Omron KM-N2-FLK User manual

Power Monitor
model KM-N2-FLK
Users Manual
1.Overview of the unit
2.Installation and wiring
3.Basic use
4.Settings needed to measure
electricity
5.Other Functions
6.
Detailed settings for communications
7.Troubleshooting
8.Appendices
Catalog no. N200-E1-03
Thank you for purchasing this power monitor, model KM-N2-FLK
(referred to as model KM-N2 in this manual).
This Users Manual describes the functions, performance, and
application methods needed for optimum use of the unit.
Please observe the following when using this unit.
• This product is designed for use by qualified personnel with a
knowledge of electrical systems.
• Before using the product, thoroughly read and understand this Users
Manual to ensure correct use.
• Keep this Users Manual in a safe location so that it is available for
reference whenever required.

Index
2
Agreement regarding use..................................................................................................4
Safety precautions .............................................................................................................7
Important safety points......................................................................................................9
Precautions for correct use.............................................................................................10
Manual revision history ...................................................................................................11
1. Overview of the unit
1.1 Main features ..............................................................................................................12
1.2 Device configuration ..................................................................................................13
1.3 Names of the parts and their functions....................................................................14
1.4 Dimensions .................................................................................................................19
1.5 Multi-circuit metering .................................................................................................21
1.6 Multi-address system.................................................................................................23
1.7 Mode configuration ....................................................................................................24
2. Installation and wiring
2.1 Attaching the body of the unit...................................................................................25
2.2 Wiring the CTs ............................................................................................................27
2.3 Wiring for power and monitored voltage input........................................................29
2.4 Fitting the CTs to the measuring wires ....................................................................31
2.5 Pulse output wiring ....................................................................................................32
2.6 RS-485 wiring..............................................................................................................36
2.7 Wiring diagrams .........................................................................................................38
3. Basic use
3.1 Turning the power on.................................................................................................41
3.2 Switching between modes.........................................................................................42
3.3 How to read the measurements ................................................................................44
3.4 How to read the setting values..................................................................................49

3
Index (continued)
4. Settings needed to measure electricity
4.1 Setting items for measuring electricity ....................................................................53
4.2 Circuit settings ...........................................................................................................54
4.3 RS-485 communication settings ...............................................................................59
4.4 Pulse output settings .................................................................................................62
5. Other Functions
5.1 Voltage assignment....................................................................................................63
5.2 Measuring high voltage .............................................................................................64
5.3 Display unit conversion .............................................................................................65
5.4 Power saving mode....................................................................................................67
5.5 Warning for voltage miss-wiring...............................................................................68
5.6 Tariff feature................................................................................................................69
5.7 Change password.......................................................................................................70
5.8 Checking software version........................................................................................71
5.9 Initialize .......................................................................................................................72
6. Detailed settings for communications
6.1 Overview of communications....................................................................................74
6.2 Modbus........................................................................................................................75
6.3 CompoWay/F...............................................................................................................84
6.4 Address map...............................................................................................................98
7. Troubleshooting
7.1 Warnings ...................................................................................................................102
7.2 Troubleshooting .......................................................................................................103
8 Appendices
8.1 Specifications ...........................................................................................................106
8.2 ASCII code table .......................................................................................................109
8.3 14 segment displays and 7 segment displays.......................................................111

