
v
Table of contents
1BASIC DESCRIPTION AND OPERATION 1
1.1 DESCRIPTION OF THE DEVICE 2
1.2 HARDWARE DESCRIPTION 3
1.3 MAIN FEATURES 3
2CONNECTION 4
2.1 MOUNTING 5
2.2 ELECTRICAL CONNECTION 6
3FIRST STEPS 8
3.1 DISPLAY OF DEVICE INFO 9
3.2 WELCOME SCREENS 9
3.3 LCD DISPLAY INFORMATION 10
4SETTINGS 13
4.1 INTRODUCTION 14
4.2 MIQEN SOFTWARE 14
4.3 CONNECTION 15
4.4 SETTINGS 17
4.5 MEASUREMENTS 23
5MEASUREMENTS 25
5.1 ONLINE MEASUREMENTS 26
5.2 SELECTION OF AVAILABLE QUANTITIES 27
5.3 CALCULATION AND DISPLAY OF MEASUREMENTS 28

TABLE OF CONTENTS
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User’s Manual WM3M4 &WM3M4C
6DIGITAL SIGNATURE (VALID ONLY FOR WM3M4C) 30
6.1 INTRODUCTION 31
6.2 DIGITAL SIGNING PROCEDURE 31
6.3 ENERGY METER CRYPTOGRAPHIC FUNCTIONS EXPLANATION 32
6.4 CONSUMPTION MEASURING AND DIGITAL SIGNING PROCEDURE 33
6.5 CRYPTO REGISTER DEFINITIONS 33
6.6 POWER LOSS BEHAVIOUR 43
6.7 UNEXPECTED RESET BEHAVIOUR 43
7TECHNICAL DATA 44
7.1 ACCURACY 45
7.2 MECHANICAL CHARACTERISTICS OF INPUT 45
7.3 ELECTRICAL CHARACTERISTICS OF INPUT 46
7.4 SAFETY AND AMBIENT CONDITIONS 47
7.5 EU DIRECTIVES CONFORMITY 48
7.6 DIMENSIONS 49
8ABBREVIATION/GLOSSARY 50

BASIC DESCRIPTION AND OPERATION
User’s Manual WM3M4 &WM3M4C
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1BASIC DESCRIPTION AND OPERATION
The following chapter presents basic information about WM3M4 & WM3M4C three-phase energy
meters required to understand its purpose, applicability and basic features connected to its operation.
In this chapter you will find:
1.1 Description of the device 2
1.2 Hardware description 3
1.3 Main features 3

BASIC DESCRIPTION AND OPERATION
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User’s Manual WM3M4 &WM3M4C
1.1 Description of the device
1.1.1 Functionality of WM3M4 & WM3M4C
The WM3M4 & WM3M4C energy meters are MID certified meters, intended for energy
measurements in the three-phase and single-phase electrical charger stations. The WM3M4C energy
meter features high temperature operation and digital signing for a charging event, whereas WM3M4
features only high temperature operation. Both meters measure energy directly in 4-wire networks
according to the principle of fast sampling of voltage and current signals. A built-in microprocessor
calculates power, energy, current, voltage, power factor, power angle, frequency, harmonics of THD
voltage and THD current harmonics. WM3M4C meter can detect and log events relevant for charging
via RS485 communication. Thus the meter can produce relevant digital signature for charging event.
1.1.2 Appearance
1. RS485 terminals
2. Current terminals –to load
3. LCD display
4. IR COMM PORT –on side
5. QR code (valid only for WM3M4C)
6. DIN-Rail fitting
7. LED indicator (1000 imp/kWh)
8. Current terminal –source (max 40 A)
LCD
Number of digits: 8 (6+2)
Height of digits: 6.52 mm
LED
Colour: red
Pulse rate: 1000 imp/kWh
LED on: no load indication
Figure 1: Appearance of a three-phase electrical energy meter WM3M4C
The energy meters have a built-in optical (IR) communication port on the side as a standard. A special
WM-USB adapter (size 1 DIN module) can easily be attached to it. It can be used for direct
communication with a PC to change settings of devices without any communication installed.
On the housing there are two terminals, A(16) and B(15) for RS485 communication.
Terminals can be sealed with a protective cover to prevent unauthorized access. They are fixed in
accordance with EN 60715.

