Riken Keiki GD-F3A-SC-A User manual

Oxygen Gas Detector Head
GD-F3A-SC-A
Operating Manual
(PT2-150)
PT2E-2490

[CAUTIONS ON OPERATION]
This is a fixed type gas detector (head) and alarm instrument to detect oxygen gas in air. The
gas alarm instrument is a safety instrument, not an analyzer nor measuring instrument to make
quantitative and qualitative analysis or measurement.
Please understand following points and use this detector head correctly.
1. The indication on this detector has some changes against fluctuation of atmospheric
pressure. Especially, take care about alarm action at the time of depression caused by
typhoon.
It may also fluctuate against the environmental (temperature, humidity, etc.) change around
detector head.
2. Alarm level for gas alarm instrument shall be set within the performance of the instrument.
Our standard alarm level is 18% by volume for the prevention of oxygen deficiency.
3. This is not control equipment, but a safety instrument.
Use the alarm contact from gas alarm instrument only for external alarm light or buzzer.
And the analog output signal shall be used only for external indicator or recorder.
We do not assume indemnification for any accident or damage caused by other control
purpose than the above.
4. To maintain the performance of this gas detector, the regular maintenance service including
the regular parts replacement and adjustment described in this manual shall be required.
Also every 6 months regular maintenance and gas calibration are required since this is a
safety instrument.

1
TABLE OF CONTENTS
１．PRODUCT OUTLINE
１－１． Preface ……………………………………………………………………… 3
１－２． Application for use ………………………………………………………… 3
１－３． Identification of each signal word ………………………………………… 3
２．IMPORTANT INSTRUCTIONS FOR THE SAFETY
２－１． Danger items………………………………………………………………… 4
２－２． Warning items………………………………………………………………… 4
２－３． Caution items………………………………………………………………… 4
２－４． Cautions for the explosion proof (In case of intrinsically safe system)…… 4
３．PRODUCT FUNCTION
３－１． External drawing……………………………………………………………… 5
３－２． Name of each part and functions…………………………………………… 6
３－３． System composition ………………………………………………………… 7
４．HOW TO USE
４－１． Before operation……………………………………………………………… 9
４－２． Installation place …………………………………………………………… 9
４－３． Maintenance space ………………………………………………………… 9
４－４． Installation work …………………………………………………………… 9
４－５． Caution at wiring construction …………………………………………… 10
４－６． Applicable cable …………………………………………………………… 10
４－７． Example of cable connection ……………………………………………… 10
５．OPERATION METHOD
５－１． Preparation before start up ……………………………………………… 12
５－２． Start up……………………………………………………………………… 12
５－３． Stopping the operation …………………………………………………… 12
６．MAINTENANCE AND INSPECTION
６－１． Inspection frequency and items …………………………………………… 13
６－２． Calibration
６－２－１． Required kit and tools for calibration…………………………… 14
６－２－２． Performing a zero adjustment …………………………………… 14
６－２－３． Performing a span adjustment…………………………………… 14
６－３． Replacing the sensor
６－３－１． Replacement frequency of the sensor…………………………… 15
６－３－２． Replacing the sensor …………………………………………… 15
６－４． Storage or treatment when not in use for a long period………………… 16
６－５． List of recommendable spare parts for regular replacement …………… 16
７．STORAGE, RELOCATION AND DISPOSAL
７－１． Procedures to storage the detector head or leave it for a long time …… 17
７－２． Procedures to relocate the detector head or use it again ………………… 17
７－３． Disposal of products ………………………………………………………… 17

2
８．MEASURES AT ABNORMAL CASE
８－１． Responding to trouble alarm ……………………………………………… 18
８－２． Before it is thought to be a trouble………………………………………… 18
９．PRODUCT SPECIFICATIONS
９－１． Standard specifications ………………………………………………… 19
９－２． Standard accessories ……………………………………………………
19
９－３． Optional accessories …………………………………………………… 19
９－４． Detection principle ……………………………………………………… 20
１０．DEFINITION OF TERMS………………………………………………… 21

