Riken Keiki SD-3 Series User manual

PT2E-2871
Gas Detector with Signal Converter
SD-3 Series
Technical Manual
2-7-6 Azusawa, Itabashi-ku, Tokyo, 174-8744, Japan
Website: https://www.rikenkeiki.co.jp/

Contents
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Contents
1. Product Overview ................................................................................................................................................. 5
1-1 Introduction .................................................................................................................................................. 5
1-2 Intended use and features .......................................................................................................................... 7
1-2-1 Models and Codes ........................................................................................................................... 7
1-2-2 Detection principles and detection target gases for individual models ........................................... 8
1-2-3 Product features ............................................................................................................................... 9
1-3 Usage zones and conditions ..................................................................................................................... 10
1-4 DANGER, WARNING, and NOTE ............................................................................................................ 11
2. Important Safety Information .............................................................................................................................. 12
2-1 Danger information .................................................................................................................................... 12
2-2 Warning information .................................................................................................................................. 12
2-3 Caution information ................................................................................................................................... 13
2-4 Safety information ...................................................................................................................................... 14
3. Product Configuration ......................................................................................................................................... 31
3-1 Main unit and accessories ......................................................................................................................... 31
3-1-1 Main unit (SD-3) ............................................................................................................................. 31
3-1-2 Main unit (SD-3SC) ........................................................................................................................ 32
3-1-3 Remote sensor head (GD-3) ......................................................................................................... 32
3-1-4 Standard accessories .................................................................................................................... 33
3-1-5 Optional accessories ...................................................................................................................... 34
3-2 Part names and functions ......................................................................................................................... 37
3-3 Block diagrams .......................................................................................................................................... 38
4. Installation ........................................................................................................................................................... 40
4-1 Installation precautions .............................................................................................................................. 40
4-1-1 General installation information ..................................................................................................... 40
4-1-2 Restrictions regarding installation .................................................................................................. 41
4-2 System design precautions ....................................................................................................................... 45
4-2-1 Using a stable power supply .......................................................................................................... 45
4-2-2 Lightning strike protective measures ............................................................................................. 45
4-3 Providing maintenance space ................................................................................................................... 46
4-4 Main unit installation .................................................................................................................................. 48
4-4-1 Vertical pole mounting .................................................................................................................... 48
4-4-2 Wall mounting ................................................................................................................................. 49
4-4-3 Attaching protective cover .............................................................................................................. 50
4-4-4 Attaching sunshade cover ............................................................................................................. 52
4-5 Remote sensor head (GD-3) installation .................................................................................................. 54
4-5-1 Wall mounting ................................................................................................................................. 54
4-5-2 Duct mounting ................................................................................................................................ 54
4-6 Connecting the grounding terminal ........................................................................................................... 56
4-7 Connecting the power and signal cables .................................................................................................. 57
4-7-1 Main unit cable and device connectors ......................................................................................... 57
4-7-2 Connecting the power and signal cables to the main unit ............................................................ 59
4-7-3 Connecting the power and signal cables to the remote sensor head (GD-3) ....................................... 62
4-7-4 Connecting the main unit (SD-3SC) and remote sensor head (GD-3) ......................................... 65
4-7-5 Connecting cables to the terminal plate ........................................................................................ 70
4-8 Mounting the sensor .................................................................................................................................. 73
4-9 Alarm relay setting (option) ....................................................................................................................... 74
4-10 Mounting the splash guard ...................................................................................................................... 77

