Riken Keiki GD-A80 Series User manual

PT2E-1856
Fixed Combustible Gas Detector Head
GD-A80 Series
GD-A80-70
Operating Manual

- 2 -
Operating Precautions
This detector is a gas detector that detects combustible or toxic gases in the air and triggers a gas alarm.
The gas detector is a safety unit, not an analyzer or densitometer which performs quantitative/qualitative
analysis/measurement for gases. Please fully understand the following points before using it, so that it can
be used properly.
1. This detector may be interfered by gases other than the gas to be detected and vapors.
Please note that the alarm may be triggered by interference. In addition, it may be fluctuated by
environmental (temperature, humidity, etc.) changes in the installation site.
2. The alarm must be set within a range where the performance of the detector can be ensured.
In facilities compliant with the High Pressure Gas Safety Act, an alarm setting below our standard alarm
setpoint may trigger a false alarm.
3. This is a safety unit, not a control unit.
4. If silicon or sulfide compounds are accumulated on the surface of sintered alloy of the gas detector
sensor used for this unit, the area of the gas sensing part becomes smaller, which may result in serious
deterioration of its sensitivity.
For safety reasons, do not use the detector under the presence of silicon or sulfide compounds even
though their amount is very small.
5. For maintenance of the detector, it must go through a regular maintenance, including replacement and
adjustment of the regular replacement parts as specified in the operating manual. In addition, because
this is a safety unit, it is recommended that a regular maintenance and a calibration are performed
every six months in accordance with the regulations.

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Contents
1 Outline of the Product
1-1. Preface.....................................................................................................................................................4
1-2. Purpose of use.........................................................................................................................................4
1-3. Definition of DANGER, WARNING, CAUTION and NOTE......................................................................4
1-4. Method of confirmation for Standards and Explosion proof specification ...............................................5
2 Important Notices on Safety
2-1. Danger cases...........................................................................................................................................6
2-2. Warning cases .........................................................................................................................................6
2-3. Precautions ..............................................................................................................................................7
2-4. Safety Information....................................................................................................................................8
3 Product Components
3-1. Main unit and standard accessories ......................................................................................................10
4 How to Use
4-1. Before using the detector.......................................................................................................................12
4-2. Precautions for installation sites ............................................................................................................12
4-3. Precautions for system designing..........................................................................................................13
4-4. How to install..........................................................................................................................................15
4-5. Installation procedure ............................................................................................................................16
4-6. How to wire ............................................................................................................................................18
5 How to Operate
5-1. Preparation for start-up..........................................................................................................................21
5-2. How to start the detector........................................................................................................................21
5-3. How to detect .........................................................................................................................................21
5-4. How to exit .............................................................................................................................................21
6 Maintenance
6-1. Maintenance intervals and items ...........................................................................................................22
6-2. Calibration method.................................................................................................................................24
6-3. Replacement parts.................................................................................................................................26
7 Storage, Relocation and Disposal
7-1. Procedures to store the detector or leave it for a long time...................................................................28
7-2. Procedures to relocate the detector or use it again...............................................................................28
7-3. Disposal of products ..............................................................................................................................28
8 Troubleshooting ..........................................................................................................................................29
9 Product Specifications
9-1. Standard specifications..........................................................................................................................30
9-2. Detection principle .................................................................................................................................32
10 Definition of Terms ....................................................................................................................................33

1 Outline of the Product 1-1. Preface
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1
Outline of the Product
1-1. Preface
Thank you for choosing our fixed combustible gas detector head GD-A80-70.
Please check that the model number of the product you purchased is included in the specifications on this
manual.
This manual explains how to use the detector and its specifications. It contains information required for
using the detector properly. Not only the first-time users but also the users who have already used the
product must read and understand the operating manual to enhance the knowledge and experience before
using the detector.
Note that the detector cannot be used alone. Use it with the dedicated indicator/alarm unit. Be sure to read
the operating manual of the indicator/alarm unit as well.
1-2. Purpose of use
This detector is a fixed type gas detector head which detects leak of combustible gases.
The detector is a safety unit, not an analyzer or densitometer which performs quantitative/qualitative
analysis/measurement for gases.
Please fully understand the features of the detector before using it, so that it can be used properly.
The detector detects abnormalities caused by presence of gases (leak) with the built-in gas sensor.
Use the detector in combination with an indicator/alarm unit that indicates a gas concentration and
triggers an alarm.
When the detector detects a leak of combustible gas, it outputs a voltage according to the gas
concentration. The indicator/alarm unit indicates the gas concentration and triggers an alarm if a preset
concentration level is exceeded.
1-3. Definition of DANGER, WARNING, CAUTION and
NOTE
DANGER This message indicates that improper handling may cause serious damage on
life, health or assets.
WARNING This message indicates that improper handling may cause serious damage on
health or assets.
CAUTION This message indicates that improper handling may cause minor damage on
health or assets.
NOTE This message indicates advice on handling.

