PT9E-0076

Pyrolyzer Unit(for GD-70D Series)

PLU-70Operating ManualPreface
Thank you for choosing the pyrolyzer unit PLU-70 designed for dedicated use with our gas detector head
GD-70D series. Please check that the model number of the product you purchased is included in thespecifications on this manual.
This pyrolyzer unit is designed for dedicated use with the gas detector head GD-70D series and must be
used in combination with the GD-70D series as the base unit.
This operating manual explains how to use the pyrolyzer unit PLU-70 installed on the gas detector head.
The basic operating procedures conform to those of the base unit, GD-70D series. This operating manual isintended as a complement to the GD-70D series operating manual.
For proper use of the pyrolyzer unit, please read and thoroughly understand both this operating manual and
the GD-70D series operating manual before use.

-2-

<Contents>
Preface ..................................................................................................................................
Important Notices on Safety ..................................................................................................
Method of confirmation for CE/UKCA marking type ...............................................................

2
4
5

1.
1-1.
1-2.
1-3.
1-4.
1-5.

Overview .......................................................................................................................
Product components .....................................................................................................
Product specifications ...................................................................................................
List of accessories ........................................................................................................
Names and functions for each part ...............................................................................
Block diagram ...............................................................................................................

6
6
7
7
8
10

2.
2-1.
2-2.
2-3.
2-4.
2-5.
2-6.

Installation .....................................................................................................................
Requirements ................................................................................................................
Installation of pyrolyzer unit ...........................................................................................
How to wire ...................................................................................................................
How to tube ...................................................................................................................
Relocate ........................................................................................................................
Disposal ........................................................................................................................

11
11
12
16
18
19
19

3.
3-1.
3-2.
3-3.

How to Operate .............................................................................................................
Preparation for start-up .................................................................................................
How to start the pyrolyzer unit .......................................................................................
How to exit ....................................................................................................................

20
20
20
21

4.

Regular Maintenance Mode ..........................................................................................

22

5.
5-1.
5-2.
5-3.
5-4.

Maintenance .................................................................................................................
Gas calibration method .................................................................................................
Other adjustments/Cleaning method .............................................................................
How to replace parts .....................................................................................................
Procedures to store the pyrolyzer unit or leave it for a long time ..................................

24
24
25
25
25

6.

Troubleshooting ............................................................................................................

26

-3-

Important Notices on Safety<Definition of DANGER, WARNING, CAUTION, and NOTE>DANGERWARNINGCAUTION
NOTE

Indicates an imminently hazardous situation which, if not avoided, will result indeath or serious injury or serious damage to the product.
The use of this symbol is to be limited to the most extreme situation.
Indicates a potentially hazardous situation which, if not avoided, could result indeath or serious injury on the human body or object.
Indicates a potentially hazardous situation which, if not avoided, may result inminor or moderate injury or some damage on the human body or objects. It
may also be used to alert against unsafe practices.
This means "ADVICE" at operation.

<Danger Cases>
DANGER
This is not an explosion-proof unit. You must not use it to detect gases exceeding the lower explosive limit (LEL).

<Warning Cases>
WARNING
Power Supply
Before turning on the pyrolyzer unit, always check that the voltage is properly applied. Do not use an unstable
power supply because it may cause malfunctions.
Need of grounding circuit
Do not cut the grounding circuit inside or outside the pyrolyzer unit or disconnect the wire from the grounding
terminal.
Tubing
The pyrolyzer unit and the base unit, gas detector head, are designed to draw gases around them under theatmospheric pressure. If excessive pressure is applied to the sampling inlet and outlet (GAS IN, GAS OUT),
detected gases may be leaked from its inside, thus leading to dangers. Be sure that excessive pressure is notapplied to the pyrolyzer unit and the gas detector head while used. Detected gases must be exhausted from thedetected gas exhausting outlet (GAS OUT) on the bottom of the gas detector head to which an exhaust tube isconnected, to a point regarded as a safe place.
Operation in a gas
Do not operate the pyrolyzer unit in a place where combustible gases or vapors are present. Operating thepyrolyzer unit in such an environment will lead to extreme dangers.
Pyrolyzer heater (pyrolyzer)
The pyrolyzer heater becomes hot. Do not touch the pyrolyzer heater because your hands may be burnt. Do nottouch the pyrolyzer heater just after power-off because it is still hot.

