PT2E-2124

2-Wire Gas Detector HeadGD-K88Di(TYPE AS)
Operating Manual(PT2-212)

Contents
1 Outline of the Product...................................................................................................................................... 31-1. Preface .................................................................................................................................................... 3
1-2. Purpose of use ........................................................................................................................................ 3
1-3. Definition of DANGER, WARNING, CAUTION and NOTE ..................................................................... 3
2 Important Notices on Safety ............................................................................................................................ 42-1. Danger cases........................................................................................................................................... 42-2. Warning cases ......................................................................................................................................... 5
2-3. Precautions .............................................................................................................................................. 62-4. Operating precautions ............................................................................................................................. 62-5. Important information about explosion-proof .......................................................................................... 7
3 Product Components ....................................................................................................................................... 93-1. Main unit and standard accessories ........................................................................................................ 93-2. Names and functions for each part ....................................................................................................... 114 How to Use .................................................................................................................................................... 124-1. Before using the detector ...................................................................................................................... 124-2. Precautions for installation sites ............................................................................................................ 124-3. Precautions for system designing ......................................................................................................... 134-4. How to install ......................................................................................................................................... 144-5. Grounding .............................................................................................................................................. 154-6. How to wire ............................................................................................................................................ 164-7. Recommended cables and terminal plate specifications ...................................................................... 164-8. System connection example ................................................................................................................. 174-9. How to Tube........................................................................................................................................... 195 How to Operate ............................................................................................................................................. 215-1. Preparation for start-up ......................................................................................................................... 215-2. Basic operating procedures................................................................................................................... 215-3. How to start the detector (power-on)..................................................................................................... 225-4. Modes .................................................................................................................................................... 235-5. Description of operation (detection mode) ............................................................................................ 24
5-6. Description of operation (maintenance) ................................................................................................ 27
5-7. How to exit ............................................................................................................................................. 30
6 Maintenance .................................................................................................................................................. 31
6-1. Maintenance intervals and items ........................................................................................................... 31
6-2. Replacement parts ................................................................................................................................ 33
7 Storage, Relocation and Disposal ................................................................................................................. 34
7-1. Procedures to store the detector or leave it for a long time .................................................................. 34
7-2. Procedures to relocate the detector or use it again .............................................................................. 34
7-3. Disposal of products .............................................................................................................................. 34
8 Troubleshooting ............................................................................................................................................. 35
9 Product Specifications ................................................................................................................................... 37
9-1. List of specifications .............................................................................................................................. 37
9-2. Detection principle ................................................................................................................................. 38
10 Definition of Terms ....................................................................................................................................... 38-2-

1 Outline of the Product1-1. Preface

1Outline of the Product1-1. Preface
Thank you for choosing our 2-wire gas detector head GD-K88Di.
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.
When the detector is used in combination with an indicator/alarm unit, read also the operating manual of
the indicator/alarm unit.

1-2. Purpose of use
 This detector is a fixed type gas detector head which detects combustible and toxic gases.
 When the detector detects gas leakage, it outputs a current according to the detected gas
concentration.
 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.

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

This message indicates that improper handling may cause serious damageon 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.

-3-2 Important Notices on Safety

2-5. Important information about explosion-proof

Important information about explosion-proof (continued) Power supply
Never fail to use the following safety maintaining device (barrier) to maintain explosion-proof
performance.
Ratings to maintain safety
Intrinsically safe circuit maximum voltage (Uo) :Intrinsically safe circuit maximum current (Io) :Intrinsically safe circuit maximum power (Po) :28 V
93 mA
0.65 W

Performance classification and group
Performance classification : iaGroup: IIC
Relations between the intrinsically safe circuit allowable inductance (Lo) and intrinsically safe
circuit external wire inductance (Lc) and between the intrinsically safe circuit allowable capacitance(Co) and intrinsically safe circuit external wire capacitance (Cc)
Intrinsically safe circuit allowable inductance (Lo) = (Lc) or more
Intrinsically safe circuit allowable capacitance (Co) = 586 pF + (Cc) or more
 Wiring
Determine the cable type to use and laying distance in consideration of the above parameters tomaintain explosion-proof performance.
Perform wiring so that a current or voltage that disturbs intrinsically safe explosion-proof
performance of the intrinsically safe circuit is not induced to the circuit due to electromagnetic orelectrostatic induction.
 Battery
The detector contains a battery for sensor backup. Observe the followings to maintain explosionproof performance.
<Usable battery>
Type: AAA alkaline dry battery
Model: LR03
Nominal voltage : 1.5 V<Battery Replacement>
Turn off the power of the detector before replacing the battery.
Never fail to use the dedicated battery storage case.
 Grounding
Never fail to ground the detector (D type grounding).
 Others
Confirm that no combustible gas is present around before opening the door of the unit.
Never disassemble or modify the unit.
Manufacturer: RIKEN KEIKI Co., Ltd.
2-7-6 Azusawa, Itabashi-ku, Tokyo, 174-8744 Japan
www.rikenkeiki.co.jp*1:

The temperature range to maintain explosion-proof performance
The temperature range to maintain gas detection performance is 0 to +40°C. (SeeSpecifications)-8-3 Product Components

3-1. Main unit and standard accessories<Standard Accessories> Filter: Dust filter CF-8350: Attached when the gas to be detected is CO (carbon monoxide).
 CF-8364- 10 -6 Maintenance

6-1. Maintenance intervals and items

6MaintenanceThe detector is an important instrument for safety.
To maintain the performance and reliability of the detector, perform a regular maintenance.
Continuing to use the detector without performing maintenance might cause the sensitivity degradation,
thus resulting in inaccurate detection.

6-1. Maintenance intervals and items
 Daily maintenance:
 Monthly maintenance: Regular maintenance:

Maintenance item

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 maintainthe performance as a safety unit.

Maintenance content

Status display check

Dailymaintenance

MonthlymaintenanceRegularmaintenanceCheck that the status indicates normal○○○
measurement state.
Gas concentration
Check that a gas to be detected is not present
displayaround the detector and that the reading○○○indicates a normal value.
External alarm test*
Inspect the alarm circuit by using the alarm test－○
○function.
Span adjustment
Perform the span adjustment by using the－－○calibration gas.
Gas alarm check
Check the gas alarm by using the calibration gas.
－－○
* Check and adjustment are performed at the indicator/alarm unit side. See the operating manual of theindicator/alarm unit for details.

- 31 -

6 Maintenance

6-1. Maintenance intervals and items<About Maintenance Services> We provide services on regular maintenance including span adjustment, other adjustments andmaintenance.
To make the calibration gas, dedicated tools, such as a gas cylinder of the specified concentrationand gas sampling bag must be used.
Our qualified service engineers have expertise and knowledge on the dedicated tools used forservices, along with other products. To maintain the safety operation of the unit, please use ourmaintenance service.
 Typical maintenance services are listed as follows. Please contact RIKEN KEIKI for more
information.

Main services
Power supply
check
Status display
check
Concentration
display check
External alarm
test**: Check the power supply voltage.
: Check that the status indicates normal measurement state.
Verify that the concentration display value is zero by using the zero gas.
Perform zero adjustment if the display is incorrect.
: Inspect the alarm circuit by using the alarm test function.

Span adjustment
Gas alarm check*::

Cleaning andrepair of the unit
(visual diagnosis)
Unit operation
check
Replacement ofconsumable parts::

 Check the alarm lamps. (Check the activation.) Check the external alarm. (Check the activation of the external alarm, such asa buzzer.)
Perform the span adjustment by using the calibration gas.
Check the gas alarm by using the calibration gas.
 Check the alarm. (Check triggering of alarm when the alarm setpoint isreached.) Check the delay time. (Check time to delay until the alarm is triggered.) Check the external alarm. (Check the activation of external alarms, such as abuzzer and reset signal.)
Check dust or damage on the surface, cover or internal parts of the unit, and clean
or repair such parts as needed.
Replace parts which are cracked or damaged.
Use the keys to check the operation of functions, parameters, etc.

: Replace consumable parts, such as a sensor and filter.

Check and adjustment are performed at the indicator/alarm unit side.

- 32 -6 Maintenance

6-2. Replacement parts

6-2. Replacement parts<Replacement of Gas Sensor>
Our service engineers need to replace and adjust the sensor. Please contact RIKEN KEIKI.

NOTE

 If adjustment to the standard gas concentration value fails even with the maximum sensitivity, it
indicates that the gas sensor has come to the end of its life. The gas sensor needs to be replaced.
 After replacing the gas sensor, electrical adjustment and calibration using the standard gas arenecessary.

<Replacement of Regular Replacement Parts>
List of recommended regular replacement parts

Part number

*

Name

Maintenanceintervals

Replacement
intervals

Quantity(pieces perunit)

0341 4062 40

Elbow

6 months

3 - 8 years

21410 3066 201410 7356 30

O-ring (flow regulator)
O-ring (sensor cap)

6 months
6 months

3 - 8 years
3 - 8 years

111836 8421 10Tube

6 months

3 - 8 years

260 mm1836 9852 80

Tube6 months

3 - 8 years

430 mm4253 9330 10Battery Assy------

1Remarks*

Replaced together with the gas sensor. The operation must be checked after replacement by aqualified service engineer.
For the stable operation of the detector and safety, ask a qualified service engineer to take care ofreplacement of the parts. Request the operation check from RIKEN KEIKI.

NOTE
In the case where the wireless energization time of the device is a total of more than half a year, thebattery replacement for the sensor may be empty.
If the sensor is not properly backed up, it may lead to a sensor failure, a change in the startup instruction,
or a startup error (E-9).

- 33 -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 on Unit>
Symptom/Display FAULTThe power
cannot be turnedon.

