TROLEX TX6351 Sentro 1 Universal Gas Detector User Manual

TX6351 Sentro 1 Universal Gas Detector

Product Information

Product Overview| Operating Features| Application| Product Options| Dimensions| Technical Information
---|---|---|---|---|---
Fixed point gas detection for safety monitoring in hazardous
areas and general purpose applications.| – 3/4 wire device with separate output signal and power
lines.
– Can be used with any Sentro eModule.
– 2-wire line powered 4 to 20 mA output signal.
– Can ONLY be used with electrochemical Sentro eModules.| Underground Mining and Tunnelling Ex ia I Ma
General Purpose| – Supply Voltage: 12 V dc from an approved power source (Type
of protection: Intrinsically safe. Ex ia, Category: I M1)
– Supply Voltage: 24 V dc (Mining Ex ia)
– Four-wire connection (0.4 – 2.0 V dc, 4 – 20 mA, Dual Relay NC,
Dual Relay NO, RS-485)
– Two-wire line powered (4 – 20 mA loop)| Dimensions: Not specified in the text extract.| – Ambient temperature limits
– Storage temperature
– Ambient pressure
– Humidity
– Protection classification
– Housing material
– Nett weight
– Cable entries
– Electrical connections
– Conductors
– Conductor size
– Terminal torque
– Information display
– Vibration limits
– Impact limits
– Calibration and setup
– Signal fix
– Fault indication
– Key coding

Product Usage Instructions

Setup and Calibration

1. Connect the product to the power source according to the
specified supply voltage.

2. If using a four-wire connection, ensure the appropriate
voltage or current output signal is selected based on the
requirements of the application.

3. If using a two-wire line powered connection, ensure the
electrochemical Sentro eModule is properly connected.

4. Set up the main display by accessing the main menu and
configuring the desired settings.

5. Access the security code to ensure authorized access to the
product’s features.

6. Calibrate the product by selecting the “Calibrate” option in
the main menu and following the calibration procedure provided in
the user manual.

7. Set up any additional options or modules required for
specific applications, such as Sentro eModules or Modbus.

Diagnostics and Maintenance

1. Monitor diagnostic messages displayed on the information
display to identify any issues or faults with the product.

2. Perform regular maintenance tasks as outlined in the user
manual to ensure optimal performance and longevity of the
product.

3. Keep a maintenance and calibration log to track any
maintenance activities performed on the product.

4. Dispose of the product properly according to local
regulations and guidelines.

Contact Details

If you require further assistance or have any questions
regarding the product, please contact our support team using the
following contact details:

Phone: [Phone Number]

Email: [Email Address]

User Manual

TX6351 · TX6352 Sentro 1 Universal Gas Detector

Leading safety technology

P5536.1600 rev D 1

TX6351 · TX6352 User Manual

TX6351 · TX6352 Sentro 1 Universal Gas Detector Contents

1. Product Overview

4 4. Setup and Calibration

31

1.1 Operating Features

4 4.1 Controls and Indicators

31

1.2 Application

5 4.2 Main Display

33

1.3 Product Options

5 4.3 Security Code Access

34

1.4 Dimensions

6 4.4 Main Menu

35

1.5 Technical Information

7 4.4.1 Calibrate

36

1.6 Electrical Details

9 4.4.2 Sentro 1 Setup

39

1.7 Sentro eModules

11 4.4.3 Output Setup

41

2. Certification

18 4.4.4 Modbus

44

2.1 Newer Sentro 1 Models with Red

4.4.5 Module Setup

44

Labels (designated .35)

18 4.4.6 Support

47

2.2 Older Sentro 1 Models with

5. Diagnostics and

Yellow Labels (not designated

Maintenance

48

.35)

20 5.1 Diagnostic Messages

48

3. Installation

23 5.2 Maintenance

49

3.1 Safety Precautions

20 5.3 Maintenance and

3.2 Tools and Test

Calibration Log

52

Equipment Required

24 5.4 Disposal

53

3.3 Siting Recommendations

25 Disclaimers

53

3.4 Connections

26 Trademarks

54

3.4.1 0.4 to 2 V / 2 to 10 V Analogue

Contact Details

54

Output Signal

26 Document History

54

3.4.2 4 to 20 mA Analogue

Output Signal

27

3.4.4 Contact Output Signal

28

3.4.5 RS485 Data Output Signal 29

3.5 Connecting in Hazardous

Areas

30

P5536.1600 rev D 3

1. Product Overview

TX6351 TX6352

3/4 wire device with separate output signal and power lines. Can be used with any Sentro eModule
2-wire line powered 4 to 20 mA output signal. Can ONLY be used with electrochemical Sentro eModules

1.1 Operating Features
· Fixed sensor for detection of Toxic Gases and Flammable Gases · Exclusive pre-calibrated plug-in gas sensing modules for many types of gas · LCD readout and visual LED alarm indicators · Choice of output signal format · Heavy duty housing to IP65 · EMC compliant · STEL and TWA monitoring for selected gases

4

P5536.1600 rev D

TX6351 · TX6352 User Manual
1.2 Application
Fixed point gas detection for safety monitoring in hazardous areas and general purpose applications.

