Carbon Dioxide Detector

KS-7R
Instruction Manual Keep this manual for easy reference.
 Carefully read this manual prior to use.
 This manual describes the standard model. If your unit has end-user-specificoptions, this manual will be superseded by your delivery specifications.

Instruction Manual No.
GAE-139-03
September 2022

Table of Contents
1. Introduction ................................................................................................................................1
2. General Precautions ..................................................................................................................2
3. Package Contents .....................................................................................................................3
4. Unit Dimensions and Components ............................................................................................4
4-1. Outer Appearance ..............................................................................................................4
4-2. Inner Components .............................................................................................................5
5. Installation .................................................................................................................................6
6. Wiring ........................................................................................................................................96-1. Pin Terminal/Insulated Sleeve Installation .......................................................................10
6-2. Wire Connection/Disconnection to/from Terminal Block .................................................. 11
6-2-1. Power Terminal Block ............................................................................................... 11
6-2-2. External Output Terminal Block ................................................................................. 11
6-3. Cable Tie Installation ....................................................................................................... 11
7. Operation .................................................................................................................................127-1. Precautions before Use ...................................................................................................127-2. Operating Procedure .......................................................................................................127-3. LCD Operation .................................................................................................................14
7-3-1. LCD ...........................................................................................................................14
7-3-2. Normal Operation Status ...........................................................................................14
7-3-3. Full Scale and Alarm Set Values Display ..................................................................15
7-3-4. Peak Value Display and Reset ..................................................................................15
7-3-5. Operation during Gas Alarm .....................................................................................15
7-4. User Mode .......................................................................................................................16
7-4-1. User Mode Operation ................................................................................................16
7-4-2. Switching Maintenance Mode On/Off [Mode 1] ........................................................17
7-4-3. Zero Adjustment [Mode 2] .........................................................................................18
7-4-4. Air Adjustment [Mode 3] ............................................................................................18
7-4-5. Alarm Test [Mode 4] ..................................................................................................19
7-4-6. Alarm Event History [Mode 5] ...................................................................................20
7-4-7. Clock Setting [Mode 6] ..............................................................................................21
7-5. Maker Mode .....................................................................................................................22
7-5-1. Maker Mode Activation ..............................................................................................22
7-5-2. Alarm Set Value Change ...........................................................................................23
8. Maintenance ............................................................................................................................24
8-1. Inspection Contents and Frequency ................................................................................24
8-2. Clock Battery Replacement .............................................................................................26
9. Troubleshooting .......................................................................................................................28
10. Specifications.........................................................................................................................30
11. Warranty ................................................................................................................................31
12. Expected Sensor Life ............................................................................................................31
13. Detection Principle ................................................................................................................32
14. Glossary ................................................................................................................................33
15. Proper Product Disposal at End of Life .................................................................................34

1. Introduction
Thank you for purchasing the New Cosmos KS-7R carbon dioxide detector.
To ensure safe and reliable operation, please read this instruction manual prior to use.
This unit detects carbon dioxide and is intended for use in a non-hazardous indoor area, e.g., office,laboratory, or clean room, for the early detection of a gas leak.
The unit will relay the gas concentration value as an analog signal (4-20mADC) to external
equipment while simultaneously displaying the gas concentration value on its display.
This unit monitors carbon dioxide levels, and when they reach a preset level, the unit will produce
audio-visual alarms and activate relay contacts.

This manual uses Danger, Warning, Caution and Note symbols to draw attention toprocedures, materials, methods, and processes, which require particular attention.
DANGER : Indicates an imminently hazardous situation that can result indeath or serious injury.
WARNING : Indicates a potentially hazardous situation that may result in deathor serious injury.
CAUTION: Indicates a hazardous situation that may result in minor injury orproperty damage.

NOTE: Provides information on product handling.

-1-2. General Precautions

Carefully read this manual prior to use.
Follow the precautions below to ensure safe operation.
Only use this product in accordance with the applicable laws and regulations.
Only a qualified electrician with knowledge of wiring and installation procedures should perform
wiring and installation.
WARNING▪ In the event of a gas alarm, follow the safety procedures in accordance with yourcompany's regulations.
▪ This product is not explosion-proof and should not be installed in a hazardous area.
▪ Secure the cover by tightening the two fastening screws. Proper gas detection is notpossible if the cover is not tightly closed.

CAUTION▪ Do not disassemble, modify, or alter the structure of this unit or its electrical circuits.
Doing so may compromise the performance of the product.
▪ This product is not drip-proof equipment and should be kept away from water.
▪ Condensation inside the product may cause a device failure. If used continuously in ahigh humidity environment, take measures to prevent condensation.
▪ The product’s analog output resolution is 1,000 steps. Because of the difference inresolution or number of displayed gas concentration digits between this product andhigh-layer monitoring software, or connected impedance, some errors in displayed gas
concentration value may be observed.
If the fault threshold needs to be set via analog output, set it to 1.0 mA.

NOTEOperation during power outage
In the event of a power outage during operation, the detector will automaticallyresume operation once power is restored, provided the main power switch, under
the cover, is in the on (up) position.

-2-

3. Package Contents
The following items are included in a standard package. If any items are missing or
damaged, please contact New Cosmos or its authorized representative for replacement.
Item

Quantity

Description

CO2 detector (KS-7R)

1

Mounting screw

2

M5x12 with spring washer (wall mounting)

Cable tie

1

To be used to bundle electric cables

Pin terminal

9

Insulating sleeve

9

Instruction manual

1

Inspection certificate

1

To be crimped to cables and inserted into theterminal block
To be installed in a crimped pin terminal to provide
insulation
This manual-3-4. Unit Dimensions and Components
4-1. Outer Appearance(Dimensions are in mm)

Item

Component

Description/Function
Slide up and lift the cover to access to the main power switch and towire external cables. This cover is normally closed.
Houses one mounting screw, and two fastening screws that attach thecover to the unit. This cover is normally closed.

