PT2E-18711

Fixed Combustible/
Toxic Gas Detector HeadGD-A80 Series
GD-A80，GD-A80D
GD-A80V，GD-A80DV
GD-A80S，GD-A80DS
GD-A80N，GD-A80DN
Operating Manual

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 canbe 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 byenvironmental (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 eventhough their amount is very small.

5.

For maintenance of the detector, it must go through a regular maintenance, including replacement andadjustment 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.

-2-Contents
1.Outline of the Product ....................................................................................................................................... 4
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 ............................................................................................................................ 6
2-1. Danger cases ........................................................................................................................................... 6
2-2. Warning cases ......................................................................................................................................... 7
2-3. Precautions .............................................................................................................................................. 8
2-4. Safety Information .................................................................................................................................... 9
3.Product Components ...................................................................................................................................... 12
3-1. Main unit and standard accessories ...................................................................................................... 12
4.How to Use ..................................................................................................................................................... 14
4-1. Before using the detector....................................................................................................................... 14
4-2. Precautions for installation sites ............................................................................................................ 14
4-3. Precautions for system designing .......................................................................................................... 15
4-4. How to install.......................................................................................................................................... 17
4-5. Installation procedure ............................................................................................................................ 18
4-6. How to wire ............................................................................................................................................ 20
4-7. How to tube (* For suction type) ............................................................................................................ 24
5.How to Operate .............................................................................................................................................. 25
5-1. Preparation for start-up .......................................................................................................................... 25
5-2. How to start the detector........................................................................................................................ 25
5-3. How to detect ......................................................................................................................................... 25
5-4. How to exit ............................................................................................................................................. 26
6.Maintenance ................................................................................................................................................... 27
6-1. Maintenance intervals and items ........................................................................................................... 27
6-2. Calibration method ................................................................................................................................. 29
6-3. Replacement parts ................................................................................................................................. 31
7.Storage, Relocation and Disposal .................................................................................................................. 33
7-1. Procedures to store the detector or leave it for a long time ................................................................... 33
7-2. Procedures to relocate the detector or use it again ............................................................................... 33
7-3. Disposal of products .............................................................................................................................. 33
8.Troubleshooting .............................................................................................................................................. 34
9.Product Specifications .................................................................................................................................... 36
9-1. Standard specifications .......................................................................................................................... 36
9-2. Detection principle ................................................................................................................................. 40
10.Definition of Terms.......................................................................................................................................... 43-3-

1 Outline of the Product1-1. Preface

1

Outline of the Product1-1. Preface
Thank you for choosing our fixed combustible/toxic gas detector head GD-A80 series.
Please check that the model number of the product you purchased is included in the specifications on thismanual.
This manual explains how to use the detector and its specifications. It contains information required forusing 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 readthe 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 or toxic 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.
The suction type of the detector uses an external pump, etc. to introduce gas and performs gas
detection.
Use the detector in combination with an indicator/alarm unit that indicates a gas concentration andtriggers an alarm.
When the detector detects a leak of combustible or toxic gas, it outputs a voltage according to the gas
concentration. The indicator/alarm unit indicates the gas concentration and triggers an alarm if apreset concentration level is exceeded.

1-3. Definition of DANGER, WARNING, CAUTION andNOTE
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.

-4-2 Important Notices on Safety

2-4. Safety Information

2-4. Safety Information
Necessary information for explosion proof construction of Model GD-A80 series.
This product is diffusion gas detector which is called type GD-A80, and used in connection with indication
alarm.
This product also can be used as suction gas detector, type GD-A80D by attaching suction chamber.
<ATEX/IECEx/UKEX Specifications>Technical Data
(Protection Method)(Group)(Category)(Type of Protection and Marking code)(Equipment Protection Level)(Ambient Temperature)*(Electrical Data)
Electrical rating :Flameproof enclosure “d”
II
2G
Ex db IIC T4 Gb
Gb-40C to +53C

GD-A80(D)DC3.0V 430mA or DC5.0V 200mA
GD-A80(D)V
DC6.5V 205mA or DC3.5V 350mA
GD-A80(D)S
DC3.0V 500mA or DC5.0V 200mA
GD-A80(D)N
DC3.3V 170mA or DC1.0V 220mA(Certificate numbers)
IECEx DNV 21.0052X
DNV 21 ATEX 64381X
DNV 22 UKEX 25925X(Applicable Standard)
EN IEC 60079-0 : 2018，EN 60079-1: 2014
IEC60079-0 (2017), IEC60079-1 (2014-06)
BS EN IEC60079-0: 2018, BS EN 60079-1: 2014
*The ambient temperature range which maintain a capability of explosion proof of the label on thedetector is -40～+53℃. However, the available operating temperature range is -20～+53℃.
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 measuring function according to schedule 1, paragraph 24 of the Regulation is not covered in this UKtype examination. It shall comply with the requirements from the relevant UK Designated Standards which
provide guidance on the performance of gas detection equipment.”
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.

