Riken Keiki SD-1DGH User manual

PT2E-1700
Smart Transmitter/Gas Detector Head
SD-1DGH
Operating Manual
(PT2-170)
Request for the Customers
•Read and understand this operating manual before using the detector.
•Use the detector in accordance with the operating manual.
•Regardless of warranty period, we shall not make any indemnification for accidents and
damage caused by using this product.
The compensation shall be made only under the warranty policy of products or parts
replacement.
•Because this is a safety unit, a regular maintenance for every six months and daily
maintenance must be performed.
•If any abnormality is found in the detector, notify it to RIKEN KEIKI immediately.

Necessary information for explosion proof construction of Model SD-1
About Model SD-1
The Model SD-1 is a fixed mount, continuous-monitoring detector head and provides a
4-20mA signal which indicates the target gas reading for use by a gas monitoring controller,
recording device, or programmable controller.
Three sets of relay contacts, two controlled by the gas alarms and one by the fail alarm.
Technical Data
(Protection Method) Flameproof enclosure “d”
(Certificate numbers) IECEx KEM 10.0036X
KEMA 10ATEX0083 X
(Group) II
(Category) 2G
(Type of Protection and Marking code) Ex d IIC T5
(Equipment Protection Level) Gb
(Ambient Temperature) -20°C to 60°C
(Electrical Data) Supply voltage: 24 V dc (Typ.)
Output signal: 4 to 20 mA
(Applicable Standard) IEC 60079-0: 2007，IEC 60079-1: 2007
EN 60079-0: 2009，EN 60079-1: 2007
(Manual number) PT2E-160
Installation
＋
－
＋
－
Hazardous Location
(Zone 1)
Nonhazardous Location
GasDetector(SD‐1)
←→
InstallationDiagram
Signal Signal
CVVSCable
Indicator

- 3 - SD-1DGH
<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
2 Important Notices on Safety .................................................................................... 5
2-1. Danger cases .......................................................................................................... 5
2-2. Warning cases......................................................................................................... 6
2-3. Precautions ............................................................................................................. 7
2-4. Safety information ................................................................................................... 8
3 Product Components............................................................................................... 9
3-1. Main unit and standard accessories ........................................................................ 9
3-2. Names and functions for each part.......................................................................... 10
3-3. Block diagram.......................................................................................................... 11
4 How to Use.............................................................................................................. 12
4-1. Before using the detector ........................................................................................ 12
4-2. Precautions for installation points ............................................................................ 12
4-3. Precautions for system designing............................................................................ 13
4-4. How to install ........................................................................................................... 15
4-5. How to wire.............................................................................................................. 16
4-6. How to tube ............................................................................................................. 21
5 How to Operate ....................................................................................................... 22
5-1. Preparation for start-up............................................................................................ 22
5-2. Basic operating procedures..................................................................................... 22
5-3. How to start the detector ......................................................................................... 23
5-4. Modes......................................................................................................................25
5-5. User mode............................................................................................................... 26
5-6. How to exit............................................................................................................... 28
6 Operations and Functions ....................................................................................... 29
6-1. Gas alarm activation................................................................................................ 29
6-2. Fault alarm activation .............................................................................................. 30
6-3. External output operation ........................................................................................ 31
6-4. Other functions ........................................................................................................ 32
7 Maintenance............................................................................................................ 33
7-1. Maintenance intervals and items ............................................................................. 33
7-2. Regular maintenance mode .................................................................................... 35
7-3. Gas calibration method............................................................................................ 44
7-4. Parts replacement ................................................................................................... 47
8 Storage, Relocation and Disposal ........................................................................... 48
8-1. Procedures to store the detector or leave it for a long time ..................................... 48
8-2. Procedures to relocate the detector or use it again ................................................. 48
8-3. Disposal of products ................................................................................................ 48
9 Troubleshooting....................................................................................................... 49
10 Product Specifications ............................................................................................. 51
10-1. List of specifications ................................................................................................ 51
10-2. List of accessories................................................................................................... 52
10-3. Detection principle................................................................................................... 53
11 Definition of Terms................................................................................................... 54

