Diffusion Type Gas Detector
KD-12HT series
Instruction Manual Keep this manual for easy reference.
 Carefully read this manual prior to use.
 This manual describes the standard model. If your unit contains customer-specificoptions, the delivery specifications will supersede this manual.

Instruction Manual No.
GAE-162-02
September 2022

 Unit Dimensions andComponents

 Sensor Unit Replacement
Pages 30 and 31

Pages 5 to 9

 Wiring Display and Operation
Modes

Pages 13 to 17

Page 1924 V
power
supplyIndicator

ShieldE.g., External
alarmEarth terminals

 Maintenance, Operational
Checks/Procedures
Pages 21 to 31

 Troubleshooting
Page 32

Table of Contents
Introduction .................................................................................................................... 1
General Precautions...................................................................................................... 2
Package Contents ......................................................................................................... 4
Unit Dimensions and Components................................................................................ 5
4.1. Exterior Appearance (KD-12HT-T) ......................................................................... 5
4.2. Exterior Appearance (KD-12HT-L) ......................................................................... 6
4.3. Exterior Appearance (Main Body) .......................................................................... 7
4.4. Display and Controls .............................................................................................. 8
4.5. Terminal Block ........................................................................................................ 9
Installation ................................................................................................................... 10
5.1. Guideline ............................................................................................................... 10
Wiring........................................................................................................................... 13
6.1. Guideline ............................................................................................................... 13
6.2. Wiring/Connection ................................................................................................ 14
Precautions before Use ............................................................................................... 17
Display at Power-up (Warm-up) .................................................................................. 18
Display and Operation Modes ..................................................................................... 19
Trouble Alarms ............................................................................................................ 20
Maintenance, and Operational Checks/Procedures ................................................... 21
11.1. Routine Check and Annual Inspection................................................................ 21
11.2. Calibration Gas Preparation ............................................................................... 22
11.3. Calibration ........................................................................................................... 24
 Maintenance Mode .................................................................................................. 24
 Zero Adjustment ....................................................................................................... 25
 Fine Span Adjustment .............................................................................................. 26
 Coarse Span Adjustment ......................................................................................... 27
 Full-scale and Alarm Set Values Display ................................................................. 28
 Test Mode ................................................................................................................. 29
11.4. Sensor Unit Replacement ................................................................................... 30
Troubleshooting ........................................................................................................... 32
Specifications .............................................................................................................. 33
Warranty ...................................................................................................................... 36
Life Expectancy of Sensor .......................................................................................... 36
Service Life of Detector ............................................................................................... 36
Detection Principles ..................................................................................................... 37
Glossary ...................................................................................................................... 37

Introduction
 Thank you for purchasing the New Cosmos KD-12HT series diffusion type gas detector.
Before use, please read this instruction manual carefully to ensure safe and reliable operation.
 There are two models depending on the probe shape (straight and L-shaped), KD-12HT-T and
KD-12HT-L. In addition, two sizes of the flanges are available depending on the location inwhich the detector is installed.
 The KD-12HT detector can detect gas generated inside a heated area (e.g., drying furnace)
during manufacturing process. It is intended for use in industrial facilities for the early detectionof a gas leak/centralized gas monitoring by relaying the gas concentration value as an analog
signal to an external device while simultaneously displaying the gas concentration value on its
display.
If gas concentrations reach a preset level, the red ALARM LED will start blinking and activate
an external relay contact, thus helping prevent incidents such as fires, and explosions.
 Periodic maintenance is essential to maintain the reliability of your detection system. Performperiodic maintenance in accordance with the instructions given in this manual.

Symbols Used in this Instruction ManualThis manual uses Danger, Warning, Caution and Note symbols to draw attention to procedures,materials, methods, and processes, which require particular attention.

DANGER

Indicates an imminently hazardous situation that can result in death orserious injury.

WARNING

Indicates a potentially hazardous situation that may result in death orserious injury.

CAUTION

Indicates a hazardous situation that may result in minor injury or property
damage.

NOTE

Provides information on product handling.

1General Precautions
 Carefully read this manual prior to use.
 To ensure safe operation, follow the precautions below.
 Only use this product in accordance with the applicable laws and regulations.

WARNING

Ground the detector to prevent electric shocks.

In the event of a gas leak alarm, follow safety procedures in accordance with yourcompany's regulations.



Before opening any part of the gas detector, ensure no explosive atmosphere is present.



The cable gland (not included) shall be ATEX/UKEx/IECEx-certified as “Flameproof
Enclosure ‘db’”, and shall meet the below special conditions of use.

Special conditions of use


If used in an ATEX hazardous area, an ATEX-certified cable gland (not included) must be
used in accordance with EN IEC 60079-0:2018 and EN 60079-1:2014.

If used in an UKEx hazardous area, an UKEx-certified cable gland (not included) must be
used in accordance with EN IEC 60079-0:2018 and EN 60079-1:2014.

If used in an IECEx hazardous area, an IECEx-certified cable gland (not included) must
be used in accordance with IEC 60079-0:2017 Edition 7.0 and IEC 60079-1:2014 Edition
7.0.



Fasteners (M5x16 hexagonal head screws) must have a yield stress of at least 450
N/mm2.



Cable entry requirements for cable gland:

Thread size:

G3/4 or PF3/4

Pitch:

1.81 mm

Minimum depth of engagement:

10.86 mm

Minimum threads engaged:

6 threads

Ambient temperature
Main body:-10C to 50C

Probe:

0C to 160C

The dimensions of the flameproof joint between the case and the case cover of the
KD-12 flameproof housing must meet the minimum requirements specified in EN/IEC
60079-1. Please contact the manufacturer for inspection, repair or adjustment of theflameproof joint.



If any damage or deformation of the enclosure or joint surfaces is found during
maintenance/inspection, cease using the detector and contact New Cosmos or its
authorized representative.



Be careful not to damage the gas detector during installation/maintenance. Keep joint
surfaces clean and free from any damage. Contaminates such as scratches, fingerprints,
dirt and oil may adversely affect the explosion-proof characteristics of the device.

Use a conductor with a cross-sectional area of at least 4mm2 for grounding the detector.

2

CAUTION


Wiring and installation should only be performed by a qualified electrician with knowledgeof wiring/installation procedures.



