ROOTECH Accura MD-GAS User manual

Notice
About Manual
Rootech Inc. reserves the right to make changes in the device specifications shown in this User Guide
without notice. Rootech Inc. advises customers to obtain the latest specifications of device before giving
orders to confirm that the information being relied on by the customer is up to date.
In the absence of written agreement to the contrary, Rootech Inc. assumes no liability for Rootech Inc.
applications assistance, customer’s system design, or infringement of patents or copyrights of third parties
by or arising from the use of devices described herein.
The information contained in this document is believed to be accurate at the time of publication, however,
Rootech Inc. assumes no responsibility for any errors which may appear here and reserves the right to
make changes without notice.
Limitation of Liability
Where applicable law allows and does not prohibit or restrict such limitation, Rootech, Inc’s liability for
anything relating to this product shall be limited to the price paid for the product.

Notice
Accura MD-GAS User Guide
Page 2
ⓒ 2014 Rootech Inc. All Rights Reserved
Notice
Symbols
Caution
Indicates the presence of dangerous voltage which can cause severe injury or death if
proper precautions are not followed.
Caution
Alerts users of the presence of hazards which can cause injury to persons, property damage
or damage to the device if proper precautions are not followed.
Note
Indicates major instructions for the installation, operation, and maintenance of the product.
Indicates alternative voltage or current.
Indicates direct voltage or current.
Installation Considerations
The installation, operation, and maintenance of the product should be performed only by qualified,
competent personnel that have received appropriate training for high voltage and current devices.
Caution
If hazardous voltages are mishandled while installing and operating the product in the field, it can cause
serious injury or death.
During normal operation of the product, hazardous voltages are present on the terminals that connect
PTs/CTs, digital inputs, power, and external I/O circuits. The PT/CT secondary can produce lethal voltage or
current caused by the energy of the primary.
Standard safety precautions should be followed during the installation and maintenance of the product,
including removing PT fuses and shorting CT secondaries.
Install the product in enclosures or a similar cabinet to prevent access to the terminal strips of the product
after wiring.

Accura MD-GAS User Guide
Notice
ⓒ 2014 Rootech Inc. All Rights Reserved
Page 3
Caution
Observe the following instructions, or it may cause permanent damage to the product.
Do not apply voltages and currents that exceed the input ratings of the PT and CT to the product.
Using the device for other purposes not specified by the manufacturer can cause severe damage to the
product.
Connect the chassis ground terminal of the product to the earth ground to protect the device from noise
and surge. Failure to properly connect the chassis ground will void the warranty of the product.
About the Manual
Rootech, Inc. reserves the right to make changes in the product specifications shown in this User Guide
without prior notice. We recommend that customers should obtain the latest information on product
specifications and the manual before making orders.
In the absence of written agreements, Rootech, Inc. assumes no liability for applications assistance, customer’
s system design, or infringement of patents or copyrights induced by third parties arising from the use of
the products described herein.
We endeavor to provide accurate information in the document. However, we are not responsible for any
errors which may appear here and reserves the right to make changes without prior notice.
Limitation of Liability
Where applicable law allows and does not prohibit or restrict such limitation, Rootech, Inc’s liability for this
product shall be limited to the amount actually paid by customers for the product.