4
2
Agreement regarding use
Unless otherwise specifically agreed, you agree that the conditions in this agreement apply to your use of this Omron
product, irrespective of the place of purchase.
1. Definitions
This defines some terms used in this agreement.
(1) Omron products: FA system equipment, general-purpose control devices, sensors, and electronic/mechanical
components under Omron brand.
(2) Catalogs: Omron catalogues, including, without limitation, Omron "Best" Control Equipment Catalog, and
General Catalog for Electronic/Mechanical Components, specifications, instructions and user manuals for
Omron Products, whether or not provided electronically.
(3) Usage Conditions: Usage conditions, rating, performance, operating environment, handling instructions,
warnings, restrictions on use, etc. of Omron Products described in the Catalogs.
(4) Customer Application: Any application of Omron Products by a customer to include, but are not limited to,
embedding and/or using Omron Products in their parts/components, electronic substrates, devices, equipment
or systems manufactured by customers.
(5) Fitness: (a) fitness for a particular purpose, (b) performance, (c) non-infringement of third-party intellectual
property, (d) compliance with laws and regulations and (e) conformity to standards of an Omron Product in the
Customer Application.
2. Cautions regarding content
Be aware of the following points with regard to the content of Catalogs.
(1) Rated values and performance values are based on stand-alone tests using each separate condition, and
Omron does NOT warrant any rated values and performance values for multiple composite conditions.
(2) Reference data is provided for your reference only. Omron does NOT warrant that Omron Products work
properly at all times as provided in the reference data.
(3) Application examples are provided for your reference only. Omron does NOT warrant the Fitness of Omron
Products under such application.
(4) Omron may discontinue the production of Omron Products or change their specifications for the purpose of
improving such products or for other reasons entirely at its own discretion.
3. Precautions
You are deemed to accept the following terms when you adopt or use Omron Products:
(1) Use Omron Products in compliance with Usage Conditions including rating and performance.
(2) Confirm Fitness of Omron Products in Customer Application and use your own judgment to determine the
appropriateness of using them in such application. Omron does NOT warrant the Fitness of Omron Products in
Customer Application.
(3) Confirm beforehand that Omron Products are properly wired and installed for their intended use in your overall
system.
(4) When using Omron Products, make sure to (i) maintain a margin of safety in relation to the published rated and
performance values, such as introducing redundancy, (ii) design to minimize risks to any Customer Application
in case of failure of any Omron Products, (iii) adopt system-wide safety measures to notify risks to users, and
(iv) conduct regular maintenance on Omron Products and Customer Application.

5
Agreement regarding use (continued)
(5) Omron Products are designed and manufactured as general-purpose products for use in general industrial
products. They are not intended to be used in the applications described below, therefore if you use Omron
products in these applications, Omron provides no warranty for Omron products. However, this excepts cases
where the use is a special use intended by Omron or where Omron has specifically agreed, even when used in
the following applications.
(a) Applications with stringent safety requirements (For example, nuclear power control equipment, combustion
equipment, aerospace equipment, railway equipment, elevator and lift equipment, amusement equipment,
medical equipment, safety equipment, and other applications that could cause physical injury or result in the loss
of life.)
(b) Applications that require high reliability (For example, supply systems for gas, water and electricity, etc., 24 hour
continuous operating systems, financial settlement systems and other applications that handle rights and
property.)
(c) Applications under severe conditions or in severe environments (For example, outdoor equipment, equipment
exposed to chemical contamination, equipment exposed to electromagnetic interference and equipment
exposed to vibration and shocks.)
(d) Applications under conditions or environments not described in catalogs or other publications.
(6) In addition to the applications listed in 3.(5) (a) to (d), the products in this publication are not intended for use in
automobiles (including for two-wheeled vehicles, and this description applies hereafter). Do not use for
applications involving fitting to automobiles. Consult Omron staff for information about products suitable for use
in automobiles.