Explosion-proof wiring and installation should only be performed by a qualified electrician
with knowledge of explosion-proof components/installation procedures.

Do not disassemble, modify, or alter the structure of this unit or its electrical circuits.
Doing so may compromise the explosion-proof nature of the product.



Do not use the product in a place or near a place where silicone sealant/vapor may bepresent. Doing so may compromise the performance of the product.

3

Package Contents
A standard package consists of the following items. If any items are missing or damaged,please contact New Cosmos or its authorized representative for replacement.
Standard package

Optional Items
Calibration cap (GCP-09) *3
Gas calibration kit (Z-001K)
2-bulb hand pump
Capillary for 2-bulb hand pumpGas detector
Accessory kit *1
Gasket (dia. 10-11)
x 1 pcGasket (dia. 12-13)
x 1 pcWasher (dia. 12)x 1 pcFlange gasket (PTFE) x 1 pc
Hex wrench (2 mm)
Hex wrench (4 mm)

x 1 pc *2
x 1 pc *2

Instruction manual *2
Magnetic stick (MJ-1) *2*1. A gasket (dia.11-12) and a washer (dia.14) have been preinstalled in the detector when
delivered.
*2. One pc is provided per order.
*3. KD-12 series optional items

WARNING Do not use the magnetic stick for any purposes other than its intended use.
 Keep in mind that when the magnetic stick attracts magnetic objects, tools, iron pieces,
etc., your hands may be pinched and injured.
 For those allergic to metals, skin may become chapped or irritated if the magnet comes incontact with bare skin. If symptoms appear, do not touch the magnet.
 Magnets easily fracture and corrosion may form from the fractured surfaces.
Particles/chips may enter the eye and cause injury. Do not drop the magnetic stick orbump it against a hard surface.
 The components of the magnet may dissolve in water. Do not drink water exposed to themagnetic stick.
 Keep the magnetic stick away from electronic medical devices such as cardiac
pacemakers. Failure to do so may impair the normal operation of such devices.

CAUTION Keep the magnetic stick away from magnetic tapes, floppy disks, and bank/credit cards.
Failure to do so may magnetize them, making them unusable.
 Keep the magnetic stick away from high-precision devices such as personal computers
and watches. Failure to do so may cause a device failure.

4Unit Dimensions and Components
4.1. Exterior Appearance (KD-12HT-T)③

Main body

Probe(Dimensions are in mm)

Item

Component

1

Main body2

Earth terminal (external)

3

Cable entry

4

Cable gland

5

Sensor unit

6

Probe (straight)

7

FlangeDescription/Function

Used for grounding the frame
Thread size: G3/4 or PF3/4
Pitch: 1.81 mm
Min. depth of engagement: 10.86 mm
Min. engaged threads: 6 threads
Applicable cable gland*1 must be provided by end user.
Used for securing the sensor unit cableThread size: G3/4
Incorporates a built-in gas sensor
Connects the main body and the sensor unit
Probe is to be inserted into a furnace
JIS B 2220
Nominal pressure: 5K
Nominal size: 25A or 50A*1. Cable gland should be ATEX/UKEx-certified according to EN IEC 60079-0:2018 and EN
60079-1:2014 for use in an ATEX/UKEx hazardous area, and IECEx-certified according to IEC
60079-0:2017 Edition 7.0 and IEC 60079-1:2014 Edition 7.0 for use in an IECEx hazardous area.

54.2. Exterior Appearance (KD-12HT-L)③

Main body
Probe(Dimensions are in mm)

Item

Component

1

Main body2

Earth terminal (external)

3

Cable entry

4

Cable gland

5

Sensor unit

6

Probe (L-shaped)

7

FlangeDescription/Function

Used for grounding the frame
Thread size: G3/4 or PF3/4
Pitch: 1.81 mm
Min. depth of engagement: 10.86 mm
Min. engaged threads: 6 threads
Applicable cable gland*1 must be provided by end user.
Used for securing the sensor unit cableThread size: G3/4
Incorporates a built-in gas sensor
Connects the main body and the sensor unit
Probe is to be inserted into a furnace
JIS B 2220
Nominal pressure: 5K
Nominal size: 25A or 50A*1. Cable gland should be ATEX-certified according to EN IEC 60079-0:2018 and EN 60079-1:2014
for use in an ATEX hazardous area, and IECEx-certified according to IEC 60079-0:2017 Edition 7.0
and IEC 60079-1:2014 Edition 7.0 for use in an IECEx hazardous area.

64.3. Exterior Appearance (Main Body)④(Dimensions are in mm)

Item

Component

1

Status LED (3 places)2

Magnetic switch (4 places)

3

Display4

M5x16 hexagonal headscrews (4 places)

Description/Function
Indicate the status of the unit:
power (green), alarm (red), and fault (amber)
Insert the magnetic stick into each magnetic switch
opening to operate
Displays the gas concentration, parameter value andstatus message
Secures the case coverUse 4mm hex key wrench (included).

7

4.4. Display and Controls
⑥

⑦

ＫＤ－１２

KD-12ＨＴGAS DETECTOR

①

POWER

③

ALARM

MODE

⑤
④

②
ENTER

TROUBLE

ＥｘｄⅡＣＴ５⑧
Magnetic Switches
Use the magnetic stick (MJ-1) to operate the magnetic switches.
Item

Component

Description/Function

1

MODE switch

Changes the operation mode or cancels the current
operation

2

ENTER switch

Confirms a setting or executes an operation3

🔺 (up) switch

Increases the parameter value4▼ (down) switch

Decreases the parameter value

Item
5

Component

Description/Function
Displays gas concentration, parameter value and status
message

Display

Status LEDs
Item

Component

Description/Function

6

POWER LED, green

When lit, the unit is on

7

ALARM LED, red

When lit, alarm notification

8

TROUBLE LED, amber

When lit, fault (device error) detected84.5. Terminal Block
Terminal block
24V(+) 1
GND

2

Signal 3
ZA

4

ZC

5

POWER －
4～20mA
＋

E
Slot
クランプ
(5 places)

Leverレバー(5 places)

Earth terminal(internal)

1
2
3
4
5
Gasketas
Sensor connector

Item

E

Name

Description/Function

1

24 V (+)

Power supply voltage (+)

2

GNDPower supply voltage (-) and analog signal (-) common

3

Signal4-20mA analog signal (+)