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5. Usage Instructions .............................................................................................................................................. 79
5-1 Preparations for startup ............................................................................................................................. 79
5-2 Startup ....................................................................................................................................................... 80
5-3 Basic operation flow .................................................................................................................................. 82
5-4 Operating procedure ................................................................................................................................. 83
5-5 User mode ................................................................................................................................................. 84
5-5-1 User mode setting items ................................................................................................................ 84
5-5-2 Switching to user mode ................................................................................................................. 85
5-6 Performing zero calibration ....................................................................................................................... 86
5-7 Checking settings ...................................................................................................................................... 88
5-7-1 Checking alarm setpoints .............................................................................................................. 88
5-8 Shutting down ............................................................................................................................................ 90
6. Alarm Activation .................................................................................................................................................. 91
6-1 Gas alarm activation .................................................................................................................................. 91
6-1-1 Alarm activation .............................................................................................................................. 91
6-1-2 Contact operation (auto reset) ....................................................................................................... 92
6-1-3 Contact operation (self-latching) .................................................................................................... 93
6-1-4 Alarm response .............................................................................................................................. 96
6-2 Fault alarm activation ................................................................................................................................ 96
6-3 Warning operation ..................................................................................................................................... 97
6-4 External output operation .......................................................................................................................... 98
6-4-1 For target gases other than oxygen .............................................................................................. 98
6-4-2 When the target gas is oxygen .................................................................................................... 102
6-5 Functions to ensure correct alarm activation .......................................................................................... 105
6-5-1 Zero suppression function ........................................................................................................... 105
6-5-2 Automatic sensor recognition function ........................................................................................ 106
7. Maintenance ..................................................................................................................................................... 107
7-1 Maintenance intervals and items ............................................................................................................ 107
7-2 Maintenance mode .................................................................................................................................. 109
7-2-1 Maintenance mode setting items ................................................................................................. 109
7-2-2 Switching to maintenance mode ................................................................................................. 110
7-3 Performing tests (test mode) ................................................................................................................... 112
7-3-1 Performing gas test ...................................................................................................................... 112
7-3-2 Performing alarm test ................................................................................................................... 113
7-3-3 Performing fault test ..................................................................................................................... 115
7-3-4 Performing LED test ..................................................................................................................... 116
7-3-5 Performing memory test (RAM test) ............................................................................................ 117
7-4 Performing calibration ............................................................................................................................. 118
7-4-1 Calibration preparation ................................................................................................................. 118
7-4-2 Performing zero calibration .......................................................................................................... 123
7-4-3 Performing span adjustment ........................................................................................................ 124
7-5 Setting environmental settings 1 ............................................................................................................. 128
7-5-1 Inhibit setting ................................................................................................................................ 128
7-5-2 Alarm setpoint setting................................................................................................................... 129
7-5-3 Date and time setting ................................................................................................................... 130
7-6 Setting environmental settings 3 ............................................................................................................. 131
7-6-1 Double range external output setting ............................................................................. 132
7-7 Parts replacement ................................................................................................................................... 133
7-7-1 Sensor replacement ..................................................................................................................... 133
7-7-2 Replacement of periodic replacement parts ................................................................................ 133
8. Storage, Relocation, and Disposal ................................................................................................................... 134
8-1 Procedures for storage or when not in use for extended periods .......................................................... 134
NC

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8-2 Procedures for relocation or reuse .......................................................................................................... 136
8-3 Product disposal ...................................................................................................................................... 136
9. Troubleshooting ................................................................................................................................................ 137
9-1 Product abnormalities .............................................................................................................................. 137
9-2 Reading abnormalities ............................................................................................................................. 138
10. Product Specifications ...................................................................................................................................... 140
10-1 SD-3 specifications ................................................................................................................................ 140
10-1-1 SD-3 (model without EC barrier) ................................................................................................. 140
10-1-2 SD-3 (model with EC barrier) ....................................................................................................... 143
10-1-3 Electrical ratings (SD-3) ............................................................................................................... 146
10-2 SD-3SC + GD-3 specifications ............................................................................................................. 147
10-2-1 SD-3SC + GD-3 (model without EC barrier) ............................................................................... 147
10-2-2 SD-3SC + GD-3 (model with EC barrier) .................................................................................... 150
10-2-3 Electrical ratings (SD-3SC + GD-3) ............................................................................................. 153
10-3 Detection target gases for individual detection principles .................................................................... 154
10-3-1 Non-dispersive infrared absorption type (Infrared type) .............................................................. 154
10-3-2 New ceramic type ........................................................................................................................ 155
10-3-3 Semiconductor type ..................................................................................................................... 156
10-3-4 Hot-wire semiconductor type ....................................................................................................... 158
10-3-5 Electrochemical type .................................................................................................................... 160
11. Appendix ........................................................................................................................................................... 161
11-1 Detection principle ................................................................................................................................. 161
11-1-1 Non-dispersive infrared absorption type (Infrared type) .............................................................. 161
11-1-2 New ceramic type ........................................................................................................................ 162
11-1-3 Semiconductor type ..................................................................................................................... 163
11-1-4 Hot-wire semiconductor type ....................................................................................................... 164
11-1-5 Electrochemical type .................................................................................................................... 165
11-2 Terminology ............................................................................................................................................ 166
Product warranty .............................................................................................................................................. 167
Sensor warranty ............................................................................................................................................. 167
Revision History ................................................................................................................................................ 168