1 Outline of the Product 1-4. Method of confirmation for Standards and Explosion proof specification
- 5 -
1-4. Method of confirmation for Standards and
Explosion proof specification
This instrument has some specification depends on standard and explosion proof certificate. Please
confirm the detector specification before using. Please refer Declaration of Conformity that is at the end of
this manual if you have CE marking type. You can confirm instrument specification to see name plate as
follows.
ATEX/IECEx, CE marking type name plate TIIS type name plate
CE marking
Ex marking TIIS certificate

2 Important Notices on Safety 2-1. Danger cases
- 6 -
2
Important Notices on
Safety
2-1. Danger cases
2-2. Warning cases
DANGER
<About explosion-proof>
Do not attempt to repair the detector.
Do not open the lid when applying current.
For the lid, use hexagon socket head bolts specified by RIKEN KEIKI.
Do not repair the explosion-proof joint surface.
If a scratch, crack or other abnormality is found on the container or explosion-proof structure
j
oint surface, sto
p
usin
g
the detector immediatel
y
and contact RIKEN KEIKI.
WARNING
Need of grounding circuit
Do not cut the grounding circuit or disconnect the wire from the grounding terminal.
Defects in protective functions
Before starting the detector, check the protective functions for defects. When seeming defects are
found in the protective functions, such as protective grounding, do not start the detector.
Zero adjustment in the atmosphere
When the zero adjustment is performed in the atmosphere, check the atmosphere for freshness
before beginning the adjustment. If interference gases exist, the adjustment cannot be performed
properly, thus leading to dangers when the gas leaks.
Do not install the detector in a place where silicone, chloride or sulfide is present consistently.
If the detector is installed in such a place, the sensor life will be shortened significantly due to
poisoning, resulting in a dangerous situation where proper gas detection cannot be performed.
Response to gas alarm
Issuance of a gas alarm indicates that there are extreme dangers. Take proper actions based on
your judgment.

2 Important Notices on Safety 2-3. Precautions
- 7 -
2-3. Precautions
CAUTION
Do not use a transceiver or other radio wave transmitting device near the detector.
Radio wave from a transceiver, etc. near the detector or its cables may disturb operations. If a
transceiver or other radio wave transmitting device is used, it must be used in a place where it
disturbs nothing.
Do not disassemble/modify the detector.
Disassembling/modifying the detector will invalidate the warranty of the performance.
Please use the detector properly in accordance with the operating manual.
Never fail to perform a regular maintenance.
Since this is a safety unit, a regular maintenance must be performed to ensure safety. Continuing to
use the detector without performing a maintenance will deteriorate the sensitivity of the sensor, thus
resulting in inaccurate gas detection.

2 Important Notices on Safety 2-4. Safety Information
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2-4. Safety Information
Necessary information for explosion proof construction of Model GD-A80-70.
This product is diffusion gas detector which is called type GD-A80-70, and used in connection with
indication alarm.
<ATEX/IECEx Specifications>
Technical Data
(Protection Method) Flameproof enclosure “d”
(Group) II
(Category) 2G
(Type of Protection and Marking code) Ex db II CT4
(Equipment Protection Level) Gb
(Ambient Temperature)* -40℃to +70℃
(Electrical Data)
Electrical rating : DC3.0V 430mA or DC5.0V 200mA
(Applicable Standard) EN IEC 60079-0 : 2018，EN 60079-1 : 2014
IEC60079-0 : 2017, IEC 60079-1 : 2014-06
*The ambient temperature range that can maintain explosion protection, and is not operating temperature
range that ensures product performance. For the operating temperature, see “9.Product Specifications”.
Specific conditions of “X”-mark:
Regarding ATEX specification, the measuring function according to Annex II paragraph 1.5.5 of the
Directive is not covered by this EU-type examination.
It shall comply with the requirements from the relevant European harmonized standards which provide
guidance on the performance of gas detection equipment and safety devices.
The flameproof joints not intended to be repaired.
Fasteners used for enclosure are from stainless steel property class A2-70.
Cable gland may not provide sufficient clamping. User shall provide additional clamping against the cable
pulling and twisting.
Installation
Cable
Indicator etc.
GasDetector (GD‐A80)
Hazardous Location Nonhazardous Location
InstallationDiagram
Terminals
forsensor
Sensor
Gas Detector
(GD-A80-70)
Installation Diagram
Hazardous Location Nonhazardous Location
Indicator etc.