-9-2 Important Notices on Safety

2-4. Safety Information

Installation【DG-A80(D)／A80(D)S／A80(D)N】【GD-A80(D)V】
Installation Diagram

Installation Diagram
Hazardous Location

Nonhazardous Location

Gas Detector

Nonhazardous Location

Hazardous Location
Gas Detector

GD-A80(D)GD-A80(D)V

GD-A80(D)SGD-A80(D)N

Indicator etc.

Indicator etc.

Terminals

Terminals
for sensor

SensorSensorfor sensor

Cable

Cable

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2 Important Notices on Safety

2-4. Safety Information<Japan Ex Specifications>Technical Data
(Protection Method)

Flameproof enclosure(Explosion-proof class)

Ex d ⅡC T4(Ambient Temperature) *-40C to +53C(Electrical Data)
Electrical rating :GD-A80(D)DC3.0V 430mA or DC5.0V 200mA

GD-A80(D)V

DC6.5V 205mA or DC3.5V 350mA

GD-A80(D)S

DC3.0V 500mA or DC5.0V 200mA

GD-A80(D)N

DC3.3V 170mA or DC1.0V 220mA(Applicable Standard)
JNIOSH-TR-NO. 43(2008)*The ambient temperature range which maintain a capability of explosion proof of the label on thedetector is -40～+53℃. However, the available operating temperature range is -20～+53℃.

Installation【DG-A80(D)／A80(D)S／A80(D)N】【GD-A80(D)V】

Installation Diagram

Installation Diagram
Hazardous Location

Nonhazardous Location

Gas Detector

Nonhazardous Location

Hazardous Location
Gas Detector

GD-A80(D)GD-A80(D)V

GD-A80(D)SGD-A80(D)N

Indicator etc.

Indicator etc.

Terminals

SensorTerminals
Sensorfor sensor

for sensor

Cable

Cable

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4 How to Use

Protection against
lightning

Grounding*

4-3. Precautions for system designing

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 isprevented 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.)
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, sothat signals may be attenuated by installing the arrester. Before installing a lightning arrester,
verify that it works properly.

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6 Maintenance

6-1. Maintenance intervals and items

6

MaintenanceThe detector is an important instrument for the purpose of safety.
To maintain the performance of the detector and improve the reliability of safety, perform a regular
maintenance.
Continuing to use the detector without performing maintenance will compromise the sensitivity of the gas
sensor, thus resulting in inaccurate detection.

6-1. Maintenance intervals and items

Daily maintenance:
Monthly maintenance:
Regular maintenance:

Perform maintenance before beginning to work.
Perform maintenance on the alarm circuit (alarm test) once a month.
Perform maintenance once or more for every six months to maintain theperformance as a safety unit.

Maintenance item

Maintenance content

Power supply
check*1
Status display
check*1
Flow rate check*2

Check that the power lamp lights up.

Concentration
display check*1

Filter check*2
Alarm test*1
Spanadjustment*1
Gas alarm
check*1

Check that the fault lamp does notlight up.
Check the flow rate to findabnormalities.
Check that the concentration display
value is zero. When the reading isincorrect, perform the zeroadjustment after ensuring that nointerference gases exist around it.
Check the dust filter for dust or
clogging.
Inspect the alarm circuit by using thealarm test function.
Perform the span adjustment byusing the calibration gas.
Check the gas alarm by using thecalibration gas.

Daily
maintenance

Monthly
maintenanceRegularmaintenance

○

○

○

○

○

○

○

○

○

○

○

○

○

○

○

－

○

○

－

－

○

－

－

○

*1. Check and adjustment are performed at the indicator/alarm unit side. See the operating manual of theindicator/alarm unit for details.
*2. Suction type only

- 27 -

6 Maintenance

6-3. Replacement parts<Replacement of Regular Replacement Parts>
List of recommended regular replacement parts

*

No.

Item

Maintenanceintervals

Replacement
intervals (year)

Quantity(pieces/unit)

Part number

1

Rubber seal (sensor)

6 months

3 - 8 years

14262 4545 102

Suction cap

6 months

3 - 8 years

1

The operation must be checked after replacement by our service engineer. For the stable operation of
the detector and safety, ask our service engineer to take care of replacement of the part. Request
RIKEN KEIKI for operation check.

NOTE



The above replacement intervals are recommendation only. The intervals may change dependingon the operating conditions. These intervals do not mean the warranty periods either.
The result of the regular maintenance may determine when to replace the parts.