Underground Mining and Tunnelling Ex ia I Ma
TX6351.01i TX6352.01i
General Purpose TX6351.03 TX6352.03
1.3 Product Options

Supply Voltage: 12 V dc from an approved power source
Type of protection: Intrinsically safe. Ex ia
Category: I M1
Supply Voltage: 24 V dc

TX6351.01i TX6352.01i

Mining Ex ia

Four-wire connection

0.4 – 2.0 V dc

.11

4 – 20 mA

.12

Dual Relay NC

.14

Dual Relay NO

.17

RS-485

.15

Two-wire line powered

4 – 20 mA loop

.12

Certification

Certification

(older models with yellow

(newer models with red

labels)

labels)

IECEx (AUS) GrpI

.06 MASC/IECEx GrpI

EAC GrpI

.14 ATEX/IECEx/UKEX GrpI

ATEX/IECEx GrpI

.19

MASC GrpI

.05

.35.05 .35.19

General Purpose

Four-wire connection

Button configuration

TX6351.03.00

4-20mA Dual Relay NC Dual Relay NO

.12 Internal buttons

.01

.14 External buttons

.02

.17

RS-485

.15

2-10Vdc

.16

TX6352.03.00 Two-wire line powered

4 – 20 mA

.12

P5536.1600 rev D 5

1.4 Dimensions

6

P5536.1600 rev D

1.5 Technical Information

TX6351 · TX6352 User Manual

Ambient temperature limits Storage temperature Ambient pressure Humidity Protection classification Housing material Nett weight Cable entries Electrical connections Conductors Conductor size Terminal torque Information display Vibration limits
Impact limits Calibration and setup
Signal fix
Fault indication
Key coding

-20 to +40 °C
-20 to +60 °C
800 to 1100 mbar
15 % to 90 % non-condensing
Dust and waterproof to IP65. Gas Port: IP54.
Reinforced polymer with static charge dissipation
530 g
2 x M20
4 mm barrier/clamp terminals
A maximum of two per terminal
A maximum of 2.5 mm²
2.4 Nm maximum
128 x 64 dot graphic backlit LCD
Vibration limits (IEC 60079-29-1): · 10 to 30 Hz – 1.00 mm total excursion · 31 to 150 Hz – 19.6 m/s2 acceleration peak
20 joules (housing)
Digitally controlled ZERO and SPAN pushbutton setting
The analogue output signal of the sensor is fixed during calibration to prevent false alarms from being initiated
Under range signal transmitted and fault display for: · Loss of communications from the sensing
module · Sensing module absent for more than 10
seconds · Sensor over-range protect
Coding stops prevent insertion of a non-valid sensing module.

P5536.1600 rev D 7

Alarms STEL and TWA Output signals

Programmable GENERAL alarms and HIGH alarms with an LED indicator. The two adjustable alarm setpoints are preset during manufacture to default values appropriate to the type of sensor, determined by the sensing module being used.
Automatic setting of STEL and TWA limits to EH40 standards. STEL: Exposure over 15-minute successive periods TWA: Exposure over a continuous rolling 8-hour period
0.4 to 2 V / 2 to 10 V 4 to 20 mA Dual relay contacts. NO or NC to specification RS485 Modbus datacomms

8

P5536.1600 rev D

1.6 Electrical Details

TX6351 · TX6352 User Manual

General Purpose TX6351
Supply voltage: Max. line load: Type of sensor: Supply current:

3/4 wire. Remote powered

4 to 20 mA analogue output

18 to 28 V

500 at 24 V

Toxic

Flammable

40 mA

40 mA

Infrared 60 mA

TX6351
Supply voltage: Type of sensor: Supply current:

3/4 wire. Remote powered

Dual output contacts NC/NO

20 to 28 V

Toxic

Flammable

35 mA

45 mA

Infrared 60 mA

TX6351
Supply voltage: Line: Type of sensor: Supply current:

3/4 wire. Remote powered

RS485 datacomms output

14 to 28 V

Modbus protocol

Toxic

Flammable

40 mA

40 mA

Infrared 60 mA

TX6352
Supply voltage: Max. Line Load: Type of Sensor:

2 wire. Line powered 4 to 20 mA analogue output 18 to 28 V 300 Toxic only

TX6351

3/4 wire. Remote powered

2 to 10 V analogue output

Supply voltage:

14 to 28 V

Minimum line load:

10 K

Type of sensor:

Toxic

Flammable

Supply current @ 24 V: 20 mA

60 mA

Infrared 80 mA P5536.1600 rev D 9

Mining and Tunnelling TX6351
Supply voltage: Max. line load: Type of sensor: Supply current @ 12 V: TX6351
Supply voltage: Type of sensor: Supply current @ 12 V: TX6351
Supply voltage: Line: Type of sensor: Supply current @ 12 V: TX6351
Supply voltage: Min. line load: Type of sensor: Supply current @ 12 V: TX6352
Supply voltage: Max. line load: Type of sensor:

3/4 wire. Remote powered

4 to 20 mA analogue output

10 to 14 V

220 maximum @ 12 V dc

Toxic

Flammable

48 mA

70 mA

3/4 wire. Remote powered

Dual output contacts NC/NO

10 to 14 V

Toxic

Flammable

60 mA

85 mA

3/4 wire. Remote powered

RS485 datacomms output

10 to 14 V

Modbus protocol

Toxic

Flammable

25 mA

60 mA

3/4 wire. Remote powered

0.4 to 2 V analogue output

10 to 14 V

10 K

Toxic

Flammable

20 mA

60 mA

2 wire. Line powered 4 to 20 mA analogue output 10 to 14 V 90 Toxic only

Infrared 91 mA
Infrared 105 mA
Infrared 80 mA
Infrared 80 mA

10

P5536.1600 rev D

TX6351 · TX6352 User Manual 1.7 Sentro eModules
Plug-in pre-calibrated modules with standardised output data.
· Each module stores all the necessary data about its type identification, sensing range and specific calibration. This data is automatically recognised by Sentro when the module is loaded into the module bay.
· The modules are pre-calibrated so can be substituted at any time by a replacement module ­ usually of the same type, but an alternative may be inserted if required.
· Insert coding stops to prevent non-valid module combinations. · The sensing module will identify itself when plugged into the sensor housing and
auto configuration will take place. · All Sentro Modules have two output alarm signals for GENERAL alarm and HIGH
alarm. Default values are entered during manufacture and these can be changed to preferred values. · The alarm signals can be set to illuminate built-in flashing LED indicators. · The signals can operate the two GENERAL alarm and HIGH alarm relays on the CONTACT OUTPUT version of Sentro 1. · Service replacement modules can be specified using the appropriate gas type code from the eModule order reference table on the datasheet · The order reference is also marked on the back of the eModules. · The order reference may vary for some eModules dependent upon the year of manufacture of the base unit:
P5536.1600 rev D 11

Flammable gases · Poison resistant catalytic sensor

INDICATIVE VALUES ONLY, OTHER RANGES AND CALIBRATIONS CAN BE

SUPPLIED TO SPECIFICATION

The sensor can be configured to respond to many flammable

gases and vapours. It is usual to calibrate to methane in terms of %LEL or %volume.

Section 4.4.5

TX6350

.240

.246

.244

Sensing element Sensing range
Linearity Max. Drift @ 25°C Response time t(63) Response time t(90) Sensing element life Warm up time Stabilisation time GENERAL alarm HIGH alarm

Methane CH4

Methane CH4

Methane CH4

Poison resistant pellistor with active temperature compensation

0 to 100% LEL based on 4.4%v/v

0 to 4% v/v

0 to 5% v/v

Linear up to 3% v/v

3% to 5% ±0.25%

±0.25% CH4 v/v per month

<15 secs

<20 secs

5 years in clean atmosphere

<5 mins in air or 1% v/v CH4

15 mins

10% LEL (.240)

0.40% (.246)

0.50% (.244)

25% LEL (.240)

1.00% (.246)

1.25% (.244)

• Response times are tested by flowing test gas using the calibration kit referred to in section 5.2 Maintenance.

Checkpoint
Not suitable for use with the TX6352 4 to 20 mA two wire, line powered version of Sentro.

Checkpoint
The pellistor is automatically protected against exposure to excessively high concentrations of gas.

12

P5536.1600 rev D

TX6351 · TX6352 User Manual

Toxic gases · Electrochemical cells

INDICATIVE VALUES ONLY, OTHER RANGES AND CALIBRATIONS CAN BE

SUPPLIED TO SPECIFICATION

Selected toxic gas modules are equipped with automatic

STEL/TWA calculation in accordance with EH40.

Section 4.4.5

TX6350
Sensing element Sensing range
Linearity Drift Repeatability Response time t(63) Response time t(90) Operating life Relative humidity Operating temperature GENERAL alarm HIGH alarm
STEL & TWA

.250.50 Carbon Monoxide
CO 0 to 50 ppm
18 ppm 15 ppm 200 ppm 30 ppm

.250.250
Carbon Monoxide
CO

.250.300
Carbon Monoxide
CO

.250.500
Carbon Monoxide
CO

Electrochemical cell

.251
Hydrogen Sulphide
H2S

.252
Sulphur Dioxide
SO2

0 to 250 ppm

0 to

0 to

300 ppm 500 ppm

±2% FS

2% per month

±2%

0 to 50 ppm

0 to 20 ppm

<20 secs

<30 secs <20 secs

<30 secs

<45 secs

2 years

15 to 90% non-condensing

<30 secs

-10 to +40°C

38 ppm
75ppm 200 ppm 30 ppm

45 ppm
90 ppm 200 ppm 30 ppm

75 ppm
150 ppm 200 ppm 30 ppm

8 ppm
15 ppm 10 ppm 5 ppm

3 ppm
6 ppm 1 ppm 0.5 ppm

• Response times are tested by flowing test gas using the calibration kit referred to in section 5.2 Maintenance.

P5536.1600 rev D 13

Toxic gases · Electrochemical cells – continued

INDICATIVE VALUES ONLY, OTHER RANGES AND CALIBRATIONS CAN BE

SUPPLIED TO SPECIFICATION

Selected toxic gas modules are equipped with automatic

STEL/TWA calculation in accordance with EH40.

