Panasonic KW2M-A User manual

WUME-KW2MAX-0207/2016
Eco POWER METER
KW2M-A/KW2M-X
User’s Manual

Cautions for Your Safety
Read the manual carefully before installing, running and maintenance for proper operation.
Before using, master the knowledge of the equipment, safety information and all of other
notes.
This manual uses two safety flags to indicate different levels of danger.
WARNING
A handling error could cause serious physical injury to an
operator and in the worst case could even be fatal.
●Apply appropriate personal protective equipment (PPE) and follow safe electrical work
practices. In the USA, see NFPA 70E.
●Always take precautions to ensure the overall safety of your system, so that the whole
system remains safe in the event of failure of this product or other external factor.
●Do not use this product in areas with inflammable gas. It could lead to an explosion.
●Exposing this product to excessive heat or open flames could cause damage to the
lithium battery or other electronic parts.
●Do not open the secondary side of CT during power on the primary side current.
It might cause electric shock or CT breakdown.
CAUTION
A handling error could cause serious physical injury to an operator
or damage to the equipment.
●To prevent abnormal exothermic heat or smoke generation, use this product at the
values less than the maximum of the characteristics and performance that are assured in
these specifications.
●Do not dismantle or remodel the product. It could lead to abnormal exothermic heat or
smoke generation.
●Do not touch the terminal while turning on electricity. It could lead to an electric shock.
●Use the external devices to function the emergency stop and interlock circuit.
●Connect the wires or connectors securely. The loose connection might cause abnormal
exothermic heat or smoke generation.
●Do not allow foreign matters such as liquid, flammable materials, metals to go into the
inside of the product. It might cause exothermic heat or smoke generation.
●Do not undertake construction (such as connection and disconnection) while the power
supply is on.
●Never remove the terminal block under applying current to load.
It might cause electric shock or CT breakdown.
●Do not use at secondary side circuit of inverter. It might cause exothermic heat or
damage.
Copyright and trademark
●Panasonic Industrial Devices SUNX Co., Ltd. owns the copyright of this manual.
●We stiffly refuse the reproduction of without permission from this manual.
●Modbus Protocol is a communication protocol that the Modicon Inc. developed for PLC
and Modbus is the registered trademark of Schneider Electric.
●Other company names and the product names are the trademarks or registered
trademarks of each company.

Introduction
Thank you very much indeed for purchasing the KW2M-A
Eco-POWER METER.
In this manual, we explain the usage of KW2M-A
Eco-POWER METER in detail.