1. Product Overview 1-1 Introduction
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1
Product Overview
1-1 Introduction
Thank you for purchasing the SD-3 Gas Detector with Signal Converter (“product” hereinafter).
This operating manual describes product operating procedures and specifications. It provides information
essential to correct use of the product.
Make sure you have read and fully understood the contents of this manual before using the product.
Keep this operating manual on hand to allow ready reference during use.
The contents of this manual are subject to change without notice to allow product improvements. Any
duplication or reproduction of this manual without permission is prohibited, whether in whole or in part.
Riken Keiki accepts no liability for accidents or damage resulting from use of the product, whether within or
outside the warranty period.
Be sure to read the warranty policy at the end of this document.
Before using the product, please confirm that the model of the product you purchased matches the model of the
product covered by this operating manual.
<Models covered by this operating manual>
Diffusion type Suction type
Main unit
SD-3RI SD-3DRI
SD-3NC SD-3DNC
SD-3GH SD-3DGH
SD-3GHS SD-3DGHS
SD-3SP SD-3DSP
SD-3EC SD-3DEC
SD-3ECS SD-3DECS
SD-3ECB SD-3DECB
Main unit SD-3SC
Remote
sensor head
GD-3RI
GD-3NC
GD-3GH
GD-3GHS
GD-3SP
GD-3EC
GD-3ECS
GD-3ECB

1. Product Overview 1-1 Introduction
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<This operating manual>
In this operating manual, where descriptions differ according to the detection principle, these are indicated by
the following icons:
Non-dispersive infrared absorption type
(infrared type)
New ceramic type
Semiconductor type
Hot-wire semiconductor type
Electrochemical type
Operating procedures and specifications for which no icons appear apply to all detection principles.
The display examples provided in this operating manual apply when the detection target gas is combustible
(display units: %LEL).
RI
NC
GH
SP
EC

1. Product Overview 1-2 Intended use and features
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1-2 Intended use and features
The product is a fixed explosion-proof device for continuous monitoring of combustible gases, toxic gases, and
oxygen in the air.
An alarm is triggered if combustible gases, toxic gases, or oxygen exceeding preset concentrations are
detected in the air.
The detection results are not intended to assure life or safety.
1-2-1 Models and Codes
SD-3 ① ② （ ③ 1 0 0 ⑦ ⑧ ）
[Remote type: Main unit (SD-3SC) + Remote sensor unit (GD-3)]
SD-3SC ( ③ 1 0 0 ⑦ ⑧ )
GD-3 ① ②
① Diffusion type/suction type selection ⑥Performance certification
Blank Diffusion type 0 None [Standard]
D Suction type (introduced via external unit) 1 -
② Sensor type selection 2 -
RI Infrared type 3 -
NC New ceramic type ⑦Range setting*
GH Semiconductor type 0 Single range [Standard]
GHS Semiconductor type (selectable for CS2
only) 1 Double range +4-16 (selectable
with NC only)
SP Hot-wire semiconductor type 2 Double range + L4-20 (selectable
with NC only)
EC Electrochemical type (selectable for
CO/O2 only) 3 Double range + H4-20 (selectable
with NC only)
ECS Electrochemical type (selectable for H2S
only) ⑧Output type selection
ECB Electrochemical type (selectable for
gases other than CO/O2/H2)
0 4-20 mA + HART [Standard]
③ Cable connectors 1 4-20 mA + HART + contact (3c)
0 Connector 1 + Connector 2 [Standard] 2 -
1 Connector 1 + Connector 2+ Connector
4 + Connector 5
*HART communication is unavailable when double range
(optional) is selected.
④ Explosion-proof
1 ATEX/IECEx [Standard]
2 -
3 -
4 -
⑤ Functional safety
0 None [Standard]
1 -
Example: Cable connectors
Standard
Standard
Optional
Optional
Connector
1
Connector
2
Connector
4
Connector
5
Connector
3 *Not used