2 Important Notices on Safety 2-4. Safety Information
- 9 -
<TIIS Specifications>
Technical Data
(Protection Method) Flameproof enclosure
(Explosion-proof class) Ex d ⅡCT4
(Ambient Temperature) * -40℃to +70℃
(Electrical Data)
Electrical rating : DC3.0V 430mA or DC5.0V 200mA
(Applicable Standard) JNIOSH-TR-NO.43(2008)
*The ambient temperature range that can maintain explosion protection, and is not operating temperature
range that ensures product performance. For the operating temperature, see “9.Product Specifications”.
Installation
Cable
Indicator etc.
GasDetector (GD‐A80)
Hazardous Location Nonhazardous Location
InstallationDiagram
Terminals
forsensor
Sensor
Gas Detector
(GD-A80-70)
Installation Diagram
Hazardous Location Nonhazardous Location
Indicator etc.

3 Product Components 3-1. Main unit and standard accessories
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3
Product Components
3-1. Main unit and standard accessories
<Main Unit> (including a cable gland)
[Side view][Front view]
Fixing
bracket
Cable gland
Hexagon socket set
screw
Hexagon socket
head bolt
(with
drop-prevention
mechanism)
External
grounding
terminal
Cable connecting
port G3/4
Main unit
Cover
Sensor
Guard
Nameplate

3 Product Components 3-1. Main unit and standard accessories
- 11 -
<Standard Accessories>
Operating manual ･･････････････････ one
Fixing bracket ････････････････････ one
Rubber seal (ID ø12 mm)*1 ････････ one
Rubber seal (ID ø13 mm) ･･････････ one
Washer (ID ø12 mm)*1 ･･････････････ one
Washer (ID ø14 mm) ･･･････････････ one
Eccentric washer (ID ø11. 8 mm)*1 ･･･ one
Eccentric washer (ID ø12. 8 mm) ･････ one
Hex key wrench ････････････････････ *2
*1. Attached to the suction type only.
*2. Installed to the detector head as standard before shipment.
[Rear view]
Internal
grounding
terminal
Cable
connection
terminal plate
(Interior of main unit)

4 How to Use 4-1. Before using the detector
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4
How to Use
4-1. Before using the detector
Not only the first-time users but also the users who have already used the detector must follow the
operating precautions.
Ignoring the precautions may damage the detector, resulting in inaccurate gas detection.
The fixed combustible gas detector head GD-A80-70 is used in combination with an indicator/alarm unit that
indicates a gas concentration and triggers an alarm.
Once the detector detects a leak of combustible gas, it outputs a voltage according to the gas concentration.
The indicator/alarm unit indicates the gas concentration and triggers an alarm if a preset concentration level
is exceeded.
The detector may react to the gases other than the gases to be detected. When an alarm is triggered after
gas detection, check if the cause of the alarm is attributable to the gases to be detected or other gases.
As a precondition, a gas detector needs to be energized always and operating normally to fulfill the role of
detecting gases. To meet the precondition, it is important to check the daily operation status. For the check
of operation status, see "6-1. Maintenance intervals and items".
4-2. Precautions for installation sites
Do not install the detector in a place with vibrations or shocks.
The detector consists of sensitive electronic parts. The detector must be installed in a stable place without
vibrations or shocks and it cannot drop.
Do not install the detector in a place exposed to water, oil or chemicals.
When selecting installation points, avoid a place where the detector is exposed to water, oil or chemicals.
Do not install the detector in a place where the range of operating temperatures is exceeded.
The detector must be installed in a stable place where the operating temperature is maintained and do not
change suddenly.
For the operating temperature, see “9.Product Specifications”.
CAUTION
This is a precision device. Because the detector may not provide the specified performance in
some places (environments), check the environment in the installation point, and then take
appropriate actions if necessary.
Because the detector plays an important role for safety and disaster prevention, as many units
of the detector as needed must be installed in appropriate points.
Because points where gases leak and remain easily are different depending on the types of
gases and the working areas, please decide carefully on installation points and the number of
units to be installed.