Inhaltsverzeichnis
KW2M-A/X User's Manual 1
Table of Contents
Table of Contents.....................................................................................................................................1
Chapter 1 Cautions before using..............................................................................................................3
Chapter 2 Introduction..............................................................................................................................6
2.1 Model number.......................................................................................................................................... 6
2.2 Measurement specifications.................................................................................................................... 6
2.3 Measurement values ............................................................................................................................... 7
Chapter 3 Part description........................................................................................................................9
3.1 Parts Names............................................................................................................................................ 9
3.2 Key functions ........................................................................................................................................... 9
Chapter 4 Wiring ....................................................................................................................................10
4.1 Main unit terminal arrangement............................................................................................................. 10
4.2 Measured circuit..................................................................................................................................... 11
4.3 Connection expansion units to the main unit......................................................................................... 12
4.4 Wiring Diagrams .................................................................................................................................... 13
4.5 How to attach the Current Transformer (CT)......................................................................................... 15
4.6 For Input Connection ............................................................................................................................. 17
4.7 For Output Connection .......................................................................................................................... 17
4.8 RS485 Communication.......................................................................................................................... 18
4.9 Low Voltage Directive............................................................................................................................ 19
4.10 Symbol List .......................................................................................................................................... 20
Chapter 5 Settings..................................................................................................................................21
5.1 Setting Flow........................................................................................................................................... 25
5.2 Password entry...................................................................................................................................... 27
5.3 Password initialize ................................................................................................................................. 28
5.4 How to make settings using the keys .................................................................................................... 29
5.4.1 Settings for power measurement................................................................................................. 29
5.4.2 Settings for communication (RS485) ........................................................................................... 30
5.4.3 Settings for communication (Ethernet)......................................................................................... 32
5.4.4 Settings for optional functions...................................................................................................... 34
5.4.5 Password setting.......................................................................................................................... 37
5.4.6 Confirmation window.................................................................................................................... 38
5.5 How to set up the device by web browser............................................................................................. 39
5.5.1 Overview of tabs with setting items.............................................................................................. 39
5.5.2 Settings for Power Measurement................................................................................................. 40
5.5.3 Settings for Demand and Power Rates........................................................................................ 42
5.5.4 Settings for Pulse Input................................................................................................................ 44
5.5.5 Settings for Pulse Output ............................................................................................................. 45
5.5.6 Settings for Ethernet and RS485 communication........................................................................ 48
5.5.7 System setup................................................................................................................................ 50
Chapter 6 Miscellaneous functions.........................................................................................................52
6.1 Power quality measurement and logging function................................................................................. 52
6.2 Pulse output function............................................................................................................................. 52
6.2.1 Output depends on integral electric power................................................................................... 52
6.2.2 Stand-by alarm............................................................................................................................. 52
6.2.3 Under voltage alarm..................................................................................................................... 52
6.2.4 Over voltage alarm....................................................................................................................... 52
6.2.5 Power interruption alarm.............................................................................................................. 52
6.2.6 Under current alarm ..................................................................................................................... 52
6.2.7 Current alarm ............................................................................................................................... 52
6.2.8 Power alarm................................................................................................................................. 53
6.2.9 Other alarms................................................................................................................................. 53
6.2.10 Output depends on count value................................................................................................. 53
6.2.11 Level output................................................................................................................................ 53
6.3 Counter function..................................................................................................................................... 53
6.4 Demand function.................................................................................................................................... 54
6.4.1 Block interval demand.................................................................................................................. 54
6.4.2 Current Demand........................................................................................................................... 55
6.4.3 Max. demand value...................................................................................................................... 55
6.4.4 Demand alarm output................................................................................................................... 55
6.4.5 Behavior during power failure and recovery................................................................................. 55

Inhaltsverzeichnis
2 KW2M-A/X User's Manual
Chapter 7 Display of values....................................................................................................................56
7.1 Changing the monitor display................................................................................................................ 56
7.2 Changing the monitor display................................................................................................................ 57
7.2.1 Single-phase two-wire system ..................................................................................................... 57
7.2.2 Single-phase three-wire system................................................................................................... 59
7.2.3 Three-phase three-wire system ................................................................................................... 61
7.2.4 Three-phase four-wire system ..................................................................................................... 63
7.2.5 Instantaneous power.................................................................................................................... 65
7.2.6 Total integral power...................................................................................................................... 66
7.2.7 Total integral export power........................................................................................................... 66
7.2.8 Current.......................................................................................................................................... 67
7.2.9 Voltage ......................................................................................................................................... 67
7.2.10 Power factor............................................................................................................................... 68
7.2.11 Frequency .................................................................................................................................. 68
7.2.12 Current unbalancing................................................................................................................... 68
7.2.13 Voltage unbalancing................................................................................................................... 68
7.2.14 Current THD............................................................................................................................... 69
7.2.15 Voltage THD............................................................................................................................... 69
7.2.16 Current n-order Harmonics......................................................................................................... 69
7.2.17 Voltage n-order Harmonics ........................................................................................................ 69
7.2.18 Pulse input value........................................................................................................................ 70
7.2.19 Conversion value for integral active power................................................................................ 70
7.2.20 Conversion value for integral export power................................................................................ 71
7.3 Logging Mode........................................................................................................................................ 72
7.3.1 Max. demand value...................................................................................................................... 72
7.4 Demand Mode ....................................................................................................................................... 73
7.4.1 Block Interval Demand (sliding block、fixed block)....................................................................... 73
Chapter 8 Monitoring measured values via Web browser (Monitor Web) ..............................................75
Chapter 9 Creating web contents (Customer Web)................................................................................76
9.1 How to upload web contents to the device............................................................................................ 77
9.2 How to download web contents from the device................................................................................... 78
Chapter 10 How to update the firmware.................................................................................................80
Chapter 11 Specifications.......................................................................................................................82
11.1 General specifications ( main unit and expansion unit)....................................................................... 82
11.2 Measurement Specifications................................................................................................................ 83
11.3 Output Specifications (main unit only)................................................................................................. 84
11.4 Input Specifications (main unit only).................................................................................................... 85
11.5 Demand monitor and control specifications......................................................................................... 86
11.6 Communication Specifications............................................................................................................. 86
11.7 Self-diagnostics and troubleshooting................................................................................................... 87
Chapter 12 Dimensions..........................................................................................................................88
12.1 Main unit .............................................................................................................................................. 88
12.2 Expansion unit ..................................................................................................................................... 88
Revision History .....................................................................................................................................89