1 Outline of the Product 1-1. Preface
SD-1DGH - 4 -
1
Outline of the Product
1-1. Preface
Thank you for choosing our smart transmitter/gas detector head SD-1DGH. 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.
Although the number of digits to display varies depending on the detection range, this manual provides
explanation using a detection range from 0 to 100.0 as examples (such as examples of LED display).
1-2. Purpose of use
•This detector is a fixed type gas detector head that detects leak of combustible/toxic gases and performs
the alarm activation when the gas concentration is over the setting value.
•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 in the air caused by presence of gases or other reasons (leak) with
the built-in gas sensor. The concentrations of detected gases are displayed on the seven-segment LED.
•An external pump etc. outside the detector introduces gas to perform gas detection.
•The detector has a built-in alarm contact and can be used either as a gas alarm, fault alarm, or common
(gas, fault) alarm.
•The detector outputs gas concentration in 4 – 20 mA.
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.

2 Important Notices on Safety 2-1. Danger cases
- 5 - SD-1DGH
DANGER
About explosion-proof
•The window plate material is a polycarbonate resin. Do not use organic solvents and alkali types
(liquid or vapor). It may cause the color and shape of the window plate to be changed.
•Do not open the lid when applying current.
•Do not attempt to repair the detector.
•For the lid, use hexagon socket head bolts specified by RIKEN KEIKI.
•Do not apply a strong force or shock to the window plate. The explosion-proof performances may
be deteriorated due to damages. The explosion protection conditions for the detector is "low
(2J)" possibility of mechanical damage.
2
Important Notices on
Safety
2-1. Danger cases

2 Important Notices on Safety 2-2. Warning cases
SD-1DGH - 6 -
WARNING
Power supply
Before turning on the detector, always check that the voltage is properly applied. Do not use an
unstable power supply because it may cause malfunctions.
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.
Tubing
The detector is designed to draw gases around it under the atmospheric pressure. Be sure that
excessive pressure is not applied to the sampling inlet and outlet (GAS IN, GAS OUT) of the
detector. Detected gases must be exhausted from the detected gas exhausting outlet (GAS OUT) to
which an exhaust tube is connected, to a point regarded as a safe place.
External connection
Before connecting the detector to the external control circuit, securely connect it to a protective
grounding circuit.
Zero adjustment in the atmosphere
When the zero adjustment is performed in the atmosphere, check the atmosphere for freshness
before beginning the adjustment. If other gases exist, the adjustment cannot be performed properly,
thus leading to dangers when the gas leaks.
Response to gas alarm
Issuance of a gas alarm indicates that there are extreme dangers. Take proper actions based on
your judgment.
2-2. Warning cases

2 Important Notices on Safety 2-3. Precautions
- 7 - SD-1DGH
CAUTION
Do not use a transceiver near the detector.
Radio wave from a transceiver near the detector or its cables may disturb indication reading. If a
transceiver is used, it must be used in a place where it disturbs nothing.
To restart the detector, wait for five seconds or more before doing it.
Restarting the detector within five seconds may cause errors.
Verify that the flow rate corresponds to the specified flow rate before using the detector.
If it does not correspond to the specified flow rate, gas detection cannot be performed properly.
Check whether the flow rate is unstable or lost.
Attach the dust filter before using the detector.
Before using the detector, attach the specified filter to prevent disturbances by possible gas
adsorption or air dust.
A dust filter to be used varies depending on the gas to be detected. For more information on dust
filters, please contact RIKEN KEIKI.
Observe the operating restrictions to prevent condensation inside the tube.
Condensation formed inside the tube causes clogging or gas adsorption, which may disturb
accurate gas detection. Thus, condensation must be avoided. In addition to the installation
environment, carefully monitor the temperature/humidity of the sampling point to prevent
condensation inside the tube. In particular, when detecting a gas which is dissolved into water and
corrodes contacted materials, such as a strong acid gas, the gas is undetectable and furthermore
may corrode internal parts. Please observe the operating restrictions.
Do not use the external output of the detector to control other units.
This is not a control unit. It is not allowed to use the external output of the detector to control other
units.
Do not disassemble/modify the detector, or change the settings if not necessary.
Disassembling/Modifying the detector will invalidate the warranty of the performance. Changing the
settings without understanding the specifications may cause alarm malfunctions. Please use the
detector properly in accordance with the operating manual.
Avoid applying organic solvents and others to the window plate for a long time.
The window plate material is a polycarbonate resin. When organic solvents (liquid or
highly-concentrated vapor) and others are applied to the plate for a long time, its color and shape
may be changed.
Do not forget 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.
2-3. Precautions