1. Product Overview 1-2 Intended use and features
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1-2-2 Detection principles and detection target gases for individual models
The product is available in the following models, depending on the specific detection method and detection
principle.
Check the specifications before use to confirm that correct gases will be detected in accordance with the
intended purpose.
<List of detection target gases by model>
Main unit
model
Detection
method Detection principle
Detection target gas
Remarks
Combus-
tible gas
Toxic
gas Oxygen
SD-3RI
Diffusion
Non-dispersive infrared
absorption type
(infrared type)
〇 〇
SD-3NC New ceramic type 〇
SD-3GH Semiconductor type 〇 〇
SD-3GHS Semiconductor type 〇 CS2 (carbon disulfide) only
SD-3SP Hot-wire semiconductor
type 〇 〇
SD-3EC Electrochemical type 〇 〇
SD-3ECS Electrochemical type 〇
H2S (hydrogen sulfide)
only
SD-3ECB Electrochemical type 〇 With EC barrier*
SD-3DRI
Suction
Non-dispersive infrared
absorption type
(infrared type)
〇 〇
SD-3DNC New ceramic type 〇
SD-3DGH Semiconductor type 〇 〇
SD-3DGHS Semiconductor type 〇 CS2 (carbon disulfide) only
SD-3DSP Hot-wire semiconductor
type 〇 〇
SD-3DEC Electrochemical type 〇 〇
SD-3DECS Electrochemical type 〇
H2S (hydrogen sulfide)
only
SD-3DECB Electrochemical type 〇 With EC barrier*
*Differs depending on detection target gas.

1. Product Overview 1-2 Intended use and features
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<List of detection target gases by model (remote sensor type)>
Main unit model SD-3SC
Remote
sensor head
model
Detection
method Detection principle
Detection target gas
Remarks
Combus-
tible gas
Toxic
gas Oxygen
GD-3RI
Diffusion
Non-dispersive infrared
absorption type
(infrared type)
〇 〇
GD-3NC New ceramic type 〇
GD-3GH Semiconductor type 〇 〇
GD-3GHS Semiconductor type 〇 CS2 (carbon disulfide)
only
GD-3SP Hot-wire semiconductor
type 〇 〇
GD-3EC Electrochemical type 〇 〇
GD-3ECS Electrochemical type 〇
H2S (hydrogen sulfide)
only
GD-3ECB Electrochemical type 〇 With EC barrier*
*Differs depending on detection target gas.
<Sensor models and detection principles>
Sensor model Detection principle
IRF Infrared type
NCF New ceramic type
SGF Semiconductor type
SHF Hot-wire semiconductor type
ESF Electrochemical type
1-2-3 Product features
<Standard specifications>
 The product is constructed with a stainless steel housing suitable for both indoors and outdoors use.
 Requires a 24 V DC (DC 18 V to 30 V) power supply.
 The gas concentration, status, and command selection menu are displayed using seven-segment LEDs.
 The concentration of the gas detected is converted to a 4 - 20 mA analog output (NAMUR NE43 compliant)
or a digital HART output signal.
 It can be connected to a Riken Keiki monitoring system or programmable logic controller (PLC) via a ceiling
fitting or approved cable gland.
<Optional specifications>
 The product can be operated as a standalone unit by setting an alarm relay. Using the product as a
standalone unit allows control of devices without the need for a central controller.*1
*1: Using the product as a standalone unit requires additional alarm signal settings.

1. Product Overview 1-3 Usage zones and conditions
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1-3 Usage zones and conditions
The product is approved for use in areas where gases classified in explosive gas groups IIA, IIB, or IIC may be
present. This refers to use limited to hazardous zones categorized as Zone 1 or Zone 2 within the product
operating temperature range.