Cautions before using
KW2M-A/X User's Manual 3
Chapter 1 Cautions before using
■About this product
Eco-POWER METER is designed chiefly to manage saving energy.
It cannot be legally used for billing.
■Installation environment
◇Do not use the unit in the following environments.
・Where the unit will be exposed to direct sunlight and where the ambient temperature is outside
the range of -10 to 50C.
・Where the ambient humidity is outside the range of 30 to 85% RH (at 20°C), non-condensing and
where condensation might occur by sudden temperature changes
・Where inflammable or corrosive gas might be produced
・Where the unit will be exposed to excessive airborne dust or metal particles
・Where the unit will be exposed to water, oil or chemicals
・Where organic solvents such as benzene, paint thinner, alcohol, or strong alkaline solutions such
as ammonia or caustic soda might adhere to the product
・Where direct vibration or shock might be transmitted to the product, and where water might wet
the product
・Where the place near high-voltage cable, high-voltage device, power line, power device.
・Where the place near a machinery with transmission function such as amateur radio.
・Where the place near a machinery which occurs the big switching serge
◇Please use the Unit according to the specifications described in this manual. Otherwise, it may
malfunction or cause fire and an electric shock.
・Connect to the power supply in compliance with the rating.
・Refer to the wiring diagram to ensure proper wiring for the power supply, input and output.
・Use the wire that conforms to the rated current.
・Do not perform wiring or installation with a live line. It may also lead to circuit burnout or fire by
way of the secondary CT side opening.
■Installation
・Eco-POWER METER is designed to be used in a control panel.
・If the additional noise effects the power supply line, incorrect measurements may result.
・Installation and wiring must be performed by expert personnel for electrical work or electric
piping.
・Do not add an excess power to the display. It might break the inner liquid crystal.
・Although the case is made from fireproof resin, do not mount it next to flammable materials. Also,
avoid placing it directly on top of materials that catch fire easily.
・If the operating power supply surge exceeds the following value, the internal circuit could be
destroyed, so be sure to use a surge absorption element.
Surge voltage
6,000V
Surge wave form
Standard surge waveform
The above value is the surge-voltage
resistance at ± (1.2/50)μs of
single-polarity full-wave voltage.
[± (1.2/50) μs single-polarity full-wave voltage]