Section 4.4.5

TX6350
Sensing element Sensing range Linearity
Drift
Repeatability Response time t(63) Response time t(90) Operating life Relative humidity Operating temperature GENERAL alarm HIGH alarm
STEL & TWA

.254

.254.10

.257

.259

.261

Nitrogen Dioxide
NO2

Nitrogen Dioxide
NO2

Oxygen O2

Nitric Oxide NO

Electrochemical Cell

Hydrogen H2

0 to 20 ppm

0 to 10 ppm

0 to 25%

0 to 50 ppm

0 to 1000 ppm

±2% FS

±0.3% vol

±5% FS

±2% FS

2% per month

10% per year

2% per month

±2%

<20 secs

N/A

<20 secs

<30 secs

<30 secs 2 years

<60 secs

<30 secs

<40 secs

2 years 15 to 90% non-condensing

2 years

-10 to +40°C

3 ppm
6 ppm 1 ppm 0.5 ppm

1.5 ppm
3 ppm 1 ppm 0.5 ppm

19% (under)
23% (over) N/A N/A

8 ppm
15 ppm 10 ppm 25 ppm

150 ppm
300 ppm N/A N/A

• Response times are tested by flowing test gas using the calibration kit referred to in section 5.2 Maintenance.

14

P5536.1600 rev D

TX6351 · TX6352 User Manual
Checkpoint Toxic gas Sentro eModules have a very low power consumption, enabling 4 to 20 mA two wire TX6352 line-powered version of Sentro to be used.
Checkpoint All values listed are nominal and slight variations may occur depending upon operating conditions. · The natural level of oxygen available in the atmosphere is influenced by relative humidity
and temperature. The oxygen sensor will react to these changes. · Sudden changes in atmospheric pressure will also cause temporary instability in
electrochemical sensors which may exceed 60 seconds. · Long periods of use in extremely high or low humidity may affect the response of the
sensor and shorten the life of electrochemical sensors. · Nitric oxide sensors must be continuously powered to maintain calibration stability. If
power has been absent for more than 10 minutes, it may take 24-48 hours for the sensor to restore stability. Do not calibrate until the output signal is steady. · The presence of high levels of carbon dioxide (over 5%) may have a minor effect on the accuracy of the oxygen sensor.
Checkpoint Periodic calibration of the gas sensor should be carried out whilst it is in service. For oxygen and carbon monoxide gas sensors Trolex recommends that this is carried out every three weeks. For other gas sensors Trolex recommends that this is carried out in accordance with best practice for the industry where the gas sensor is being used, and should take into consideration local operating conditions.
P5536.1600 rev D 15

Carbon Dioxide/Methane Gases · Infrared sensor INDICATIVE VALUES ONLY, OTHER RANGES AND CALIBRATIONS CAN BE SUPPLIED TO SPECIFICATION The sensor is highly specific to the selected gas and exhibits consistent sensing accuracy with superior long-term stability.
The linear response means that it can be calibrated for low gas concentrations and high concentrations up to 100% by volume.

TX6350
Sensing element Sensing range Zero drift Repeatability

.243
Methane CH4
0 to 5% v/v ±0.05% v/v per month ±0.1% v/v

.245
Methane CH4
0 to 100% LEL ±1% LEL per month ±2% LEL

.242

.278.2

.278

Methane CH4

Carbon Dioxide
CO2

Infrared

Carbon Dioxide
CO2

0 to 100% v/v

0 to 2% v/v

0 to 5% v/v

±0.5% v/v per month

±0.05% v/v per month

±2% v/v

±0.05% v/v

.279 Carbon Dioxide
CO2
0 to 100% v/v ±1% v/v per month ±2% v/v

*Response time t(63)

<15 secs

*Response time t(90)
Operating life
Relative humidity

<30 secs
<5 years 15 to 90% non-condensing

Operating temperature

-10 to +40°C

GENERAL alarm
HIGH alarm

0.5% v/v 1.25% v/v

10% LEL 25% LEL

10% v/v 25% v/v

0.3% v/v 0.6% v/v

0.75% v/v 1.5% v/v

15% v/v 30% v/v

• Response times are tested by flowing test gas using the calibration kit referred to in section 5.2 Maintenance.

16

P5536.1600 rev D

TX6351 · TX6352 User Manual
Checkpoint – Carbon Dioxide Sensors Normal atmosphere contains carbon dioxide which will affect the sensor signal so nitrogen gas must be used to accurately calibrate the zero value. Power should be applied to the sensor and the nitrogen applied for at least 5 minutes to ensure that the sensor has stabilised. Checkpoint Not suitable for use with the TX6352 4 to 20 mA two wire, line powered version of Sentro 1.
P5536.1600 rev D 17

2. Certification and Conformity
2.1. Newer Sentro 1 models with red label (designated .35)
ATEX certification for use in underground mines (Group I) in European Union. Complies with ATEX Directive 2014/34/EU. Standards: EN IEC 60079-0:2018 EN 60079-11:2012
UKEX certification for use in underground mines (Group I) in Great Britain (England, Scotland and Wales). Complies with UK Regulations 2016 S.I. 2016/1107 Standards: EN IEC 60079-0:2018 EN 60079-11:2012
IECEx (International) certification for use in underground mines (Group I). Standards: IEC 60079-0:2017 IEC 60079-11:2011
MASC IA certification for use in underground mines (Group I) in South Africa. Standards: IEC 60079-0:2017 IEC 60079-11:2011

18

P5536.1600 rev D

TX6351 · TX6352 User Manual

Product Code: TX6351.01i.xx.35.19
Sentro 1 TX6352.01i.12.35.19
Sentro 1 TX6351.01i.xx.35.05
Sentro 1 TX6352.01i.12.35.05
Sentro 1

Ex Certificate Number: CML 20ATEX2271X IECEx CML 20.0158X CML 21UKEX2323X
MASC M/21-8496 X IECEx CML 20.0158X

Ex Certification Code: I M1
Ex ia I Ma -20 °C Ta +40 °C
Ex ia I Ma -20 °C Ta +40 °C

The following Safety Description applies to the equipment listed above:

Model No.