-4-<Precautions>
CAUTION
Do not use a transceiver (walkie-talkie) near the pyrolyzer unit.
Radio wave from a transceiver near the pyrolyzer unit or its cables may affect reading. When using a transceiver,
it must be used in a place where it disturbs nothing.
To restart the pyrolyzer unit, you must wait five seconds more before doing it.
Restarting the pyrolyzer unit within five seconds may cause errors.
Attach the dust filter before using the pyrolyzer unit.
Before using the pyrolyzer unit, attach the specified filter to prevent disturbances by possible gas adsorption or air
dust.
A dust filter to be used varies depending on the gas to be detected. For more information on dust filters, pleasecontact our sales department.
Observe the operating restrictions to prevent condensation inside the tube.
Condensation formed inside the tube causes clogging or gas adsorption, which may disturb accurate gas
detection. Thus, condensation must be avoided. In addition to the installation environment, carefully monitor thetemperature/humidity of the sampling point to prevent condensation inside the tube. In particular, when detecting
a gas which is dissolved into water and corrodes contacted materials, such as a strong acid gas, the gas isundetectable and furthermore may corrode internal parts. Please observe the operating restrictions.
Do not disassemble/modify the pyrolyzer unit, or change the settings if not necessary.
Disassembling/Modifying the pyrolyzer unit will invalidate the warranty of the performance. Changing the settings
without understanding the specifications may cause alarm malfunctions. Please use the pyrolyzer unit properly inaccordance with the operating manual.
Do not forget to perform a regular maintenance.
Since this is a safety unit, a regular maintenance must be performed to ensure its safety. Continuing to use thepyrolyzer unit without performing a maintenance will compromise the sensitivity of the sensor, thus resulting ininaccurate gas detection.

Method of confirmation for CE/UKCA marking type
The CE/UKCA marking is labeled on the detector in case of comply with CE/UKCA mark. Please confirm the
instrument specification before using. Please refer Declaration of Conformity that is at the end of thismanual if you have CE/UKCA marking type.
You can confirm instrument specification to see the CE/UKCA mark as follows.

CE/UKCA Mark

CE/UKCA mark label (Back of front cover)

-5-

1

Overview
1-1. Product components<Pyrolyzer Unit (PLU-70)><Standard Accessories> Operating manual Protective rubber cap (to be removed when using thepyrolyzer unit) Dedicated handling lever (for wiring) Dedicated U-tube<Gas Detector Head GD-70D Series (Base Unit: Option)>* This pyrolyzer unit is designed for dedicated use with the gas
detector head GD-70D series. Use the pyrolyzer only after
installation on the base unit, GD-70D series.

-6-

Gas detector

1-2. Product specifications
Power Display
Recommended
Power Cable
Power SupplyPower
consumption
Tube Connecting
Hole
Operatingtemperature
Operating humidity
Structure
External
Dimensions
WeightOuter Color

POWER lamp on (green)
Cable of CVV, etc.(1.25sq) - 2-core
24VDC 10%
Max. 25 W
Rc1/4 (O.D Φ6-1t half-union for Teflon tube<PP>supplied)
0-40C (at a constant condition)
30-80%RH (Non-condensing)Box type/Wall mounted type
Approx. 70(W)x120(H)x145(D) mm (projection potions excluded)
Approx. 0.9 kg
PLU main unit: grey
Front door: white1-3. List of accessoriesOperating manualProtective rubber cap
Dedicated handling lever
Dedicated U-tube-7-1-4. Names and functions for each part<Appearance>

M5 mounting hole
Fan exhaust holePower lamp

GAS IN
Protective cover for power switch

Power switch
Screw for grounding earth rod
GD-70D connecting tube

External wire hole

Connector for PoE

GD-70D connecting cable(Unit: mm)-8-

<Components of the Pyrolyzer Unit>
PLU main unit

Power lamp
Inside the PLU main unit
(with the front cover open)

Wall-mounted unit

Lock lever
Pyrolyzer heater
For tubing to the gas detector head

GAS INCAUTION Each unit consists of precision parts. When a unit is detached, be careful not to drop it. Dropping theunit compromises its original performance or causes malfunctions.

<Wall-mounted Unit>
Mounting hole: A hole for wall-mount.

Terminal plate: A power terminal (2P).