6
Agreement regarding use (continued)
4. Warranty
The warranty for Omron Products are as follows:
(1) Warranty period: The Warranty shall apply for one year from the date of purchase.
(Unless otherwise described in Catalogs.)
(2) Warranty content: Omron will provide, at its own discretion, either of the following two services as the sole
remedy for a malfunctioning Omron Product:
(a) Repair of the malfunctioning Omron Product(s) at an Omron maintenance service location at no charge to the
customer (This repair service is not available for electronic/mechanical parts.)
(b) Replacement of the malfunctioning Omron Product(s) with the same number of replacement/alternative products
at no charge to the customer.
(3) Exceptions: This warranty of Omron Products does not apply if the cause of the malfunction falls under any of
the following:
(a) Usage in a manner other than the original intended use for the Omron Products.
(b) Usage other than as described in the Usage Conditions.
(c) Usage that is not in accordance with Section 3 (Precautions) above.
(d) Modification or repair made to the Omron Products by other than Omron personnel.
(e) Software program by other than Omron staff
(f) Causes which could not have been foreseen with the level of science and technology at the time of shipping
from Omron.
(g) Causes other than those above originating from other than Omron or Omron Products (including force majeure
such as natural disasters).
5. Limitation of liability
The warranty express in this agreement is the entire warranty for this Omron product.
Omron and dealers selling Omron products accept no responsibility for damages arising from the use of Omron
products.
6. Export control
Comply with the applicable laws and regulations of Japan and related nations relating to security export controls
when exporting or providing this Omron product or technical documents to non-residents. If you do not comply with
these laws and regulations, we may be unable to supply you with Omron products or technical documents.
Notice
• It is not permitted to reproduce, copy, or reprint this manual in part or in full without permission.
• Changes to this manual may be made without notice.
• Every effort has been made to ensure the accuracy of this manual, however please contact us or your dealer
at one of the addresses shown at the back of this manual if you find any unclear points or errors.
At this time, please also advise us of the catalog number found at the back of this manual.

7
Safety precautions
Regarding the displays used to ensure safe operation and their meanings
The following indications and symbols are used in this manual for precautions so that you can use the product
safely. The precautions here include important information regarding safety. Please follow these instructions.
The indications and symbols are as follows.
Warning displays
Meanings of the symbols
Caution Indicates a potentially hazardous situation which, if not avoided, will
result in minor or moderate injury, or there may be property damage.
•Mandatory actions
Indicates a general action that must be performed by the user.
•Explosion caution
Indicates possibility of explosion under special conditions.
•Electrical shock caution
Indicates possibility of electric shock under special conditions.
•Disassembly prohibition
This indicates that there is the danger of electric shock or other injury if the unit
is disassembled.
•General prohibitions
Indicates a general prohibition without particular categorization.

8
Safety precautions (continued)
* CT: Current Transformer
Caution
Property damage may occur due to fire.
Tighten the terminal screws to the specified torques.
After tightening the screw, check that the screw is not loose.
M3.5 screw : 0.8N·m
M3 screw : 0.5 to 0.6N·m
M3 screw (KM-NCT-E's output terminal) : 0.3N·m
Minor or moderate injury or property damage may occur due to explosion.
Do not use in locations exposed to flammable or explosive gases.
Breakdown or explosion may occasionally occur.
Use the power voltage and load within the specified and rate ranges.
Electric shock may occasionally occur.
Do not touch any of the terminals while the power is being supplied.
Electric shock may occasionally occur.
Always make sure that the power to the circuit the CT is being attached to is turned
OFF before connecting the CT*.
Electric shock may occasionally occur.
Be sure to mount to coated wire with at least the basic insulation when mounting KM-
NCT-E.
Burns may occasionally occur.
Do not touch the product while power is being supplied or immediately after power is
turned OFF.
Use the electric wire that heat resistant temperature is 85 degrees or more when wiring
to the product.
Minor electric shock, fire, or malfunction may occasionally occur.
Do not supply a current to the CT input terminal that exceeds the maximum CT
secondary current.
Minor electric shock, fire, or malfunction may occasionally occur.
Never disassemble, modify, or repair the product.