4

ZA

5

ZC

and

Earth terminal(internal)

External relay contact

Used for grounding the frame

9Installation
5.1. Guideline

WARNING Before opening any part of the gas detector, ensure no explosive atmosphere ispresent.
 The cable gland (not included) shall be ATEX/UKEx/IECEx-certified as “Flameproof
Enclosure ‘db’”, and shall meet the special conditions of use on page 2.
 If used in an ATEX hazardous area, an ATEX-certified cable gland (not included)
must be used in accordance with EN IEC 60079-0:2018 and EN 60079-1:2014.
 If used in an UKEx hazardous area, an UKEx-certified cable gland (not included)
must be used in accordance with EN IEC 60079-0:2018 and EN 60079-1:2014.
 If used in an IECEx hazardous area, an IECEx-certified cable gland (not included)
must be used in accordance with IEC 60079-0:2017 Edition 7.0 and IEC
60079-1:2014 Edition 7.0.
 Fasteners (M5x16 hexagonal head screws) shall have yield stress of at least 450
N/mm2.
 The dimensions of a flameproof joint between the case and the case cover of the
KD-12 flameproof housing must meet the minimum requirements specified in
EN/IEC 60079-1. Please contact the manufacturer for inspection, repair or
adjustment of the flameproof joint.
 Cable entry requirements for cable glandThread size: G3/4 or PF3/4
Pitch: 1.81 mm
Minimum depth of engagement: 10.86 mm
Minimum threads engaged: 6 threads

CAUTION Be careful not to damage the gas detector during installation. Keep joint surfaces
clean and free from any damage. Contaminates such as scratches, fingerprints, dirt
and oil may adversely affect the explosion-proof characteristics of the device.
 Do not install the gas detector in the following conditions:- Ambient temperature is outside of the specified operating temperature range(10C to 50C for main body and 0C to 160C for probe).
- Condensation prone areas- Exposure to water- Presence of corrosive gas- In the vicinity of equipment which can generate high frequencies or a magnetic
field- In environments where silicone sealant/gas is or may be used

Install the gas detector in a place where it can be easily accessed for maintenanceor inspection.

 Install the gas detector in a place free from vibration.
 Install the gas detector in a place free from sudden temperature changes.
 Avoid impacts to the gas detector.
 Burn risk. Be careful to avoid possible hot air from the mounting aperture during
installation or removal of the gas detector.
10Secure the gas detector to the mounting location (e.g., furnace’s wall) by using the flange. The
flange specifications are given below.
The sensor unit’s outside diameter is HEX32. The mounting hole which the sensor unit andprobe fit through should be 36 mm in dia. or more.
For fine adjustment of the direction of the detector face, untighten the two hexagonal screws toadjust the face to the right position, and then retighten the screws to firmly secure the detector.

Hexagonal screw
Nominal dia. 2 mm
(2 places)
For fine adjustment

Sensor unit
FlangeProbe
Probe
FlangeSensor unit

Flange Specifications

JIS B 2220
Nominal pressure：5K
Nominal size：25A
Flange thickness：10 mm
Recommended screw： M10

JIS B 2220
Nominal pressure：5K
Nominal size：50A
Flange thickness: 14 mm
Recommended screw： M12(Dimensions are in mm)

11

The case cover of the detector needs be able to open during installation, wiring, or sensor
replacement. Make sure to keep sufficient space so that the cover can be opened to 90° or
more.

(Dimensions are in mm)

12Wiring
6.1. Guideline
Use explosion-proof wiring when installing the detector in a hazardous area.

WARNING Before opening any part of the gas detector, ensure no explosive atmosphere is present.
 The cable gland (not included) shall be ATEX/UKEx/IECEx-certified as “Flameproof
Enclosure ‘db’”, and shall meet the special conditions of use on page 2.

CAUTION Wiring and installation should only be performed by a qualified electrician withknowledge of explosion proof components/installation.
Cable Work
 Use a shielded cable with 1.25 to 2.00 mm2 wires, such as a CVV-S cable. Sheath the cable ina protective tube, such as a metal conduit or carbon steel pipes, or other protective structure,such as a metal or concrete duct. When using a protective tube, use a cable heat-resistant to70C.
 When using the external relay contact function of the product, a five-conductor cable, with amaximum cable conductor size of 1.25 mm2 is required. If only the analog signal function isused without the external relay contact function, then a three-conductor cable, with amaximum cable conductor size of 2.00 mm2, is required.
 When using a pressure-resistant explosion-proof gasket type cable gland (not included), use acable whose outer diameter matches the inner diameter of the gasket by referring to the tablebelow. Firmly tighten the cable gland with a hex wrench, to the appropriate values as shown on
the ‘Cable gland length after tightening’ column in the table below to prevent the formation of aflame path for explosive gas or fire.
 Connecting a cable with another cable outside the gas detector is not recommended. Direct orbranching connections of cables should be done inside the gas detector by using terminals.
 For sensor replacement, this product needs to be detached. Allow an extra length of 50 cm or
more in the cable.
Table 6-1.. Cable gland length after tightening
Gasket inner
Cable outerdia. (mm)dia.(mm)(Marked ongasket)WasherInner dia.

Cable gland length after tightening
L (mm)(mm)

Optional or included

10-11

Dia. 10-11

12

55.1 (Cable dia.10) - 58.1 (Cable dia.11)

Included

11-12

Dia. 11-12

14

55.0 (Cable dia.11) - 58.1 (Cable dia.12)

Included (pre-installed)

12-13

Dia. 12-13

14

54.8 (Cable dia.12) - 58.0 (Cable dia.13)

Included

13-14

Dia. 13-14

15

54.5 (Cable dia.13) - 58.0 (Cable dia.14)

14-15

Dia. 14-15

15

54.3 (Cable dia.14) - 57.9 (Cable dia.15)* A gasket (dia.11-12) and a washer (dia.14) have been preinstalled in
the detector when delivered.
* A gasket (dia 10-11) and a gasket (dia. 12-13) and a washer (dia.12)
are included in the standard package when delivered.

13

Optional

Cable gland length
after tightening (L)6.2. Wiring/Connection

WARNING

Before opening the case cover of the gas detector, be sure to eliminate possible sourceof ignition. Disconnect the power supply to the detector and all devices connected to it(e.g., indicator unit and signal converter).