1. Product Overview 1-4 DANGER, WARNING, and NOTE
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1-4 DANGER, WARNING, and NOTE
This operating manual uses the following categories to indicate potential damage/hazards if the user disregards
the information provided and uses the product incorrectly:
DANGER This indicates situations in which improper handling may result in fatal or
serious injury or significant property damage.
WARNING This indicates situations in which improper handling may result in serious injury
or significant property damage.
CAUTION This indicates situations in which improper handling may result in minor injury
or minor property damage.
Additionally, usage recommendations are indicated as follows:
NOTE This indicates items that will be helpful to know when using the product.

2. Important Safety Information 2-1 Danger information
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2
Important Safety
Information
2-1 Danger information
DANGER
 Do not open the cover while the power is turned on. When opening the cover, use a portable gas
detector or other similar device to confirm that there is no gas present in the vicinity.
 Do not attempt to repair the product.
 Do not attempt to repair or replace the explosion-proof bonding surface. If you observe scratches, cracks,
or deformation on the housing or explosion-proof bonding surface, stop using the product immediately
and contact Riken Keiki promptly.
2-2 Warning information
WARNING
 Before turning on the power for the product, be sure to confirm that the power source meets the specified
voltage requirements.
Using power supplies other than the stipulated voltage will damage the product. Do not use unstable
power supplies. Doing so may result in malfunctions.
 Do not disconnect the protective grounding wire or terminal.
 Before operating the product, check the protective functions for defects.
Do not operate the product if you suspect any problems with the protective grounding or other protective
functions.
 Connect to a protective ground before connecting to external control circuits.
 Before adjusting zero for the surrounding atmosphere, confirm that the surrounding atmosphere contains
clean air.
The presence of interference gases will prevent proper air calibration. The presence of miscellaneous
gases is also extremely dangerous because the product may not detect actual gas leaks correctly.
 A gas alarm indicates the presence of extreme danger. The user must take appropriate action after taking
suitable steps to ensure safety.
 Do not immerse the product in organic solvents for extended periods. The flame arrester components are
made of polyphenylene sulfide (PPS) resin.

2. Important Safety Information 2-3 Caution information
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2-3 Caution information
CAUTION
 The product operation may be affected by radio waves emitted from walkie-talkies or other radio
transmitters used near the product or its cables. Position walkie-talkies or other similar devices so that
they do not affect the product operation.
 Wait at least 10 seconds before turning the power back on again after turning off. The product may not
function correctly if the power is turned back on immediately.
 The product is not a control device. Never use the product output to control other devices.
 Do not disassemble or alter the product. Product performance cannot be guaranteed if the product is
disassembled or modified.
 Do not alter settings unnecessarily unless you are fully aware of the consequences. Doing so may result
in improper alarm function. Avoid performing any operations not described in this operating manual.
 The product is a safety device. Be sure to maintain the product at regular intervals to ensure safety.
Continuing to use the product without adequate maintenance will result in sensor sensitivity degradation
and prevent proper gas detection.

2. Important Safety Information 2-4 Safety information
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2-4 Safety information
<Product overview>
 The products have an explosion-proof construction.
 Sensors are divided into three different types, depending on the corresponding detection principles. The
detection methods are divided into the diffusion type and suction type. Suction-type sensors should be used
with a suction cap fitted.
 The product is a fixed, continuous monitoring detector. It can be connected to a gas monitoring control unit,
recorder, or programmable control unit to output the measured gas readings as a 4 - 20 mA signal or HART
signal.
 The following three sets of output specifications are available for this product:
・ No alarm relay, no digital communication
・ 3 alarm relays (contact output) (alarm relays operate in conjunction with gas alarms and faults), no
digital signal
・ No alarm relay, digital communication (RS-485 output)
 The electrochemical sensor is made into an explosion-proof construction by using an EC barrier.
<Detection principles and models>
 The models corresponding to the individual detection principles are as follows. The models are classified by
detection principle and detection method.
Detection principle (Detection method: Diffusion type) Model
Optical sensor Non-dispersive infrared absorption type (infrared
type)
SD-3RI
Solid state sensor Semiconductor type SD-3GH
SD-3GHS
New ceramic type SD-3NC
Hot-wire semiconductor type SD-3SP
Electrochemical sensor Electrochemical type SD-3EC
SD-3ECS
SD-3ECB
Detection principle (Detection method: Suction type) Model
Optical sensor Non-dispersive infrared absorption type (infrared
type)
SD-3DRI
Solid state sensor Semiconductor type SD-3DGH
SD-3DGHS
New ceramic type SD-3DNC
Hot-wire semiconductor type SD-3DSP
Electrochemical sensor Electrochemical type SD-3DEC
SD-3DECS
SD-3DECB

