Iskra WM3x6 Series Operating manual

User’s Manual
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Energy meters WM3x6
Three-phase electrical energy meter WM3-6
Three-phase electrical energy meter WM3M6
November 2018 • Version 1.01

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User’s Manual
Three-phase electrical energy meter
WM3x6
User and Installation manual

User’s Manual
iii
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 a
three-phase energy meter WM3x6.
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 three-phase energy meter WM3x6.
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.
Beforeswitchingthedevice ON
Check the following before switching on the device:
Nominal voltage.
Terminals integrity.
Protection fuse for voltage inputs (recommended maximal external fuse size is 65 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 and voltage level of I/O module.

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User’s Manual
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.

BASIC DESCRIPTION AND OPERATION
User’s Manual
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Table of contents
1BASIC DESCRIPTION AND OPERATION 1
1.1 DESCRIPTION OF THE DEVICE 2
1.2 THREE-PHASE ENERGY METERS APPLICATION 3
1.3 MAIN FEATURES 3
2CONNECTION 4
2.1 MOUNTING 5
2.2 ELECTRICAL CONNECTION 6
3FIRST STEPS 10
3.1 INDIVIDUAL PHASE MEASUREMENT UNIT 11
3.2 DISPLAY OF DEVICE INFO 12
3.3 SOFTWARE FUNCTIONS 13
3.4 LCD USER INTERFACE 14
3.5 LIMITS 24
3.6 FREEZE COUNTERS 29
4SETTINGS 31
4.1 INTRODUCTION 32
4.2 MIQEN SOFTWARE 32
5TECHNICAL DATA 39
5.1 ACCURACY 40
5.2 MECHANICAL CHARACTERISTICS OF INPUT 41
5.3 ELECTRICAL CHARACTERISTICS OF INPUT 41
5.4 SAFETY AND AMBIENT CONDITIONS 43
5.5 EU DIRECTIVES CONFORMITY 44
5.6 DIMENSIONS 44
6ABBREVIATION/GLOSSARY 45
7APPENDICES 46
7.1 APPENDIX A: MODBUS COMMUNICATION PROTOCOL 46
7.2 APPENDIX B: M-BUS 60

BASIC DESCRIPTION AND OPERATION
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1BASIC DESCRIPTION AND OPERATION
The following chapter presents basic information about a three-phase energy meter WM3x6 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 THREE-PHASE ENERGY METERS APPLICATION 3
1.3 MAIN FEATURES 3

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1.1 Description of the device
The three-phase energy meters WM3-6, WM3M6 (MID certified) are intended for energy
measurements in three-phase electrical power network and can be used in residential, industrial and
utility applications. 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 active/reactive/apparent
power and energy, current, voltage, frequency, power factor, power angle and frequency (for each
phase and total sum) from the measured signals. This smart meter can also perform basic harmonic
analysis (THDU, THDI). This enables quick overview of harmonic distortion either coming from a network
or generated by the load. Microprocessor also controls LCD, LED, IR communication and optional
extensions.
Connecting terminals can be sealed up against non-authorised access with protection covers. They are
built to be fastened according to EN 60715 standard.
1.1.1 Appearance
Figure 1: Appearance of three-phase electric energy meter WM3x6
1Current terminals –to load
2AUX terminals (options):
-RS485
-M-BUS
-PULSE OUTPUT
-TARIFF INPUT
3IR COMM PORT –ON SIDE
4Information display
5DIN-Rail fitting
6User button and LED
indicator (1000 imp/kWh)
7Current terminal –source
(max 65 A)
LCD
Number of digits: 8 (7+1)
Height of digits: 4.52 mm
LED
Colour: red
Pulse rate: 1000 imp/kWh
LED on: no load indication
1
2
3
4
6
2
7
5