1

Cover

2

Screw cover3

Gas detection port

4

Status indicator

5

LCD

6

AL2 alarm LED, red

7

AL1 alarm LED, amber

8▲ (Up) button

During normal operation, press to display the highest peak value ofgas concentration after powering-up on the LCD.
Used for making settings in combination with other buttons.

9▼ (Down) button

Used for making settings in combination with other buttons.

Gas inlet to the CO2 sensor.
During normal operation all three green internal LEDs are lit. In theevent of an 1st/2nd stage alarm, four internal amber/red LEDs lightsequentially.
Displays CO2 concentration, parameter values, error code
, and status icons.
Flashes red in the event of a 2nd stage alarm. The LED will become
solid if reset by pressing the RESET button.
Flashes amber in the event of a 1st stage alarm. The LED will become
solid if reset by pressing the RESET button.

-4-

Item

Component

Description/Function

10

RESET button

During normal operation, press to display the full scale and alarm set
values. Used for muting an on-going audio alarm.

11

POWER button

Press and hold for three seconds to turn on/off the detector.

12

Speaker opening

Opening for audio.

13

Cable entry (3 places)

Make a cutout (cable entry) with a nipper to connect external cables tothe terminals.

14

Maintenance button

Recessed button used for making settings.

4-2. Inner Components

Item

Component

Description/Function
Slide up and lift the cover to access to the main power switch andto wire external cables. This cover is normally closed.
Houses one mounting screw, and two fastening screws that attach
the cover to the unit. This cover is normally closed.
Located under the screw cover.
Screws that attach the screw cover to the unit.

1

Cover

2

Screw cover3

Fastening screw (2 places)

4

Terminal block

Connect to external wiring.

5

Main power switch

Turns on/off the main power.

-5-5. Installation
WARNING▪ This product is not explosion-proof and should not be installed in a hazardous area.
▪ Do not use the product at an area where the CO2 concentration is less than 360 ppm.

CAUTION▪ Avoid strong mechanical shock, impact or vibration to the detector by dropping or
bumping. Failure to do so may impair the performance of the detector.
▪ Do not install the detector in the following conditions.
- Outdoors- Exposure to water spray- Outside the following operating temperature/humidity-10 to +50°C (no rapid temperature change)
0 to 85% RH (no condensation)- Presence of corrosive gas- Exposure to impact or vibration- Presence of high frequencies or a magnetic field- Exposure to electrical noise- Exposure to dust
- Exposure to high winds (higher than 6 m/s or 13.4 mph)
▪ Install the detector in a location that ensures easy access for maintenance.
▪ Install the detector vertically with the sensor on top. Proper gas detection is not possible
if installed inverted, at an angle, or horizontally.
▪ CO2 is heavier than air, so the recommended sensor height is 150 cm (head height)
unless otherwise required by applicable laws or regulations. Install the unit with its gas
detection port free from obstructions.
▪ Secure the cover by tightening the two fastening screws. Proper gas detection is notpossible if the cover is not tightly closed.
▪ Do not use or store the detector where alcohols, acetone, or volatile oil is present. Thatmay compromise the product’s detection performance.
▪ Do not use or store the detector where chlorine or corrosive gas is present. That may
compromise the product’s detection performance.
▪ Exposure to alkali metals especially salt spray) or other inorganic elements may
contaminate the sensor and compromise the detection performance.
▪ Accurate measurement is not possible, if installed beyond standard sea-levelatmospheric pressure range (e.g. at high-altitude).
▪
NOTE▪ Leave a distance of more than 30 mm from each side of the detector for
removal purpose.
▪ Leave a distance of more than 50 mm from the top of the detector to allow thecover to slide open.
▪ Leave enough space for cable wiring below the detector.
-6-Clearance for coverto slide

SensorMounting hole

Cable entry(Dimensions are in mm)

Wall-mount the detector using two M5 mounting screws (pitch: 134) according to the following
procedure.
1.
2.
3.
4.

Open the screw cover.
Loosely install the mounting screw (top).
Loosen the two fastening screws.
Slightly pull the cover forward.

1. Open screw cover

3. Loosen two
4. Pull cover forward
2. Loosely install
mounting screw (top) fastening screws

Screw cover

Cover

-7-

5.
6.
7.

Slide the cover up (cover is open).
Firmly tighten the mounting screw (bottom) to secure the detector to the wall.
Slide the cover down (cover is closed).
7. Slide cover down

5. Slide cover up

6. Tighten mounting screw(bottom)

8.
9.
10.
11.

While pressing the cover down toward the case,Tighten the mounting screw (top).
Secure the screw cover to the case with the two fastening screws.
Close the screw cover.
10. Tighten two fastening screws
9. Tighten mounting screw

8. Press down
cover

Case

CAUTION
Secure the cover by tightening thetwo fastening screws. Proper gas
detection is not possible if the cover
is not tightly closed.

-8-6. Wiring
WARNING▪
▪

Remove any power source during wiring work to prevent electric shocks.
After wiring is completed, close the detector’s cover to prevent electric shocks.
CAUTION▪

▪
▪
▪

New Cosmos is not responsible for the cost or any damage resulting from controllingexternal equipment (e.g. interlock) by using the detector’s outputs (e.g. analog output,
alarm relay contact output).
Connect wires to their corresponding terminals by referring to the marking on theterminal block.
Keep the connection cable away from the electrical power line.
When using with external devices, isolate the product’s 4-20mA analog output frompower lines of external devices in order to prevent inflow current and noise.