3
１．PRODUCT OUTLINE
１－１． Preface
Thank you for purchasing our fixed type Oxygen Detector Head GD-F3A-SC-A.
First of all, verify that the model number of this product is identical with specifications
described in this manual. This manual is a guide to operation of the GD-F3A-SC-A. All
persons who use unit for the first time and who has ever used this unit are requested to read
through the manual to understand the content before use.
１－２． Application for use
This is a diffusion type oxygen detector head applying the galvanic cell type oxygen sensor
and is used in combination with indicator / alarm unit to show oxygen content. Read the
instruction manual for indicator / alarm unit as well as this manual.
This unit is designed as drip-proof construction for outdoor installation.
Also, it can be used as intrinsically safe system in combination with zener barrier (option) to
be able to install in hazardous area.
１－３． Identification of each signal word
This manual contains the following headings to ensure the safe and effective operation.
Indicates an imminently hazardous situation which, if not avoided,
will result in death or serious injury or serious damage to the
product.
This signal word is to be limited to the most extreme situation.
Indicates a potentially hazardous situation which, if not avoided,
could result serious injury to the human body or object.
Indicates a potentially hazardous situation which, if not avoided, may
result in minor or moderate injury or some damage to the human body
or objects. It may also be used to alert against unsafe practices.
This means “ADVICE” regarding operation.
DANGER
WARNING
CAUTION
* NOTE

4
２. IMPORTANT INSTRUCTIONS FOR THE SAFETY
２－１．Danger items
２－２．Warning items
２－３．Caution items
２－４．Caution for explosion proof (In case of intrinsically safe design)
In case of non-explosion poof system, do not use this unit at the place where combustible gas
may exist.
・Do not cut the wire for protective ground both inside and outside of instrument. Or, do not
disconnect the connection of the ground terminals.
・Before starting the operation, check if any defect is not found on the protective grounding.
If there is any defect on the protective functions such as protective grounding, do not start the
operation.
・It is very dangerous if the instrument gives oxygen deficiency alarm.
Take appropriate measures based on your judgment at that time.
・Perform gas calibration at proper interval.
・Do not change or remodel the circuit/structure of this unit.
・Do not disassemble the sensor since there is a electrolyte inside.
If your finger touches the electrolyte, wash your finger away with water immediately.
WARNING
・Do not use a walky-talky around the instrument.
The indication might be affected by the electromagnetic wave generated by the walky-talky if it is
used near the instrument. When the walky-talky is used, be away enough from the instrument
not to affect.
・Do not control other equipment by using outputs of this detector.
This is not a control equipment. It is prohibited to control other equipment by using outputs of
this detector.
CAUTION
・Do not use this detector head expect for the measurement of oxygen content in a mixture of air
and combustible gas or vapors, or a mixture of air and toxic gases.
・When cleaning this unit, do not use dry cloth but use the wet cloth not to change the static
electricity on plastic part.
CAUTION
DANGER

6
３－２．Name of each part and functions
① Oxygen sensor : Galvanic type sensor to detect oxygen content.
② Sensor holder : This is a retainer to hold the oxygen sensor
(equipped filter inside).
③ Sensor lead : Lead wires for oxygen signal outputs.
④ Terminal strip 1 : Relayed terminal for sensor lead and external cable.
⑤ Cable gland : Entrance to lead the cable (φ8～φ11mm) from outside.
⑥ Hinge : Hinge for front door.
⑦ Lock : Lock for front door.
⑧Mounting hole : Mounting hole to fix this unit on the wall surface.
⑨Terminal strip 2 : Relayed terminal for input/output signal use to the signal converter.
⑩4mA adjusting hole : VR hole to adjust 4 mA of 4-20mA output(factory set)
⑪SPAN adjusting hole : VR hole to adjust SPAN
⑫ZERO adjusting hole : VR hole to adjust ZERO
⑬Front door : Front door for the unit
⑭Signal converter : Circuit unit to convert the sensor output into 4-20mA
⑮Protective earth bolt : Bolt for protective grounding.
⑬ ⑨
⑩
⑧
④
⑥
⑦
①
②
⑤
⑮
③
⑭
⑫
⑪

