Riken Keiki SD-1 User manual

PT2E-2195
Smart transmitter/Gas Detector Head
SD-1
（TYPE GP S）
Operating Manual
(PT2E-160)
(PT2-160)

Operating Precautions
This detector is a gas detector that detects combustible gases in the air and triggers a gas alarm.
The gas detector is a safety unit, not an analyzer or densitometer which performs quantitative/qualitative
analysis/measurement for gases.
Please fully understand the following points before using it, so that it can be used properly.
1. This detector may be interfered by gases and vapors other than the gas to be detected.
Please note that the alarm may be triggered by interference. In addition, it may be fluctuated by
environmental (temperature, humidity, etc.) changes in the installation site.
2. The alarm must be set within a range where the performance of the detector can be ensured.
In facilities compliant with the High Pressure Gas Safety Act, an alarm setting below our standard
alarm setpoint may trigger a false alarm.
3. This is a safety unit, not a control unit.
The alarm contact output of the detector must be used for an external alarm lamp/buzzer, while the
alarm signal output must be used for an indicator or external recorder.
If these outputs are used to control other units, we shall not be responsible for any malfunctions.
4. The gas sensing part of the gas detection sensor installed in this detector is made of metal porous
sintered alloy permeated with an oxidation catalyst.
If silicon or sulfide compounds are accumulated on the surface of porous sintered alloy, the area of the
gas sensing part becomes smaller, which may results in serious deterioration of its sensitivity.
For safety reasons, do not use the detector under the presence of silicon or sulfide compounds even
though their amount is very small.
5. For maintenance of the detector, it must go through a regular maintenance, including replacement and
adjustment of the regular replacement parts as specified in the operating manual. In addition, because
this is a safety unit, it is recommended that a regular maintenance and a gas calibration are performed
every six months in accordance with the regulations.
6. This detector is SIL2 ceritified for single application. SIL 2 is Safety Integrity Level by safety
instrumentation functioning omni-PFD avg .
If compliance with functional safety standards is desired, please use it in accordance with this operating
manual and the separate safety manual for installation, use and maintenance.
If it does not comply, the safety Integrity level will be lowered.

Operating Precautions
- 1 -
<Contents>
1 Outline of the Product ......................................................................................................... 2
1-1. Preface............................................................................................................................ 2
1-2. Purpose of use ................................................................................................................ 2
1-3. Definition of DANGER, WARNING, CAUTION, and NOTE ............................................. 2
1-4. Method of confirmation for Standards and Explosion proof specification ........................ 3
2 Important Notices on Safety................................................................................................ 4
2-1. Danger cases .................................................................................................................. 4
2-2. Warning cases................................................................................................................. 5
2-3. Precautions ..................................................................................................................... 6
2-4. Safety information ........................................................................................................... 7
3 Product Components .......................................................................................................... 9
3-1. Gas detector 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. Installation procedure ...................................................................................................... 16
4-6. How to wire...................................................................................................................... 18
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 ............................................................................................................................. 24
5-5. User mode....................................................................................................................... 25
5-6. How to exit....................................................................................................................... 27
6 Operations and Functions................................................................................................... 28
6-1. Gas alarm activation........................................................................................................ 28
6-2. Fault alarm activation ...................................................................................................... 29
6-3. Warning activation ........................................................................................................... 29
6-4. External output operation ................................................................................................ 30
6-5. Other functions ................................................................................................................ 31
7 Maintenance ....................................................................................................................... 32
7-1. Maintenance intervals and items ..................................................................................... 32
7-2. Proof Test ........................................................................................................................ 34
7-3. Gas calibration method ................................................................................................... 34
7-4. Parts replacement ........................................................................................................... 37
8 Storage, Relocation and Disposal....................................................................................... 39
8-1. Procedures to store the detector or leave it for a long time ............................................. 39
8-2. Procedures to relocate the detector or use it again ......................................................... 39
8-3. Disposal of products........................................................................................................ 39
9 Troubleshooting .................................................................................................................. 40
10 Product Specifications......................................................................................................... 42
10-1. List of specifications ...................................................................................................... 42
10-2. Detection principle......................................................................................................... 46
11 Definition of Terms............................................................................................................... 47

1 Outline of the Product 1-1. Preface
- 2 -
1
Outline of the Product
1-1. Preface
Thank you for choosing our smart transmitter/gas detector head SD-1(TYPE GP S). 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.
1-2. Purpose of use
The detector is a fixed type gas detector head that detects leak of combustible gases and that performs the
alarm activation when the gas concentration is over the setting value.
This 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.
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.