4 How to Use 4-3. Precautions for system designing
- 13 -
Do not install the detector in a place exposed to direct sunlight or sudden changes in the temperature.
When selecting installation points, avoid a place where it is exposed to direct sunlight or radiant heat
(infrared rays emitted from a high-temperature object), and where the temperature changes suddenly.
Condensation may be formed inside the detector, or the detector cannot adjust to sudden changes in the
temperature.
Keep the detector (and its cables) away from noise source devices.
When selecting installation points, avoid a place where high-frequency/high-voltage devices exist.
Do not install the detector in a place where maintenance of the detector cannot be performed or where
handling the detector involves dangers.
Regular maintenance of the detector must be performed.
Do not install the detector in a place where the machinery must be stopped when maintenance is performed
in its inside, where parts of the machinery must be removed to perform maintenance, or where the detector
cannot be removed because tubes or racks, etc. prevent access to it. Do not install the detector in a place
where maintenance involves dangers, for example, near a high-voltage cable.
Do not install the detector in machinery which is not properly grounded.
Before installing the detector in machinery, the machinery must be grounded properly.
Do not install the detector in a place where interference gases exist around it.
The detector must not be installed in a place where interference gases exist around it.
4-3. Precautions for system designing
Introducing protective measures against lightning
If cables are installed outside the factory/plant, or if internal cables are installed in the same duct as the
cables coming from outside the factory/plant, "lightning" will cause problems. Because lightning acts as a
large emission source while cables act as a receiving antenna, devices connected to the cables may be
damaged.
Lightning cannot be prevented. Cables installed in a metal conduit or under the ground cannot be
completely protected from inductive lightning surge caused by lightning. Although complete elimination of
disasters caused by lightning is impossible, the following protective measures can be taken.
WARNING
Do not install the detector in a place where silicone, chloride or sulfide is present consistently.
If the detector is installed in such a place, the sensor life will be shortened significantly due to
poisoning, resulting in a dangerous situation where proper gas detection cannot be performed.
CAUTION
An unstable power supply and noise may cause false alarms.
The descriptions in this section must be reflected on the designing of a system using the
detector.

4 How to Use 4-3. Precautions for system designing
- 14 -
Protection against
lightning
Take appropriate measures in accordance with the importance of the facilities and
the environment.
Provide protection by a lightning arrester (cable arrester).
(Although inductive lightning surge can be transmitted through the cable, it is
prevented by installing a lightning arrester before the field devices and central
processing equipment. For information on how to use a lightning arrester,
please contact the manufacturer.)
Grounding In addition to lightning, there are more sources of surge noise. To protect units
from these noise sources, the units must be grounded.
* The lightning arrester has a circuit to remove a surge voltage which damages field devices, so that
signals may be attenuated by installing the arrester. Before installing a lightning arrester, verify
that it works properly.

4 How to Use 4-4. How to install
- 15 -
4-4. How to install
<Installation Dimensions>
Unit: mm
<Maintenance Space>
Unit: mm
The following installation requirements must be met to install the detector.
Attach the detector to the wall or others using two M5 screws.
Maintenance space Maintenance space
CAUTION
Do not install the detector in a place where maintenance of the detector cannot be performed or
where handling the detector involves dangers.
Regular maintenance of the detector must be performed.
Do not install the detector in a place where the machinery must be stopped when maintenance is
performed in its inside, where parts of the machinery must be removed to perform maintenance, or
where the detector cannot be removed because tubes or racks, etc. prevent access to it. Do not
install the detector in a place where maintenance involves dangers, for example, near a
high-voltage cable.
Fixing
bracket
Maintenance space Maintenance space

4 How to Use 4-5. Installation procedure
- 16 -
4-5. Installation procedure
(1) Attach the cable gland, rubber seal, washer and eccentric washer to the main unit of GD-A80-70 as
shown in the following figure.
Put the cable through the cable gland, eccentric washer, washer and rubber seal in this order.
Then draw the cable into the detector head and attach a crimped terminal for M4 screw to the end of
the cable (EM CCE/F, etc.). For the wiring method, see "4-6. How to wire".
Diffusion type
NOTE
Maximum surface roughness of the enclosure face for sealing is Ra6.3μm.
Hexagon socket head
bolt
M5 x 20
Washer
Pressure proof packing gland
compatible cable (EM CCE/F, etc.)
Eccentric washer
(Note) Tapered side
should face cable
gland
Rubber seal
Cable gland
WARNING
If a scratch, crack or other abnormality is found on the container or explosion-proof structure
joint surface, stop using the detector immediately and contact RIKEN KEIKI.
CAUTION
If it is difficult to tighten the cable gland, grease its screw part and then tighten it with the tool.