2. Important Safety Information 2-4 Safety information
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 The SD-3SC is used with a remote sensor head (GD-3) from among the following models:
Detection principle (Detection method: Diffusion type)
Model
GD-3
(Remote sensor head)
SD-3
Optical sensor Non-dispersive infrared absorption
type (infrared type)
GD-3RI
SD-3SC
Solid state sensor Semiconductor type GD-3GH
GD-3GHS
New ceramic type GD-3NC
Hot-wire semiconductor type GD-3SP
Electrochemical sensor Electrochemical type GD-3EC
GD-3ECS
GD-3ECB
WARNING
 The SD-3EC and GD-3EC models are subdivided by the type of explosion-proof construction of the
flame arrester fitted to the sensor and whether they include an EC barrier.
The expected explosion-proof performance cannot be ensured if the incorrect flame arrestor is used. Do
not replace with a different flame arrester.
 The SD-3GH and GD-3GH models are subdivided by the type of explosion-proof construction of the
flame arrester fitted to the sensor.
The expected explosion-proof performance cannot be ensured if the incorrect flame arrestor is used. Do
not replace with a different flame arrester.

2. Important Safety Information 2-4 Safety information
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<Explosion-proof performance data>
The range of ambient temperatures in which explosion-proof performance can be maintained will differ depending
on whether the optional lightning arrester is fitted.
Refer to the following performance data for each model:
<Without lightning arrester>
Model
Explosion-
proof
construction Group Category Explosion-proof
class EPL Ambient temperature*1
SD-3RI
d II 2G Ex db IIC T6/T5 Gb -50 °C ≤ Ta ≤ +60 °C /+70 °C
SD-3DRI
GD-3RI
SD-3GH
d II 2G Ex db IIC T5/T4 Gb -50 °C ≤ Ta ≤ +44 °C /+70 °C
SD-3DGH
GD-3GH
SD-3GHS
d II 2G Ex db IIC T6/T4 Gb -50 °C ≤ Ta ≤ +47 °C /+70 °C
SD-3DGHS
GD-3GHS
SD-3NC
d II 2G Ex db IIC T5/T4 Gb -50 °C ≤ Ta ≤ +44 °C /+70 °C
SD-3DNC
GD-3NC
SD-3SP
d II 2G Ex db IIC T5/T4 Gb -50 °C ≤ Ta ≤ +55 °C /+70 °C
SD-3DSP
GD-3SP
SD-3EC
d II 2G Ex db IIC T4 Gb -50 °C ≤ Ta ≤ +70 °C
SD-3DEC
GD-3EC
SD-3ECS
d II 2G Ex db IIC T4 Gb -50 °C ≤ Ta ≤ +70 °C
SD-3DECS
GD-3ECS
SD-3ECB
d+i II 2G Ex db ia IIC T4 Gb -40 °C ≤ Ta ≤ +70 °C
SD-3DECB
GD-3ECB
SD-3SC*2 d II 2G Ex db IIC T6/T5/T4 Gb -50 °C ≤ Ta ≤ +47 °C /+55 °C
+70 °C
SD-3SC*3 d II 2G Ex db IIC T5/T4 Gb -50 °C ≤ Ta ≤ +44 °C /+70 °C
SD-3SC*4 d II 2G Ex db IIC T6/T5 Gb -50 °C ≤ Ta ≤ +60 °C /+70 °C
SD-3SC*5 d II 2G Ex db IIC T4 Gb -40 °C ≤ Ta ≤ +70 °C
*1: The ambient temperature refers to temperatures in the range within which explosion-proof performance can be
maintained. It does not imply the temperature range within which the required product performance may be
achieved. For information on the operating temperature range, refer to ‘10-3 Detection target gases for individual
deterction principles’.
*2: When used in combination with GD-3GHS, GD-3SP, GD-3EC, and GD-3ECS
*3: When used in combination with GD-3GH and GD-3NC
*4: When used with the GD-3RI
*5: When used in combination with GF-3ECB