The knockout holes for cable entry are provided
on the back and bottom of the unit, and can beremoved using a nipper.
Use a shielded cable (with 0.5 to 1.25mm2 wires)up to 500m in length with an outside diameter of
10.5mm or less.

Knockout hole on the back

Knockout hole on the bottom

NO contacts
Signal+-ZA1 ZA2 TA

COM

P

+

N

-

E

D C

SignalE-

ZA1/ ZB1

N

R

+

P

ZA2/ZB2

Power supply, 24 VDC

Earth terminal for grounding the detector+-

Analog output, 4-20mA DC

1st stage alarm relay contact(Dry NO or NC)
2nd stage alarm relay contact(Dry NO or NC)

TA/TB

Fault alarm relay contact (Dry NO or NC)

COM

CommonDC

Not used

NO: Normally Open
NC: Normally Closed-9-6-1. Pin Terminal/Insulated Sleeve Installation
Recommended parts/tools
Part

Model (Manufacturer)

Remarks
Shielded cable (with 0.5-1.25mm2 wires)Electric cableOuter diameter: 10.5mm or less
(Included in package)

Pin terminal

TC1.25-16 (Nichifu)

Insulating sleeve

VC1.25 (Nichifu)(Included in package)

Crimping tool

NH1 (Nichifu)

1.25

Used for 0.25- 1.65mm2 twisted wire

Terminal block (reference)
Part
Power terminal block
External output terminal block

Model (Manufacturer)
ML-1400-S1L-3P(Sato Parts)
FFKDSA1/H1-5, 08-8
(Phoenix Contact)

Remarks
Diameter: 0.65-1.6mm
Diameter: 0.2-1.5mm

1) Wire stripping
Strip the wire.
Recommended stripped wire length: 5.5mm

5.52) Pin terminal installation
Insert the stripped wire into a pin terminal until
1mm of stripped wire can be seen from the endof the pin terminal’s barrel.

1

Pin Terminal

3) Terminal crimping
Crimp the center of the barrel.
Barrel4) Insulating sleeve installation
Attach an Insulating sleeve to the crimped pin
terminal.
NOTE

Completely insert the pin terminal into
the insulating sleeve. Not doing so may
cause an insufficient pin length when
wired to the terminal block, which may
result in a poor connection.

- 10 -

Insulating sleeve
Completely insert

6-2. Wire Connection/Disconnection to/from Terminal Block
6-2-1. Power Terminal Block(Connection)

Insert each pin terminal to its
corresponding slot on the terminal block.

(Disconnection)

While pressing the release button with a
precision screwdriver (recommended tip
thickness: 2.6 mm), lift the pin terminal.

6-2-2. External Output Terminal Block(Connection)(Disconnection)

Insert each pin terminal to its
corresponding slot on the terminal block.

While pressing the release button with a
precision screwdriver (recommended tip
thickness: 3.0 mm), lift the pin terminal.

6-3. Cable Tie Installation
Use a cable tie for bundling the in-coming cables throughthe cable entry and secure them to the unit’s wall.
The unit has a cable tie holder inside its case near thebottom.
Pre-install a cable tie by feeding it through the tie holder
and make a loop. To easily bundle the wiring of in-coming
cables to the terminal block, feed these cables throughthis loop and secure to the case wall.

Cable tie

Cable entry- 11 -

7. Operation
7-1. Precautions before Use

▪
▪
▪

▪

CAUTION
Before turning on the unit, check that all wiring is correct. Refer to 6. “Wiring” or delivery
specifications if provided.
Ensure there is no target or interfering gas in the air before use.
Before the sensor output is stable, the relay contacts may possibly activate after the
warm-up completes. If the relay contact outputs are used to interlock external devices,
release the interlocks to prevent possible activation, if necessary.
During the warm-up, the analog signal output is fixed at 4mA and the external relay
contacts are disabled.

7-2. Operating Procedure
1) Follow steps 1, 3, 4, and 5 of 5. “Installation” toslide up and open the cover. (The cover is not
fully opened.)
1. Open the screw cover.
3. Loosen the two fastening screws.
4. Slightly pull the cover forward.
5. Slide the cover up (cover is open).

Screw cover

Cover
Main powerswitch2) Set the main power switch to the on (up)position.

Partlyopen3) Follow steps 7, 8, and 10 of 5. “Installation” toclose the cover and tighten the screws.
7. Slide the cover down (cover is closed).
8. While pressing the cover toward the case,
10. secure the screw cover to the case with thetwo fastening screws.

Status indicator
LCD

POWER button

CAUTION
Secure the cover by tightening thetwo fastening screws. Proper gas
detection is not possible if the cover
is not tightly closed.

- 12 -

4) Press and hold the POWER button for three seconds to turn on the detector. (two beeps) The threegreen LEDs inside the status indicator start flashing and “- - - -” is displayed on the LCD. The
warm-up cycle lasts two minutes. During the warm-up cycle, the analog output is fixed at 4 mA,
gas and fault alarms are deactivated, and the detector cannot enter to User mode.

Warm-up operation

Normal operation

5) When the warm-up cycle is completed, the three green flashing LEDs inside the status indicator
become solid, the gas concentration is displayed on the LCD, and normal operation starts.
6) Perform an alarm test. (Refer to 7-4-5. “Alarm Test”)
Confirm that an alarm activates.
7) To turn off the detector, press and hold the POWER button for three seconds to stop its operation,then set the main power switch to the off (down) position.
CAUTION
If the gas detector has not been powered for a long period of time (i.e. between shipment
and initial energization), it may take longer for the sensor to stabilize.