4 How to Use 4-5. Installation procedure
- 17 -
(2) Cable gland must be tightened with 30N ꞏm or more of torque. Then tighten the hexagon socket set
screw to fix the cable gland.
<Drip-proof Cover>
Two optional drip-proof covers (round and square drip-proof covers) are available for the GD-A80 series.
Select an appropriate cover for the installation environment ( installation direction etc.) . Use a square
drip-proof cover for an inferior environment condition such as a place with a risk of water splash. Use a
round drip-proof cover when the detector is used on a ship.
<Direct insertion unit>
For detection combustible gas and solvent vapor in a duct, optional direct insertion unit is available for the
GD-A80-70.
Hexagon socket set screw
M4 x 6
[Round drip-proof cover] [Square drip-proof cover]
GD-A80
Fixing
bracket
Rubber seal
t2
Flange
(SPCC t3.2)
Wire

4 How to Use 4-6. How to wire
- 18 -
4-6. How to wire
NOTE
Before wiring, read also the operating manual of the indicator/alarm unit to be connected carefully.
<Recommended Cables>
GD-A80-70 EM CCE/F or equivalent cable (1. 25 or 2 mm2), 4-core
＜Parts. Length table of outside conductor lead-in＞
Cable overall outer diameter
(mm)
Rubber seal inner
diameter
(mm)
Washer inner
diameter
(mm)
Eccentric washer
(mm)
ø 9. 5 - 10. 5 ø11 ø12 ø10.8
ø10. 5 - 11. 5 ø12 ø12 ø11.8
ø11. 5 - 12. 5 ø13 ø14 ø12.8
ø12. 5 - 13. 0 ø13.5 ø14 ø13.8
WARNING
Do not put a metal object or other foreign substances inside the external connection terminal
box when attaching the lid.
Ignoring this may damage the device or impair the explosion-proof performance.
Draw the cable to the detector by the means that do not impair the explosion-proof
performance.
Connect the power to the indicator/alarm unit after all wiring work is completed. Wiring with the
power connected may pose a risk of short circuit between terminals or electric shock.
CAUTION
When wiring, be careful not to apply stresses on the detector when (overweight) cables are
installed.
Temperature of cable inlet may reach +5℃than ambient.
The cables must not be installed together with the motor power cables, etc. When these cables
must be installed together for unavoidable reasons, use a metal conduit. The conduit must be
connected to a grounding circuit.
When stranded wires are used, prevent wires from contacting each other.
Use cables of upper temperature limit 75℃and over.
Use appropriate cables to wire.
inner diameter
inner diameter inner diameter
Rubber seal
Washe
r
Eccentric washer

4 How to Use 4-6. How to wire
- 19 -
NOTE
The following table shows an example of overall outer diameters of cables. Use them for reference.
The overall outer diameters must be checked because they somewhat vary between manufacturers.
Number of core EM CCE/F 1. 25 mm2EM CCE/F 2 mm2
2 ø9.4 ø10.5
3 ø9.9 ø11.0
4 ø11.0 ø12.0
5 ø11.5 ø13.0
6 ø12.5 ø14.0
(1) The numbers 3, 4, 5 and 6 are shown on the terminal plate of the detector head. Perform wiring in the
correct wiring order according to the following connection diagrams.
When attaching the lid of the detector head, be careful not to squeeze the cable. (To make the work
easier, fasten the cable gland temporarily to the detector head.)
Screw size: M4
<Wiring Example>
Indicator/alarm unit
terminal plate
GP-5001 etc.
Detector head terminal
plate
GD-A80-70
12
11
13
14
15
EM CCE/F, 4-core
1. 25 or 2 mm
2
Internal grounding
terminal
Cable
connection
terminal
p
late
M4 screw

4 How to Use 4-6. How to wire
- 20 -
(2) Attach the lid of the detector head and tighten four hexagon socket head bolts securely.
NOTE
Hexagon socket head bolts with a grade of "A2-70" are used.
Contact RIKEN KEIKI when the bolt is lost or replacement is necessary.
<Grounding>
Connect the detector to your grounding terminal with the external terminal .
Hex key wrench
Hexagon socket head bolts
(M5 x 20)
WARNING
Be sure to use the bolts supplied with the unit to attach the lid of the detector head.
Also, be sure to attach four bolts.
Using the bolts other than those supplied with the unit will impair the explosion-proof
performance.
When wiring is completed, check for wrong wiring once again before turning on the power.
If the power is turned on with wrong wiring, sensor disconnection will occur and the unit will
become unavailable.
WARNING
Before turning on the detector, never fail to connect it to a grounding terminal.
For stable operation of the detector and safety, it must be connected to a grounding terminal.
Do not connect the grounding wire to a gas pipe.
The grounding must be made as D type grounding (below 100 Ωof grounding resistance).
For the grounding wire, use cable lugs to safely connect it to a grounding terminal without
looseness or twist.
To connect the grounding wire to the internal grounding terminal of the unit, use a crimped
terminal to which a wire with a cross-section area of 4 mm2or more can be attached.