- 32 -

8 Troubleshooting

8

Troubleshooting
The Troubleshooting does not explain the causes of all the malfunctions which occur on the detector. This
simply helps to find the causes of malfunctions which frequently occur. If the detector shows a symptom
which is not explained in this manual, or still has malfunctions even though remedial actions are taken,
please contact RIKEN KEIKI.
<Abnormalities of Readings>*
Take remedial actions to indicator/alarm unit as well See the operating manual of the indicator/alarm
unit for details.
Symptoms

The reading rises(drops) and it remainsso.

CausesDrifting of sensor
outputPresence ofinterference gas

Slow leakA gas alarm is triggered
despite of no gas leakand no otherabnormalities at thedetection point.

Slow response

Actions
Perform zero adjustment.
Disturbances by interference gases, such as solvents,
cannot be eliminated completely. For information on
actions, such as removal filter, please contact RIKEN
KEIKI.
A very small amount of the gas to be detected may beleaking (slow leak). Because ignoring it may cause
dangers, take a remedial measure, i.e., taking actions
the same as those for the gas alarm.

Environmental
changes

Perform zero adjustment.

Presence ofinterference gas

Disturbances by interference gases, such as solvents,
cannot be eliminated completely. For information on
actions, such as removal filter, please contact RIKEN
KEIKI.

Disturbance by noise

Turn off and restart the detector.
If such a symptom is observed frequently, takeappropriate measures to eliminate the noise.

Sudden change inthe environment

When the environment (temperature, etc.) changes
suddenly, the detector cannot adjust to it and is affectedby it.
In some cases, the detector triggers an indication alarm.
Because the detector cannot be used under sudden andfrequent environmental changes, any preventive actions
to eliminate them should be taken by the user.

Deteriorated sensor
sensitivity
Cloggeddust filter
Bent, clogged orleakedsuction/exhaust tube
Condensation isformed inside thesuction tube.

Replace the sensor with a new one.
Replace the dust filter.
Fix the defective parts.
Fix the defective parts.

- 34 -

8 Troubleshooting

Span adjustment
impossible

Improper calibration
gas concentration
Deteriorated sensor
sensitivity

Use the proper calibration gas.
Replace the sensor with a new one.

- 35 -

9 Product Specifications

9-1. Standard specifications

9

Product Specifications
9-1. Standard specifications[Diffusion type]＜ATEX/IECEx/UKEX Specifications＞
Model
Detection
principle
Gas to be
detected
Detection method
Transmission
cable

GD-A80Catalytic
combustion or new
ceramic
Combustible gasesin the air

GD-A80V

GD-A80S

GD-A80N

Semiconductor

Hot-wiresemiconductor

Thermal conductivity

Combustible/toxic Combustible/toxic
gases in the airgases in the air
Natural diffusion typeCombustible gases in
the air/inert gas

1.25 or 2.0 mm2
CVV, 4-core orequivalent

CVVS, 3-core orequivalent

CVVS, 4-core or equivalent

Cable connecting
Pressure proof packing gland G3/4 [Rubber seal ID] ø12 for mounted, ø13 for attached
port
Operating-20 - +53°C (At a constant condition)
temperatures*
Operating
Below 95% RH (Non-condensing)humidities
Structure
Wall mounting type, 2B (50A) pipe attachable
Explosion-proof
Flame-proof enclosures
structure
Explosion-proof
II2G Ex db IIC T4 Gb (ATEX/UKEX)
class
Ex db IIC T4 Gb (IECEx)
External
Approx. 78 (W) x 163 (H) x 105 (D) mm (Fixing brackets excluded)
dimensions
WeightApprox. 1.0kg
Paint color
Munsell 7. 5BG5/2*The ambient temperature range which maintain a capability of explosion proof of the label on thedetector is -40～+53℃. However, the available operating temperature range is -20～+53℃.

- 36 -

9 Product Specifications

9-1. Standard specifications[Suction type] ＜ATEX/IECEx/UKEX Specifications＞
Model
Detection
principle
Gas to be
detected

GD-A80D
Catalytic
combustion or new
ceramic
Combustible gasesin the air

Detection method
Flow rate
Transmission
cable

GD-A80DV

GD-A80DS

GD-A80DN

Semiconductor

Hot-wiresemiconductor

Thermal conductivity

Combustible/toxic
gases in the air

Combustible/toxic
gases in the air

Combustible gases in
the air/inert gas

Suction type (introduced by an external pump unit)
0. 8 - 2 L/min
1.25 or 2.0 mm2
CVV, 4-core orequivalent

CVVS, 3-core orequivalent

CVVS, 4-core or equivalent

Cable connecting
Pressure proof packing gland G3/4 [Rubber seal ID] ø12 for mounted, ø13 for attached
port
Operating-20 - +53°C (At a constant condition)
temperatures*
Operating
Below 95% RH (Non-condensing)humidities
Structure
Wall mounting type, 2B (50A) pipe attachable
Explosion-proof
Flame-proof enclosures
structure
Explosion-proof
II2G Ex db IIC T4 Gb (ATEX/UKEX)
class
Ex db IIC T4 Gb (IECEx)
External
Approx. 78 (W) x 163 (H) x 123 (D) mm (Fixing brackets excluded)
dimensions
WeightApprox. 1.0kg
Paint color
Munsell 7. 5BG5/2*The ambient temperature range which maintain a capability of explosion proof of the label on thedetector is -40～+53℃. However, the available operating temperature range is -20～+53℃.