2 Important Notices on Safety 2-4. Safety information
SD-1DGH - 8 -
2-4. Safety information
Observe the followings to maintain an explosion-proof system.
<Overseas Specifications>
Outline of the product
•This detector is a fixed type gas detector head that detects leak of combustible/toxic gases and
performs the alarm activation when the gas concentration is over the setting value.
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 in the air caused by presence of gases or other reasons
(leak) with the built-in gas sensor. The concentrations of detected gases are displayed on the
seven-segment LED.
•The detector has a built-in alarm contact and can be used either as a gas alarm, fault alarm, or
common (gas, fault) alarm.
•The detector outputs gas concentration in 4 – 20 mA.
Technical data
Explosion-proof structure Flame-proof enclosures "d"
Certificate numbers IECEx KEM 10.0036X
KEMA 10ATEX0083 X
Group II
Category 2G
Explosion-proof class Exd IICT5
Protection level (EPL) Gb
Ambient temperature -20ºC to 60ºC
Rating Power voltage: 24 VDC (Typ.)
Output signal: 4 - 20 mA
Applied standards IEC 60079-0:2007, IEC 60079-1:2007
EN 60079-0:2009, EN 60079-1:2007
System configuration
Manufacturer
RIKEN KEIKI CO., LTD.
2-7-6 Azusawa, Itabashi-ku, Tokyo, 174-8744 Japan
Web site: http://www.rikenkeiki.co.jp/english
+
-
+
-
Hazardous location
(Zone1)
Gas detector head (SD-1DGH)
←→
Installation diagram
Signal Signal
CVVS Cable
Display
Non-hazardous location

3 Product Components 3-1. Main unit and standard accessories
- 9 - SD-1DGH
CAUTION
Use the supplied dedicated control key to operate the detector. If products other than these
accessories are used, key operations cannot be accepted properly.
3
Product Components
3-1. Main unit and standard accessories
<Main Unit> (including a cable gland)
<Standard Accessories>
•Operating manual
•Dedicated handling lever (used for the wiring)
•Dedicated control key
Display
Sensor
part
External cable inlet part for
power supply and signals
Inlet and outlet of flow path

3 Product Components 3-2. Names and functions for each part
SD-1DGH - 10 -
3-2. Names and functions for each part
(1) MENU/ESC key Used to enter the maintenance mode.
It is also used to cancel in a specific mode.
(2) SET key It is used for value confirmation and so on in a specific mode.
(3) ▲key Used to switch menus or change a value (UP).
(4) ▼key Used to switch menus or change a value (DOWN).
(5) Power lamp
Power lamp:
Detection mode: It lights up in green.
Maintenance mode: It blinks in green.
(6) Alarm lamp Alarm lamp. It lights up in red when the alarm setpoint value is
reached.
(7) Fault lamp Fault lamp. It lights up in yellow when an abnormality is detected in
the detector.
(8) Concentration value display Displays the gas concentration and so on.
NOTE
•The nameplate on the front side of the detector (see the figure on
the right) shows the precautions to be taken for explosion-proof
performances. Read these precautions as well as "2. Important
Notices on Safety."
•The detector manufactured in accordance with the overseas
specifications has a nameplate on the front side that shows also the
serial number, date of manufacture, etc.
INST.No.: Serial number
DATE: Date of manufacture
(8) Concentration
value display
(5) Power lamp (6) Alarm lamp (7) Fault lamp
(1) MENU/ESC key
(2) SET key (4) ▼key
(3) ▲key

3 Product Components 3-3. Block diagram
- 11 - SD-1DGH
3-3. Block diagram
<Electric Diagram>
Sensor
Controller
(CPU)
POWER INPUT (24 VDC)
Power supply part
Gas alarm contact (ALARM)
Contact activation
• De-energized
(De-energized at a normal
environment)
• ON-ALARM
(Closed contact at an
alarm time)
Alarm contact controller
Display
(POWER) (ALARM) (FAULT)
Seven-segment LED
(four-digit)
Magnetic operation part
(MENU/ESC) (▲) (▼) (SET)
Transmitter
• 4 – 20 mA transmission

4 How to Use 4-1. Before using the detector
SD-1DGH - 12 -
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
4-1. Before using the detector
Not only the first-time users but also the users who have already used the product must follow the operating
precautions.
Ignoring the precautions may damage the detector, resulting in inaccurate gas detection.
4-2. Precautions for installation points
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.
<Japanese Specifications> -20 to 53ºC
<Overseas Specifications> -20 to 60ºC
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.