Lock lever: A lever to lock the PLU main unit.

-9-

1-5. Block diagram<Electric Diagram>
Display(POWER lamp)

Pyrolyzer(Pyrolyzer heater)
PL-70

Fan

Controller(CPU)

Flow Sensor 1
Total flow rate

Power supply circuit
Flow Sensor 2
Bypass flow rate

Power supply part
POWER INPUT(DC:24V)<Tubing Diagram>- 10 -

2

Installation
2-1. Requirements
Not only the first-time users but also the users who have already used the product must follow the operating
precautions.
Ignoring the precautions may damage the pyrolyzer unit, resulting in inaccurate gas detection.

CAUTION After you receive the pyrolyzer unit, start using the pyrolyzer immediately.

<Precautions for Installation Sites>

 Install the pyrolyzer unit near the base unit, gas detector head GD-70D series. Since the pyrolyzer
unit is a precision device like the gas detector head, the precautions for installation sites shall conformto those of the gas detector head. (See the operating manual for the GD-70D series.)< Precautions for System Designing > An unstable power supply and noise may cause malfunctions or false alarms.
 The designing of a system using the pyrolyzer unit must reflect the contents of the operating manualof the base unit, gas detector head GD-70D series, and the descriptions in this section.

Using a stable power supply
The pyrolyzer unit must be provided with the following power supply.
Power supply voltage

Allowed time of
momentary blackout
Others24 VDC 10% (the terminal voltage of the pyrolyzer unit)
Up to 10 millisecond(To recover from the momentary blackout for 10 milliseconds or more, restart thepyrolyzer unit.)
To ensure continuous operation and activation, install a UPS outside the pyrolyzer unit.
Do not use it with a power supply of large power load or high-frequency noise.
Use a line filter to avoid the noise source if necessary.
- 11 -

Heat radiation designing

Do not block the ventilation holes when you install the pyrolyzer unit on or under the gas detector head.
It is recommended that installation points of the sets should be away from each other for 10 mm or more.
Intervals between installation points must be at least 5 mm.
When it is installed in the closed instrumentation board, attach ventilation fans above and below theboard.

CAUTION When the internal temperature of the pyrolyzer unit reaches about 60C, a trouble alarm is issued
by the gas detector head, resulting in a halt of the pyrolyzer heater. Since the internal
temperature rises to ten-odd degrees higher than the ambient temperature, take care not to let
the ambient temperature exceed 40C. Provide a clearance of 30 mm or more above thepyrolyzer unit to prevent a rise in the internal temperature.

2-2. Installation of pyrolyzer unit
CAUTION Install the pyrolyzer unit near the base unit, gas detector head GD-70D series. See thedescriptions in this section and the gas detector head GD-70D series operating manual before
carrying out installation.
 Before installing the pyrolyzer unit, remove the protective rubber caps from GAS IN and GAS
OUT. If the pyrolyzer unit turned on with the rubber caps remaining while the installation, applied
overload may damage the pump and sensor. Do not forget to remove the caps.

- 12 -

<Install Dimension and Maintenance Space>
Leave the diagonal line area so that the installation space is reserved.

(170)

(300)
(30)

(150)

When installing by using 2 screws

Maintenance space

PLU-70(Left)

Maintenance spacetalling by using 3 screws

Maintenance space

Maintenance space

Gas detector
head(Right)PLU-70(Left)CAUTION(Unit: mm)

Maintenance space

Maintenance space

Gas detector
head(Right) The installation points of the pyrolyzer unit PLU-70 and the gas detector head GD-70D series
should be away from each other for 80 5 mm (with a clearance of 5 to 15 mm).
It is recommended that installation points of the sets should be away from each other for 10 mm
or more. Intervals between installation points must be at least 5 mm.
 The PLU-70 must be installed on the LEFT of the gas detector head GD-70D series.

- 13 -

<Installation of Wall-mounted Unit>
Attach the wall-mounted unit in the installation surface using two or three M5 screws.

Recommended mounting screw
Length of 8 mm or more
Flat washer of Φ10 mm or less (small round)

After the wall-mounted unit is attached to the wall, install the PLU main unit on the wall-mounted unit.

CAUTION Install the unit so that its surface is in intimate contact with the wall-mounted unit. A space
between the unit and the wall-mounted unit may invite unnecessary vibrations and noises.