- 37 -

9 Product Specifications

9-1. Standard specifications[Diffusion type]＜Japan Ex Specifications＞
Model
Detection
principle
Gas to be
detected
Detection method
Transmission
cable

GD-A80Catalytic
combustion or new
ceramic
Combustible gasesin the air

GD-A80V

GD-A80S

GD-A80N

Semiconductor

Hot-wiresemiconductor

Thermal conductivity

Combustible/toxic Combustible/toxic
gases in the airgases in the air
Natural diffusion typeCombustible gases in
the air/inert gas

1.25 or 2.0 mm2
CVV, 4-core orequivalent

CVVS, 3-core orequivalent

CVVS, 4-core or equivalent

Cable connecting
Pressure proof packing gland G3/4 [Rubber seal ID] ø12 for mounted, ø13 for attached
port
Operating-20 - +53°C (At a constant condition)
temperatures*
Operating
Below 95% RH (Non-condensing)humidities
Structure
Wall mounting type, 2B (50A) pipe attachable
Explosion-proof
Flame-proof enclosures
structure
Explosion-proof
Ex d IIC T4 (Japan Ex)
class
External
Approx. 78 (W) x 163 (H) x 105 (D) mm (Fixing brackets excluded)
dimensions
WeightApprox. 1.0kg
Paint color
Munsell 7. 5BG5/2*The ambient temperature range which maintain a capability of explosion proof of the label on thedetector is -40～+53℃. However, the available operating temperature range is -20～+53℃.

- 38 -

9 Product Specifications

9-1. Standard specifications[Suction type] ＜Japan Ex Specifications＞
Model
Detection
principle
Gas to be
detected

GD-A80D
Catalytic
combustion or new
ceramic
Combustible gasesin the air

Detection method
Flow rate
Transmission
cable

GD-A80DV

GD-A80DS

GD-A80DN

Semiconductor

Hot-wiresemiconductor

Thermal conductivity

Combustible/toxic
gases in the air

Combustible/toxic
gases in the air

Combustible gases in
the air/inert gas

Suction type (introduced by an external pump unit)
0. 8 - 2 L/min
1.25 or 2.0 mm2
CVV, 4-core orequivalent

CVVS, 3-core orequivalent

CVVS, 4-core or equivalent

Cable connecting
Pressure proof packing gland G3/4 [Rubber seal ID] ø12 for mounted, ø13 for attached
port
Operating-20 - +53°C (At a constant condition)
temperatures*
Operating
Below 95% RH (Non-condensing)humidities
Structure
Wall mounting type, 2B (50A) pipe attachable
Explosion-proof
Flame-proof enclosures
structure
Explosion-proof
Ex d IIC T4 (Japan Ex)
class
External
Approx. 78 (W) x 163 (H) x 123 (D) mm (Fixing brackets excluded)
dimensions
WeightApprox. 1.0kg
Paint color
Munsell 7. 5BG5/2*The ambient temperature range which maintain a capability of explosion proof of the label on thedetector is -40～+53℃. However, the available operating temperature range is -20～+53℃.

- 39 -

10 Definition of Terms

10

Definition of Terms
Catalytic
combustion typeNew ceramic
Semiconductor
Hot-wiresemiconductor
Thermalconductivity
Initial clear
Full scale
% LEL
ppm
Calibration

This is a principle of the sensor installed in GD-A80(D).
See "9-2. Detection principle" for details.
This is a principle of the sensor installed in GD-A80(D).
See "9-2. Detection principle" for details.
This is a principle of the sensor installed in GD-A80(D)V.
See "9-2. Detection principle" for details.
This is a principle of the sensor installed in GD-A80(D)S.
See "9-2. Detection principle" for details.
This is a principle of the sensor installed in GD-A80(D)N.
See "9-2. Detection principle" for details.
Output from the detector head fluctuates for a while after turning on the power.
This is a function to prevent triggering alarm during that time.
Maximum value of the detection range.
A unit that assumes the lower explosive limit of the combustible gas to be detected
as 100.
A concentration unit that means part per million of the combustible gas to be
detected.
Adjusts the readings to the calibration gas concentration value by using thecalibration gas.

- 43 -