- 13 -

7-3. LCD Operation
7-3-1. LCD
2

3

4

5
1
Item

8

7

Icon/Display

6
Description/Function

1

Audio alarm icon

Lit during active audio alarm.

2

AL1 icon

1st stage alarm notification.

3

AL2 icon4

Concentration value and information

5

Unit of measurement

2nd stage alarm notification.
CO2 concentration value, parameter values, error
code, etc.
A unit of gas concentration.

6

Clock battery level indicator

Lit when the clock battery level is low.

7

Alarm event history icon

Lit when an alarm event is being accessed.

8

Maintenance mode icon

Lit when Maintenance mode is active.

▪
▪

CAUTION
The LCD indication is fixed at “360 ppm”, even if the actual gas concentration is less.
The audio alarm icon is not displayed when your detector is a silent alarm option(specified at time of order).

7-3-2. Normal Operation Status

Operation buttons

During normal operation the green status indicator is fully lit,
the gas concentration value is displayed on the LCD, and
the AL1 and AL2 alarm LEDs are off.

POWER button
RESET button▲(UP) button▼(DOWN) button
Maintenance button- 14 -

7-3-3. Full Scale and Alarm Set Values Display▪ Press the RESET button (one beep) to display the “full scale concentration”, “1st stage alarm set
value”, and “2nd stage alarm set value” in sequence.

7-3-4. Peak Value Display and Reset▪ Press the ▲ button. (one beep) The “peak value after powering-up” and “PEAK” will be displayedalternately.

E.g. Peak value is 1000 ppm.

▪ To return to the normal gas concentration display, press the RESET button. (one beep)
The display will show the full scale value and alarm set values, then return to the normal gas
concentration display.
▪ To reset the peak value, press the ▲ and ▼ buttons at the same time. (two beeps)
The peak value is reset then the display returns to the normal gas concentration display.

7-3-5. Operation during Gas Alarm▪ When the CO2 concentration reaches the alarm set value, the alarm LED flashes, the statusindicator sequentially-flashes and the audio alarm sounds.
NOTE

Audio alarm mute: If the RESET button is pressed during a gas alarm, the audio
alarm will be muted and the flashing alarm LED(s) will become solid. If the
RESET button is pressed and held, the alarm will not be muted.

▪ There are two options to clear a gas alarm, manual-resetting and self-resetting. By default, thedetector is set to self-resetting mode. Please specify the alarm clearance option at the time oforder.
▪ The alarm hysteresis range is 200 ppm. The alarm will not be cleared until the gas concentration
exceeds the alarm set value by more than the hysteresis value. E.g. when the alarm set value is2000 ppm and an alarm is activated, the alarm will not be cleared until the concentration reaches
1800 ppm or lower.
NOTE

Alarm relay contact reset: If the RESET button is pressed while theconcentration is below “alarm set value – hysteresis”, the alarm relay contact will
return to its normal position and the alarm LED will turn off.

- 15 -

< 1st stage alarm >▪ AL1 alarm LED (amber) flashes and the status indicator sequentially-flashes amber.
▪ Audio alarm beep: Fast, high and low beep tones.
▪ COM-ZA1 alarm relay contact closes (when normally open contacts are used). / COM-ZB1
alarm relay contact opens (when normally closed contacts are used).
< 2nd stage alarm >▪ AL2 and A1 alarm LEDs (red and amber) flash and the status indicator sequentially-flashes
red.
▪ Audio alarm beep pattern: Very fast high and low beep tones.
▪ COM-ZA2 alarm relay contact closes and COM-ZA1 alarm relay contact remains closed(when normally open contacts are used). / COM-ZB2 alarm relay contact opens and
COM-ZB1 alarm relay contact remains open (when normally closed contacts are used).

7-4. User Mode
▪ During User mode, gas detection, alarm operation, analog output, and contact
output activation are active as during normal operation mode. However, audio
alarm mute and alarm clearance are not active and cannot be used.
▪ Return to normal operation mode after using User mode.

NOTE

7-4-1. User Mode Operation▪ To enter User mode, press the maintenance button while
the unit is on. After one beep, “1” and its abbreviatedmode name “MT” will be alternately displayed.
Use a rounded pin (e.g. precision screwdriver) for pressing the Maintenancebutton.

NOTE▪ To select the mode options, use the ▲ and ▼ buttons.
▪ To confirm your selection, press the maintenance button. To return to the previous step, press
the RESET button.
▪ To execute the selected mode, press and hold the maintenance button for three seconds.
▪ To return to normal operation mode, press and hold the RESET button for five seconds.

Mode
1
2

Mode name
Switching Maintenance mode on/off
Zero adjustment

3

Air adjustment

456Alarm test
Alarm event history
Clock setting- 16 -

Abbreviated mode name
MT0 ppm
400 ppm(target concentration level)
AL T
AL H
DATE

7-4-2. Switching Maintenance Mode On/Off [Mode 1]
WARNING
During Maintenance mode, the gas alarm relay contacts and gas alarm audio aredisabled. Turn off Maintenance mode during normal operation.

1) Enter User mode. Press the ▲ / ▼ button to
select “1”. (each press of the button is followed by
one beep) “MT” and “1” (mode number) will be
alternately displayed.
2) Press the maintenance button. (one beep)“OFF” will flash.

3) Press the ▲ button. (one beep)“ON” will flash.

4) Press and hold the maintenance button for threeseconds (beep pattern: short–long–short–short) to
confirm the selection.
The maintenance icon is displayed, and “1” and“MT” will be alternately displayed, indicating thatthe unit is in Maintenance mode.