Abnormaloperations--Causes
The wiring is not correct.
The terminal plate isremoved.

Actions
Connect the wiring properly.
Connect the terminal plate properly.

Abnormalities/momentary
blackout of power supply
systemProvide the rated voltage.
Take measures such as checking or adding
the UPS, power supply line filter and insulationtransformer.

Cable abnormalities(open circuit/notconnected/short circuit)

Check the wiring of detector and related
devices around it.

Disturbances by sudden
surge noise, etc.

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

Abnormalities of ROM,
RAM or EEPROM insidethe detector
The capacity of thebattery for backing up thesensor is gone.
The sensor is notconnected or improperlyconnected.
Faults of the sensor

Systemabnormalities
E-9●Sensorabnormalities
E-1●Low flow rate*
E-5●

Clogged filter

When powered
ON, the LCD
display may turnOFF for a while(up to 30
seconds).

——

Please contact RIKEN KEIKI.

Replace the battery.
Check if the sensor cable is securely fastened
to the terminal plate.
Please contact RIKEN KEIKI.
Replace the filter. * Optional

If it shows successfully the measurementmode display, there is no problem.

- 35 -8 Troubleshooting<Abnormalities of Readings> * Take remedial actions to indicator/alarm unit as well See the operating
manual of the indicator/alarm unit for details.
Symptoms
CausesActions
Drifting of sensor
output

The reading rises(drops) and does not goback.

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

Slow response
Span adjustment
impossible

Perform zero adjustment.
It is difficult to eliminate interference gases, such as
solvents completely. Please contact RIKEN KEIKI toarrange removal filters.
A very small amount of the gas to be detected may
be leaking (slow leak). Because ignoring it may cause
dangers, take a remedial measure, i.e., taking actions
the same as those for the gas alarm.

Presence ofinterference gas

Slow leakEnvironmentalchanges

Perform zero adjustment.

Presence ofinterference gas

It is difficult to eliminate interference gases, such as
solvents completely. Please contact RIKEN KEIKI toarrange removal filters.

Disturbance by noise

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

Sudden change in theenvironment

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

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.

- 36 -9 Product Specifications

9Product Specifications
9-1. List of specifications
Model
Detection principle
Gas to be detected
Concentration display
Detection range
Detection method
Sampling condition
Suction flow
Alarm preset point
Alarm accuracy

GD-K88Di
Electrochemical type
Toxic gases
7-segment LCD (4 digits)
Depends on the gas to be detected
Aspirator suction method
Atmosphere equivalent(Compressed air:0.1～0.7MPa)
0.5L/min±10%
Depend on Detectable gas
Within ±30% to the alarm setpoint value(under an identical condition)

Alarm-delay time
(under an identical condition)

Gas alarm typeGas alarm indication
Gas alarm action
Trouble alarm・Selfdiagnosis
Trouble alarm indication
Trouble alarm action
Transmission method
Transmission
specifications
Communication schemePower supply
Power consumption
Transmission cable
Transmission distance
Safety maintaining device
Piping port

Operating temperature
Operating humidity
Structure
Explosion-proof
structure
Explosion-proof classExternal dimensions

60 seconds or less(by providing the gas 1.6 times the alarm
setpoint(excluding delay in the tube and in the communication))Two-step alarm(H-HH)
A warning message is indicated(AL1/AL2)
Latching or non latching
System failure/Sensor failure
content display
Non latching
2-wire analog transmission+ digital transmission (HARTcommunication)
4-20mADC (load resistance: 300Ω or less)
HART 7
24VDC±10%
Approx.0.6W
Shielded cable of CVVS, etc. (1.25mm2) - 2-core
Up to 1km with CVVS 1.25mm2 (up to 600m between the detector headand Zener Barrier)
Zener Barrier (MTL7728ac/MTL7728+/MTL7728-) or
insulating barrier (MTL5541/RN221N-J1/KFD2-SCT4-Ex1)
Gas inlet/Gas outlet:Rc1/4(O.Dφ6-1t half-union for Teflon
tube<material:PP>supplied)
Compressed air inlet<material:SS303>:Rc1/4
0 - +40℃(non-rapidly-vary)
30 - 70%RH (non-condensing)
Wall mounted type
Intrinsically safe explosion-proof structure, with safety
maintaining device (barrier) used
Ex ia ⅡC T4 Ga
Approx. 220(W)x265(H)x90(D)mm (projection portions excluded)- 37 -10 Definition of Terms
Manual Log
Rev.

Amendment

Issue data0First issue

2017/5/16

1

Correction NOTE at 6-2(P.33). Correction E-9(P.35).

2019/3/15

234

Addition Troubleshooting〈Abnormalities on Unit〉 (P.35).
Correction Product Specifications (P.37).
Correction 2-5, 9-1

2019/9/2

2021/4/13

Addition 4-7
Type change of insulating barrier 9-1

2023/4/3- 39 -