Ground the gas detector to prevent an electric shock.

CAUTION

Connect wires to their corresponding terminals.



Keep the connection cable (power and signal lines from the detector) away from otherpower lines.

Connecting Power and Signal Lines If needed, use dedicated breakers for power lines going to devices connected to the detector,
such as an indicator unit or a signal converter.
 Use a shielded cable that has 1.25 to 2.00 mm2 wires, such as a CVV-S cable.
 Ensure that the power voltage supplied to the gas detector is within the specifications.
 Ensure that the load resistance of the signal line, including the resistance of the wire, is not
more than 300 ohm.

NOTE
Single-point grounding (grounding at a single point) is mandatory. Do not ground the gas
detector via the earth terminal (external/internal) located on the gas detector when it is groundedon the power supply side. Doing so creates 2-point grounding. Grounding on the power supply
side (right side of the drawing) is recommended as shown in the drawing below.
KD-12

CVV-S cable

Cable shield(+) Power
電源
24V
(-)
supply(24 V)
指示計(-) Indicator(+) ユニット
unit
External
equipment(e.g., alarm)

Earth terminal on
power supply side
Do not ground when groundedon power supply side×

Earth terminal locatedon gas detector

Grounded on power
supply side

Figure 6-1. Typical Wiring Connection when Grounded on Power Supply Side14

Typical System Configuration

Gas detectors
KD-12
Gas detector

Indicator unit

Gas detection Security control
systemsystem

KD-12
KD-12

V2M
KD-12

S-500

Gas
vision

KD-12
One to one configuration

Monitoring multiple detectors

Figure 6-2. Typical System Configuration
 Refer to the instruction manual of each device for full information.

External Earth Terminal Connection

WARNING

Direct contact between the case and the terminal will compromise the explosion-proof
nature of the product. When grounding the external earth terminal of the detector, placea plain washer between the case and the terminal to prevent the terminal from having
direct contact with the gas detector.

Use a conductor with a cross-sectional area of at least 4mm2 for grounding thedetector.

Place a plain flat washer between the case and the terminal.

Case

Plain flat washer
Nominal dia.: 4mm
Material: Stainless steel

Screw with captive spring washer and plain washer
Size: M4x8
Pitch: 0.7 mm
Material: Stainless steel

Cable lug (4mm2)

Figure 6-3. Typical External Earth Terminal Connection

15

Terminal Block Wiring Procedure

CAUTION Do not touch or let any tool (e.g., flat-head screwdriver, wrench) touch the inside surfaceof the case or case cover. Keep joint surfaces clean and free from any damage.
Contaminates such as scratches, fingerprints, dirt and oil may adversely affect the
explosion-proof characteristics of the device.
 Be careful not to damage the circuit board or harness with a tool (e.g., flat-headscrewdriver, wrench) while operating the levers.
 While operating the levers with a tool (e.g., flat-head screwdriver, wrench), avoid
diagonal stress to them.
 Do not excessively stress each lever once it reaches its stop position.
 When closing the case cover, make sure it does not catch on the gasket or any loose
cables.

(1) Ensure that 24V power supply is used.
*Do not supply power to the gas detector before the wiring is complete.

(2) To open the case cover, loosen the four hexagonal head screws located at the four cornersof the case cover using the 4mm hex wrench (included).

Hexagonal head screw(4 places)(3) Loosen the sealing nut of the cable gland (not included). Feed the cable (3-wire or 5-wirecable, as needed) through the gland cable.

Cable gland (not included)(4) Press down on each lever of the terminal block with a flat-head screwdriver to open thecorresponding slot.

16

(5) Insert the tip of each wire into the slot.
Connect the (PWR+) wire to the slot marked “24V(+)”. Connect the (PWR-) wire to the slot
marked “GND”. Connect the (Analog 4-20mA) wire to the slot marked “Signal”.
As needed, connect the external relay contact wires to the slots marked “ZA” and “ZC”.

Terminal block(6) Remove the screwdriver from the lever to close it. This will securely connect the wire to theterminal.
(7) Check that the connected wires are secure in their corresponding terminals.
(8) Tighten the sealing nut.
(9) Close the case cover. Attach the case cover to the case by tightening the four hexagonalhead screws at the four corners of the case cover with the hex wrench (yield stress of atleast 450 N/mm2).

Precautions before Use

CAUTION Before turning on any of the devices connected to this product (e.g., indicator unit, signal
converter), check that all wiring is correct, particularly between the gas detector andindicator unit or signal converter.

 In Case of Gas Leakage

DANGER Remain calm and check that there is no fire present. Do not touch any electric switches
under any conditions. Sparks caused by turning on or off electric switches may cause an
ignition.

WARNING If there is a gas leak alarm, take the necessary measures specified by your company.
 If a gas leak occurs indoors, open the windows and doors to ventilate the room.
 Identify the location of the gas leak, and promptly take the necessary measures.

17

Display at Power-up (Warm-up)

CAUTION Check that there is no gas present before powering on the gas detector.
 When the sensor output is not stable, the external relay contact may possibly activate. To
prevent possible activation of the external relay contact after the warm-up is complete,release the interlocks of the external devices, if needed.
 During the warm-up, the analog signal is fixed at 4.0 mA (default) and the external relay
contact does not activate.

NOTE The magnetic stick is not usable during the warm-up.
 The warm-up cycle lasts approx. 30 seconds once the unit is powered.

(1)

Once the unit is powered, the warm up process will begin. All the status LEDs (green,amber and red) and the display will be lit.

(2)

While the status LEDs (green, amber and red) are lit, the display shows the following
messages for one second each in the order below.
Software version number installed in this gas detector
Full scale value
Example: [] %LEL is displayedwhen the full-scale value is 100%LEL.

Alarm set value
Example: [] %LEL is displayedwhen the alarm set value is 25%LEL.

(3)

The POWER LED (green) blinks for approx. 25 seconds.

(4)

When the blinking POWER LED (green) becomes solid, the warm-up cycle is completed
and the detector is now in gas monitoring mode.

NOTE If the sensor unit has not been energized for a long time of period (e.g., from factory to initial
power-up), it may take some time for the sensor output to stabilize.
 If needed, energize the gas detector for approx. one week, and perform the zero and span
adjustments before use. Refer to 11.3 “Calibration” on page 24 for adjustments.