NOTE

If the unit is returned to normal operation mode
while in Maintenance mode, the “concentration
value” and “- - - -” will be alternately displayed
and the maintenance icon will remain displayed.

5) To end Maintenance mode, take the steps 1) to 4)
above to switch Maintenance mode from “ON” to"OFF". Confirm the maintenance icon has turned
off.

- 17 -

Maintenance icon

7-4-3. Zero Adjustment [Mode 2]
CAUTION▪ Do not perform a zero adjustment. Accurate detection is not possible without proper
adjustment.
▪ To adjust the sensor, a zero or air adjustment is necessary. Air adjustment isrecommended.
▪ Sensor adjustment (air/zero adjustment) should only be performed by qualified
technician. For adjustment, contact your New Cosmos representative (fees apply).
Enter User mode. Press the ▲/▼ button to select “2”.
(each press of the button is followed by one beep)“0 ppm” and “2” will be alternately displayed.

7-4-4. Air Adjustment [Mode 3]
CAUTION▪ Do not perform an air adjustment. Accurate detection is not possible without proper
adjustment.
▪ To adjust the sensor, a zero or air adjustment is necessary. Air adjustment isrecommended.
▪ Sensor adjustment (air/zero adjustment) should only be performed by qualified
technician. For adjustment, contact your New Cosmos representative (fees apply).
▪ 400 ppm CO2 gas is used for air adjustment.

Enter User mode. Press the ▲/▼ button to select “3”.
(each press of the button is followed by one beep)“ *** ppm” (target concentration level) and “3” will be
alternately displayed.

- 18 -(E.g. Target concentration level is 400 ppm)

7-4-5. Alarm Test [Mode 4]
When an alarm test is executed, the alarm test value (concentration) will be displayed on the LCD,
and corresponding analog output and alarm outputs (gas alarm relay contacts, audio alarm, alarmLEDs) will activate. This will allow the user to test the alarm operation.
NOTE▪ If the unit is in Maintenance mode, the gas alarm relay contacts and gas alarm
audio are disabled (alarm LEDs and analog outputs are active).
▪ The possible test value range is from 0 to 5000 ppm.

CAUTION▪ An alarm test activates the alarm relay contacts of the detector. If the alarm relay contact
outputs are used to interlock external devices, release the interlocks before the alarm test,
if necessary. Notify those concerned before starting gas detection system inspection.
▪ Observe the applicable laws and regulations.

1) Enter User mode. Press the ▲/▼ button to select “4”.
(each press of the button is followed by one beep)“AL T” and “4” will be alternately displayed.
2) Press the maintenance button. (one beep).
The current alarm test value (ppm) will be
displayed.
3) To change the alarm test value (ppm), press the ▲/▼button.
NOTE

To increase/decrease the test value,press the ▲/▼ button. Holding the
button continuously
increases/decreases the value.

4) Press and hold the maintenance button for threeseconds to start an alarm test. (two beeps)5) To cancel the ongoing alarm test, press the RESET
button. (one beep) The current alarm test value (ppm)
will be displayed.
(Note: If the RESET button is pressed and held, thealarm will not be cancelled and the unit will return tonormal operation mode.)6) To change the test value, repeat steps 3) to 5).
7) Press and hold the RESET button for five seconds toreturn to normal operation mode.

- 19 -(E.g. Test value iscurrently set to 2000 ppm)

(E.g. Test value ischanged to 5000 ppm)

7-4-6. Alarm Event History [Mode 5]
Up to the 10 most recent alarm events can be displayed (automatically updated).
For each alarm event, the following sequence of information is displayed: peak value (ppm) during
the alarm, starting and ending times (year/month/day/time) of the alarm.
Press the RESET button to return to the previous screen.
1) Enter User mode. Press the ▲/▼ button to select “5”.
(each press of the button is followed by one beep)“AL H” and “5” will be alternately displayed.
2) Press the maintenance button (one beep) The mostrecent alarm event number “H1” will be displayed. If
there is no alarm event, “INIT” will be displayed.
(No alarm events)

3) Use the ▲ button (each press of the button isfollowed by one beep) to select (display) the desired
alarm event from H1 to H10.
NOTE

Each press of the ▲ button cycles through alarm events. The sequence is
H1, H2, to H10, and INIT. To delete all the alarm events, select “INIT”, thenpress and hold the maintenance button for three seconds. (beep pattern:
short–long–short–short) It is not possible to delete single alarm events.

4) Press the maintenance button. (one beep)
The alarm event history icon is present,
and the display alternates between “AL”
and the “peak value” (ppm) for theselected event.

Alarm event
history icon

(E.g. Alarm peak value is 3000 ppm)

5) Each press of the ▼ button cycles through the details of the selected alarm event. The
sequence is: starting year, date, and time and ending year, date, and time of the event.

(Start of alarm)(year)(End of alarm)(year)(Start of alarm)(month. day)(End of alarm)(month. day)(Start of alarm)(time)(End of alarm)(time)- 20 -

6) Press the RESET button (one beep) to display theselected alarm event number “H *”.
To display other alarm events, repeat steps 3) to 5).
(E.g. H1 is selected)

To delete all the alarm events, select “INIT” in step 3),
then press and hold the maintenance button for threeseconds. (beep pattern: short–long–short–short).
All alarm events are now deleted.