<Detaching and Attaching PLU Main Unit>
10mm

Attaching PLU Main Unit
At the position of 10 mm above the wall-mounted unit, press the
PLU main unit onto the wall-mounted unit. Be sure to fit both side
hooks of the wall-mounted unit in the grooves of the PLU mainunit.
Then press down the PLU main unit to fix it. The lock at thebottom of the PLU main unit clicks to fix it properly. Make surethat the top center of the wall-mounted unit is above the PLU
main unit as viewed from front.

When pressing the PLU mainunit, align the side mark with thehook of the wall-mounted unit forsmooth installation.
Make sure that the top of thewall-mounted unit is above the
PLU main unit.

The lock clicks.
- 14 -

Detaching PLU Main Unit
While pushing the sky blue lever toward the wall-mounted unit,
hold up the PLU main unit.
If you cannot move the PLU main unit, insert a larger flatheadscrewdriver while pushing the lever, and you can easily detach it
as shown below. Do not rotate or move up and down the flatheadscrewdriver. Simply insert it into the wall-mounted unit.

CAUTION Be careful not to drop the PLU main unit when
detaching it. Also, check the secure installation of the
PLU main unit after attaching it to the wall-mounted
unit. If the PLU main unit is not securely installed, it
might fall, causing an unexpected injury or a damageof the unit.
 Turn the power off before detaching or attaching the
PLU main unit.

- 15 -

2-3. How to wire
CAUTION Be careful not to mistake the wall-mounted unit of the pyrolyzer unit with that of the gas detector head
GD-70D series because they have different numbers of terminals (2P for the PLU-70 and 10P for thegas detector head).
 Install wiring for the pyrolyzer unit in the same way as for the gas detector head. For "Specifications ofTerminal Plate," "How to Connect to Terminal Plate," "How to Clamp Cables," and "Grounding," seethe operating manual of the gas detector head GD-70D series and install wiring accordingly.

<Figure of Terminal Plate>
1

2

+

24VDC

Use the dedicatedhandling lever.

<Connecting to the Gas Detector Head>
Connect the PLU-70 and the gas detector head using a dedicated communication cable extending from the PLU-70.

Left side
PLU-70

Right side
Gas detector head
GD-70D

Dedicated
communication cableInstall the PLU-70 on the left and the gas detector head on
the right when viewed from the front.
Before making the connection, ensure that the PLU
communication connector on the gas detector head is readyfor use.
The dedicated communication connector is a lock type.
Check that the connector is firmly locked when you attach it.
Unlock the connector before you detach it.
<Communication Cable Connector>
Lock

Insert the dedicatedcommunication cable
into the connector of
the gas detector head.
- 16 -

CAUTION

 Do not hang the communication cable.
 The communication cable connector has a lock feature. Unlock the connector before you detach it.
Pulling out a locked connector may result in a trouble such as breaking of the wire.

NOTE<Use of the PLU Communication Connector on the Gas Detector Head GD-70D Series> Insert a small flathead screwdriver into a gap where the lug of the communication connector cover is
protruding, and pull it up in the direction of an arrow in the figure to remove it. Be careful not to damage theconnector pins inside by pushing in the flathead driver.
 The communication connector cover is a one-piece component of covers for a dedicated communication
cable for the PLU and a LAN cable. Since the cover can be easily split, use it in a way that suits your needs.
Keep the cover attached to the connector while it is not connected.
 When you attach the cover, first fit the lug to the gas detector head base unit and then push in the cover.

- 17 -

2-4. How to tube

 Install tubes between the pyrolyzer unit and the gas detector head GD-70D series, putting thepyrolyzer unit in front of the gas detector head.
 Like the gas detector head, the pyrolyzer unit has a Rc1/4 thread inside of the sampling
inlet/outlet (GAS IN, GAS OUT), to which polypropylene unions are normally attached. Connect
the tubes basically in the same way as for the gas detector head. (See the operating manual for
the GD-70D series.)<Connecting to the Gas Detector Head>
To use the gas detector head GD-70D series and the pyrolyzer unit PLU-70 in combination, install tubes torealize a flow in the following direction:GAS IN -> PLU-70 -> Gas detector head GD-70D series -> GAS OUT. Please use the dedicated U-tube supplied with the pyrolyzer to connect between the PLU-70 and the gas
detector head (between the PLU-70 OUT and the gas detector head IN).