18

Display and Operation Modes
When the alarm set value is exceeded
Maintenance mode

Display

Power-up(Warm-up)

Gas monitoring
mode

Test mode

Green LED blinks

Red LEDGreen
blinks
LED is lit

Red LED
Green blinks
LED is lit

Gasconcentration
value isdisplayed
The value slowly
approaches tozero whenpowered on inclean airAnalogsignal4-20 mA

Relay
Contact
operation(Normally
Open)

Gas
monitoringmode

Red LED blinks
Green LED is lit[
Gasconcentration isdisplayed

Test mode

]

[

]

[Set
concentration]
Test from 10%
to 110% of fullscale is possible[Gas
concentration][Test value]

displayedalternately

displayedalternately

Fixed at 4.0mA

Gas
concentration
value is output

Test value is
outputGas
concentration
value isoutput

Test value is
outputNot activated.

Activated

Activated

Not activated.

Not activated.

(Open)(Closed)(Closed)(Open)(Open)

19

Trouble Alarms
 This product has a self-diagnosis function, and a trouble (fault) alarm will activate if a problem
is found.
 This product alerts the user of a problem by showing the corresponding error code on thedisplay when a trouble alarm activates. The error codes are listed in the table below.
 When a trouble alarm activates, the analog signal becomes 0.9 mA or less.
Error codeon display

Amber
TROUBLE
LED

Problem

Blinking

Power supply
voltage drop

Probable cause

Solution

Insufficient power
supply voltage

Check the power supply
voltage.

Sensor error

Sensor connector
disconnected ordamaged sensor wire

Check that the sensor
connector is securely
connected.
If the sensor connector
is defective or if the wireis damaged, contact
New Cosmos or its
authorized
representative forrepair.

Zero adjustment
error

Gas is present in theambient air

Perform zeroadjustment in clean air.

Blinking

Off

.
Off

Off

Span adjustment
error

Incorrect gas type
and/or concentration
used for adjustment

Check the gas type andconcentration ofcalibration gas. If they
are incorrect, replace
the gas with correctone. Perform fine span
adjustment with thecorrect calibration gas.
Check the gas type andconcentration ofcalibration gas. If they
are correct, perform
coarse span
adjustment.

 If a code other than the ones listed is displayed, refer to 12. “Troubleshooting”. If the productdoes not reset to normal operation after taking the steps shown in the table or if your problem
is not listed in the table, please contact New Cosmos or its authorized representative.
 If the detector goes into any unintended mode during adjustment or setting, cease using thedetector and consult with your system administrator.

20

Maintenance, and Operational Checks/Procedures
11.1. Routine Check and Annual Inspection
 Routine checks are carried out by the user, while annual inspections are performed by New
Cosmos or its authorized representative.
Frequency

Min.1 per
month

Item

Procedure Check that POWER LED (green) is lit.
 Check that gas concentration value isdisplayed.
 Check gas detector for corrosion.
 Check mounting screws for corrosion.
Replace any worn or damaged parts.

Visual check

Routinecheck

Apply the test gas to the gas detector andcheck the operation of the alarm.

Every twomonthsCheck alarm
operation by using
actual gas sample

 Attach the calibration cap to the detector,
apply test gas, and check the operation of thealarm.
Check that the sensor unit is free from objects
that may interfere with the gas diffusion.

Detector vicinity

Annualinspection

Min.1 peryear

Contact New Cosmos or its authorized representative for inspection.

 Use optional items (e.g., calibration cap, gas calibration kit) when actual gas is used forcheck.

Important Notice for Annual Inspection
In order to ensure the reliability of this gas detection and alarm system, it is vital to performperiodic maintenance and inspections. Further, it is necessary to carefully perform inspection
and calibrations by using actual gas (combustible or poisonous gas). It is highly
recommended that a maintenance contract with a New Cosmos local representative bemade for the performance of annual inspections.
Installation, inspection, maintenance, calibration and proof testing shall only be performed bytrained personnel.

2111.2. Calibration Gas Preparation
 Prepare calibration gas (actual gas) for inspection or maintenance use.
 Typical method to prepare calibration gas, toluene, is given below as an example.
(1) Required tools and items-

Toluene reagent-

Gasbag with two openings-

Gas sampling bag-

Syringe-

Measuring pump-

Calibrator for toluene(2) Preparation
a. Clean the inside of the gasbag with ambient air.
b. Completely remove air from the gasbag.
c. Decide the inlet and outlet of the bag.
d. Determine the target gas concentration value by referring to the calibration table.

NOTE

Be careful when checking the calibration table to avoid misreading.

(3) Calibration gas preparation

CAUTION Avoid contact between the toluene reagent and the tube while injecting toluene into thegasbag. Inaccurate concentration may result.
 If abnormality (e.g. unusual smell) is found in the atmosphere, immediately cease the gas
preparation.
a. Sample the specified amount of toluene reagent in a syringe.
For example, to produce 30%LEL (= 3600 ppm) toluene gas in 20L gasbag,
b. Sample 20L of clean air with the measuring pump. Inject the air into the gasbag
through its inlet.
c. Inject toluene reagent into the gasbag through its inlet.
d. Inflate the bag with clean air until reaching the 20L.
e. Leave the gas inside the bag at room temperature for approx. 30 minutes before use,
to allow the liquid inside the bag to evaporate completely.

22

DANGER
Ensure that there is no open flame or source of ignition when handling a flammable gas.

(4) Check the gas concentration value of he prepared gas.
a. Check that the reagent inside the gasbag completely evaporates.
b. Use a portable gas detector to measure the concentration value from the outlet of thegasbag.
c. Check that there is no deviation between the measured value and…

NOTE If the obtained gas concentration deviates from the target value by more than ±5%, startover to prepare the calibration gas.
 Inexact calibration gas can be used for checking the alarm operation. When calibrating thedetector, the gas concentration must be checked with a calibrated gas detector (e.g. New
Cosmos portable gas detector, Model: XP-3110) before the calibration.

23

11.3. Calibration

CAUTION For calibration with actual gas, the detector needs to be removed from the external
equipment (e.g., drying furnace).
For calibration, use the dedicated calibration cap (sold separately).
After use in connection with a high-temperature furnace, the probe and its surroundingarea become very hot. Allow them to cool down to the room temperature before staring
calibration.