Warranty
Accura MD-GAS User Guide
Page 4
ⓒ 2014 Rootech Inc. All Rights Reserved
Warranty
Rootech Inc. provides warrants for two years from the product receipt date only to the original purchaser
of the products and software that are sold or licensed by the company.
To obtain warranty service, the purchased products should be free from serious defects in material and
workmanship.
The software is provided in an up-to-date version, thus we do not offer any warranty for the software
product.
In order to make a product claim under the warranties described above, the original purchaser should
immediately contact Rootech headquarters. Upon receiving claims, Rootech will check out the product
either at where the purchaser is or at the company after receiving the product from the customer, who is
responsible for the cost of shipping the product. After inspecting the product, we will provide repair or
replacement services for the product.
Rootech will decide at its discretion whether to repair or replace it or give a refund for the product for
when the warranty period for the product expired or issues related to the product are not applicable for
warranty terms and conditions.
Limitation of Warranty
The Warranty does not apply to uninterrupted or error-free operation of the product or cover normal wear
and tear of the product or costs caused by the removal, installation, or troubleshooting of the customer's
electrical systems.
Defects caused by any of the following factors are not covered under the warranty.
◼Improper use(alteration, accident, misuse, abuse) or failure to act in accordance with installation,
operation or maintenance instructions
◼Unauthorized modifications, changes or repair attempts
◼Failure to comply with applicable safety standards & regulations
◼Damages coming from when transporting or storing the product
◼Damages caused by the force majeure event, including fire, flood, earthquakes, storm damage,
overvoltage & lightning
◼If the original identification marks(trade-mark, serial number, etc.) have been defaced, altered, or removed
Rootech shall not be liable for any other claims except the claims made by customers, including the original
purchaser, his employees, agents, or contractors for any loss, damage, or expense incurred related to the
purchased product when the above warranty terms and conditions are not fulfilled.
Any technical assistance with system design provided by Rootech's personnel or representatives shall be

Accura MD-GAS User Guide
Warranty
ⓒ 2014 Rootech Inc. All Rights Reserved
Page 5
deemed to be a suggestion. The original purchaser is responsible for determining the feasibility of such
suggestions and should conduct tests to prove their feasibility.
It is the original purchaser’s responsibility to determine the suitability of the product and associated
documentation. The original purchaser should acknowledge that 100% 「up」time is not realizable because
of possible hardware or software defects. The original purchaser should recognize that such defects and
failures may cause inaccuracies or malfunctions.
No agency, corporate entity, or employee of Rootech or other companies has authority to amend, modify
or extend the terms and conditions of this warranty in any way without express written authorization from
Rootech Inc.
Standard Compliance
Process Control Equipment
E324900
MSIP-REM-RTE-ACCURA-MD-GAS

Revision History
Accura MD-GAS User Guide
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ⓒ 2014 Rootech Inc. All Rights Reserved
Revision History
The following versions of Accura MD-GAS User Guide have been released.
Revision
Date
Description
1.00
August 7, 2014
Initial release
1.10
September 15, 2014
Added content on environmental conditions, including temperature and
humidity
Added the setup mode and event mode
1.11
November 21, 2014
Upgraded content on PPM conversion based on the methane gas standard
1.20
December 18, 2014
Added the Notice, Standard Compliance, Warranty, and Contents sections
1.21
January 8, 2015
Extended the range of power supply input voltage
1.22
February 10, 2015
Changed content related to standards
1.23
March 17, 2015
Modified incorrect images in the setup mode section
1.30
April 12, 2018
Added the definite time characteristics of events
1.31
October 18 2018
Added installation precautions
1.32
February 8, 2022
Updated information on certifications
Changed the product’s dimensions, as well as the image and text on the cover
page
1.40
January 26, 2024
Added cautions when installing and operating the product

Accura MD-GAS User Guide
Contents
ⓒ 2014 Rootech Inc. All Rights Reserved
Page 7
Contents
Chapter 1 Installation and Wiring...................................................................................................................................... 9
Before Installation ...................................................................................................................................................................................................9
Components.....................................................................................................................................................................................................9
Dimensions........................................................................................................................................................................................................9
Installation................................................................................................................................................................................................................ 10
Panel Mounting ...........................................................................................................................................................................................11
DIN-Rail Mounting..................................................................................................................................................................................... 11
Wiring ...............................................................................................................................................................................................................12
Chapter 2 Accura MD-GAS Operation/Setup................................................................................................................. 13
Power Supply.......................................................................................................................................................................................................... 13
Functions ..................................................................................................................................................................................................................13
Gas Measurement and Event Detection..........................................................................................................................................13
Digital Output...............................................................................................................................................................................................14
Operation Mode.......................................................................................................................................................................................... 15
Button Operation ........................................................................................................................................................................................ 16
LCD Screen...............................................................................................................................................................................................................17
Display Mode................................................................................................................................................................................................ 17
Event Mode.................................................................................................................................................................................................... 18
Setup Mode...................................................................................................................................................................................................18
LED Display.............................................................................................................................................................................................................. 22
Appendix A Specifications................................................................................................................................................. 23
Appendix B Standards........................................................................................................................................................ 24
Appendix C Ordering Information ................................................................................................................................... 25