4 How to Use 4-3. Precautions for system designing
- 13 - SD-1DGH
CAUTION
An unstable power supply and noise may cause malfunctions or false alarms.
The descriptions in this section must be reflected on the designing of a system using the detector.
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 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 other gases exist around it.
The detector must not be installed in a place where other gases exist around it.
4-3. Precautions for system designing
Using a stable power supply
The external output and alarm contact of the detector may be activated when the power is turned on, when
momentary blackout occurs, or while the system is being stabilized. In such cases, use a UPS, or take
appropriate actions on the receiving side of output signals.
The detector must be provided with the following power supply.
Power supply
voltage 24 VDC (17 – 26.4 VDC): Terminal voltage of the detector
Allowed time of
momentary blackout
Up to 10 milliseconds
(To recover from the momentary
blackout for 10 milliseconds or more,
restart the detector.)
Example of actions
To ensure continuous operation and
activation, install a UPS outside the
detector.
Others
Do not use it with a power supply of
large power load or high-frequency
noise.
Example of actions
Use a line filter to avoid the noise source
if necessary.

4 How to Use 4-3. Precautions for system designing
SD-1DGH - 14 -
CAUTION
•In principle, do not activate inductive load at the alarm contact of the detector. (In particular,
never use the inductive load to activate a fluorescent lamp or motor.)
•If inductive load is activated, relay it with an external relay (contact amplification). However,
because the coil of an external relay also involves inductive load, select a relay at a lower
voltage (100 VAC or below), and then protect the contact of the detector with an appropriate
surge absorbing part, such as a CR circuit.
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.
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. Before installing a lightning arrester, verify that it works properly.
Proper use of alarm contact
The alarm contact of the detector is used to transmit signals to activate an external buzzer, an alarm lamp or
a rotating lamp. Do not use the detector for controlling purpose (e.g., controlling the shutdown valve.)
The specifications for the alarm contact of the detector are based on the resistant load conditions. If
inductive load is used at the alarm contact, the following errors will occur easily because counter
electromotive force is generated at the contact.
•Deposition, defective insulation or defective contact at the relay contact
•Damage of any electric parts due to high-voltage generated inside the detector
•Abnormal operations by an out-of-control CPU
If load is to be activated, appropriate measures must be taken to stabilize the operation of the detector and
protect the alarm contact referring to the following information.
•Relay it with an external relay at a lower voltage of 100 VAC or below (contact amplification). At the same
time, the surge absorbing part SK1 suitable for the specifications must be attached to the external relay.
•In addition, the surge absorbing part SK2 must be attached to the loaded side of the external relay if
necessary.
•It may be recommended that the surge absorbing part should be attached to the contact for certain load
conditions. It must be attached to an appropriate position by checking how the load is activated.

4 How to Use 4-4. How to install
- 15 - SD-1DGH
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 prevent access to it. Do not install
the detector in a place where maintenance involves dangers, for example, near a high-voltage
cable.
4-4. How to install
<Installation Dimensions and Maintenance Space>
The following installation requirements must be met to install the detector.
•Attach the detector on the wall and others using four M5 screws.
A
larm contact
Power
supply
Power
supply
Coil Load
External relay
(low voltage relay) *SK1, SK2: Surge absorbing parts
SD-1DGH