 Maintenance Mode

CAUTION During the maintenance mode, the external relay contact does not operate even if gas
concentrations reach or exceed the alarm set value. The detector in the maintenancemode maintains this status and the display shows [].
 The maintenance mode can be canceled by taking the steps (1) to (4) below, turning off
the detector or automatically cancelled after an 8 hours waiting period. Ensure that thedetector is not left in the maintenance mode as gas detection will not be possible for 8hours when it will automatically reset.

NOTE
 Use the magnetic stick for the switch operation.
 Carefully handle the magnetic stick during operation or setting, because it has a strong
attractive force. Refer to 3 “Package Contents” for full information.

(1)

While in the gas monitoring mode, press the MODE switch, then press the 🔺 switch withinapprox. 2 seconds.

(2)

The detector displays
E.g.

first, followed by a number.

is displayed when the power-up operation has been completed and nofurther operation has been done.

(3)

is not displayed, press the 🔺 or ▼ switch to set the value

If the number
to

.

(4)

Press the ENTER switch.

(5)

Ifand the gas concentration value are alternately displayed, the detector is
now in maintenance mode.

(6)

While

(7)

The maintenance mode can be canceled by performing the steps (1) to (4) above thenturning off the detector, or by waiting for 8 hours.

is displayed, the maintenance mode is still ongoing.

24 Zero Adjustment

CAUTIONTo prevent possible activation of the external relay contact during the zero adjustment,
set the detector to maintenance mode or release the interlocks of the external devices, if
needed.
Perform a zero adjustment in a place where there is no target or interfering gas in theambient atmosphere.

NOTE Use the magnetic stick for the switch operation.
 Carefully handle the magnetic stick during operation or setting, because it has a strong
attractive force. Refer to 3 “Package Contents” for full information.
 If an error code is displayed, refer to 10 “Trouble Alarms”.

(1)

While in the gas monitoring mode, press the MODE switch, then press the 🔺 switch withinapprox. 2 seconds.

(2)

The detector displays(3)

If the number

first, followed by a number.
is not displayed, press the 🔺 or ▼ switch to set the value to.

(4)

Press the ENTER switch.

(5)

When the following messages are displayed, the zero adjustment is complete.

↓

↓

(6)

Upon completion of the zero adjustment, the detector will automatically return to the gas
monitoring mode.

25 Fine Span Adjustment

CAUTIONTo prevent possible activation of the external relay contact during the fine span
adjustment, set the detector to maintenance mode or release the interlocks of theexternal devices, if needed.
 Only New Cosmos technician or personnel who have completed a maintenance seminarcan perform a span adjustment.

NOTE
 Use the magnetic stick for the switch operation.
 Carefully handle the magnetic stick during operation or setting, because it has a strong
attractive force. Refer to 3 “Package Contents” for full information.
 Complete a zero adjustment before performing fine span adjustment.
 Perform a coarse span adjustment if

oris displayed.

 If an error code is displayed, refer to 10 “Trouble Alarms”.

(1)

Attach a gasbag with the corresponding calibration gas to the gas detector. Apply gas at aneven flow using 2-bulb pump and capillary (optional) or equivalent.

Calibration cap

Apply calibration gas(2)Allow time for the sensor to become exposed to the gas.

(3)

While in the gas monitoring mode, press the MODE switch, then press the 🔺 switch withinapprox. 2 seconds.

(4)

The detector displays(5)

If the number
tofirst, followed by a number.
is not displayed, press the 🔺 or ▼ switch to set the value.

(6)

Press the ENTER switch.

(7)

The detector displays(8)

Press the 🔺 or ▼ switch of the detector to adjust the display of the detector to the actual
calibration gas concentration.

(9)

Press the ENTER switch.

first, followed by the present gas concentration.

(10) Fine span adjustment is complete whenis displayed.

(11) Upon completion of the fine span adjustment, the detector will automatically return to thegas monitoring mode.
(12) Remove the gasbag.

26

 Coarse Span Adjustment
Perform coarse span adjustment, if

oris displayed.

CAUTIONTo prevent possible activation of the external relay contact during the coarse span
adjustment, set the detector to maintenance mode or release the interlocks of theexternal devices, if needed.
 Only New Cosmos technician or personnel who have completed a maintenance seminarcan perform a span adjustment.

NOTE
 Use the magnetic stick for the switch operation.
 Carefully handle the magnetic stick during operation or setting, because it has a strong
attractive force. Refer to 3 “Package Contents” for full information.
 Precise adjustment is not possible using coarse span adjustment only. Perform a fine span
adjustment once the coarse span adjustment is complete.
 If an error code is displayed, refer to 10 “Trouble Alarms”.

(1)

Attach a gasbag with the corresponding calibration gas to the gas detector. Apply gas at aneven flow using 2-bulb pump and capillary (optional) or equivalent.

(2)

Allow time for the sensor to become exposed to the gas.

(3)

While in the gas monitoring mode, press the MODE switch, then press the 🔺 switch withinapprox. 2 seconds.

(4)

The detector displays(5)

If the number
to
.

(6)

Press the ENTER switch.

(7)

The detector displays(8)

Press the 🔺 or ▼ switch to set the displayed value closest to the actual calibration gas
concentration.

(9)

Press the ENTER switch.

first, followed by a number.
is not displayed, press the 🔺 or ▼ switch to set adjust the value

first, followed by the present gas concentration.

(10) Coarse span adjustment is complete whenis displayed.

(11) On completion of the coarse span adjustment, the detector will automatically return to thegas monitoring mode.
(12) Remove the gasbag.

27 Full-scale and Alarm Set Values Display
NOTE Use the magnetic stick for the switch operation.
 Carefully handle the magnetic stick during operation or setting, because it has a strong
attractive force. Refer to 3 “Package Contents” for full information.
 The full-scale and alarm set values are only displayed and cannot be changed by the user.

(1)

While in the gas monitoring mode, press the MODE switch, then press the 🔺 switch withinapprox. 2 seconds.

(2)

The detector displays(3)

If the number
tofirst, followed by a number.
is not displayed, press the 🔺 or ▼ switch to set the value.

(4)

Press the ENTER switch.

(5)

The following messages are displayed in the order below so that the user can check thefull-scale and alarm set values.