Figures
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Figures
Fig 1.1 Accura MD-GAS Components .................................................................................................................................................9
Fig 1.2 Accura MD-GAS Front .................................................................................................................................................................9
Fig 1.3 Accura MD-GAS Rear...................................................................................................................................................................9
Fig 1.4 Accura MD-GAS Side ................................................................................................................................................................10
Fig 1.5 Panel Mounting............................................................................................................................................................................11
Fig 1.6 DIN-Rail Mounting .....................................................................................................................................................................11
Fig 1.7 Power Supply and DO Wiring............................................................................................................................................... 12
Fig 2.1 Accura MD-GAS Front View................................................................................................................................................... 13
Fig 2.2 Relationship between Sensor Resistance and Concentration(ppm)...................................................................14
Fig 2.3 Application of DC Relay........................................................................................................................................................... 15
Fig 2.4 Application of AC Relay ........................................................................................................................................................... 15
Fig 2.5 LED/DO Operation [Button Input After the End Event in DO Button-Clear Configuration].................. 21
Fig 2.6 LED/DO Operation [Button Input After the End Event in DO Self-Clear Configuration] ........................ 21
Fig 2.7 LED/DO Operation [Button Input During the Event:.................................................................................................22
LED and DO Reset regardless of DO Reset Configuration] ...................................................................................................22

Accura MD-GAS User Guide
Chapter 1 Installation and Wiring
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Page 9
Chapter 1 Installation and Wiring
Before Installation
Components
Fig 1.1 Accura MD-GAS Components
Accura MD-GAS
Mounting wings L/S
Two mounting screws
Dimensions
Fig 1.2 Accura MD-GAS Front
Fig 1.3 Accura MD-GAS Rear

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Fig 1.4 Accura MD-GAS Side
Installation
The following environmental specifications should be considered when installing and operating the product.
Environmental Conditions
Description
Operating temperature
-20 –70 ℃(-4 –158 ℉)
Safe operating temperature 1
-20 –60 ℃(-4 –140 ℉)
Storage temperature
-20 –85 ℃(-40 –185 ℉)
Operating humidity
5 –95% (non-condensing)
Caution
You should take cautions when installing and operating the product in the following circumstances since
it can cause degraded sensor performance and reduced lifespan of the sensor.
- When it is exposed to silicone vapors
- When it is exposed to highly corrosive materials such as H2S, SOx, Cl2, HCl, etc.
- When it is contaminated by alkaline metals (e.g. salt water spray)
- When it is in contact with water

Accura MD-GAS User Guide
Chapter 1 Installation and Wiring
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Page 11
Panel Mounting
Fig 1.5 Panel Mounting
Please observe the following precautions for the installation location of Accura MD-GAS module.
1) Determine where to install the module considering the flow path of combustible gases.
2) If there is no specific gas flow path, install it in the upper part of the installation space, considering the
rise of gas.
DIN-Rail Mounting
Fig 1.6 DIN-Rail Mounting

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Wiring
①Connect the external 9 –24 V DC power supply to the power input ports [+/-].
②Connect cables to the DO ports.
Fig 1.7 Power Supply and DO Wiring

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Chapter 2 Accura MD-GAS Operation/Setup
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Page 13
Chapter 2 Accura MD-GAS Operation/Setup
Fig 2.1 Accura MD-GAS Front View
Power Supply
Item
Description
Connector type
Terminal block[+/-]
Wire specification
1.5 –3.5 mm2 (16 –12 AWG)
Power supply voltage
DC voltage 9 –24 V ± 10 %
Current consumption
90 mA @ DC 24 V
with DO(Digital Output) relay ON
200 mA @ DC 9 V
Functions
Gas Measurement and Event Detection
Item
Description
Gas sensor
Model
TGS 813
Type
Tin dioxide(SnO2) semiconductor
Detection
Wide range of combustible gases
Measuring range of gas concentration 1
100 –10,000 [ppm]
Event
Detects the occurrence of an "Over" event 2based on the threshold value
1. It is concentration in ppm[parts per million] converted as shown in Fig 2.2: the output resistance of the gas sensor is
presumed as an average value of 10 kΩbased on the methane concentration of 1000 ppm, and measurements are
performed in the condition where the load resistance of the gas sensor is 18 kΩ.
2. An “Over”event consists of a start event and an end event.