Cautions before using
4 KW2M-A/X User's Manual
・External noise up to the level shown below is treated as noise voltage, but levels higher than this
could lead to malfunctioning or damage to the internal circuit. Although the case is made from
fireproof resin, do not mount it next to flammable materials.
Between operating power supply terminals
Noise voltage
1,500V
Noise wave form (noise simulator)
Rise time: Pulse width: 1μs, 50ns
Polarity: Cycle: 10ms
Note) Accurate measurement may not be possible if excessive noise gets added to the input line.
･This product is designed to be used only with our options.
Options from other companies are not compatible.
■Measurement accuracy
･If there is some distortion by harmonic or waveform, it may not measure correctly.
Please check with the actual system before adopts it.
・It might not measure an instantaneous current such as an inrush current or an welding machine.
・When measuring the below loads, it might not satisfy with the accuracy guarantee: Out of rating
current, load with low power factor, load with winding current, load with ferromagnetic field
・Power factor operation is a method assuming balanced load. The error might be big when it
measures unbalanced load.
・If the voltage to be measured is not the rated frequency (commercial frequency), it may take time
to stabilize THD (total harmonic distortion).
■Static electricity
・Discharge static electricity touching the grounded metal etc. when you touch the unit.
・Excessive static electricity might be generated especially in a dry place.
■Cleaning
・Wipe dirt of the main unit with soft cloth etc. When thinner is used, the unit might deform or be
discolored.
■Power supply
・Connect a breaker to the voltage input part for safety reasons and to protect the device.
The breaker that connects to the voltage input part must arrange at the position easily reached,
and display shows it is the breaker of the equipment.
・Do not turn on the power supply or input until all wiring is completed.
■Before power on
Please note the following points when turning on power at the first time.
・Confirm there are neither wiring rubbish nor especially an electrical conduction when installed.
・Confirm neither the power supply wiring, the I/O wiring nor the power-supply voltage are wrong.
・Tighten the installation screw and the terminal screw surely.
・Use an electric wire applicable to the rated current.
■Before change the setup
Set the password carefully.
In order to avoid unexpected change the settings, it can set password. However, if you forget the
password you can’t change the settings.
We recommend you to note the password when you set and change the password.

Cautions before using
KW2M-A/X User's Manual 5
■Precautions on using networks
This product supports various network connections therefore it is likely to be subject to the following security
risks.
1. Leakage and outflow of information via this product
2. Illegal operation by third party with malicious acts
3. Interference and shut down by third party with malicious acts
It is recommended to take network security measures such as below for protecting against these risks under
your responsibility.
・Use this product on the network that has been ensuring safety by using firewall
・Check and extermination against the infection of computer viruses and unauthorized program are you
make sure that you have performed regularly
・To protect against unauthorized attacks, set the user name and password, and to limit the users who
can log in.
・Restrict access by user authentication so that authentication information (user name, password) and
network configuration information and equipment inside information is not leak on the network.
・Before you access this product via browser, close other windows.
・After you access this product via browser, close all browsers.
・Change password regularly.
・Do not install the place where it can be disassembled or remodeled easily.
We do not accept liability for the following cases.
1) Guarantee for any kind of damages to the things/products, caused by physical defects of the product.
2) When the other conditions than the ones specified in these specifications exist for handling, storage
and transportation of the product after the delivery.
3) When damage is caused by the unpredictable phenomena with the technique that was practiced
before the product delivery.
4) When damage is caused by natural disasters such as an earthquake, flood, fire, war and artificial
disasters.
5) When necessary countermeasures are not taken to establish a system despite the precautions
described in this specifications.

Introduction
6 KW2M-A/X User's Manual
Chapter 2 Introduction
With the KW2M-A Eco-POWER METER, electrical power (voltage, current, etc.), power factor,
frequency, etc. are measured using AC voltage and AC current input via one of the following systems:
single-phase two-wire system, single-phase three-wire system, three-phase three-wire system or
three-phase four-wire system.
In addition, the KW2M-A measures harmonics and THD for power quality measurement.
By connecting the expansion unit to the main unit you can measure up to 8 circuits (up to 24 circuits of
single-phase 2-wire system). One unit can measure 2-circuits.
■Eco-POWER METER is designed chiefly to manage and help save energy. It is neither intended
nor can it be legally used for billing.
2.1 Model number
Model name
Model number
KW2M-A Eco-POWER METER main unit
AKW263100A
KW2M-A Eco-POWER METER expansion unit
(power measurement)
AKW272100A
* It is not possible to take measurement with only the expansion unit. Every expansion unit must be
connected to a main unit.
2.2 Measurement specifications
Phase/Wire system
Single-phase two-wire
Single-phase three-wire
Three-phase three wire
Three-phase four-wire
(1P2W)
(1P3W)
(3P3W)
(3P4W)
(common)
Applicable power system
100V system, 200V system, 400V system
Measurement circuit
Main unit
1-system 2-circuit
(when measuring 1P2W: 1-system 6-circuit)
Expansion unit
1-system 2-circuit
(when measuring 1P2W: 1-system 6-circuit)
Input measurement voltage
0 to 690V AC *0 to 300V for UL61010-1
Input measurement current
1 to 65,535A
Applicable current sensor
Secondary side output: 1A or 5A