1 Outline of the Product 1-4. Method of confirmation for Standards and Explosion proof specification
- 3 -
1-4. Method of confirmation for Standards and
Explosion proof specification
This instrument has some specification depends on standard and explosion proof certificate. Please
confirm the detector specification before using. Please refer Declaration of Conformity that is at the end of
this manual if you have CE marking type. You can confirm instrument specification to see name plate as
follows.
ATEX/IECEx, CE marking type name plate TIIS type name plate
TIIS certificate
CE marking
Ex marking

2 Important Notices on Safety 2-1. Danger cases
- 4 -
2
Important Notices on
Safety
2-1. Danger cases
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.
Ambient temperature:
ATEX/IECEx Specifications: -20 to +60°C
TIIS Specifications: -20 to +53°C
Do not replace parts at your sole discretion but contact RIKEN KEIKI if the transparent window has a
crack or the explosion-proof joint surface is abnormal, or the clamping screw or bolt is changed, lost
etc.
Do not repair the explosion-proof joint surface.
Be careful not to hit sharp tools against the window plate.

2 Important Notices on Safety 2-2. Warning cases
- 5 -
2-2. Warning cases
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.
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 a gas alarm
Issuance of a gas alarm indicates that there are extreme dangers. Take proper actions based on your
judgment.

2 Important Notices on Safety 2-3. Precautions
- 6 -
2-3. Precautions
CAUTION
Do not use a transceiver near the detector.
Radio wave from a transceiver near the detector or its cables may disturb commands. 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.
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 compromise the sensitivity of the sensor, thus
resulting in inaccurate gas detection.

2 Important Notices on Safety 2-4. Safety information
- 7 -
2-4. Safety information
Necessary information for explosion proof construction of 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.
<ATEX/IECEx Specifications>
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 db IIC T5
(Equipment Protection Level) Gb
(Ambient Temperature) -20C to +60C
(Electrical Data) Supply voltage: 24 V±10% dc (Typ.)
Output signal: 4 to 20 mA
(Applicable Standard) IEC 60079-0: 2017，IEC 60079-1: 2014-06
EN IEC 60079-0: 2018，EN 60079-1: 2014
(ManualNumber) PT2E-160
Installation
＋
－
＋
－
Hazardous Location
(Zone 1)
Nonhazardous Location
GasDetector(SD ‐1)
←→
InstallationDiagram
Signal Signal
CVVSCable
Indicator

2 Important Notices on Safety 2-4. Safety information
- 8 -
<TIIS Specifications>
Technical Data
(Protection Method) Flameproof enclosure
(Explosion-proof class) Ex d IIC T5 X
(Ambient Temperature) -20C to 53C
(Electrical Data) Supply voltage: DC24V±10% 125mA
Analogsignaloutput:DC24V25mA
Contact output (Contact capacity): AC250V 0.5A (Load resistance)
DC30V 0.5A (Load resistance)
(Applicable Standard) JNIOSH-TR-NO. 43(2008)
Installation
＋
－
＋
－
Hazardous Location
(Zone 1)
Nonhazardous Location
GasDetector(SD ‐1)
←→
InstallationDiagram
Signal Signal
CVVSCable
Indicator

3 Product Components 3-1. Gas detector and standard accessories
- 9 -
3
Product Components
3-1. Gas detector and standard accessories
<Main Unit> (including a cable gland or an adapter)
【ATEX/IECEx Specification】
【TIIS Specification】
Adapter A (NPT1/2)
Cable gland (G3/4)

3 Product Components 3-2. Names and functions for each part
- 10 -
<Standard Accessories>
Operating manual･･････････････････ one
Dedicated handling lever (used for the wiring) ･･････････････････ one
Dedicated control key････････ The supplied quantity depends on the number of units to be delivered.
1 to 10 units one
11 to 20 units two
21 to 50 units three
over 51 units four
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.
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.
Note that the control key is made of extremely strong magnet. Putting it close to a magnetic product,
such as a credit card and ID card, may damage the stored data.
(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 -
3-3. Block diagram
<Electric Diagram>
Sensor
Controller
(CPU)
POWER INPUT (24 VDC)
Power supply part
1.Gas alarm contact (ALARM)
or
2.Fault contact (FAULT)
or
3.Select either gas alarm or
contact (ALARM/FAULT)
Contact activation
De-energized (De-energized
at a normal state)
ON-ALARM (Closed contact at
an alarm state)
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
- 12 -
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.
<ATEX/IECEx Specifications> -20 to +60ºC
<TIIS Specifications> -20 to +53ºC
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 exist.
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 installation points and the number of units to be installed.