Chapter 2 Accura MD-GAS Operation/Setup
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Fig 2.2 Relationship between Sensor Resistance and Concentration(ppm)
Digital Output
When an event occurs, the maximum PPM value and the event LED blink on the screen, and the digital
output is also turned on.
Channel 1
Connector name
DO1
Ground
DO1G
Item
Description
Port type
Terminal block
Wire specification
1.5 –3.5 mm2 (16 –12 AWG)
Output type
Latch/ Periodic pulse 1
Turn-on time
Max. 6 msec
Turn-off time
Max. 3 msec
Isolation
AC 2,000 V for 1 minute
Maximum rating
AC 250 V 5 A, DC 110 V 0.3 A, DC 30 V 5 A
1. A latch maintains the current output status, and a periodic pulse occurs repeatedly at the configured time interval.
Pulse period and pulse on-time can be set.

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Chapter 2 Accura MD-GAS Operation/Setup
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Page 15
Fig 2.3 Application of DC Relay
Fig 2.4 Application of AC Relay
Note
It is recommended that you should use a clamp diode or varistor in order to ensure that the rated
voltage of the digital output is not exceeded while switching DO operation modes.
Operation Mode
Mode
Description
Display Mode
Displays the measured PPM value and the output status of the DO in sequence
Event Mode
If a start event occurs, the screen automatically changes to the event mode.
When an event occurs, the maximum ppm value of gas and the event LED blink.
Users can reset the event mode by long pressing the SET button, and the screen returns
to the display mode.
Setup Mode
Configures events and the DO

Chapter 2 Accura MD-GAS Operation/Setup
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Button Operation
The SET button is used to reset the event mode, or check and change setup items.
Event Mode Reset
Button
Function
[Display Mode]
Displays the measured PPM value and the output status of the DO in
sequence
[Event Mode]
If an event occurs, the screen automatically changes to the event mode.
Automatic
switch
When an event occurs, the maximum ppm value of gas and the event
LED blink. The digital output is also turned on.
Long press 1
Users can reset the event mode by long pressing the SET button, and
the screen switches to the display mode. When the event mode is reset,
the event LED is turned off, and the digital output is also turned off.
1. Release the button after pressing it for 1 second.
2. Users can configure the digital output to be automatically turned off when an end event is detected.
Performing Device Setup and Checking Setup Items
Button
Function
[Display Mode]
Displays the measured PPM value and the output status of the DO in
sequence
[Setup Mode]
Short press 1
Go to the setup mode.
[The setup menu is sequentially selected each time the SET button is
pressed.]
Long press 2
Enter the edit mode. A preset value blinks and can be changed.
Short Press
Select the preset value to change by pressing the button.
[The setup value changes sequentially each time the button is pressed.]
Long press
Save the selected setup value. And then the screen stops blinking.
[Go to the next setup menu.]
1. Press the button and release it immediately. 2. Release the button after pressing it for 1 second.
Note
If there is no button operation for 10 seconds in the setup mode, the screen automatically returns to the
display mode. If there is no button operation for 25 seconds in the edit mode, it automatically returns to
the display mode.

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Chapter 2 Accura MD-GAS Operation/Setup
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Page 17
LCD Screen
Display Mode
Accura MD-GAS module displays the measured PPM value and the output status of the DO, and the screens
appear in the following sequence. If you short press the SET button in the display mode, the screen switches
to the setup mode.
PPM
Output Status
Gas PPM Display
The screen displays the ppm value converted from the output voltage of Accura MD-GAS module’s gas
sensor as shown in Fig 2.2.
Display
Description
PPM [d][d][d] 1
Gas PPM [parts per million]
100 –10.0k
Displays a value from 100 ppm to 10,000 ppm
1. d →decimal number
DO Status Display
Display
Description
CLS [Closed]
Displays the DO is in closed status
OPN [Open]
Displays the DO is in open status