7
３－３．System composition
(1) Intrinsically safe system
1. The oxygen detector shall be used as following composition.
2. The safety retainer to be connected with oxygen detector shall be passed the type approval as it is.
Also it shall satisfy the following conditions.
(1) Rating of safety retainer
Max voltage of intrinsic-safety circuit: Below 28V
Max current of intrinsic-safety circuit: Below 93 mA
Max power of intrinsic- safety circuit: Below 0.65W
(2) Performance division and group
Performance division: ia
Group : ⅡC
(3) Relations between allowable inductance (Lo) and allowable capacitance (Co)
of intrinsic-safety circuit, and external wiring inductance (Lw) and capacitance(Cw)
of intrinsic-safety circuit.
Lo ≧ Li + Lw
Co ≧ C + Cw
3. When making wiring connection for intrinsic-safety circuit, take care not to induce an electric
current and voltage which will spoil the performance of intrinsically safe by the electromagnetic
induction or electrostatic induction to the intrinsic-safety circuit.
WARNING
！
Detector
head
Zener barrier
Indicator
/alarm
unit
Hazardous area Non-hazardous area
In-between head and zener barrier:
CVVS 1.25mm2 2-core or equivalent(max 250m)
However, that of head and indicator/alarm unit:
CVVS 1.25mm2 2-core or equivalent(max 2km)
4-20mA
Hazardous
area
Non-hazardous
area
Safety retainer
Oxygen detector
Ｌｉ≒ 0
Ｃｉ≒ 0
≒ 0 shows a negligible value
Ｌｉ
Ｃｉ
Ｌｏ
Ｃｏ
Ｌｗ
Ｃｗ

11
GD-F3A-SC-A
Example of intrinsically safe system
・ Do not alter, noｒ remodel the parts, etc.
・ Use the circuit breaker as for the power of indicator/alarm unit. Also it shall be mounted
nearby indicator/alarm unit and be specified that it is for power interruption of
indicator/alarm unit.
・ Ground the zener barrier separately corresponding to the A-class grounding with ground
resistance of 10Ω or less.
・ Use the specified cable.
・ For system installation, operation and maintenance, take care not to damage the intrinsically
safe design.
・ The power of the indicator/alarm unit shall be turned on after completion of all wirings. If
each wiring is carried out in the power on condition, short-circuit between terminals or an
electrical shock may be occurred.
* NOTE
When wiring, read the operating instructions for the connected indicator/alarm unit.
1
3
24
Detector head
Indicator/alarm
unit
Zener barrier
（MTL7728ac）
Max. 2 km
Hazardous area
Non-hazardous area
Connection cable Connection
cable
WARNING
CAUTION
！
CVVS 1.25mm
2
or
e
q
uivalent
(
max 250m
)

12
５．OPERATION METHOD
５－１．Preparation before start up
Before making power on, take care of the following. If do not keep this, there is the danger
of electrical shock and damage of instrument.
５－２．Start up
①This detector head does not equip a power switch. Analog outputs of oxygen sensor
are converted to 4-20mA and transmitted to the indicator/alarm unit through the
connected cable.
As far as the cable has been connected correctly, this system starts operation by
putting on the power switch in indicator/alarm unit.
②Be sure to perform gas calibration at the time of new installation.
Correct reading may not be obtained before gas calibration.
５－３．Stopping the operation
This system stops operation by putting off the power in indicator/alarm unit, since this unit has
no power switch.
・Make protective grounding.
・Check that the wiring with outer unit is made correctly.
・Check that the supply voltage is within the rating.
WARNING
・At the new installation, adjust the reading in indicator/alarm unit according to 「6-2.
Calibration」.
CAUTION
！

13
６．MAINTENANCE AND INSPECTION
Gas detection and alarm instrument is kept in continuous operation over a long time and must
perform a vital role as a safety device. For this purpose, periodical inspection must be made.
The High-pressure Gas Safety Act in Japan sets forth the obligation of periodical inspection of
the gas detection and alarm instrument.
- Maintenance Contract –
Be sure to perform the regular maintenance inspection since this is an instrument for
security and safety. If this detector head founds defective, contact our nearest agent or
RIKEN KEIKI soon.
６－１．Inspection frequency and items
The inspection includes a daily inspection which a person in charge of control and operation of
the gas detection instrument performs inspection before work once a day, and a monthly
inspection carried out once a month, and periodical inspections conducted by the service
personnel designated by manufacturer. The inspection items are confirmation of lights,
concentration indication and alarm function on the indicator/alarm unit side. It is also necessary
to carry out gas calibration at least every 6 months. The law in Japan sets forth that the unit
must issue an alarm during the circuit inspection related to alarm while providing normal
operation, at least, once a month.
To maintain the safety operation of the gas detection instrument, it is recommended to keep
the maintenance contract with our authorized distributor for regular maintenance, adjustment
and overhaul etc including the gas sensitivity adjustment (gas calibration).
For the detail of maintenance contract, contact our nearest agent or RIKEN KEIKI.
・This is a safety instrument and the inspection every 6 months or more is
mandatory to ensure the safety. If the unit is used by continuously
without inspection, the sensor sensitivity may change, resulting in failure
of correct detection.
WARNING
！
* NOTE
・Be sure to inform sections concerned beforehand when performing
alarm test or gas calibration. For the equipment connected with output
signal from indicator/alarm unit, perform them after disconnecting the
output signal.
・Special trained engineer for gas detection instrument can perform
maintenance work and inspection accurately and efficiently. Then, it is
recommended to contact our authorized agent for maintenance and
inspection.