↓↓
Full scale value↓↓
Alarm set t value(6)

After the full-scale and alarm set values are displayed, the detector will automatically returnto the gas monitoring mode.

28 Test Mode
Test mode is used to set the test value.

CAUTIONTo prevent possible activation of the external relay contact during the test mode, set thedetector to maintenance mode or release the interlocks of the external devices, if
needed.

 The test mode can be canceled by taking the steps (1) to (4) below, turning off thedetector or automatically cancelled after an 8 hours waiting period.

NOTE
 Use the magnetic stick for the switch operation.
 Carefully handle the magnetic stick during operation or setting, because it has a strong
attractive force. Refer to 3 “Package Contents” for full information.

(1)

While in the gas monitoring mode, press the MODE switch, then press the 🔺 switch withinapprox. 2 seconds.

(2)

The detector displays(3)

If the number
to
.

(4)

Press the ENTER switch.

(5)

The following messages are displayed in the order below.

first, followed by a number.
is not displayed, press the 🔺 or ▼ switch to set the value↓
Test value
Tests are possible with a concentration range from 10% to 110% of the full-scale value.
For example, if the full scale is 2000 ppm, the test is possible using a range from 200 to
2200 ppm. If the full scale is 100%LEL, the test is possible using a range from 10%LEL to
110%LEL.

(6)

Press the 🔺 or ▼ switch to set the value to your desired calibration gas concentration. The
test will automatically start once the value is set.
If the set value is outside the operating range,orwill be displayed.

(7)

To end the test mode, press the ENTER or MODE switch.

(8)

Ending the test with the ENTER switch will save the tested value.
Ending the test with the MODE switch, will save the previously saved value.

2911.4. Sensor Unit Replacement

WARNING Disconnect the power supply to the gas detector before replacing the sensor unit. Failure
to do so may cause a source of ignition.

CAUTION Only New Cosmos technician or personnel who have completed a maintenance seminar
can replace the sensor unit.
 Burn risk. Be careful to avoid possible hot air from the mounting aperture during
installation or removal of the gas detector.
 The probe and sensor unit reach a very high temperature. Allow them to cool down
before sensor unit replacement.
 Handle the sensor unit with care. Failure to do so may result in broken components suchas the sensor wire or in a failure of the sensor.
 When the sensor output becomes unstable while replacing the sensor unit, the external
relay contact may possibly activate. To prevent possible activation of the external relay
contact during the replacement, release the interlocks of the external devices, if needed.
 When removing or installing the sensor unit, take care not to twist the harness of thesensor connector.
 When closing the case cover, make sure it does not catch on the gasket or any loose
cables.

30

The sensor unit is different depending on the detector model.
Use an appropriate sensor unit.
Detector model
KD-12HT-T
KD-12HT-L

Sensor unit type
EK-12HT-T
EK-12HT-L

4mm hexagonal headscrew (4 places)

Sensor unit

FlangeFlangeSensor unit

KD-12HT-T

KD-12HT-L

31

Troubleshooting Before requesting repair, please refer to the table below. If the detector does not return tonormal after performing the corresponding steps in the table, or if your issue is not found in thetable, consult New Cosmos or its authorized representative.
 If the gas detector goes into any unintended mode during adjustment or setting, cease using
the detector and consult with your system administrator.
Problem

Probable cause

POWER LED (green)
does not turn on

Steps

Incorrect wiring

Check and rewire.
Check the power
supply voltage.

Low voltage state

Check that the sensor
connector is securely
connected.

TROUBLE LED (amber)blinks or error code isdisplayed

If there is a possibilityof a defective sensor ordamaged sensor wire,
contact New Cosmos
or its authorized
representative.

Page14
Wiring/Connection

Product is inmaintenance mode

Set the product to gas
monitoring mode.

Page 24
Maintenance Mode

Product is inmaintenance mode

Set the product to gas
monitoring mode.

Page 24
Maintenance Mode

Incorrect wiring

Check and rewire.

Page14
Wiring/Connection

Incorrect alarm point
setting

Check the alarm
setting.

Page 28
Full-scale andAlarm Set Values
Display

Product is in test mode

Set the product to gas
monitoring mode.

Page 29
Test Mode

Defective sensor unit,
disconnected connector,
or damaged sensor wire.

Gas concentration value
andare blinking
alternately

External relay contact
does not function (noalarm signal to external
equipment)

Analog signal does notchangeValue andblinking alternately

are

Sensor output is too high

Value andblinking alternately

are

Sensor output is too low

Cannot make or adjust
setting

Reference pagePage14
Wiring/Connection

Product is in warm-up
cycle

32

Gas concentration
exceeds the full scalevalue. Check theambient environment.
Perform zeroadjustment in clean air.

Page 25
Zero Adjustment

Operate the productafter the 30-second
warm-up cycle iscompleted.

Page 18
Display at Power-up(Warm-up)

Specifications
Model
Detection principle
Sampling method

KD-12HT-T
Catalytic sensor
Diffusion type

KD-12HT-L

Target gas

N-Methyl-2-Pyrrolidone (NMP)

Detection range
Gas concentration display

0-100%LEL
Four-digit seven-segment LED display

Alarm set value

As per delivery specifications

Alarm accuracy

25% of alarm set value under identical conditions

Alarm delay

Less than 30 seconds with a gas concentration that is 1.6 times higher
than the alarm set concentration

Alarms During gas alarm (single stage only), the red ALARM LED blinks.
 During trouble alarm in the event of sensor disconnection, zero drift,
power supply voltage error, internal EEPROM communication error, theamber TROUBLE LED blinks.