7-4-7. Clock Setting [Mode 6]
Clock is used when recording alarm events.
1) Enter User mode. Press the ▲/▼ button to select “6”.
(each press of the button is followed by one beep)“DATE” and “6” will be alternately displayed.
2) Press the maintenance button. (one beep) “YEAR”
and “ * * * * (year)” will be alternately displayed.
3) Select the item to change with the ▲ button. The
item and its currently set value will be displayed.
NOTE

Each press of the ▲ button cycles through: “YEAR”, “MON” (month),“DAY”, “HOUR” and “MIN” (minute).

When selecting “YEAR”, for example,
4) Press the maintenance button. (one beep) The currently
set year will be displayed.

(E.g. Year is currently
set to 2018)

5) Change the set value by using the ▲/▼ button.

(E.g. Changed from 2018 to 2019)6) Press and hold the maintenance button for threeseconds to confirm the change. (beep pattern: short–
long–short–short) “YEAR” and the set year will be
alternately displayed.

(confirmed)

7) To change the other items, repeat steps 3) to 6).
8) Press and hold the RESET button for five seconds(two beeps) to return to normal operation mode.

- 21 -(Back tonormal operation mode)

7-5. Maker ModeAll the items set in Maker mode (e.g., alarm set value) are password-protected.
WARNING▪
▪
▪

Incorrect settings in Maker mode may change the detector’s specifications. Never
operate in a way other than as described in this instruction manual.
Only a selected administrator should make changes in Maker mode.
Gas detection is not possible while in Maker mode. To exit and return to normal
operation, power cycle the unit before use.

7-5-1. Maker Mode Activation
There are two methods to enter Maker mode.
1. Turn off the detector. Then simultaneously press and hold the ▲ and ▼ and POWER buttons
for three seconds (two beeps) to activate Maker mode.
2. Press and hold the maintenance button while in normal operation mode.

The software version is displayed, followed by all the LCD segments displayed, and finally “775”starts flashing. Now Maker mode is active.

MaintenancebuttonSoftware version

All LCD segments
turn on“775” flashes.
Maker Mode is active.

Main power switch

CAUTION
Only enter 775 to enter Maker mode.

- 22 -

7-5-2. Alarm Set Value Change
1) Refer to 7-5. “Maker Mode”.
Enter Maker mode. “775” flashes.
2) Press the maintenance button. (one beep)“AL 1” will be displayed and the AL1 icon will turn on.

3) Use the ▲ button (one beep) to select the alarmstage, AL1 or AL2.
NOTE

Each press of the ▲ button alternates
between “AL1” and “AL2”.

4) Press the maintenance button to confirm the selection.
(one beep) The current alarm set value for the selectedalarm stage will be displayed.

5) Change the alarm set value by using the ▲/▼ button.

6) Press and hold the maintenance button for at least threeseconds to confirm the change. (beep pattern: short–long–short–short)“AL1” or “AL2” will be displayed.
NOTE(E.g. Changed to 25ppm)

If the alarm set value change is not
successful, the unit will beep two times andthe previous set value remains displayed. In
this case, press and hold the POWER button
for three seconds to turn off the unit, thenrepeat the procedure. If the unit still fails tochange the alarm set value, contact your New
Cosmos representative for repair.

7) To change another alarm set value, repeat steps 3) to 6).
8) To end the procedure, press and hold the POWER button for three seconds to turn off theunit.
9) Press and hold the POWER button for three seconds to restart the unit in normal
operation mode. Check the alarm set values. (Refer to 7-3-3. “Full Scale and Alarm Set
Value Display”.)- 23 -

8. Maintenance
Daily checks are carried out by the user, while monthly and annual inspections are performed by theuser, New Cosmos or its authorized representative.

Important Notice for MaintenanceIn order to ensure the reliability of the gas detector, it is vital to perform periodic air
adjustment on the gas sensor. It is highly recommended that a maintenance contract with alocal New Cosmos representative be made for the performance of scheduled adjustment
and replacement.

8-1. Inspection Contents and Frequency
Start-up

Expansionor
relocation

1) Concentration display

VV2) Alarm test

V

V

Check items

Periodic Inspection
Monthly

Annually

Daily
check
V

V
V*

3) Air adjustment (gas calibration)V*4) Sensor replacement

Every 5 years* Contact your New Cosmos representative for air adjustment/sensor replacement (fees apply).

1) Concentration Display
Check that the CO2 concentration is displayed on the LCD and that the detector operates
properly.
2) Alarm Test
Check that an alarm activates correctly by conducting an alarm test. Refer to 7-4-5. “Alarm
Test”.
CAUTION▪

▪

Perform an alarm test in accordance with the applicable local laws and regulations. For
example, an applicable law in Japan specifies that alarm activation must be checked by
performing a circuit check once every month.
An alarm test activates the alarm relay contacts of the detector. If the alarm relay contact
outputs are used to interlock external devices, release the interlocks before the alarm
test, as necessary.
Notify those concerned before starting gas detection system inspection.

- 24 -

3) Air Adjustment (Gas Calibration)
To ensure reliable gas sensor performance, perform an air adjustment at least once a year.
CAUTION▪

▪
▪

Air adjustment should be performed by qualified technician only. For air adjustment,
contact your New Cosmos representative (fees apply). Accurate gas detection is notpossible without a proper air adjustment.
400 ppm CO2 gas is used for air adjustment.

4) Sensor Replacement
It is highly recommended to replace the sensor every 5 years when used in a normal
environment. However, if any abnormality, e.g., a significant decrease in sensor sensitivity, isfound during a periodic inspection or daily check, the sensor needs to be replaced. Contact your
New Cosmos representative for sensor replacement.
NOTE

Even if the detector is unused for a long period of time, replace the sensor 5
years from the purchase date. Contact your New Cosmos representative forsensor replacement (fees apply).