BASIC DESCRIPTION AND OPERATION
User’s Manual WM3M4 &WM3M4C
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1.2 Hardware description
The whole system of the WM3M4 & WM3M4C energy meters is equipped with the following units:
Stand-alone unit.
Power supply unit.
Process unit (MCU microcontroller) with IR communication, LED display, LCD support, and
EEPROM.
Additional unit for RS485 communication.
Communication:
Every meter is equipped with IR optical communication and RS485 communication. Both
use the MODBUS protocol. It is used for setting and reading a meter with the WM-USB
adapter or RS485 adapter. The WM3M4 & WM3M4C energy meters can also be connected
to SG (smart gateway). It is intended to connect various equipment into the communication
network.
The LED shows the state of active energy. It flashes in proportion to the received active
energy. When there is no load, the LED lights up.
1.3 Main features
3 DIN modules width three-phase direct connected DIN-rail mounting meter.
Class 1 for active energy according to EN 62053-21.
MID approval WM3M4 & WM3M4C for class B according to EN 50470-3.
Reference frequency 50 Hz or 60 Hz.
Maximum current (Imax) 40 A
Basic current 5 A (Ib)
Reference voltage 3x230 V/400 V ().
Voltage operating range (-20 % ... +15 %).
Two row display 6+2 digit (10 Wh resolution) with backlight.
Multifunctional front LED.
IR Serial communication.
RS485 Serial communication.
Measurement of
oPower (active/reactive/apparent for each phase and total)
oEnergy (active - bidirectional).
oVoltage (each phase).
oCurrent (each phase).
oPhase to phase voltage.
oPhase to phase angle.
oFrequency.
oPower factor (each phase and total).
oPower angle (each phase and total).
oTHD of voltage.
oTHD of current.
Crypto engine (Hash, signature) for generation of secure datasets (valid only for WM3M4C).
Possibility to connect as a single phase (on L3).
Remote control for backlight LCD.
Secure data transfer (digital signature) (valid only for WM3M4C).
70°Cambient operation temperature.
Sealable terminal cover.

CONNECTION
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User’s Manual WM3M4 &WM3M4C
2CONNECTION
This chapter deals with the instructions for connection of the WM3M4 & WM3M4C energy meters.
Both the use and connection of the device include handling with dangerous currents and voltages. The
connection shall thus be performed ONLY by a qualified person using appropriate equipment. ISKRA,
d.o.o. does not take any responsibility regarding the use and connection. If any doubt occurs regarding
connection and the use in the system which device is intended for, please contact a person who is
responsible for such installations.
In this chapter you will find:
2.1 Mounting 5
2.2 Electrical connection 6

CONNECTION
User’s Manual WM3M4 &WM3M4C
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2.1 Mounting
The WM3M4 & WM3M4C energy meters are intended for DIN-rail mounting. In the case of using the
stranded wire, the ferrule must be attached before the mounting.
Figure 2: Dimensional drawing and rear connection terminals position

CONNECTION
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User’s Manual WM3M4 &WM3M4C
2.2 Electrical connection
WARNING
Wrong or incomplete connection of voltage or other terminals can cause non-operation or
damage to the device.
The meters are used for direct connection into the four-wire networks or single-phase (L3) operation.
They are also equipped with communication terminals. Pictures below are showing equipped
combination.
Recommended installation:
1Mounting to DIN rail according to DIN EN60715
2Main inputs:
a. Contacts capacity: rigid (flexible) 2.5 mm2… 25 (16) mm2
b. Connection screws: M5
c. Maximum torque: 3.5 Nm (PZ2)
d. Length or removed isolation: 10 mm
3Communication terminals:
a. Contact capacity: 1 mm2 … 2.5 mm2
b. Connection screws: M3
c. Maximum torque: 1.2 Nm (PZ2)
d. Length or removed isolation: 8 mm
PLEASE NOTE
Neutral wire must be connected to the meter.

CONNECTION
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Figure 3: Three - phase connection diagram
Figure 4: Single-phase connection diagram

FIRST STEPS
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User’s Manual WM3M4 &WM3M4C
3FIRST STEPS
Programming WM3M4 & WM3M4C energy meters is very transparent and user-friendly. Numerous
settings are organized in groups according to their functionality.
In this chapter you will find basic programming steps:
3.1 Display of device info 9
3.2 Welcome screens 9
3.3 LCD Display information 10

FIRST STEPS
User’s Manual WM3M4 &WM3M4C
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3.1 Display of device info
Energy meters have LCD display with following layout.
Layout of LCD:
1Total kWh inport
2User settable line
34 digit label
4kWVA display
5kWh display
Figure 5: Layout of LCD
3.2 Welcome screens
LCD segment test
Figure 6: LCD segment test
FW identification window
and MID relevant counters:
1MID unlock counter
2FW upgrade counter
3CRC of main FW
4CRC of measuring
modules FW
5FW version
Figure 7: FW identification window and MID relevant counters