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1.2 Three-phase energy meters application
Energy meters have built-in optical (IR) communication port on the side as a standard. 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.
Energy meters could also be connected with iHUB-L1 or Bicom by optical communication (IR).
Optional the meter can be equipped with the following communications:
RS485 serial communication with the MODBUS protocol,
M-BUS serial communication,
Communication modules enables data transmission and thus connection of the measuring places into
the network for the control and management with energy.
Instead of communication modules, there can be also tariff input (option) or built-in pulse output
(option).
Tariff input provides measurement of two tariffs for selected energy registers.
Pulse output is sending data to the devices for checking and monitoring consumed energy.
On the housing there are only two terminals, thus only one functional extension is possible (serial
communication, tariff input, pulse output).
1.3 Main features
Three-phase direct connected DIN-rail mounting meters up to maximum current (Imax) 65 A.
Basic current (Ib) 5 A.
MID approval (option for WM3M6).
Class 1 for active energy according to EN 62053-21 and Baccording to EN 50470-3 .
Class 2 for reactive energy according to EN 62053-23.
Reference frequency 50 Hz and 60 Hz.
Bidirectional energy measurement (import/export).
Reference voltage 3x230 V/400 V ().
Voltage operating range (-20 % ... +15 %).
Pulse output according to EN 62053-31 (option).
Tariff input (option).
RS485 serial communication (option).
M-BUS serial communication (option).
Display LCD 7+1 digit (100 Wh resolution).
Multifunctional front LED.
LED constant 1000 imp/kWh.
Built-in optical (IR) communication port.
Measurement of
opower (active, reactive, apparent) and energy (each phase and total).
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).
oActive tariff (option).
3-DIN rail width mounting according to EN 60715.
Sealable terminal cover.
THD of voltage and THD of current.

CONNECTION
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2CONNECTION
This chapter deals with the instructions for three-phase electrical energy meter WM3x6 connection.
Both the use and connection of the device includes handling with dangerous currents and voltages.
Connection shall therefore be performed ONLY a by a qualified person using an appropriate equipment.
ISKRA, d.d. does not take any responsibility regarding the use and connection. If any doubt occurs
regarding connection and 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

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2.1 Mounting
Threee-phase electrical energy meter WM3x6 is intended only for panel mounting. Pluggable
connection terminals allow easier installation and quick replacement should that be required.
This device is not intended for usage as portable equipment and should be used only as a fixed panel
mounted device.
Figure 2: Dimensional drawing and rear connection terminals position

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Figure 3: Neutral
connection of energy
meters
2.2 Electrical connection
WARNING
Wrong or incomplete connection of voltage or other terminals can cause non-operation or
damage to the device.
Meter is used for direct connection into the four-wire networks. Meter can be equipped with different
modules. Pictures below are showing equipped combinations.
Recommended installation:
1Mounting to DIN rail according to DIN EN60715
2Power contacts:
a. Power contacts capacity 2.5 mm2 –16 mm2
b. Connection screws M5
c. Max torque 3.5 Nm
3Auxiliary terminals:
a. Auxiliary terminals contact capacity 1 mm2–2.5 mm2
b. Auxiliary terminals screws M3
c. Max torque 1.2 Nm
PLEASE NOTE
Neutral wire must be connected to the meter.

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Figure 4: Connection
diagram for M-BUS
option
Figure 5: Connection
diagram for pulse
output option
Figure 6: Connection
diagram for tariff input
option

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Figure 7: Connection
diagram for RS485
Complete WM3x6 system is assembled with three main units and optionally communication unit:
Individual phase measurement unit.
Power supply unit (based on configuration).
Processing unit (MCU) with IR communication, LED indicator, LCD support and EEPROM.
Optionally available different communication units or extension modules (RS485, M-BUS,
TARIFF, PULSE).
2.2.1 Communication connection
For communication with outside world multiple manners are used:
IR communication module using MODBUS protocol is equipped on each meter. It can be used
for setting and testing the meter using WM-USB adapter.
Pulse output (option) module is used for counting number of pulses depending on consumed
energy.
Tariff input (option) module is used to set active tariff.
LED diode is used for indication of no-load condition and test output proportional to measured
active energy. It can be also switched to reactive energy for test purpose using IR
communication.
RS485 (option) communication module is galvanic isolated form meter. It enables setting the
meter, data readout in the network and tariff setting.
M-BUS (option) communication module is galvanic isolated form meter. It enables setting the
meter, data readout in the network and tariff setting.
Push button is used to select display of desired measured or group of them.

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Table 1: Survey of
communication
connection
Auxiliary terminal
15
16
M-Bus
M-
M+
Pulse output
SO-
SO+
Tariff input
AC2
AC1
RS485*
B
A
*It is recommended to use ferrite bead on
communication line RS485 (two turns) to reduce
radiated emission.
PLEASE NOTE
Check labels on the side of the meter to check what modules are built in.
Auxiliary terminal
15
16
Digital input
X
L (switch)
Digital output
N (latching switch)
X
PLEASE NOTE
The digital input connects the phase via the switch. Through the digital output, the latching
switch gets connected to a neutral wire. The switch is only active when the latching switch is
off.