BottomGAS INGAS OUT

Right side
Gas detector head

Left side
PLU-70From the PLU-70 to the gas detector head
(Dedicated flow path)

CAUTION Making incorrect tube connections may result in inaccurate gas detection. Double-check the tube
connections for errors.
No error message is displayed in particular even if the dedicated U-tube is connected incorrectly(i.e., from the gas detector head to the PLU-70).
 Use the dedicated U-tube supplied with the pyrolyzer unit to connect between the PLU-70 andthe gas detector head. Using other components invalidates the warranty of the performance.
- 18 -

2-5. Relocate
When the pyrolyzer unit is relocated, select a new place in accordance with "Precautions for installation site"and "2-2. Installation of pyrolyzer unit".
For information on wiring and tubing, see "2-3. How to wire" and "2-4. How to tube". The unpowered timemust be minimized when the pyrolyzer unit is relocated.

CAUTION When you use a relocated or stopped/stored detector again, do not forget to perform a gas
calibration. For information on readjustment including gas calibration, please contact our sales
department.

2-6. Disposal
When the pyrolyzer unit is disposed of, it must be treated properly as an industrial waste in accordance withthe local regulations.

- 19 -

3

How to Operate
3-1. Preparation for start-up
Before connecting a power supply, read and understand the following precautions. Ignoring theseprecautions may cause an electric shock or damage the pyrolyzer unit.
 Check that the pyrolyzer unit and the base unit, gas detector head GD-70D, are connected properly (using
dedicated cables and tubes).
 Connect the pyrolyzer unit to a grounding circuit.
 Check that the wiring (power supply wiring) is connected to external power source properly.
 Check that the power supply voltage is compliant with the specifications.
 Check that the dust filter is attached properly.

3-2. How to start the pyrolyzer unit
 Before turning on the power switch, check that the pyrolyzer unit
is installed properly.
 The power switch is protected by a cover to prevent access to it
in a normal time. To turn ON/OFF the power switch, rotate theswitch cover. (Return the switch cover to the original position
after the switching is completed.) Turn ON the power switch.
The power lamp blinks (and starts to stay lit in an hour).
When the switch coveris closed

When the switch coveris openON

Pyrolyzer unit connection indicator First turn on the power switch of the pyrolyzer unit PLU-70, andthen turn on the power of the base unit, gas detector head
GD-70D series. Check that the gas detector head enters theinitial clear status and has been started.
 During the start-up procedure, check that the pyrolyzer unit
connection indicator appears on the LCD display of the gas
detector head.

- 20 -

<Start-up Procedures (Gas Detector Head)>

Initial Clear

PW

A1

A2

F

LCD

●

○

○

○

──────

PW:POWER
A1:ALM1A2:ALM2
F:FAULT●:Lamp on○:Lamp off

WARM UP↓↓

Gas
Specifications
Display

●

○

○

○

30.0ppm
NF3↓↓

Detection Mode

●

○

○

○

0.0ppmNF3

NOTE
Conduct the operation procedures after start-up using the base unit, gas detector head. For specificoperation procedures, see the operating manual of the gas detector head GD-70D series.

CAUTION The pyrolyzer unit must be warmed up until the pyrolyzer reaches a specified temperature and isstabilized.
Warm up the pyrolyzer unit for about one hour when you use it for the first time or have not used
it for a long period (The power lamp on the pyrolyzer unit blinks for one hour after power-on).
 Additionally, the gas detector head (sensor unit) also must be warmed up. Warm up the gas
detector head at the same time as the pyrolyzer unit.
(See the operating manual for the GD-70D series.)

3-3. How to exit
To turn off the pyrolyzer unit, open the switch cover on the bottom of the PLU main unit, and turn "OFF" thepower switch. Then, turn off the power supply (24 VDC) to the pyrolyzer unit.

 To turn off the pyrolyzer unit, first turn off the power of the base unit, gas detector head GD-70D
series, in a reverse procedure to turning on the pyrolyzer unit. (See the operating manual for the
GD-70D series.) If you turn off the pyrolyzer unit before the gas detector head, a trouble alarm (pyrolyzer
abnormalities) is issued.

- 21 -

4

Regular Maintenance Mode
You can check the data (parameters) of the pyrolyzer unit using the menu in the maintenance mode of thegas detector head. The data is displayed on the LCD of the gas detector head.