Introduction
KW2M-A/X User's Manual 7
2.3 Measurement values
Item
Unit
Display data range (see note)
Instantaneous
power
Active
W
-999.99G to 999.99G
Present value
Max. value
Min. value
Reactive
var
Apparent
VA
Total integral
power
(import)
Active
Wh
0.000k to 9999.9P
Present value
Reactive
varh
Apparent
VAh
Total integral
power
(export)
Active
Wh
0.000k to 9999.9P
Present value
Reactive
varh
Current
A
0.000 to 99.999k
Present value
Max. value
Min. value
Voltage
V
0.00 to 999.99k
Power factor
-1.000 to 0.000 to 1.000
Frequency
Hz
0.00 to 99.99
Pulse count value
0.000 to 99999999
Present value
Power conversion value
0.000 to 99999999
Present value
Note: The heading “Display data range”refers to the range than can be shown on the main unit display.
It does not refer to the range of values that can be measured.
・Power Quality
Item
Display data range
Unbalanced current
Each phase
0.00 to 300.00%
Present value
Max. value
Min. value
Unbalanced voltage
Each phase
Current THD
(total harmonic distortion)
Each phase
0.00 to 400.00%
Present value
Voltage THD
(total harmonic distortion)
Each phase
Current harmonics
(2nd to 31st )
Each phase
Voltage harmonics
(2nd to 31st )
Phase
Line
Hour meter
ON-time
0.0 to 99999.9 h
OFF-time
Stand-by time
Maintenance time
Note: If the voltage to be measured is not the rated frequency (commercial frequency), it may take time
to stabilize the THD (total harmonic distortion).

Introduction
8 KW2M-A/X User's Manual
・Demand
Item
Unit
Display data range
Present demand *1
Active
W
0.000k to 999.9M
Present value
Max. demand
Reactive
var
Apparent
VA
Active (export)
W
Reactive (export)
var
Current
A
Note: Please use this demand function as your standard. The demand value calculated with this function
is not guaranteed.
<Glossary>
The following term definitions apply:
THD
(total harmonic
distortion)
Ratio of harmonic distortion (voltage or current) to the fundamental frequency. The
lower the value, the less distortion.
Harmonics
Sinusoidal wave other than the fundamental frequency. Its frequency is a
whole-number multiple of the fundamental frequency. The frequency that has 2
times frequency (half wavelength) is called 2nd-order harmonics.
Voltage
unbalancing
The difference between all phases minus voltage due to the load unbalancing.
It is calculated as shown below.
|Max. (Min.) voltage of all phases－average voltage|
x 100 (%)
Average voltage
Current
unbalancing
The difference between all phases minus current due to the load unbalancing.
It is calculated as shown below.
|Max. (Min.) current of all phase－average current|
x 100 (%)
Average current
Power
interruption
Voltage under 5% of rating is kept for min. 5ms.
Under voltage
Set the ratio for the rated voltage and it is used for threshold.
Voltage under the set ratio is kept for min. 5ms and will be judged as under voltage.
Under current
Set the ratio for the rated current and it is used for threshold.
Current under the set ratio is kept for min. 5ms and will be judged as under current.
Over current
Set the ratio for the rated current and it is used for threshold.
Current over the set ratio is kept for min. 5ms and will be judged over current.
Demand by
IEC61557-12
Based on IEC61557-12 Performance measuring and monitoring devices (PMD)
Sliding block interval
demand
The device calculates by measured power via CT for the interval you have
set. The interval can be set from 1 to 60 (min.) in 1-minute increments (the
increment is defined in “power demand interval 2”). The device calculates
the demand during the latest finished interval and displays the value.
Fixed block interval
demand
The device calculates by measured power via CT for the interval you have
set. The interval can be set from 1 to 60 (min.) The device calculates the
demand during the latest finished interval and displays the value. After one
interval finishes, the next interval starts.
Current demand
The device calculates the current demand based on a thermal demand
meter. It measures an average current (current demand) within the setting
interval and the max. value is considered as the max. current demand.