2. Important Safety Information 2-4 Safety information
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<With lightning arrester>
Model
Explosion-
proof
construction Group Category Explosion-proof
class EPL Ambient temperature*1
SD-3RI
d II 2G Ex db IIC T6/T5 Gb -40 °C ≤ Ta ≤ +60 °C/+70 °C
SD-3DRI
GD-3RI
SD-3GH
d II 2G Ex db IIC T5/T4 Gb -40 °C ≤ Ta ≤ +44 °C /+70°C
SD-3DGH
GD-3GH
SD-3GHS
d II 2G Ex db IIC T6/T4 Gb -40 °C ≤ Ta ≤ +47 °C /+70°C
SD-3DGHS
GD-3GHS
SD-3NC
d II 2G Ex db IIC T5/T4 Gb -40 °C ≤ Ta ≤ +44 °C /+70 °C
SD-3DNC
GD-3NC
SD-3SP
d II 2G Ex db IIC T5/T4 Gb -40 °C ≤ Ta ≤ +55 °C /+70 °C
SD-3DSP
GD-3SP
SD-3EC
d II 2G Ex db IIC T4 Gb -40 °C ≤ Ta ≤ +70 °C
SD-3DEC
GD-3EC
SD-3ECS
d II 2G Ex db IIC T4 Gb -40 °C ≤ Ta ≤ +70 °C
SD-3DECS
GD-3ECS
SD-3ECB
d+i II 2G Ex db ia IIC T4 Gb -40 °C ≤ Ta ≤ +70 °C
SD-3DECB
GD-3ECB
SD-3SC*2 d II 2G Ex db IIC
T6/T5/T4 Gb -40 °C ≤ Ta ≤ +47 °C /+55 °C
+70 °C
SD-3SC*3 d II 2G Ex db IIC T5/T4 Gb -40 °C ≤ Ta ≤ +44 °C /+70 °C
SD-3SC*4 d II 2G Ex db IIC T6/T5 Gb -40 °C ≤ Ta ≤ +60 °C /+70 °C
SD-3SC*5 d II 2G Ex db IIC T4 Gb -40 °C ≤ Ta ≤ +70 °C
*1: The ambient temperature refers to temperatures in the range within which explosion-proof performance can be
maintained. It does not imply the temperature range within which the required product performance may be
achieved. For information on the operating temperature range, refer to ‘10-3 Detection target gases for individual
deterction principles’.
*2: When used in combination with GD-3GHS, GD-3SP, GD-3EC, and GD-3ECS
*3: When used in combination with GD-3GH and GD-3NC
*4: When used with the GD-3RI
*5: When used in combination with GF-3ECB