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Event Mode
The screen automatically switches to the event mode when a start event occurs. In the event mode, the
maximum PPM value and the event LED blink, and the digital output is also turned on. When the event
occurs, the previously saved maximum PPM value is reset, and the module measures the maximum value
again from the starting point of the event. Thus, it displays the maximum PPM value of the most recent
event.
Maximum Gas PPM Display
Display
Description
Max [d][d][d] 1
Displays the maximum gas value in PPM
k segment
Indicates thousands
1. d →decimal number
Event Mode Reset
The event mode is reset by long pressing the SET button, and the screen switches to the display mode.
The event LED also stops blinking, and the digital output is also turned off. Users can configure to
automatically reset the DO when an end event is detected. For details, refer to the “Setup Mode>DO Reset”
section.
Setup Mode
Each time the SET button is short pressed, the next setup menu is selected.
Event
Event
Threshold1
Event
Hysteresis1
Definite
time 1
DO
Type
DO
Period 2
DO
On time 2
DO
Polarity
DO
Reset
DO
Control 3
1. If the event settings are Off, it is not displayed.
2. If the DO type is set to Latch, it is not displayed.
3. If the event settings are On, it is not displayed.
Note
If there is no button operation for 10 seconds in the setup mode, the screen automatically returns to the
display mode. If there is no button operation for 25 seconds in the edit mode, it automatically returns
to the display mode.

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Chapter 2 Accura MD-GAS Operation/Setup
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Page 19
Event Setup
When the event parameter is set to on, the event LED is turned off, and the DO is reset according to the
preset DO polarity.
Event
oFF[Off]
Event detection mode disabled
on[On, default]
Event detection mode enabled
An “Over”event 1occurs the measured value rises above the threshold
value for event detection and the definite time elapses.
1. An “Over”event consists of a start event and an end event.
Threshold Setup
The event threshold value can be set only when the event settings are On.
Event Threshold
[d][d][d] 1
Default 2000 ppm
Event threshold value
Range: 110 - 9,990 ppm [0.11k - 9.99k]
1. d →decimal number
Hysteresis Setup
The event hysteresis value can be set only when the event settings are On.
Event Hysteresis
[d][d][d] 1
Default 500 ppm
Event hysteresis value
Range: 10 - 999 ppm
1. d →decimal number
Definite Time Setup
The definite time for event detection can be set only when the event settings are On.
Time Delay for an Over Event
[d].[d] 1
default 1.0 sec
0.5 –5.0 sec / 0.5 sec step
1. d →decimal number

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Item
Description
Start level
Threshold value for event detection
End level
Threshold value –Hysteresis value
Start event
A start event occurs when the measured value exceeds the threshold value for event detection
and the definite time elapses. A start event occurs again only if the measured value rises above
the threshold value again after the value drops below the end level and an end event occurs.
The Event LED blinks only when a start event occurs.
End event
An end event occurs when the measured value drops below the end level. The Event LED is
turned off only with the SET button.
Hysteresis
When the measured values often exceed and fall below the threshold value for event detection,
it can cause multiple events to occur. Thus, for effective event management, it is necessary to
set up a proper hysteresis level.
DO Type Setup
DO Type
Lat[Latch: default]
The status of the contact point is maintained.
PuL[Pulse]
Pulses occur repeatedly at the configured time interval.
DO Period Setup
The DO period can be set only when the DO type is set to pulse.
DO Period
[d][d].[d] 1
Setup of the cycle during which a pulse occurs [second]
Default 0.4 sec
Range: 0.2 –65.5 seconds
1. d →decimal number
DO On Time Setup
The DO on time can be set only when the DO type is set to pulse.
DO On time
[d][d].[d] 1
Setup of the pulse On time [second]
Default 0.2 sec
Range: 0.1 –65.4 seconds
1. d →decimal number
DO Polarity Setup
DO Polarity
nrM[Normal: default]
Initial contact status is open. When an event occurs, the contact
gets closed.
rEu[Reverse]
Initial contact status is closed. When an event occurs, the contact
gets open.