Power Input

TX6351.01i.11.35

TX6351.01i.12.35

TX6351.01i.15.35

Terminal 5 w.r.t. 6 Ui = 14.4V Ci = 0 Li = 0

TX6351.01i.14.35

TX6351.01i.17.35

TX6352.01i.12.35

Terminal 1 w.r.t. 2 Ui = 14.4V Ci = 0 Li = 0

Output type 0.4V ­ 2V
4mA ­ 20mA RS485
Relays NC Relays NO

Output

Terminal 1 w.r.t. 2 or 3

Ui = 14.4V

Uo = 14.4V

Io = 40mA

Po = 0.135W

Ci = 0

Li = 0

Terminal 1 w.r.t. 2 or 3

Ui = 14.4V

Uo = 14.4V

Io = 0.477A

Po = 1.72W

Ci = 0

Li = 0

Terminal 1 w.r.t. 3 (RS485 A)

Terminal 2 w.r.t. 3 (RS485 B)

Parameters for each output:

Ui = 6.88 V Uo = 5.88 V

Ci = 0

Io = 66 mA

Li = 0

Po = 97 mW

Terminal 1 w.r.t. 2 (Relay 1)

Terminal 3 w.r.t. 4 (Relay 2)

Ui = 30 V

Uo = 0

Ci = 0

Io = 0

Li = 0

Po = 0

Terminal 1 w.r.t. 2 (Relay 1)

Terminal 3 w.r.t. 4 (Relay 2)

Ui = 30 V

Uo = 0

Ci = 0

Io = 0

Li = 0

Po = 0

Loop powered N/A

P5536.1600 rev D 19

The following Specific Conditions of Use apply to the certificates listed above: · The cable entries to the supply and output terminals shall be made via cable glands which provide a minimum degree of protection of IP54. · Under certain extreme circumstances, unearthed metal parts of the enclosure may store an ignition-capable level of electrostatic charge. The equipment shall either be earthed via the integral earthing terminal or the user/installer shall implement precautions to prevent the build-up of electrostatic charge. When not earthed, the capacitance of the metallic label to earth is >10pF.
2.2 Older Sentro 1 models with yellow label (not designated .35)
ATEX certification for use in underground mines (Group I) in European Union. Complies with ATEX Directive 2014/34/EU. Standards: EN 60079-0:2012 EN 60079-11:2012

IECEx (International) certification for use in underground mines (Group I) in Australia (including New South Wales) and New Zealand. Standards: IEC 60079-0:2011 IEC 60079-11:2011
EAC certification for use in underground mines (Group I) in Eurasian Customs Union (including Russia). Standards: 31610.0-2014 (IEC 60079-0:2011) IEC 60079-1:2013 31610.11-2014 (IEC 60079-11:2011) 60079-25-2012
MASC IA certification for use in underground mines (Group I) in South Africa. Standards: SANS (IEC) 60079-0:2012 SANS (IEC) 60079-11:2012

20

P5536.1600 rev D

Product Code: TX6351.01i.xx.19
Sentro 1 TX6352.01i.12.19
Sentro 1 TX6351.01i.xx.06
Sentro 1 TX6352.01i.12.06
Sentro 1 TX6351.01i.xx.06
Sentro 1 TX6352.01i.12.06
Sentro 1 TX6351.01i.xx.05
Sentro 1 TX6352.01i.12.05
Sentro 1

TX6351 · TX6352 User Manual

Ex Certificate Number:
Sira 09ATEX2352X IECEx SIR 09.0147X

Ex Certification Code:
I M1 Ex ia I Ma -20 °C Ta +40 °C

IECEx ITA 14.0006X

Ex ia I Ma -20 °C Ta +40 °C

RU C-GB.AA87.B.0015819

PO Ex ia I Ma X -10 °C Ta +40 °C

MASC M/11-419X

Ex ia I Ma -20 °C Ta +40 °C

The following Specific Conditions of Use apply to the IECEx ITA 14.0006X certificate:

· The following safety parameters are applicable to the Sentro 1 Sensors/Transmitters:

Model

Terminals

Input Parameters Ui Ii Pi Ci Li

5 wrt 6 14.4V 1 – 2 *3

TX6351.01i.11

1 wrt (2 or 3)

–

–

–

–

–

5 wrt 6 14.4V 1 – 2 *3

TX6351.01i.12

1 wrt (2 or 3)

–

–

–

–

–

5 wrt 6 14.4V 1 – 2 *3

TX6351.01i.15

1 wrt 2 2 wrt 3

6.88V *1

–

0 0

TX6351.01i.14 TX6351.01i.17

5 wrt 6 1 wrt 2 3 wrt 4

14.4V 1 30V 1 30V *1

–

2 3 0 0 0 0

TX6352.01i.12

1 wrt 2

14.4V 1 – 2 *3

Output Parameters

Uo Io

Po Co Lo*5

–

–

–

–

–

14.4V 40mA 135mW *4 292mH

–

–

–

–

–

14.4V 447mA 1.72W *4 2.1mH

–

–

–

–

–

5.88V 66mA 97mW *4 26mH

–

–

0

0

0

0

–

–

–

–

–

0

0

0

0

0

0

–

0

0

1 ­ li 2 ­ Ci Ci
3 ­ Li 4 ­ Co
*5 ­ Lo

Not critical Ci = 0, unless a rModule is connected to the Sentro 1, then Ci=0.38uF plus the
of the external sensors connected to the rModule. Total Li of all external sensors and equipment connected to the rModule. 1uF, unless the conditions stated in 60079-11:2011, Clause 10.1.5.2 part b can be satisfied. Is calculated using the formula ½ Lo(lo*1.5)²=525uJ.