Part description
KW2M-A/X User's Manual 9
Chapter 3 Part description
3.1 Parts Names
<Front>
<Bottom view>
3.2 Key functions
Key
Functions
<MODE>
Measuring mode
Switches the device to setting mode
Setting mode
Switches the device to setting confirmation mode and
measuring mode
<SET>
Setting mode
Saves setting items and setting values
<SET>
(press and hold for
3seconds)
Measuring mode
Demand mode
Activates lock mode
Lock mode
Deactivates lock mode
<SHIFT/∧>
<ITEM/＞>
Measuring mode
Selects a measuring item to display
Setting mode
Select a setting value
Demand mode
Selects a demand item to display
<MODE>+<SET>
Measuring mode
Demand mode
Selects unit to display
<MODE>+<SHIFT/∧>
Measuring mode
Switches to demand mode
Demand mode
Switches to measuring mode
●Lock mode
In this mode, all keys are locked. No input can be made. When you press <SET> continuously for
about 3 seconds, lock mode is activated and the lock mark is displayed. Press <SET> continuously for
about 3 seconds again to deactivate lock mode.
Power supply
terminals
Display
Voltage input
terminals
Operation keys
Indicators
Ethernet port
Left: port 1
Right: port 2
RS485
communication
terminals
Pulse I/O
terminals
Current input
terminals

Wiring
10 KW2M-A/X User's Manual
Chapter 4 Wiring
Make sure to wire the device correctly according to the terminal arrangement and the wiring diagrams.
Please connect a fuse or a breaker to the power supply for safety reasons and to protect the device.
The device has no built-in power switch, circuit breaker or fuse for measured voltage input parts.
Therefore, it is necessary to install them in the circuit near this unit.
Do not turn on the power supply or input until all wiring is completed.
4.1 Main unit terminal arrangement
Power supply terminals
Terminal
number
1
2
Functions
L +
N－
Power supply
Voltage input terminals
Terminal
number
1
2
3
4
5
6
7
Functions
V1
NC
V2
NC
V3
NC
Vn
Measured
voltage
V ACant
Measured
voltage
V ACant
Measured
voltage
V ACant
Measured
voltage
*Do not use NC (V ACant) terminals.
Current input terminals
Terminal
number
1
2
3
4
5
6
7
8
9
10
11
12
Functions
K
L
K
L
K
L
K
L
K
L
K
L
CH1(CT1)
CH1(CT2)
CH1(CT3)
CH2(CT1)
CH2(CT2)
CH2(CT3)
Measured current (CH1)
Measured current (CH2)
RS485 communication terminals
Terminal
number
1
2
3
4
5
6
Functions
+
+
-
-
END
END
*Each terminal is connected internally.
Pulse I/O terminals
Terminal
number
1
2
3
4
5
6
Functions
+
-
+
-
+
-
Pulse input
Pulse output (CH1)
Pulse output (CH2)
* OUT1 and OUT2 are insulated.
The input voltage to each terminal is as follows.
Terminal
Phase and wire system
Terminal No.
Input voltage
Power
supply
Single-phase two-wire
1 - 2
(L+ - N－)
100-240V AC
Voltage input terminals
Measured
voltage
input
Single-phase two-wire
1 - 7
(V1-Vn)
0-690V AC
(L-L)
Single-phase three-wire
1 - 5 - 7
(V1-V3-Vn)
0-690V AC
0-345V AC
(L-L)
(L-N)
Three-phase three-wire
1 - 5 - 7
(V1-V3-Vn)
0-690V AC
(L-L)
Three-phase four-wire
1 - 3 - 5 - 7
(V1-V2-V3-Vn)
0-690V AC
0-398V AC
(L-L)
(L-N)