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3FIRST STEPS
Programming a three-phase electrical energy meter WM3x6 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 INDIVIDUAL PHASE MEASUREMENT UNIT 11
3.2 DISPLAY OF DEVICE INFO 12
3.3 SOFTWARE FUNCTIONS 13
3.4 LCD USER INTERFACE 14
3.5 LIMITS 24
3.6 FREEZE COUNTERS 29

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3.1 Individual phase measurement unit
The microprocessor is used to process the voltage and current samples from the AD converter. It
calculates the RMS voltage, RMS current, active and reactive power, U-I phase angle, first harmonic of
voltage, first harmonic of current, the DC voltage, DC current, peak to peak voltage, peak to peak
current, THD of voltage and THD of current. The internal temperature and supply voltage is measured
also.
Metering functions are done with the processing unit. There are four different energy counters, which
can be configured each to measure one of seven different types of energy. For MID meters, this energy
counters are configured only in production. For Non-MID counters they can be also reconfigured during
use. These are:
Total Absolute Active Energy (kWh)
Total Absolute Reactive Energy (kvarh)
Total Absolute Apparent Energy (kVAh)
Import Active Energy (kWh)
Export Active Energy (kWh)
Import Reactive Energy (kvarh)
Export Reactive Energy (kvarh)
The energy register is a count of pulses. The number of CE units per pulse is a constant in the meter
calibration data. Function add () adds the current interval’s power data to a “remainder” variable. If this
variable is larger than one pulse, then the number of pulses is added to the energy register, and
remainder variable is decreased by the number of CE units that represent the same amount of energy.
Measuring values are averaged within 1 second and displayed on the LCD at the same interval.
Parameters which can be shown are:
1Energy registers:
I. Energy counter 1 (mandatory)
II. Energy counter 2
III. Energy counter 3
IV. Energy counter 4
2Actual measured values:
I. Active Power, total, ph1, ph2, ph3
II. Reactive Power, total, ph1, ph2, ph3
III. Apparent Power total, ph1, ph2, ph3
IV. Power Factor, total, ph1, ph2, ph3
V. Voltages U1, U2, U3
VI. Phase to phase voltages U12, U13, U23
VII. Frequency
VIII. Current I1, I2, I3
IX. Power Angle total
Parameter cycling period is settable from 5 seconds to 60 seconds. Cycling period and the definition of
parameters for LCD scrolling are configured via RS485 or IR communication.

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For MID approved meters only active energy is approved –non resettable counters. The approved active
energy counters are coded with the following codes:
1110 –Import Active Power, Tariff 1
1120 –Import Active Power, Tariff 2
1130 –Import Active Power, Tariff 1&2
1210 –Export Active Power, Tariff 1
1220 –Export Active Power, Tariff 2
1230 –Export Active Power, Tariff 1&2
1310 –Total Active Power, Tariff 1
1320 –Total Active Power, Tariff 2
1330 –Total Active Power, Tariff 1&2
Import/export is defined on the basis of sum of phase powers P1 + P2 + P3. If the sum of phase powers
is positive, import register counts, if the sum of phase powers is negative, export register counts.
3.2 Display of device info
Energy meters have LCD display with following layout.
1Tariff setting for displayed counter / actual tariff
2(→) Energy import/active power import
(←) Energy export/active power export
3kWh display
4kvarh display
5Actual Value
6Info:
VAh display
PF –power factor
VA –apparent power
PA –power angle
Four numbers - Code of MID approved energy
counter.
7A –currently active counter, nr –non resettable
counter or r –resettable counter
8W –active power
var –reactive power
9Inductive or capacitive load
10 Active phase display
Figure 8: Layout of LCD
Energy counter displays (up to 4 counters) are displaying current energy counter settings (tariff,
import/export/total, active/reactive/apparent), its value and actual activity (counting (A)/not counting
( )).
Other displays are displaying actual value of measured quantity (P-W, Q-var, S, PF, U, f and I), direction
of active energy flow (import / export), reactance (inductive / capacitive) and active tariff (regarding
tariff input).
Energy registers are displayed with resolution 7 + 1 (kWh, kvarh and kVAh). The meter can be set to
Test measuring mode which displays energy registers with better resolution. The test mode is used for
test purposes during type testing and test of meter constant during initial verification. After power off
meter automatically goes back to normal operation.