FIRST STEPS
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User’s Manual WM3M4 &WM3M4C
3.3 LCD Display information
LCD Display has 2 rows with 8 digits each and 4 digit label. Display scrolls automatically. Displayed
quantities and scroll time can be set via communication by MiQen software. Top row always displays
imported active energy consumption.
Row 2 is configurable to display following values:
BIT 8
Export active
energy counter
Status:
A-
BIT 7
SW version
Status LCD:
SoF
BIT 6
Serial number
Status LCD:
Sn
BIT 5
Time
Status LCD:
1st digit: Clock status (see Table 5)
Digits 2-4 options:
Loc (Local time), or
Utc (UTC time)
BIT 4
Date
Status LCD:
hh.mm
(time - e.g.: 00 (hour).11 (minutes))
BIT 3
Custom String
Status LCD:
LCD Custom string label (see Table 3);
Available characters (see chapter 3.3.2)
BIT 2
Transaction
number
Status LCD:
tr.no
BIT 1
Duration
Status LCD:
Charging power (e.g.: 3h 13min 42s)
BIT 0
Energy
consumption
Status LCD:
1st digit: Clock status (see Table 5)
2nd digit: Charging status (see Table 6)
3rd digit: Reserved
4th digit: Reserved
Table 1: LCD ROW2 Configuration

FIRST STEPS
User’s Manual WM3M4 &WM3M4C
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Default state is Energy consumption.
If multiple bits are selected, then values are cycling with period defined in MODBUS register 40174.
40174
LCD cycling period
Cycling time in Seconds
Table 2: LCD cycling period
Custom string is defined in register 47063:
47063
LCD Custom string
8 bytes to display on 7-segment LCD (non printable
values are replaced with empty space)
Table 3: LCD Custom string
Custom string has configurable label in register 47064:
47064
LCD Custom string label
4 bytes to display on 7-segment LCD (non printable
values are replaced with empty space)
Table 4: LCD custom string label
Value
Clock status
LCD status
0
Not sync (U)
u
1
Informative clock
i
2
Synchronized clock
S
3
Relative clock
r
Table 5: Clock sync status
Register 47000
Value
Charging Status
LCD status
0
Not charging (Idle)
I
1
Charging
C
2
Charging after power down
P
3
Charging after meter reset
d
Table 6: Charging status

FIRST STEPS
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User’s Manual WM3M4 &WM3M4C
3.3.1 LCD Error display
Errors are displayed on row 2 and have priority over other messages.
Error format is: Err 1234.
Number represents hexadecimal value of 16 bits error state.
Bit 0
Error Parameter CRC
Bit 2
Error MID-lock
Bit 3
Error phase module 1 CheckSum
Bit 4
Error phase module 2 CheckSum
Bit 5
Error phase module 3 CheckSum
Bit 6
Error Measurement module CheckSum
Bit 11
Error phase module 1 cal. data CheckSum
Bit 12
Error phase module 2 cal. data CheckSum
Bit 13
Error phase module 3 cal. data CheckSum
Bit 14
Error Crypto data CheckSum
Bit 15
Error Crypto chip failure
Table 7: Error bits
Example:
Figure 8: Error display
Err 0005 (binary representation: 0000 0000 0000 0101)
BIT0 and BIT2 are set, so we have Parameter CRC Error and MID-lock Error.
In case the meter is in Error state the start of charging process with digital signiture is blocked and the
meter needs to be replaced.
3.3.2 List of available characters on LCD
0,O,1,I,l,2,3,4,5,S,6,G,7,8,9,A,B,b,C,D,d,E,F,H,L,J,N,P,R,U,V,c,h,i,r,n,o,v,u,t,-

SETTINGS
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4SETTINGS
Settings of the WM3M4 & WM3M4C energy meters can be done via MiQen software. A setting
structure, which is similar to a file structure in an explorer, is displayed in the left part of the MiQen
setting window. Available settings of that segment are displayed in the right part by clicking any of the
stated parameters.
In this chapter, you will find a detailed description of all WM3M4 & WM3M4C energy meters features
and settings. The chapter is organized in a way to follow settings organization as in setting software
MiQen.
4.1 Introduction 14
4.2 MiQen software 14
4.3 Connection 15
4.4 Settings 17
4.5 Measurements 23

SETTINGS
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User’s Manual WM3M4 &WM3M4C
4.1 Introduction
Parameterization can be modified by serial communication (RS485) or by a special WM-USB adapter
(size 1 DIN module) and MiQen software version.
4.2 MiQen software
MiQen software is a tool for complete programming and monitoring of ISKRA measuring instruments,
connected to a PC via serial communication or by a special WM-USB adapter. A user-friendly interface
consists of six segments: devices management (Connection), instrument settings (Settings), real-time
measurements (Measurements), data analysis (Analysis), saved preffered devices (My Devices –this
action is not supported by this meter) and software upgrading (Upgrades –this action is not supported
by this meter). These segments are easily accessed utilizing icons on the left side (see Figure 6).
Figure 9: MiQen programming and monitoring software
For further managing those segments, icons on the top bar can be utilised.:
-READ SETTINGS : displays all device’s settings
-READ MEMORY : data is read directly from a device’s internal memory
-OPEN : data is read from a local database
-DOWNLOAD SETTINGS : changes should be confirmed by pressing this button when
finished programming
-SAVE : the file settings will be saved
-EXPORT : data can be exported to an Access data base, Excel worksheets or as a text file
-PRINT : data listing can be exported into PDF file or printed on a paper