9
Important safety points
Observe the following to ensure safe use of model KM-N2.
• Do not use or store the product in any of the following locations.
– Locations subject to shock or vibration
– Unstable locations
– Locations subject to temperatures or humidity outside rated ranges
– Locations subject to condensation as the result of severe changes in temperature
– Outside or otherwise exposed to direct sunlight and weather
– Locations subject to static electricity or other forms of noise
– Locations exposed to electromagnetic fields
– Locations subject to exposure to water or oil.
– Locations subject to exposure to salt water spray.
– Locations subject to corrosive gases (in particular, sulfide gas and ammonia gas).
– Locations subject to dust (including iron dust).
– Locations subject to exposure to solvents
• Use AWG24 to 14 to wire the power and input voltage terminals. The heat resistant temperature of the wire is 85
degrees or more.
• Use AWG18 to 14 to wire the CT terminals. The heat resistant temperature of the wire is 85 degrees or more.
• Use AWG24 to 14 to wire the communication terminals. The heat resistant temperature of the wire is 85 degrees or
more.
• For wiring to KM-NCT-E's output terminal, use a Y-shape terminal compatible with AWG18 to 14 electric wire (with
a cross-section of 0.75 to 2.0mm2) and M3 screw.
• The recommended tightening torque of the M3 screw of KM-NCT-E's output terminal is 0.3N·m.
• When mounting the KM-NCT-E to the measurement wire, push the fitting claw until it clicks.
• Be sure to wire properly with the correct terminal number. Do not wire unused terminals.
• Be sure to check that the wiring is correct before turning on the power.
• Before using or maintaining the product, thoroughly read and understand the instraction manual.
• Understand the user manual before setting the device.
• Do not pull cables.
• Use only as described in the INSTRUCTION MANUAL. Using the unit in a manner not described mayresult in the
safety functionality of the device being compromised.
• In order that workers may turn off the power immediately, install a branch circuit breaker conforming to
requirements in the country where the device is being used (USA: UL Listed, CANADA: cUL Listed, other country:
e.g. IEC60947-1 and IEC60947-3 ) and display instructions properly.
<Recommended ratings of a branch circuit breaker>
Rated current : 1A.
• Always check the wiring and confirm that it is correct before turning ON the power supply. Incorrect or improper
wiring may result in electrical shock, injury, accidents, failure, or malfunction.
• KM-NCT-E is a dedicated CT for KM-N2-FLK and KM-N3-FLK. Do not use it for other power monitors.
• The surface temperature of the CT may become high due to the heat generated by the primary power cable. Be
sure to check that the surface temperature of the CT went down before touching the CT immediately after turning
ON the power supply.
• Do not install the product close to heat-producing devices (those using coil elements, for instance).
• Ensure the screws fixing the DIN rails are tight. Also ensure that the DIN rails and the body are attached properly.
Looseness may cause the DIN rails, body, and wires to separate if vibrations or impacts occur.
• Use 35mm width DIN rails (OMRON, model PFP-50N/-100N).
• When mounting the product on the DIN rail, slide the DIN hook unit until a clicking sound is heard.
• Separate the product wiring from high-voltage or high-current power lines to prevent inductive noise. Do not place
the product wiring parallel to or in the same ducts or conduits as power lines. Use separate ducts, separate
conduits, or shielded cables to prevent noise.
• This is a “class A” product. In residential areas it may cause radio interference. The user may be required to take
adequate measures to reduce interference if this occurs.

10
Precautions for correct use
• This product is not categorized as "a specified measuring instrument" officially approved by an organization
specified in relevant measurement acts. It cannot be used to certify power usage.
• Set the parameters of the product so that they are suitable for the system being measured.
• Mount this product on DIN rails for use.
• Use varistors between the outer power and voltage measuring input wires when this product is installed in an
overvoltage category III environment.
• This product cannot be used to measure the inverter’s secondary side.
• Ensure that the rated voltage is reached within 2 seconds of turning the power on.
• Do not use thinners for cleaning. Use commercial alcohol.
• When cleaning the unit, make sure the power is off and wipe the surface of the unit with a soft dry cloth. Do not use
chemicals including solvents such as thinners, benzine, or alcohol.
• You cannot use the CT dedicated for use with the Omron KM series (model series KM20-CTF, model series KM-
NCT) . Use a CT whose secondary output is 1A or 5A.
• Use ferrule terminals to connect CTs to the CT terminals on the main unit to ensure the assembly complies with
standards.
• The data for active energy is saved at 5 minute intervals. The data for the 5 minutes preceding the unit powering off
may not be saved under some circumstances.
• Dispose of this product appropriately as industrial refuse in accordance with local and national regulations.
• This product is intended for use in industrial environments. Do not use it in residential environment.
Trademark Information
• Modbus is a registered trademark of Schneider Electric.
• Other company names and product names in this document are the trademarks or registered trademarks of their
respective companies.