4 How to Use 4-5. How to wire
SD-1DGH - 16 -
CAUTION
•Be careful not to damage the internal electronic circuit when wiring. In addition, be careful not to
apply stresses on the detector when (overweight) cables are installed.
•The power cables and signal cables must not be installed together with the motor power cables,
etc. When these cables must be installed together for unavoidable reasons, put the power cables
and signal cables in a metal conduit. The conduit must be connected to a grounding circuit.
•When stranded wires are used, prevent wires from contacting each other.
•Use the dedicated handling lever to wire.
•Use appropriate cables to wire.
4-5. How to wire
<Recommended Cable>
3-wire (when the contact is not used) CVVS1.25 sq - 3-core
5-wire (when the contact is used) CVVS1.25 sq - 5-core
Cable overall outer diameter
(mm)
Rubber seal inner diameter
(mm)
Washer inner diameter
(mm)
From Φ9.6 to less than Φ11 Φ11 Φ12
From Φ11 to less than Φ11.5 Φ12 Φ12
From Φ11.5 to less than Φ12 Φ12 Φ14
From Φ12 to less than Φ13 Φ13 Φ14
Φ13 Φ13.5 Φ14
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 CVV 1.25sq CVV 2sq CVVS 1.25sq CVVS 2sq
2 Φ9.5 Φ10.5 Φ10.0 Φ11.0
3 Φ10.0 Φ11.0 Φ10.5 Φ11.5
4 Φ10.5 Φ11.5 Φ11.0 Φ12.0
5 Φ11.5 Φ12.5 Φ12.0 Φ13.0
6 Φ12.5 Φ13.5 Φ13.0 Φ14.0

4 How to Use 4-5. How to wire
- 17 - SD-1DGH
CAUTION
The specified bare wire length must be observed when the wire insulation is peeled off.
Improper clamping of the wire due to a shorter bare wire length may cause defective electric
conduction or heating.
Catching the wire insulation due to a shorter bare wire length may cause defective electric
conduction or heating.
Exposing the wire due to a longer bare wire length may cause defective insulation or a short circuit.
Be careful not to break up the wire.If the wire is broken up when inserted to the terminal, this may
cause defective insulation or heating.
8 - 9 mm
<Figure of Terminal Plate>
DC+ 1
24 VDC
- (Common) 2
4 - 20 mA
Sig+ 3
Contact 4
Contact 5
<Specifications of Terminal Plate>
Specifications of terminal plate
•Rated voltage: 250 VAC
•Rated current: 12 A
However, it depends on cables to be used.
Connection conditions
•Cables: 0.25 - 2.5 mm2
•Bare wire length: 8 - 9 mm
•Connecting tool: Dedicated handling lever (accessory) or driver (edge 3.5 x 0.5 mm)
Grounding terminal

4 How to Use 4-5. How to wire
SD-1DGH - 18 -
CAUTION
A bar terminal of the specified model must be used. Using other bar terminals invalidates the
warranty of the performance.
CAUTION
The right tools must be used.
In principle, one wire can be connected to one wiring hole.
When the wire is inserted into the driver slot by mistake, it does not contact the conductive part. This
may cause defective electric conduction or heating.
When the wire is inserted under the spring by mistake, it does not contact the conductive part. This
may cause defective electric conduction or heating.
Compatible bar terminal
For a bar terminal, the following items are available.
•Bar terminal (ferrule): Model 216 Series (manufactured by WAGO)
•Crimping tool: Model VarioCrimp 4 (206-204) (manufactured by WAGO)
<How to Connect to Terminal Plate>
When cables are connected to the connectors, use the dedicated lever or a flathead screwdriver to do it as
shown below.
NOTE
<How to Use the Dedicated Handling Lever>
To check whether the wire is connected securely, pull the wire gently. (Do not pull the wire strongly.)
Push the lever with your
finger to lower the spring in
its inside.
While holding down the lever, insert the wire
into the (round) wiring hole until it reaches the
deepest point.
Once the lever is released, the wire is secured.

4 How to Use 4-5. How to wire
- 19 - SD-1DGH
CAUTION
•Tighten a cable gland with a tool until a clearance between the cable gland and a main unit case
is below 1.5 mm.
•If it is difficult to tighten the cable gland, grease its screw part and then tighten it with the tool.
<Attaching External Cable>
Cable gland
Below 1.5 mm
External cable

4 How to Use 4-5. How to wire
SD-1DGH - 20 -
WARNING
•Before turning on the detector, do not forget 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.
<Grounding>
Connect the detector to your grounding terminal with the external terminal .
<Wiring Example>
Connecting to the indicator
Connecting to the upper unit (DCS, PLC)
1 2345
GND
Sig
SD-1DGH
+24 V
RM-593, etc.
1 2345
＋
SD-1DGH
－
Upper unit
(DCS, PLC)
Relay terminal
plate
－
＋
Power supply
(
24 VDC
)