External output<Gas concentration analog signal > 4-20 mA DC (common negative with power supply)
 0.9 mA or less in the event of trouble alarm Load resistance of the analog signal line, including the resistance of thewire, is not more than 300 ohm<Gas alarm contact (single stage only)> Normally open or normally closed dry contact*1 ; normally energized or
normally de-energized *1 ; automatic resetting
 Max. load: 0.5 A resistive at 250 VAC or 0.5 A resistive at 30 VDC

Equipment or Protective
System intended for use in
Potentially Explosive
Atmospheres

Directive 2014/34/EU
SI 2016 No.1107

Explosion-proof

ATEX:
II 2 G Ex db IIC T3 Gb
UKEx:
II 2 G Ex db IIC T3 Gb
IECEx: Ex db IIC T3 Gb

Approvals

ATEX certificate No. CML 21ATEX1411X
UKEx certificate No. CML 22UKEX1374X
IECEx certificate No. IECEx CML 21.0055X

Harmonised/Designatedstandards

EN IEC 60079-0:2018
EN 60079-1:2014
IEC 60079-0:2017 Edition 7.0
IEC 60079-1:2014 Edition 7.0

Applicable cable

Cable outer diameter: 10 mm to 13 mm
 5-wire CCV-S cable (power, analog signal and relay contact)
Wire size: 1.25 mm2
 3-wire CCV-S cable (power and analog signal)
Wire size: 1.25 mm2 or 2 mm233

Operating temperature andhumidity

Power supply
Power consumption
Dimensions

Mass
Mounting method

Main body:-10C to 50C
Probe:
0C to 160C
10% to 90%RH at 0C to 50C
No sudden temperature or humidity changes. No condensation
24 VDC (18 to 30 VDC)
1.5 W during normal operation (Max. 3 W)
127 (W) x 530 (H) x 68 (D) mm
127 (W) x 321 (H) x 443 (D) mm(Excluding protruding parts and(Excluding protruding parts andincluding probe)
including probe)
Probe size inside the furnace:
Probe size inside the furnace:Dia.34 x 250 mm
Dia.34 x 250 mm
Flange size: 25A or 50A
Flange size: 25A or 50A
Approx. 3.6 kg with 25A flange
Approx. 4.1 kg with 25A flange
Approx. 4.2 kg with 50A flange
Approx. 4.9 kg with 50A flange
Using a flange- The above specifications are subject to change without notice.
- If your specifications are nonstandard, refer to the delivery specifications.
*1. Specified at the time of order.

34

External markings for explosion-proof

Nameplate detail

Serial number label detail

Rating label detail

Certificate label detail

Warning label detail

Harmonised/Designated standards

EN IEC 60079-0:2018
EN 60079-1:2014
IEC 60079-0:2017 Edition 7.0
IEC 60079-1:2014 Edition 7.035

Warranty
The warranty period is one (1) year from the date of purchase.
You are entitled to the limited warranty, if the product malfunctions due to a manufacturing defectduring normal use in accordance with the instruction manual, specifications and labels.
1. Warranty Scope
If the product fails or is found to be damaged due to a manufacturing defect during the warranty
period, and used in accordance with the instruction manual and specifications, we will provide afree replacement and repair service. This warranty covers the New Cosmos product/parts only
and not third party product/parts.
2. Warranty Exclusions (The following will be repaired at the cost of customer even during thewarranty period.)(1) Failures and damages incurred by incorrect use, deliberate acts or negligence of the user.
(2) Failures and damages caused by disaster, earthquake, storm and flood, lightning, extreme
climate, abnormal power supply voltage, excessive electromagnetic interferences, or otheracts of God.
(3) Failures and damages resulting from repair and/or modification by non-New Cosmos
certified technicians.
(4) Consumables and failures and damages resulting from improper consumable replacement.
(5) Other failures and damages not attributable to the manufacturer.

Life Expectancy of Sensor
The estimated service life of the sensor is shown in the table below. The sensor may fail toprovide correct detection after its service life expires. Replace the sensor before the expiration.
This service life assumes that maintenance is done properly and periodically and that the sensor
is not exposed to high concentration gas or gas that may cause sensor poisoning. This does not
imply that the sensor will provide correct detection values up to the end of the service life. Thus,
no warranty will be given after the one-year period is over.
Model
KD-12HT

Detection Principle(Sensor Type)
Catalytic

Life Expectancy(from the date of purchase)
Approx. 2 years

Service Life of Detector
The service life of this product is 10 years. The unit can operate for up to 10 years with astandard installation and used in accordance with the instruction manual. When the service life
has expired, replacement is needed for continued reliable performance.

36Detection Principles
Catalytic Sensor
Catalytic combustion occurs on the catalytic layer applied on a platinum coil even if the gas
concentration is well below the lower combustion limit. This causes a rise in temperature of theplatinum coil and increases its electrical resistance. This change is read as a differential voltage
using a bridge circuit. This process enables detection of combustible gases in air up to the lower
explosive limit (LEL).

Glossary
TermDefinition

Gas detector

Device used to detect the presence of a target gas and to give its
concentration in the form of an electrical signal.

Diffusion type

Sampling method using convective diffusion while placing a gas
detector at a detection point.

Flameproof enclosure(explosion-proof
enclosure)
Target gas

Enclosure in which the parts which can ignite an explosive
atmosphere are placed. This enclosure can withstand the pressure
created during an internal explosion of an explosive mixture, andprevent the ignition of an explosive atmosphere outside theenclosure.
Specific gas to be detected, concentration displayed, and used totrigger alarms.

Detection range

A range of target gas concentrations that can be displayed andtrigger alarms.

Operating temperatureand humidity ranges
Maintenance andinspection
Calibration gas(test gas)

Ambient temperature and humidity ranges in which the gas
detection and alarm system can operate normally.
Tasks performed to ensure that equipment operates normally andcorrectly.
Gas specifically prepared to calibrate/adjust the gas detection andalarm system.

Hazardous area

An area in which an explosive atmosphere is present, or may be
expected to be present, in quantities such as to require special
precautions for the construction, installation and use of electricalapparatus.

Non-hazardous area

An area in which an explosive atmosphere is not expected to bepresent in quantities such as to require special precautions for theconstruction, installation and use of electrical apparatus.

Explosive atmosphere
Lower Explosive Limit(LEL)

Mixture of air and flammable substances in the form of dust or vapor
which are within their explosive limits.
Lowest concentration (percentage) of a gas or vapor in air capableof producing a flash fire, or explosion in the presence of an ignition
source like arc, flame or heat.

37

This page intentionally left blankRevision History
Document No.

Date

Revision

GAE-162-00

July 2021

Initial issue

GAE-162-01

September 2021

01

GAE-162-02

September 2022

02

Additional copies of this instruction manual may be purchased.
Contact New Cosmos or its authorized representative for ordering.

Authorized representative:

Manufacturer:
NEW COSMOS ELECTRIC CO., LTD.
2-5-4 Mitsuya-naka, Yodogawa-ku,
Osaka 532-0036, Japan
www.newcosmos-global.com