<Pyrolyzer Heater Data Display "2-11">
Maintenance Mode (Operation on the Gas Detector Head)User ModeIn "1-8.M MODE", press the
SET key.

PW

A1

A2

F

LCD

●

○

○

○

1- 8

PW: POWER
A1: ALM1
A2: ALM2
F: FAULTM MODE●: Lamp on○: Lamp off

MAINTENANCE↓↓

Regular MaintenanceMode
2-11.PL DATAIn “2-11. PL DATA”, press the
SET key.

●

○

○

2-11

○

PL DATA
MAINTENANCE↓
PL-0.PL TEMPShow the temperature of thepyrolyzer unit.

↓
●

○

○

PL- 0

○

PL TEMP→SET

25.0CPL TEMP

MAINTENANCE

MAINTENANCE↓ ↑▼▲PL-1.PL FLOWShow the present flow rate in
the pyrolyzer heater (PL-70).
(Specified flow rate = 0.3L/min)

●

○

○

PL- 1

○

PL FLOW→
SET

MAINTENANCE

0.30
L/M
MAINTENANCE↓ ↑▼▲PL-2.PL H.TEMPShow the setting
temperature of the pyrolyzer
heater (PL-70).

●

○

○

PL- 2

○

PL H.TEMPMAINTENANCE

↓ ↑▼

▲

- 22 -

→
SET

800C
PL H.TEMPMAINTENANCE

↓ ↑▼

▲
PL-3.PL POW
Show the present electric
power of the pyrolyzer
heater (PL-70).

●

○

○

PL- 3

○

PL POW→
SET

MAINTENANCE

14725
PL POW
MAINTENANCE↓ ↑▼▲PL-4.PL VOLTShow the present voltage ofthe pyrolyzer heater (PL-70).

●

○

○

PL- 4

○

PL VOLT→
SET

MAINTENANCE

9500mVPL VOLT
MAINTENANCE↓ ↑▼▲PL-5.PL CUR
Show the present current of
the pyrolyzer heater (PL-70).

●

○

○

PL- 5

○

PL CUR→
SET

MAINTENANCE

1550mAPL CUR
MAINTENANCE↓ ↑▼▲PL-6.PL 3.3V
This is internal information of
the pyrolyzer unit. Used for
diagnosis of abnormalities, etc.

●

○

○

PL- 6

○

PL 3.3V
MAINTENANCE↓ ↑▼▲PL-7.PL 5.0V
This is internal information of
the pyrolyzer unit. Used for
diagnosis of abnormalities, etc.

●

○

○

PL- 7

○

PL 5.0V
MAINTENANCE↓ ↑▼▲PL-8.PL VER
Show the program version of
the pyrolyzer unit.

●

○

○

PL- 8

○

PL VER
MAINTENANCE↓ ↑▼▲PL-9.PL F AD1
This is internal information of
the pyrolyzer unit. Used for
diagnosis of abnormalities, etc.

●

○

○

PL- 9

○

PL F AD1
MAINTENANCE↓ ↑▼▲PL-10. PL F AD2This is internal information of
the pyrolyzer unit. Used for
diagnosis of abnormalities, etc.

●

○

○

PL-10

○

PL F AD2
MAINTENANCE↓↑

To- 23 -▲▼
PL-0.PL TEMP

→
SET

01234
56AB
MAINTENANCE

5

Maintenance
The pyrolyzer unit should be used in combination with the base unit, gas detector head GD-70D series. The
pyrolyzer unit is an important instrument for the purpose of safety as the gas detector head. To maintain theperformance of the pyrolyzer unit and improve the reliability of safety, perform a regular maintenance on it
as well as the gas detector head. For maintenance procedures, see the operating manual of the gas
detector head GD-70D series.

5-1. Gas calibration method
Perform a gas calibration in the maintenance mode (zeroadjustment mode and span adjustment mode) of the gas detector
head using the calibration gas.
 Zero adjustment gas (collected in a gas sampling bag) Span adjustment gas (collected in a gas sampling bag) Gas sampling bags

Calibrationgas

GAS OUTGAS IN

Exhaustgas

NOTE
For specific operation procedures in the zero adjustment mode and the span adjustment mode, see theoperating manual of the gas detector head GD-70D series.