For Specific Conditions of Use, Safety Description and parameters for intrinsically safe systems applicable to other certificates, please refer to the individual certificates listed above.

P5536.1600 rev D 21

Installation of equipment The installation of the product must only be carried out by competent personnel. Each installation needs to be considered with reference to the local safety regulations and authorities. Refer to the following standards for additional guidance:
– IEC/EN 60079-14 – IEC/EN 60079-25 Refer to the Certification Section of this User Manual and to the relevant certificates for any installation parameters and special conditions of safe use.
Commissioning / verification tests prior to first use.
Prior to commissioning and first use, the product shall be inspected for any visible damages and integrity of the enclosure. Never use the product that has damaged housing in hazardous locations.
Maintenance
The maintenance of the product must only be carried out by competent personnel. Maintenance shall be considered with reference to the local safety regulations and authorities. Refer to the following standards for additional guidance:
– IEC/EN 60079-17
It is recommended to periodically check the condition of the product.
The product shall only be serviced and repaired by Trolex Ltd or a local Trolex service agent approved by Trolex Ltd in order to maintain the explosion protection of the product.

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3. Installation
3.1 Safety Precautions
It is recommended that users refer to EN / IEC 60079-29-2 for guidance on the selection, installation, use and maintenance of detectors for flammable gases and oxygen, when installed in hazardous areas.
Hazardous areas Do not disassemble the sensor whilst in the hazardous area or use a sensor that has a damaged housing in the hazardous area. Irrespective of the gas being monitored, the equipment must not be installed where there is possibility of an oxygen enriched atmosphere.
Evacuation If a dangerous level of gas concentration is detected by the instrument, leave the area immediately.
Operating Life of Gas Sensors Electrochemical cells contain an electrolyte that is gradually consumed during use. The average life is about two years, dependant upon the duty cycle. The response should be checked at regular intervals.
Sensitivity Electrochemical cells for toxic gases can be affected by other interfering gases which may displace the subject gas being monitored. Steam laden atmospheres and condensation can also reduce the sensitivity.
Flammable Be aware that some toxic gases are also `flammable’ at high percentage concentrations.
Operating Limits of Catalytic Combustion Sensors Catalytic combustion sensors positively detect the presence of flammable gas. They rely upon the presence of oxygen in the atmosphere and should only be used for gas concentration up to the Lower Explosive Limit (LEL). After this point, the output becomes non- linear and may erroneously indicate that the gas concentration is below the LEL. They should not be used in oxygen enriched or deficient atmospheres.
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Discrimination Catalytic combustion sensors can detect a wide range of flammable gases but they cannot discriminate between individual gases. They will respond to most, or all, of the flammable components present in the atmosphere without distinguishing between them.

The table below shows the response variation of the catalytic combustion sensor on exposure to a range of gases and vapours at the same %LEL concentration. The figures are experimentally derived and expressed relative to the methane signal (=100).

Gas/Vapour Methane Propane n-Butane n-Pentane n-Hexane Acetylene

Relative sensitivity 100 70 70 60 60 85

Gas/Vapour Carbon Monoxide Hydrogen Ammonia Cyclohexane Ethylene

Relative sensitivity 130 120 155 55 90

Infrared sensors are highly specific to the defined gas type and may not respond to other similar gases.

Contamination The response of catalytic combustion gas sensors can be affected by air borne contaminants which will reduce the sensitivity. Substances such as silicones, tetraethyl lead, sulphur compounds and phosphate esters can cause permanent degradation (poisoning). Halogenated hydrocarbons may also cause temporary inhibition.

Interference If the atmosphere to be monitored contains a gas that dilutes or displaces the air, this may reduce the response of catalytic sensors. Similarly, steam laden atmospheres and condensation can reduce the stability.

High Concentrations of Flammable Gas Exposure of low concentration catalytic combustion sensors to concentrations of flammable gas greater than the LEL can affect the sensitivity and zero stability of catalytic elements and the calibration should be checked after such an exposure.

Toxicity Be aware that most flammable gases and vapours are also toxic at low concentrations of LEL.