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Test output is provided as LED with number of impulses proportional to active energy. Pulse constant is
1000 imp/kWh. Optionally the S0 impulse output with the same constant can be used for active energy.
Pulse output is defined to be (32 ± 2) ms long according EN 62053-31.
Energy measurement is blocked for the currents less than 20 mA. The meter measures actual voltage
and frequency. Current and power values are set to zero and there is no energy registration. No load
condition is indicated with the LED on.
If the supply voltage is too low, the energy measurements are also blocked and communication is
disabled. LCD stops to cycle and displays only value of voltage.
3.3 Software functions
Identification –SW version can be read from LCD or using RS485 or IR communication. The check sum
(CRC) of complete firmware is calculated and displayed during initialization and later it can be read from
LCD Info menu or MODBUS registers. If CRC for code is changed and does not correspond to the initial
CRC an ERROR is detected during startup and ERR 2 is shown on the LCD. This is checked after every
restart of the meter.
MID SW is separated from non MID SW –MID versions are 2.xx as non MID versions are 1.xx.
The MID version uses a MID key that prevents the upgrade of software and modification of parameters
related to energy measurement. Unlocking the key is possible only at special operating conditions which
do not appear on the field. In case the MID meter is not locked the ERR 4 is shown on the LCD. The MID
SW version counts the number of times the instrument was MID unlocked and the number could be
read from the LCD ( 5.8.1.3 LCD Info menu).
Calibration parameters can only be changed in production. They cannot be changed by upgrade or
different processes. Special factory software is used to calibrate the parameters for current, voltage,
phase angle and linearity. If these parameters were deliberately or accidentally changed, an error type
1 is detected and ERR 1 is shown on the LCD. Calibration parameters are checked every minute for
consistency and if error is found, ERR 1 is immediately shown on LCD. It is possible to upgrade the
firmware via factory software protocol. This option is available only for WM3-6 (non MID) type of meter.
The number of upgrade is counted and it could be read from the LCD ( 5.8.1.3 LCD Info menu).
There is an option for a password to protect the instrument. Password has four levels of protection.
Meter has possibility of two level user defined password (4 characters from A to Z).
Password Level 1 –enables resetting the counters (MID and non MID meters) and tariff setting (non
MID meters).
Password Level 2 –enables all available settings and resets.
If meter password is forgotten, device serial number should be sent to Iskra, d.d. to receive device
default password.
WM3-6 supports MODBUS protocol. RTU mode is used. RTU messages start and end with a silent
interval of at least 3,5 character times (t1-t2-t3-t4 as shown below). Each message is transmitted in a
continuous stream. If a silent interval of more than 1.5 character times occurs before completion of the
frame, the device flushes the incomplete message and assumes that the next byte will be the address
field of a new message. Cyclic Redundancy Check (CRC) is used.
All parameterization is done via communication with MiQen software (version 2.1 or later). WM3M6
(MID) has limited parameterization. Counter and tariff settings are not enabled. If these settings or any
measuring relevant parameters on WM3M6 (MID) were tenaciously or accidentally changed, an error
type 1 is detected and ERR 1 is shown on the LCD. Settings are checked every minute for consistency
and if error is found, ERR 1 is immediately shown on LCD.
Firmware allows also user defined parameterization software using MODBUS protocol with specified
MODBUS registers.

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3.4 LCD User Interface
The LCD display allows displaying the following measurement values:
1Four Energy registers:
I. Energy counter 1 (mandatory)
II. Energy counter 2
III. Energy counter 3
IV. Energy counter 4
2Actual measured values:
I. Active Power, total, ph1, ph2, ph3
II. Reactive Power, total, ph1, ph2, ph3
III. Apparent Power total, ph1, ph2, ph3
IV. Power Factor, total, ph1, ph2, ph3
V. Voltages U1, U2, U3
VI. Phase to phase voltages U12, U13, U23
VII. Frequency
VIII. Current I1, I2, I3
IX. Power Angle total
The measured values can be scrolled automatically or can be selected by pressing button.