Wiring
KW2M-A/X User's Manual 11
◆Applicable wire (a crimp-type terminal is recommended.)
･Stripping length: 7 to 8mm
・Power supply/Measured voltage
Screw type: M3
Tightening torque: 0.5 to 0.6N･m
Sectional area: single /stranded wire 0.13 to 6mm2(AWG26 to12)
・for 2pcs.
single/stranded wire 2pcs.×0.5 to 2.5mm2(AWG20 to 12)
・Measured current (CT input)
Screw size: Push-in type
Sectional area: single /stranded wire 0.13 to 1.5mm2(AWG24 to16)
*Use a wire suitable for the current to be measured.
・RS485 communication
Screw size: Push-in type
Sectional area: single /stranded wire 0.13 to 1.5mm2(AWG24 to16)
*Use a shielded wire for RS485 communication.
・Output/Input
Screw size: Push-in type
Sectional area: single /stranded wire 0.13 to 1.5mm2(AWG24 to16)
4.2 Measured circuit
・It is possible to use two different measurement voltages (2 circuits of same system with 1 unit).
・Each unit (main unit, expansion unit (power measurement, power measurement + pulse output)) can
measure 2 circuits of a single-phase two-wire system, and 1 circuit of a single-phase three-wire system
or three-phase three-wire system. Each unit can be used with a different phase and wire system.
However, check the wiring carefully.
・It is not possible to take measurement with only the expansion unit. Every expansion unit must be
connected to a main unit.
Up to 3 expansion units can be connected to 1 main unit.
*Power source system
・The power source system is the electrical power system from one power source (normally one
transformer).
･KW2M-A can measure 1-system max. 24-circuit of 1P2W system and 1-system max. 8-circuit of 1P3W
and 3P3W system by connecting a main unit and expansion units.
・In order to measure several systems, it is necessary to use one main unit for each system.

Wiring
12 KW2M-A/X User's Manual
4.3 Connection expansion units to the main unit
・Turn off the power of the main unit when connecting expansion units.
・Peel off the connector label on the side before connecting.
(Do not peel off the connector labels when no expansion units are to be connected.)
・Connect each male connector to a female connector. The female connector is on the other side of the
male connector.
・After connecting, push the hooks into the unit to fix the expansion unit.
・Up to 3 expansion units can be connected to 1 main unit.
Note: The communication will be stopped or the measurement data will be lost when the units are
removed or connected while the power is turned on.
Hook Hook Hook Connector label
Expansion connector (male)

Wiring
KW2M-A/X User's Manual 13
4.4 Wiring Diagrams
Please connect a breaker or a fuse to the power supply and voltage input part for safety reasons and to
protect the device.
･Recommended breaker: 3 to 15A (IEC approved or UL Listed)
･Recommended fuse: Time-lag fuse rated current 2A (IEC approved or UL Listed)
Grounding the secondary side of VT (voltage transformer) and CT (current transformer) is not necessary
with a low-voltage circuit.
*When using several CTs, set each CT approximately 1m apart. If the two CTs are set too close each
other, the device may not measure accurately due to magnetic field interferences.
◆When measuring a load with rated input voltage
Single-phase two-wire system
*One CT is needed to measure a single-phase two-wire system.
*2 CTs are needed to measure 2-circuit and 3 CTs are needed to measure 3-circuit.
*To measure 2-circuit, wire 1 and 3. To measure 3-circuit, wire 1 and 3 and 5.
Single-phase three-wire/Three-phase three-wire
*2 CTs are needed to measure single-phase three-wire system, three-phase three-wire system.
*4 CTs are needed to measure 2-circuit.