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3.2. Tools and Test Equipment Required
No special tools are needed.
3.3. Siting Recommendations
Location of Gas Detectors Each installation needs to be considered in its own right, with reference to safety authorities and in compliance with mandatory local safety regulations. The sensor must be operated in accordance with the User Manual to maintain safety, reliability and to preserve safety integrity where applicable. It is important that sensors are located in positions determined in consultation with those who have specialised knowledge of the plant or installation and of the principles of gas dispersion. Reference should also be made to those responsible for the engineering layout and topology of the plant as they will be most familiar with the nature of the potential dangers and the most likely sources of gas release. It is also important to recognise that the characteristics of the gas source can be influenced by many factors; including the relative density or buoyancy of the gas, the pressure at the point of release, the ambient temperature and the ventilation of the site. Sensor coverage cannot be simply expressed in terms of `number per unit area’. Sensors need to be sited where they are capable of monitoring those parts of a plant where gas may accumulate or where a source of gas release is expected to occur. This way, the earliest possible warning of a gas release can be given to initiate shutdown functions, alarm functions or safe evacuation of the premises.
Sensor Management A very important part of an efficient gas monitoring system is the training of plant personnel in operation and maintenance of the sensors and the complete monitoring system. Training can be provided by qualified Trolex application engineers. Once a sensor installation is complete, the sensor locations and types should be formally recorded and a planned test and maintenance procedure instituted.
STEL and TWA Specific gas sensors are equipped to automatically set STEL and TWA limits in accordance with EH40 standards. Only gases with a listed EH40 STEL or TWA value have this function enabled by default.
If the function is enabled for use, ensure that all accumulated data is reset to zero before the commencement of a working period.
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3.4 Connections
3.4.1 0.4 to 2 V / 2 to 10 V Analogue Output Signal
A low impedance two-wire voltage output signal requiring a separate power supply to the sensor. 12 V dc power can usually be derived from the monitoring instrument being used. The connection configuration works well up to 5-100 m distance between the sensor and the monitoring equipment, dependent on cabling and sensor current consumption. Both the signal and the power supply to the sensor are being carried in the common 0 V conductor so at some point ­ influenced by the length of the cable and the resistance of the cable cores ­ the current flowing in the 0 V conductor will impose an unacceptable voltage error onto the signal.
This effect can be reduced on long distance connections by increasing the size of the cable cores, or even better, by running a separate 0 V conductor to power the sensor enabling operating distances up to 1,000 m.
Alternatively, the sensor may be powered by a suitable power source close by.

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TX6351 · TX6352 User Manual 3.4.2 4 to 20 mA Analogue Output
Signal
TX6351 The output signal from terminals 1 and 2 is a conventional 4 to 20 mA two wire current regulated signal loop.
TX6352 (Toxic Sentro eModules only) The output signal from terminals 1 and 2 is a conventional 4 to 20 mA two wire current regulated signal loop. Electrochemical cells have very low power consumption so the same loop can be used to also power the sensor. No separate power supply is needed. Checkpoint The TX6352 version of Sentro is NOT suitable for flammable gas and infrared Sentro eModules.
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3.4.4 Contact Output Signal
Dual independent output contacts for remote signalling and control. Setpoint values for GENERAL alarm and HIGH alarm are setup during manufacture to prescribed levels appropriate to the type of gas intended to be monitored; determined by the gas sensing module.
The setpoints may be adjusted to preference.
Section 4.4.3
Checkpoint The relay contacts are clearance compatible for use with other intrinsically safe circuits emanating from different IS power sources.
Available with Normally Open or Normally Closed contacts.
TX6351.03.14 Normally Open (NO) TX6351.01i.14 Normally Open (NO)
TX6351.03.17 Normally Closed (NC) TX6351.01i.17 Normally Closed (NC)

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3.4.5 RS485 Data Output Signal
RS485 serial data output with analogue signal intelligence. Use in conjunction with a PC for data display and setpoint alarm warnings. Up to 32 sensors acting as slaves can communicate with the master unit on a single data cable. The address code of the sensor is marked on the duty label of the sensor.

Physical layer:

RS485

Protocol:

Trolex proprietary

Connection mode: Modbus

Number of points: 32

Maximum distance: 1,000 m

Recommended cable (specified in BS5308 Part 1) for locally powered sensors:

· 1 twisted pair

·

0.5 mm2

· Overall screen

Recommended cable for sensors that are powered through the data cable:

· 2 twisted pair

·

0.5 mm2

· Individual/overall screen

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Intrinsically Safe
Apparatus
Hazardous Area

3.5 Connecting in Hazardous Areas
Certified Intrinsically Safe for use in mining hazardous areas, category M1, when used with approved monitoring apparatus.
Power for the sensor must be derived from an approved 12 V dc power supply e.g. TX6642 Intrinsically Safe Power Supply or approved apparatus.
The installation must be in accordance with the Sentro certification parameters.

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4. Setup and Calibration
4.1 Controls and Indicators

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4.2 Main Display

TX6351 · TX6352 User Manual
Power On

NEXT/FUNCTION

SELECT/CHANGE

Checkpoint Next/Function is the Left hand key (L) and Select/Change is the Right hand key (R).

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Main Menu
Press the R key to enter the Main Menu Section 4.3
Section 4.4
Checkpoint The front cover of Sentro may be safely removed, for setup in a hazardous area, even with the power applied.
4.3 Security Code Access
A security code may be requested: Press the R key to change the digit Use the L key to increment the digits

Use the R key to select Enter and return to the Main Menu
Section 4.4

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4.4 Main Menu
(L) Prompt Bar
Calibrate Section 4.4.1
Sentro 1 Setup Section 4.4.2
Output Setup Section 4.4.3
Modbus Setup Section 4.4.4
Module Setup Section 4.4.5

TX6351 · TX6352 User Manual
Checkpoint Sentro will automatically return to the Main Display if no commands are given within 1 minute. The time limit is extended to 8 minutes during calibration to allow the gas value to stabilise.
(R)
Zero Set Test Gas Span
System Information Display Setup Alert Setup Set Security Code Exit Output Information Trim Output Zero Trim Output Span Reset Output Set Relay 1 Mode Set Relay 2 Mode Exit
Modbus Address Baud Rate TX On Delay TX Off Delay Exit
Setpoint 1 Setpoint 2 STEL/TWA Exit
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4.4.1 Calibrate
Connect a Gas Test Kit equipped with both `clean air’ and the appropriate test gas canisters.