- 25 -

8-2. Clock Battery Replacement
CAUTION
1.
2.
3.
4.

Use a “CR2032 lithium battery, coin type” for clock battery.

Press and hold the POWER button for three seconds to turn off the detector.
Open the screw cover.
Loosen the two fastening screws (these screws cannot be fully removed).
Slightly pull the cover forward.
2

3

4

1

5. Slide the cover up by holding it by the sides until the alignment markings on cover and casematch.
6. Set the main power switch to the off (down) position to turn off the main power.
CAUTION
Turn off the detector’s main
power to avoid electric shocks.

5
6. Main powerswitchAlignment mark (case)
Alignment mark (cover)

7. Pull and detach the cover from the case.
CAUTION Cover and case are connected with connector cable.
Cover
Case

CAUTION
Take care to prevent
breaking the connector
cable between the caseand the cover.

- 26 -

8. The cover can be temporarily attached on the top of the case by engaging Part A (cover) into
Part B (case).
Top of casePart ATop of coverPart BEngaged
8. Insert
9. Replace clock battery

Clock battery

9. Replace the clock battery with a new one.
CAUTION
Correctly install a battery by referring to the polarity markings on the battery holder.
10. (Reverse step 8) Pull and detach the cover from the top of the case. Attach the cover to the caseby aligning its markings to the corresponding markings on the case.
11. Set the main power switch to the on (up) position to turn on the main power.
12. (Reverse step 5) Slide the cover down by holding it by the sides to close it.
13. Open the screw cover. Tighten the two fastening screws.
CAUTION
Secure the cover by tightening the two fastening screws. Proper gas detection is notpossible if the cover is not tightly closed.
14. Close the screw cover.

- 27 -

9. Troubleshooting
Before requesting repair, please refer to the table below. If the detector does not return to normal
operation after performing the corresponding steps in the table, or if your issue is not found in the table,
consult New Cosmos or its authorized representative.
Problem

Probable cause

Solution

Reference section

Set the main power
Main power switch or
POWER button is off
Green status indicator
not lit.

switch to on position orpress and hold the
POWER button for three

7-2. Operating
Procedureseconds.
Incorrect wiring or

Check andloose connection

rewire/reconnect.

No power supplied

Supply correct power.

Product is in

Switch Maintenance

Maintenance mode

mode to OFF.

Product is in

Switch Maintenance

Maintenance mode

mode to OFF.

Incorrect alarm set

Check the alarm set

7-3-3. Full Scale andvalue

value.

Alarm Set Value Display

6. Wiring
7-1. Precaustions before
Use

Maintenance icon
displayed on LCD, andgas concentration valueand “_ _ _ _” displayed

7-4-2. Switching
Maintenance Mode
On/Offalternately.

No audio alarm.

7-4-2. Switching
Maintenance Mode
On/OffSilent alarm option
selected at time ofConsult your New Cosmos representative.

order
7-4-2. Switching

Product is in

Switch Maintenance

Maintenance mode

mode to OFF.

Alarm relay contacts doIncorrect wiring or

Check andnot activate.

loose connection

rewire/reconnect.

Incorrect alarm set

Check the alarm set

7-3-3. Full Scale andvalue

value.

Alarm Set Value Display- 28 -

Maintenance Mode
On/Off
6. WiringProblem▪ Status
indicator“E-E1”,

flashing“E-E2”, or

between“E-E3”

green

displayed

and red.

on LCD.

Probable cause

Device failure

Solution

Reference section

Press and hold the
POWER button for three▪ Audioalarm

seconds to turn off thesounds.

minutes, turn the▪ Fault
alarm

detector on again. If therelaynormal operation,

detector. After a few

unit does not return tocontact“E-S1”,

contact your New

activates.

“E-S2”, or

Cosmos representative▪ Analog
output is“E-S3”

lower

on LCD.

displayed

Sensor failure

7-2. Operating
Procedure

for repair.

than
0.9mA.

Turn off and on theMicrocomputer
Other than the above

malfunction due tonoise.

detector. If the unit does
not return to normal

7-2. Operating

operation, contact yourProcedure

New Cosmos
representative for repair.

- 29 -

10. Specifications
Detection principle
Sampling method
Target gas
Detection range *1
Display
Alarm set value

NDIR
Diffusion type
Carbon Dioxide
360 to 5000 ppm
Four-digit LCD with backlight, 5 ppm resolution
AL1: 2000 ppm, AL2: 5000 ppm
0 to 40°C: ± 5% of F.S.
Detection accuracy
Others: ± 10% of F.S.
Response time *2
T90: 90 sec., T60: 60 sec., T50: 50 sec.
▪ Gas alarm (in two stages)
1st stage alarm: AL1 alarm LED flashes (lit if the audio alarm ismuted), amber status indicator sequentially-flashes, audio alarmsounds, and AL1 icon is displayed on LCD.
Alarm
2nd stage alarm: AL1 and AL2 alarm LEDs flash (lit if the audio alarmis muted), red status indicator sequentially-flashes, audio alarmsounds, and AL1 and AL2 icons are displayed on LCD.
▪ Alarm clearance method: selectable to self-resetting (default) or
manual-resetting at the time of order.
▪ Gas concentration analog output
4-20 mADC (common negative with power supply)- Normal operation: 5.15 to 21.6 mA (360 to 5500 ppm)
- Warm-up: 4 mA
- Fault status: 0.9 mA or below
Current sensing resistor must be 300Ω or less including a wiring
resistance.
External output▪ Gas alarm relay contacts (in two stages)
Dry normally open (default) or close contacts, latching type
Selectable to self-resetting (default) or manual-resetting at the timeof order(Max load: 2 A at 30 VDC (resistance load))▪ Fault alarm relay contact
Dry normally open (default) or normally close contacts, latching type(Max load: 2 A at 30 VDC (resistance load))
Explosion-proof
Not explosion-proof
EMC:2014/30/EU/SI 2016 No.1091
Compliance *3
RoHS:2011/65/EU+(EU)2015/863/SI 2012 No.3032▪ Maintenance mode used to disable gas alarm relay contacts andOther features
gas alarm audio.
▪ Audio alarm mute
Applicable cable
0.5 to 1.25mm2 shielded cable. Outer diameter: less than 10.5mm
Cable length
Up to 500m
Operating temperature -10 to +50°C, 0 to 85%RH (No rapid temperature/humidity changes.
and humidity
No condensation)
Power supply
24 VDC ± 10%
Power consumption
1 W during normal operation, 3 W during alarm
Dimensions
W82 x H150 x D35 mm
Mass
Approx. 300g
Mounting method
Wall mounting, indoors*1: Do not use the product in an area where the CO2 concentration is less than 360 ppm.
*2: Measured under identical environment at 20°C, 50%RH and 1,013hPa.
- 30 -