Wiring
14 KW2M-A/X User's Manual
Three-phase four-wire system
*3 CTs are needed to measure three-phase four-wire system.
*6 CTs are needed to measure 2-circuit.
Vn terminal should be connected to grounded N-phase.
◆Measuring a load with exceeded input voltage
A voltage transformer (VT) is needed when you measure a load with over input voltage.
Use a VT with a secondary voltage rating of 110V.
Grounding the secondary side of VT and CT is not necessary with a low-voltage circuit.

Wiring
KW2M-A/X User's Manual 15
4.5 How to attach the Current Transformer (CT)
・Use a CT with a secondary side current of 5A or 1A.
・One CT is needed when measuring 1-circuit of 1P2W. Two CTs are needed when measuring
1P3W/3P3W (4 CTs for 2-circuit).Three CTs are needed when measuring 3P4W (6 CTs for 2-circuit).
If you use all CTs for one unit, they should be all measuring the same type of system.
・Use the coorect wire or it might cause a breakdown, burnout or electric shock.
・When connecting a CT, connect the secondary side to the terminal of the main unit first and after that
wire the primary side to a load electric wire. Incorrect order might cause an electric shock or break
the CT.
・The CT has polarity. Wire correctly according to the K and L marks. When the polarity is wrong, the
device cannot measure correctly.
･If there is some distortion by harmonic or waveform, the device may not measure correctly. Please
perform some tests with the actual system before going live.
・Separate the wiring (strong electric part) of the measured voltage input terminal (operating power
supply terminal) from the CT cable. Otherwise, noise may have an adverse effect on the accuracy.
DANGER
●Never open the secondary circuit of CT under applying current to load.

Wiring
16 KW2M-A/X User's Manual
◆How to connect a CT
(1) Turn off the power of the measured devices.
(2) Install the applicable CT.
(3) Connect the CT to the terminal block.
(4) Check that the wiring is correct, then turn on the power of the load and the KW2M-A.
Connection example:
◆How to set the parameters for CT
(1) Select CT type (option “CT-T”) according to the CT used.
(Select ‘5A’if the secondary side current of the CT used is 5A. Select ‘1A’if the secondary
side current of the CT used is 1A.)
(2) Set the primary current of measured CT at primary side current of CT setting mode (option
“CT-1”).
For example, if the measured CT is 400A/1A or 400A/5A, set to”400”.
(3) Connect the CT according to the CT direction, power side (K) to load side (L).

Wiring
KW2M-A/X User's Manual 17
4.6 For Input Connection
●Pulse input
・Contact input
Use highly reliable metal plated contacts. Since the contact’s bounce time leads directly to error in the
count value, use contacts with as short a bounce time as possible. In general, select 30Hz for
max.counting speed.
・Non-contact input (Transistor input)
Connect with an open collector. Use the transistor with the following specifications.
VCEO=20V min. IC=20mA min. ICBO=6μA max.
Use transistors with a residual voltage of max. 3V when the transistor is ON.
* Short-circuit impedance should be 1kΩ max.
Open-circuit impedance should be 100kΩ min. When the impedance is 0Ω, the drain current is
approx. 10mA.
・Input wiring
Please wire as short as possible by using a shielded wire or a metallic electric wire tube individually.
4.7 For Output Connection
●PhotoMOS relay output
・With a PhotoMOS relay output, there is no polarity.
Output: Rated capacity 30V AC/DC, 0.1A
・Do not connect devices with a voltage or load that exceeds the rated capacity (30V AC/DC,0.1A)
・Please do not exceed the maximum wire length of 100m for the outputs. If the wire is longer, it may not
work correctly due to a floating capacitance.