PT2E-1858

Fixed Combustible Gas Detector HeadGD-A80 Series

GD-A80-70
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 inserious 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 Product1-1. Preface..................................................................................................................................................... 41-2. Purpose of use ......................................................................................................................................... 41-3. Definition of DANGER, WARNING, CAUTION and NOTE...................................................................... 41-4. Method of confirmation for Standards and Explosion proof specification ............................................... 52 Important Notices on Safety
2-1. Danger cases ........................................................................................................................................... 62-2. Warning cases ......................................................................................................................................... 62-3. Precautions .............................................................................................................................................. 72-4. Safety Information .................................................................................................................................... 83 Product Components
3-1. Main unit and standard accessories ...................................................................................................... 104 How to Use
4-1. Before using the detector....................................................................................................................... 124-2. Precautions for installation sites ............................................................................................................ 124-3. Precautions for system designing .......................................................................................................... 134-4. How to install.......................................................................................................................................... 154-5. Installation procedure ............................................................................................................................ 164-6. 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 .................................................................................................................................... 33-3-

1 Outline of the Product1-1. Preface

1Outline of the Product1-1. 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 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 theproduct 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 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 andtriggers 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 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-A80-70.
This product is diffusion gas detector which is called type GD-A80-70, and used in connection withindication alarm.
<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 :(Certificate numbers)

Flameproof enclosure “d”
II2G
Ex db II CT4Gb-40℃ to +70℃

DC3.0V 430mA or DC5.0V 200mA
IECEx DNV 21.0052X
DNV 21 ATEX 64381X
DNV 22 UKEX 25925X
EN IEC 60079-0 : 2018，EN 60079-1 : 2014
(Applicable Standard)
IEC60079-0 : 2017, IEC 60079-1 : 2014-06
BS EN IEC60079-0:2018, BS EN 60079-1:2014*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.ProductSpecifications”.
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.

Installation
Installation Diagram
Hazardous Location

Nonhazardous Location

Gas Detector(GD-A80-70)
Indicator etc.

Terminals
for sensorSensor

Cable-8-2 Important Notices on Safety

2-4. Safety Information<Japan Ex 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.ProductSpecifications”.

Installation

Installation Diagram
Hazardous Location

Nonhazardous Location

Gas Detector(GD-A80-70)
Indicator etc.

Terminals
for sensor

Sensor

Cable-9-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.

- 14 -6 Maintenance

6-1. Maintenance intervals and items

6MaintenanceThe 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 regularmaintenance.
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:

Maintenance item
Power lampcheck*Status display
check*
Gasconcentration
display check*
Alarm test*
Span adjustment*
Gas alarm check*

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 content
Check that the power lamp lights up.
Check that the fault lamp does notlight up.
Check that the concentration display
value is zero. When the reading isincorrect, perform the zeroadjustment after ensuring that nointerference gases exist around it.
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

○

○

○

○

○

○

○

○

○

－

○

○

－－

○

－－

○

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

- 22 -

6 Maintenance

6-3. Replacement parts<Replacement of Regular Replacement Parts>
List of recommended regular replacement parts*No.

ItemMaintenanceintervals

Replacement
intervals (year)

Quantity(pieces/unit)

Part number

1

Rubber seal (sensor)

6 months

3 - 8 years

14262 4545 10

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.

- 27 -8 Troubleshooting

8Troubleshooting
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
Span adjustment
impossible

Actions
Perform zero adjustment.
Disturbances by interference gases, such as solvents,
cannot be eliminated completely. For information onactions, 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 onactions, 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
Improper calibration
gas concentration
Deteriorated sensor
sensitivity

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

- 29 -9 Product Specifications

9-1. Standard specifications

9Product Specifications
9-1. Standard specifications＜ATEX/IECEx/UKEX Specifications＞
ModelDetection
principle
Mounted sensor
Gas to be
detected
Detection method
Transmission
cable
Cable connecting
portOperatingtemperatures
Operatinghumidities
Structure
Explosion-proof
structure
Explosion-proof
class
External
dimensions
WeightGD-A80-70
Catalytic combustion
HW-6212
HW-6239
Combustible gas(methane excluded),
Methane, Isobutane, Hydrogen
Solvent vapor
Natural diffusion type
EM CCE/F (1.25 or 2.0 mm2), 4-core equivalentPressure proof packing gland G3/4
[Rubber seal ID] ø12 for mounted, ø13 for attached-10 - +100℃ (At a constant condition)*-40 - +70℃ (At a constant condition)

Below 95% RH (Non-condensing)
Wall mounting type, 2B (50A) pipe attachable
Flame-proof enclosures
Ⅱ 2G Ex db ⅡC T4 Gb (ATEX/UKEX)
Ex db ⅡC T4 Gb (IECEx)
Approx. 78 (W) x 163 (H) x 105 (D) mm (Fixing brackets excluded)

Approx. 1.0kg
Munsell 7. 5BG5/2
Paint color
Name plate : red*The ambient temperature range which maintain a capability of explosion proof of the label on thedetector is -40～+70℃. However, the available operating temperature range is -10～+100℃(when it
exceed +70℃, is exempt from explosion proof).

- 30 -9 Product Specifications

9-1. Standard specifications＜Japan Ex Specifications＞
ModelDetection
principle
Mounted sensor
Gas to be
detected
Detection method
Transmission
cable
Cable connecting
portOperatingtemperatures
Operatinghumidities
Structure
Explosion-proof
structure
Explosion-proof
class
External
dimensions
WeightGD-A80-70
Catalytic combustion
HW-6212
HW-6239
Combustible gas(methane excluded),
Methane, Isobutane, Hydrogen
Solvent vapor
Natural diffusion type
EM CCE/F (1.25 or 2.0 mm2), 4-core equivalent
Pressure proof packing gland G3/4
[Rubber seal ID] ø12 for mounted, ø13 for attached-10 - +100℃ (At a constant condition)*-40 - +70℃ (At a constant condition)

Below 95% RH (Non-condensing)
Wall mounting type, 2B (50A) pipe attachable
Flame-proof enclosures
Ex dⅡCT4 (Japan Ex)
Approx. 78 (W) x 163 (H) x 105 (D) mm (Fixing brackets excluded)

Approx. 1.0kg
Munsell 7. 5BG5/2Paint color
Name plate : red*The ambient temperature range which maintain a capability of explosion proof of the label on thedetector is -40～+70℃. However, the available operating temperature range is -10～+100℃(when it
exceed +70℃, is exempt from explosion proof).

- 31 -10 Definition of Terms

10Definition of Terms
Catalytic
combustion type
Initial clear
Full scale% LEL
Calibration

This is a principle of the sensor installed in GD-A80-70.
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.
Adjusts the readings to the calibration gas concentration value by using thecalibration gas.

- 33 -