11
Manual revision history
A manual revision code appears as a suffix to the catalog number on the front cover and back cover of the manual.
Revision
number Date of revision Reason for revision, pages revised
01 A April 2016 First edition
02 July 2017 Description of operability-confirmed converter: Modified
03 May 2018 Description of dedicated CT: Added
Revision number
Catalog no. N200-E1-03

12
1.Overview of the unit
1. Overview of the unit
1.1 Main features
• Supports international standards
It complies with the international IEC accuracy standards and can be connected using generic CTs.
• Multi-circuit metering
Multi-circuit metering is possible with one unit, with up to four circuits metered by 1-phase 2-wire, and up to 2
circuits metered by 1-phase 3-wire and 3-phase 3-wire. It is also possible to measure multiple 1-phase 2-wire with
different phases branching off a 1-phase 3-wire, and to simultaneously measure both 1-phase 3-wire and 1-phase
2-wire.
• Multi-address system
There can be a maximum of 4 circuits in one unit. The circuits act as independent power monitors, each able to
measure, each having different settings, and each able to be allocated different communications addresses. You
can manage individual circuits as electricity monitors from a host system, so it is easy to build a communications
system and add places for measuring.
• Pulse output
The unit has 4 ports for outputting pulses each time the active energy exceeds set values. You can allocate each
circuit a pulse output port in a multi-circuit metering setup.
• RS-485 communications
You can use the Modbus (*1) and CompoWay/F (*2) protocols for RS-485 communications.
*1. Modbus is a communications control system that conforms with the RTU Mode of the Modbus Protocol.
*2. CompoWay/F is Omron's unified communication procedure for general serial communications. It has a unified
framework format and has commands compliant with FINS which works well with Omron programmable controllers, for
instance, simplifying communications between host devices (computers for example) and components.

13
1.Overview of the unit
1.2 Device configuration
• The CT of OMRON's dedicated KM series output type cannot be used with this product.
• Although a generic CT with the secondary side output of 1A or 5A can be connected, CTs dedicated for use with
KM-N2-LFK and KM-N3-FLK of 1A output type are available as listed on the table below. By using a CT listed
below in combination with a KM-N2-FLK, the CE standard is supported including the use of CT and power
monitors.
• A cable to connect the CT and power monitor is separately required.
Breaker
Operating power and
metered voltage
Power Monitor
Model KM-N2-FLK
For example:
PLC
Pulse output 1
Host device
RS-485
Modbus
CompoWay/F
Generic CT
Pulse output 2
Pulse output 3
Pulse output 4
Generic CT
Generic CT
Generic CT
For example:
PLC
For example:
PLC
For example:
PLC
Name Model Description
CT dedicated for 1A output type
KM-NCT-E100A Rated 100A, output 1A
KM-NCT-E250A Rated 250A, output 1A
KM-NCT-E500A Rated 500A, output 1A

14
1.Overview of the unit
1.3 Names of the parts and their functions
[Main unit]
Front
Terminal panel cover removed
Name Description
1Power LED (green) Lights when power is supplied
2Error LED (red) Flashes when there is an error such as a malfunction
3Alarm LED (orange) Flashes to indicate a warning
4Communication LED (yellow) Lights when communicating
5Pulse LED (yellow) Lights during pulse output
6Communication address/Menu display
When ADDRESS is illuminated (in measuring mode):
Displays the communication address
When MENU is illuminated (in setting mode):
Displays the menu number
7Status display
OUTPUT Lights when setting pulse output
1 Lights when outputting pulse from OUT1
2 Lights when outputting pulse from OUT2
3 Lights when outputting pulse from OUT3
4 Lights when outputting pulse from OUT4
SET Lights in setting mode
8Measured value/setting
value display
Main display Displays measured values and setting values (9 places on the upper
line)
Sub display Displays the units for the measured values and the names of the
setting items (5 places on the lower line)
9Tariff display Displays the tariff number (T1 to T4) when saving active energy
(import)