14
６－２．Calibration
Perform gas calibration at new installation, 6 months inspection and sensor replacement.
６－２－１．Required kit and tools for calibration
Prepare following jigs and tools to perform zero and span adjustments.
Calibration adapter
Calibration gas (standard gas for zero and span)
Gas sampling bag for calibration gas
Suction pump to lead calibration gas
Flowmeter with flow control valve (enable to control 1.0L/min).
Ammeter(for measuring 4-20mA)
６－２－２．Performing a zero adjustment
①Plug the ammeter lead into terminals 3 and 5 of terminal strip 2 (No.3 is – and No.5 is +).
②Pack the zero gas (Nitrogen more than 99.9 vol %) into gas sampling bag.
③Connect calibration adopter, flowmeter （with flow control valve） and suction pump to
the detector head. Turn on the pump and adjust the reading of flowmeter to
1.0±0.3L/min.
④Connect gas sampling bag for calibration to the IN side of the pump.
⑤After reading by ammeter gets stable, adjust the reading to 4mA with potentiometer
in ZERO adjusting hole.
⑥Stop the supply of zero gas, disconnect calibration adapter and confirm that the
oxygen reading returns to 20.9vol% (Completion of zero adjustment).
６－２－３．Performing a span adjustment
①Plug the ammeter lead into terminals 3 and 5 of terminal strip 2(No.3 is – and No.5 is +).
②Pack the span gas (fresh air for oxygen deficiency alarm instrument and their
concentration is around preset alarm level for other purpose) into gas sampling bag.
For simple calibration, you may be possible to use an ambient air as span gas
containing 20.9vol% O2 providing that the ambient pressure is 1 atm (1000±50hpa)
and contamination in air is negligible against span gas concentration.
③Connect calibration adopter, flowmeter （with flow control valve） and suction pump to
the detector head. Turn on the pump and adjust the reading of flowmeter to
1.0±0.3L/min.
④Connect gas sampling bag for calibration to the IN side of the pump.
⑤After reading by ammeter gets stable, adjust the reading to output current
corresponding to the span gas concentration with potentiometer in SPAN adjusting
hole.
⑥Stop the supply of span gas, disconnect calibration adapter and confirm that the
oxygen reading is 20.9vol % (completion of span calibration).

16
６－４．Storage or treatment when not in use for a long period
Oxygen sensor is a kind of cell and will continue to consume its life even though it is not
used. When detector head is not used for a long period, take out the sensor from detector
head and store it at following environment to lower the consumption of sensor.
・Environment of low temperature (5～10℃)
・Environment of low oxygen content
(Put a sensor into the container and seal off the container.)
６－５． List of recommendable spare parts for regular replacement
No. Name of parts Inspection frequency Replacement interval Q’ty/unit
1 Sensor holder At sensor replacement At sensor replacement 1
* NOTE
・The replacement interval will change depending on operating condition and it does not
mean the warranty period.
Replacement interval changes according to the result of regular inspection.

17
７．STORAGE,RELOCATION AND DISPOSAL
７－１．Procedures to store the detector head or leave it for a
long time
The detector head must be stored under the following environmental conditions.
In a dark place under the normal temperature and humidity away from direct sunlight
In a place where gases, solvents or vapors are not present
７－２．Procedures to relocate the detector head or use it
again
When the detector head is relocated, select a new place in accordance with “4-2. Installation
place” and “4-4. Installation works”.
For information on wiring work, see “4-5. Caution at wiring construction”. The unpowered time
must be minimized when the detector head is relocated.
７－３．Disposal of products
When the detector head is disposed of, it must be treated properly as an industrial waste in
accordance with the local regulations.
・When using a relocated or stopped/stored detector again, never fail to perform a
calibration. For information on readjustment including calibration, please contact RIKEN
KEIKI.
CAUTION
！

18
８．MEASURES AT ABNORMAL CASE
８－１．Responding to trouble alarm
If this detector founds defective, contact our authorized agent or RIKEN KEIKI.
８－２．Before it is thought to be a trouble
・Check the wirings around the related instruments as well as this detector head.
It may be caused by improper operation.
・Re-check the detection system and contact our authorized agent or Riken Keiki.
It may be caused by cable disconnection, short circuit, etc.