2. Important Safety Information 2-4 Safety information
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<Electrical data>
Model Supply voltage Power
consumption Signal output
Option (select one)
No alarm relay/
No digital
communication
Alarm relay
(contact output)/
Resistance load
only
Digital
communication
SD-3RI 24 V DC
(18 V - 30 V
DC Max)
3.8 W Max 0 - 22 mA + HART ― 30 V DC, 1 A
250 V AC, 2 A RS-485 output
SD-3DRI
GD-3RI 1.2 W Max ― ― ― ―
SD-3GH 24 V DC
(18 V - 30 V
DC Max)
4.5 W Max 0 - 22 mA + HART ― 30 V DC, 1 A
250 V AC, 2 A RS-485 output
SD-3DGH
GD-3GH 2 W Max ― ― ― ―
SD-3GHS 24 V DC
(18 V - 30 V
DC Max)
4.5 W Max 0 - 22 mA + HART ― 30 V DC, 1 A
250 V AC, 2 A RS-485 output
SD-3DGHS
GD-3GHS 2 W Max ― ― ― ―
SD-3NC 24 V DC
(18 V - 30 V
DC Max)
4.5 W Max 0 - 22 mA + HART ― 30 V DC, 1 A
250 V AC, 2 A RS-485 output
SD-3DNC
GD-3NC 2 W Max ― ― ― ―
SD-3SP 24 V DC
(18 V - 30 V
DC Max)
3.5 W Max 0 - 22 mA + HART ― 30 V DC, 1 A
250 V AC, 2 A RS-485 output
SD-3DSP
GD-3SP 1 W Max ― ― ― ―
SD-3EC 24 V DC
(18 V - 30 V
DC Max)
2.8 W Max 0 - 22 mA + HART ― 30 V DC, 1 A
250 V AC, 2 A RS-485 output
SD-3DEC
GD-3EC 1 W Max ― ― ― ―
SD-3ECS 24 V DC
(18 V - 30 V
DC Max)
2.8 W Max 0 - 22 mA + HART ― 30 V DC, 1 A
250 V AC, 2 A RS-485 output
SD-3DECS
GD-3ECS 1 W Max ― ― ― ―
SD-3ECB 24 V DC
(18 V - 30 V
DC Max)
3.1 W Max 0 - 22 mA + HART ― 30 V DC, 1 A
250 V AC, 2 A RS-485 output
SD-3DECB
GD-3ECB 1 W Max ― ― ― ―
SD-3SC
24 V DC
(18 V - 30 V
DC Max)
5 W Max 0 - 22 mA + HART ― 30 V DC, 1 A
250 V AC, 2 A RS-485 output
<Certificate numbers>
 IECEx PRE 20.0064 X
 Presafe 20 ATEX 69725 X
* The “X” at the end of the certificate number indicates the following special operating conditions:
・ Do not attempt to repair explosion-proof joints.
・ Damage to the window plate due to strong impact may affect explosion-proof performance. The product is
subject to “Low (2J)” explosion-proof conditions, indicating risk of mechanical damage.
・ Avoid rubbing the nameplate area with a dry cloth during use, maintenance, or cleaning. Doing so may result
in a static charge buildup of up to 6 nF.
・ For information on the explosive-proof operating temperature range, refer to <Explosion-proof performance
data> in ‘2-4 Safety information’.
・ If attaching a lightning arrester to the SD-3, apply high-strength thread-locking compound to the mounting
screw.
・ The ATEX compliant models do not support the measuring functions specified in 1.5.5 of Annex II of the
ATEX directive. This directive provides guidelines on the performance of gas detectors and safety devices
and is based on the requirements of related EU harmonized standards.
・ The IECEx models do not support the measuring functions of EUT. These guidelines address the
performance of gas detectors and safety devices.

2. Important Safety Information 2-4 Safety information
19 / 168
・ The client should not try to replace the batteries.
<Applicable standards>
 IEC 60079-0:2017
 IEC 60079-1:2014
 IEC 60079-11:2011
 EN 60079-0:2018
 EN 60079-1:2014
 EN 60079-11:2012
<Operating manual no.>
 PT2-287
2-7-6 Azusawa, Itabashi-ku, Tokyo, 174-8744, Japan
Phone: [phone]
Fax: [phone]
Email: [email protected]
Website: https://www.rikenkeiki.co.jp

2. Important Safety Information 2-4 Safety information
20 / 168
<System configuration diagrams>
Display
Gas detector (SD-3)
Hazardous area
(Zone 1)
Non-hazardous
area
Installation diagram
Signal cable
POW(+)
COM(−)
Sig(+)
Sig(−)
POW(+)
COM(−)
Sig(+)
Sig(−)
RL
Y
RLY
Display
Gas detector (SD-3)
Hazardous area
(Zone 1)
Non-hazardous
area
Installation diagram
Signal cable
POW(+)
COM(−)
Sig(+)
Sig(−)
POW(+)
COM(−)
Sig(+)
Sig(−)
Signal cable