- 24 -

5-2. Other adjustments/Cleaning method<Cleaning of Detector>
Clean the pyrolyzer unit if it becomes extremely dirty. The pyrolyzer unit must be turned off while cleaning it.
Use a waste cloth to remove dust. Do not use water or organic solvent for cleaning because they may
cause malfunctions.
Because an extremely large amount of dust inside the tube may disturb the gas detection, it must be
cleaned with dry AIR, etc.

5-3. How to replace parts<Replacement of Regular Replacement Parts>
List of recommended regular replacement parts
No.

Item

1
2
3

Flow sensor
Fan
Pyrolyzer
heater

Maintenanceintervals
1 year
0.5 years-

Replacement
intervals
5 year2 - 4 years
2 - 4 years

Quantity(pieces/unit)
2
1
1

NOTE

 The above replacement intervals are recommendation only. The intervals may change depending on theoperating conditions. These intervals do not mean the warranty periods either. The result of the regular
maintenance may determine when to replace the parts.
 Replace the elbow at the same time as replacing the pyrolyzer heater.

Replacement of Flow Sensor, Fan, and Pyrolyzer Heater
After the flow sensor, fan, or pyrolyzer heater is replaced, the operation must be checked by a qualified
service engineer.
For the stable operation of the pyrolyzer unit and safety, ask a qualified service engineer to take care of
replacement of the parts that operation must be checked. Please contact our sales department.

5-4. Procedures to store the pyrolyzer unit or leave it
for a long time
The pyrolyzer unit must be stored under the following environmental conditions.
 In a dark place under the normal temperature and humidity away from direct sunlight In a place where gases, solvents or vapors are not present

CAUTION
When you use a relocated or stopped/stored detector again, do not forget to perform a gas calibration.
For information on readjustment including gas calibration, please contact our sales department.

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6

Troubleshooting
The troubleshooting does not explain the causes of all the malfunctions which occur on the pyrolyzer unit.
This simply helps to find the causes of malfunctions which frequently occur. If the pyrolyzer unit shows asymptom which is not explained in this manual, or still has malfunctions even though remedial actions aretaken, please contact our sales department.

CAUTION
This section describes troubleshooting on the pyrolyzer unit PLU-70. For information on generaltroubleshooting on the base unit, gas detector head, see the operating manual of the gas detector head
GD-70D series.

<Pyrolyzer Unit Abnormalities>
Symptom

CausesActions

Impossible Power ON

The power switch is turned off.
Abnormalities/momentary
blackout of power supply
systemTurn ON the power switch.
Provide the rated voltage.
Check the UPS, power supply line filter and insulationtransformer, and then take additional measures.
Check that the PLU main unit is properly attached to thewall-mounted unit.
Check the wiring of detector and related devices aroundit.

Abnormal Operations

Pyrolyzer
Abnormalities<<On the Gas Detector
Head>>- E-7 PL UNIT
displayed- FAULT lamp on

Improper installation of the
PLU main unit
Cable abnormalities (opencircuit/not connected/shortcircuit)Disturbances by sudden surge
noise, etc.
PLU-70 power is not turned on.
The dedicated communication
cable to the gas detector headis not connected or improperly
connected.
Abnormalities inside thepyrolyzer heater such asabnormal overheating of thepyrolyzer heater or stop of thefan(Rapid blinking of the pyrolyzer
unit power lamp).
The dedicated communication
cable has been connected by
mistake to a gas detector headthat does not need the PLU-70
as per its specifications.

Turn off and restart the pyrolyzer unit.
If such a symptom is observed frequently, takeappropriate measures to eliminate the noise.
Turn ON the power switch.
Check that the dedicated communication cable isconnected and the cable connector is securely fastened.
Check that nothing is hanging on the pyrolyzer fan andthat no foreign matter has got stuck in the fan. If it gets
hot inside a closed panel, install a fan on the panel itself
or take other necessary measure for heat dissipation.
In the case of a pyrolyzer heater or fan failure, pleasecontact our sales department because parts replacement
is required.
Reconnect the cable to a gas detector head that needs
the PLU as per its specifications (such as NF3).

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SymptomCausesA sensor unit that does notneed the PLU-70 as per its
specifications has been
installed by mistake.

Actions
Replace the sensor unit installed on the gas detector
head with a sensor unit that needs the PLU (such as
NF3).

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