 


88888
888888888
88
ywywywywyw
ywywywywyw
88888
888888888
88
ywywywywyw
ywywywywyw




LCD for display (enlarged)

15
1.Overview of the unit
1.3 Names of the parts and their functions (continued)
* Refer to "1.6 Multi-address system" (23) for circuit A.
Name Description
:CT usage display Displays the CT number (CT1 to CT4) when measuring or setting
;<</MODE key Short press: switch circuit/move place
Press and hold: switch mode
<Key Change setting or value (up)
=Key Change setting or value (down)
>ENTER key Confirm setting or value
?ESC key Cancels items or values
@Rotary SW
Sets the communication address * (left (x10): increase in units of ten,
right (x1): increase in units of 1)
ARS-485 communication
terminals
RS-485i(1) RS-485iterminal
RS-485j(1) RS-485jterminal
RS485i(2) RS-485iterminal (for crossover wiring)
RS485j(2) RS-485jterminal (for crossover wiring)
RS485 E RS-485 terminating resistor terminals
BPulse output terminal
OUT1 Pulse output 1 terminal
OUT2 Pulse output 2 terminal
OUT3 Pulse output 3 terminal
OUT4 Pulse output 4 terminal
COM Common terminal for pulse output
CVoltage input terminals Terminals for inputting the power and voltage (combined with the
input for measured voltage)
DCT input terminals Terminal for connecting the CT cables for CT1 to CT4
EDIN Hook Hook for attaching to the DIN rail

16
1.Overview of the unit
1.3 Names of the parts and their functions (continued)
Right side surface
Name Description
FTerminal layout label Label with information such as the model, power voltage, connector layout, and
serial number
GTerminal panel cover Terminal panel cover with seal



Enlarged terminal layout label

17
1.Overview of the unit
1.3 Names of the parts and their functions (continued)
[Dedicated CT]
KM-NCT-E100A, -250A
Name Function
1Label Polarity of the primary side wiring, and models are written on this label
2Output terminal block Secondary side current is output to this terminal block
3Terminal cover Protective cover of the output terminal block
4Fitting claw Claw that clamps the wire and fits the top and bottom of the transformer
5Fixing claw Used to reinforce the retention of the unit and insulation lock





(Front) (Back)
(Bottom) (Bottom (terminal cover removed))

18
1.Overview of the unit
1.3 Names of the parts and their functions (continued)
KM-NCT-E500A
Name Function
1Label Polarity of the primary side wiring, and models are written on this label
2Output terminal block Secondary side current is output to this terminal block
3Terminal cover Protective cover of the output terminal block
4Fitting claw Claw that clamps the wire and fits the top and bottom of the transformer
5Fixing claw Used to reinforce the retention of the unit and insulation lock





(Front) (Back)
(Bottom) (Bottom (terminal cover removed))

19
1.Overview of the unit
1.4 Dimensions
[Main unit]
11
90
1.4
61
66.44
43
90
45
（49）
（41.2）
Ｒ20 . 3
Ｒ20 . 3
5
43
Units (mm)
(Front)
(Right side surface)
(Left side surface)
DIN rail
Part A
Part B
Part A Dimensions
of moving part
Part A Dimensions
of moving part
Part B Dimensions
of moving part

20
1.Overview of the unit
1.4 Dimensions (continued)
[Dedicated CT]
KM-NCT-E100A, -250A
KM-NCT-E500A
45 (4) (4)34
22
(2.5)(1.5)
46.5
49.5
74.5
ɸ24
24
24
4-R8.5
CT INNER DIAMETER
Units (mm)
57 (2.5)(1.5) 40.5
22
(4)(4)
ɸ36
4-R13.5
91
61
56.5
36
36
CT INNER DIAMETER
Units (mm)