4 How to Use 4-3. Precautions for system designing
- 13 -
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 when 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±10%: 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.
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 safety retainer).
(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.
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.

4 How to Use 4-3. Precautions for system designing
- 14 -
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.
CAUTION
In principal, 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.

4 How to Use 4-4. How to install
- 15 -
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.
Tighten the hexagon socket head cap bolt fixing the lid and the main body with a tightening torque of 215.6
±24.5N･cm.
When closing the lid of the detector, make sure that there is no dust on screw, surfaces of the main body
and lid. Then apply grease as specified by RIKEN KEIKI.
NOTE
・Hexagon socket head cap bolt with strength class "A2-70" are used.
When you lost or replace it, we recommend that you ask our local sales office nearest you.
・Grease specified by RIKEN KEIKI : BARRIERTA JFE 552 (manufactured by NOK KLUBER)
If you can not prepare the specified grease, use one that meets the following requirements.
1. Material does not harden due to deterioration
2. Volatile solvent-free
3. Material does not cause corrosion at the surface
4. Silicon-free
5. Validation of suitability depends on the specifications of grease manufacturer
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.
150mm
193mm

4 How to Use 4-5. Installation procedure
- 16 -
4-5. Installation procedure
<Attaching External Cable>
【ATEX/IECEx Specification】
The ATEX / IECEx specification comes with adapter A (NPT 1/2) as
standard. Please prepare the Ex cable gland that is suitable for the adapter
【TIIS Specification】
Cable gland, Rubber seal, Washer and Eccentric washer are mounted on SD-1 main body as shown below.
Attach the parts :
Pass a Cable (e.g. CVVS) through the Cable gland, Eccentric washier, Washer, and Rubber seal, and
drawn into detector inside. (For wire methods, see "4-6 How to wire".) When installing the cable gland,
make sure that there is no dust in cable gland mounting part, hexagon socket set screw, grounding screw,
and the cable gland. Then apply grease specified by RIKEN KEIKI.
Tightens Cable gland, and then tightens hexagon socket set screw (M4×6), and fix cable gland.
Adapter
(NPT1/2)
WARNING
Do not replace parts at your sole discretion but contact RIKEN KEIKI if the transparent window has a
crack or the explosion-proof joint surface is abnormal, or the clamping screw or bolt is changed, lost etc.
CAUTION
Tighten 40 Nꞏm or larger torque value to ensure the tightening cable gland and seal plug.
Tighten the hexagon socket head cap screws fixing the cable gland with a tightening torque of 107.8
±12.7N･m.
Rubber seal
Hexagon socket set screw
（M4×6）
Cable gland
(
G3/4
)
Daub screw with
g
rease
Washe
r
Eccentric washe
r
Grounding screw
Cable gland mounting part
Cable
g
land side
Washer side
Please mind direction of
Eccentric washer
Cable
（CVVS etc.）
Main unit case
Rubber seal
Washer
Eccentric washer
Cable gland
(G3/4)
Cable gland section view

4 How to Use 4-5. Installation procedure
- 17 -
NOTE
・Our company-specified grease : BARRIERTA JFE 552 (manufactured by NOK KLUBER)
If you can not prepare the specified grease, use one that meets the following requirements.
1. Material does not harden due to deterioration
2. Volatile solvent-free
3. Material does not cause corrosion at the surface
4. Silicon-free
5. Validation of suitability depends on the specifications of grease manufacturer

4 How to Use 4-6. How to wire
- 18 -
4-6. How to wire
<Recommended Cable>
3-wire (when the contact is not used) CVVS1.25 mm2or 2.0mm2- 3-core
5-wire (when the contact is used) CVVS1.25 mm2or 2.0mm2- 5-core
<Parts. length table of outside conductor lead-in>(TIIS specification)
Cable overall outer
diameter(mm)
Rubber seal inner
diameter(mm)
Washer inner
diameter(mm)
Clamp inner
diameter(mm)
From Φ9.6 to less than Φ10.5 Φ11 Φ12 Φ10.8
From Φ10.5 to less than Φ11.5 Φ12 Φ12 Φ11.8
From Φ11.5 to less than Φ12.5 Φ13 Φ14 Φ12.8
From Φ12.5 to less than Φ13.0 Φ13.5 Φ14 Φ13.8
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.