*3: CE marking specification applies to KS-7R which uses 24 VDC power. Refer to the “EU
Declaration of Conformity” (separate document) for information on the CE marking unit.

11. 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.
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 a freereplacement or repair service. This warranty covers the New Cosmos product/parts only and notthird-party product/parts.
Warranty Exclusions
The following will be repaired at the cost of customer even during the warranty 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 other acts 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.

12. Expected Sensor LifeThe estimated service life of the sensor is shown in the table below. The sensor may fail to provide
correct detection after its service life expires. Replace the sensor before its expiration. This
expected service life assumes that maintenance is done properly and periodically and that thesensor 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.
Detection principle

Expected sensor life

Non-dispersive infrared (NDIR)
sensor

5 years- 31 -

13. Detection Principle
Non-dispersive infrared sensor (NDIR)
Gas is molecules made of different chemical atoms. Each gas has a strong absorbance of infrared lightat specific wavelengths in the 1 to 20μm Infrared spectrum, and the amount of absorbed infrared light is
proportional to its gas concentration according to the Beer-Lambert law. By using this characteristic, it ispossible to measure the gas concentration of a target gas based on the amount of infrared lightabsorbed. Furthermore, the gas selectivity of the sensor can be enhanced by the addition of an opticalfilter, which filters out all light outside of the wavelength that target gas molecules can absorb.
Typical model of NDIR is shown below.

(1)①赤外線光源
Infrared light③窓(5) Optical filter(3)
Window⑤光学フィルタ

source(7) Microcomputer
⑦演算器
CPU
ＣＰＵ

④セル

(4) Cell⑥赤外線式センサ(6) Infrared sensor(2) Light generator②光源制御部

The infrared radiation from the infrared light source (1) is chopped by the light regulator (2). The infrared
light passes through the windows (3) and cell (4) to the optical filter (5), which allows only certain
wavelengths to pass to the infrared sensor (6), which then measures the amount of infrared absorbed by
the gas. The absorbed amount is converted to an electric signal, which is converted to a gas
concentration by the microcomputer (7).

- 32 -

14. Glossary
TermDefinition

Clean air or
normal air

Standard atmosphere which contains 20.9 to 21.0% oxygen in dry condition or
atmosphere without target gas or interference gases.

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.

Target gas

Specific gas to be detected, concentration displayed, and used to trigger alarms.

Detection range

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

Alarm set value

Preset gas concentration level at which an alarm is triggered.

Operatingtemperature andhumidity ranges

Ambient temperature and humidity ranges in which the gas detection and alarmsystem can operate normally.

Maintenance andinspection

Tasks performed to ensure that equipment operates normally and correctly.

Self-resetting(or Auto-resetting)Gas alarm clearance method. When the gas concentration falls below (or above
when the alarm set value is the lower limit) the gas alarm set value after an alarm
has been signaled, relevant alarm lights, gas alarm icon and alarm relay contacts
will automatically return to their normal positions/statuses.

Manual-resetting

Gas alarm clearance method. Even if the gas concentration falls below (or above
when the alarm set value is the lower limit) the gas alarm set value after an alarm
has been signaled, relevant alarm lights, gas alarm icon, and alarm relay contacts
will not automatically return to their normal positions/statuses. Manual operationis only possible when the gas concentration is below (or above) the gas alarm set
value.

Hazardous area

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

Explosive
atmosphere

Mixture of air and flammable substances in the form of dust or vapor which arewithin their explosive limits.

Sequentially-flash

There are several LEDs inside the status indicator. In the event of a gas alarm,
one LED lights at a time and the lit LED moves from left to right.

- 33 -

15. Proper Product Disposal at End of Life
The Waste Electrical and Electronic Equipment（WEEE）directive（2012/19/EU）
is intended to promote recycling of electrical and electronic equipment and theircomponents at end of life. This symbol （ crossed-out wheeled bin ） indicatesseparate collection of waste electrical and electronic equipment in the EU countries.
This product contains two Lithium batteries. Specific battery information is given inthis instruction manual. Batteries must be recycled or disposed of properly.
At the end of its life, this product must undergo separate collection and recyclingfrom general or household waste. Please use the return and collection system
available in your country for the disposal of this product.

- 34 -

(Blank page)- 35 -

Document No.

Revision History
Date

Revision

GAE-139-00
GAE-139-01
GAE-139-02
GAE-139-03

Feb 2019
June 2019
February 2021
September 2022

0 (Initial issue)
12
3

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