Calibrate Zero
· Follow the prompt bar and screen instructions

Section 5.2

· Go to Span

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Calibrate Span using a Test Gas of EXPECTED value
· Follow the prompt bar and screen instructions
· Key Done and return to the Main Display
Press L and R together to quit and return to the main display. P5536.1600 rev D 37

Calibrate Span using a Test Gas of DIFFERENT value The display will show the concentration of Span Gas that is EXPECTED to be used. Set the expected value to agree with the actual Test Gas value:
· Follow the prompt bar and screen instructions
Press R to continue with the normal span calibration (previous page)

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4.4.2 Sentro 1 Setup

TX6351 · TX6352 User Manual

The basic functional characteristics of the sensor can be setup, or reviewed, from a choice of parameters.

System Information Display

Display Setup · The display backlight illumination may be set to on, or off, to reduce power consumption. (TX6351 only)
· The contrast of the display may be set for best visual appearance.

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Alert Setup (TX6351 only) · The integral GENERAL and HIGH visual alarms can be set to ON or OFF. · The `confidence’ condition flash can be set to ON or OFF.
Set Security Code · A four digit security code can be entered to prevent unauthorised access to the setup menu.

0000 = Security protection OFF

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4.4.3 Output Setup

TX6351 · TX6352 User Manual

The output signal format can be reviewed and setup to preferred values.

Output Information

· This is the factory setting of the output signal

· Confirm acceptance.

Trim Output Zero

· The level of the transmitted output

signal, when the sensor is measuring

a

Zero gas concentration can be

trimmed or offset.

Trim Output Span

· The level of the transmitted output

signal when the sensor is measuring

a

given Span can be trimmed or offset.

Reset Output
· Reset the Zero and Span output signal levels to the original default settings.

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Relay 1 Function Mode Relay 2 Function Mode
· This item will appear in the menu on the Contact Output version only.
· The operating function of each relay can be independently setup.

Checkpoint
The general relay function will be reversed when monitoring oxygen deficiency (i.e. the relay will de-energise when the measured gas concentration recedes from the setpoint value).

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To Reset a Latched Relay Press L to view Relay Status

TX6351 · TX6352 User Manual

Checkpoint A Relay will stay LATCHED if the initiating signal has not receded.

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4.4.4 Modbus
RS485 Output · The protocol characteristics required for the Modbus datacomms version can be setup. Sentro can then be integrated into a wider communication network or to interface with a PC or SCADA system.

Data Protocol Addresses Format Databits Stopbits Parity
Baud Rate
TX On TX Off Duplex

Modbus 1 to 255 Binary 8 1 None 300/600/1200/2400/4800/9600/ 14400/19200/28800/38400/57600/115200 0 to 99 ms 0 to 99 ms Half

4.4.5 Module Setup

The functional characteristics of the Sentro eModule may be setup to preference.

Change Setpoint 1 Change Setpoint 2

· The Sentro Module provides two adjustable setpoint output signals
· When setpoint 1 (General) is activated, the LED alarm indicators in the display window flash simultaneously at a rate of about once every two seconds. When setpoint 2 (high) is activated, they flash simultaneously at a
rate of about 2 per second.

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· The Activation mode and operating level of the setpoints can be setup to preference.

Checkpoint · The setpoint output signal data will also be available for transmission on the RS485 Modbus version of Sentro.
Checkpoint · The Contact Output version of Sentro 1 is also equipped with two relays

· The Activation will operate in the same way · The Relay Function mode can also be setup

Section 4.4.3 P5536.1600 rev D 45

STEL and TWA
· Toxic gas sensing Sentro eModules are equipped to automatically calculate STEL and TWA limits in accordance with international EH40 recommendations
· The Alert can be set to ON or OFF
· The accumulated STEL and TWA data can be reset to zero ready for the start of a new working period.

Checkpoint · STEL OVER or TWA OVER will be displayed when limits are exceeded.
· If the visual alarm has been enabled then this will also activate at level 1 when a STEL or TWA limit
is exceeded.
· For a contact output version, the STEL and TWA alert will also initiate the Activate command for Relay 1.

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If you need technical support to operate this product, or would like details of our after sales technical support packages, contact service@trolex.com.
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5. Diagnostics and Maintenance
5.1 Diagnostic Messages
Sensor over-range
Loss of signal from the sensor

Pellistor Over · The gas sensing concentration exceeds 100% LEL which is the safe working limit of the sensing element.
· The transmitted output signal from the sensor will be clamped at full scale to prevent ambiguous output data from being transmitted and will latch in this condition
· The pellistor in the gas sensing module will be switched into a PROTECT state to prevent oxidisation damage and will latch in this state.
· Check that the gas concentration has receded, then reset the module by removing it for 2 seconds.

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Module Not Fitted · The eModule has been removed and is out for more than 10 seconds
Checkpoint · Under-range output signal will be transmitted by the sensor.
5.2 Maintenance
Output Signal · Check the accuracy of the sensor at pre-determined intervals by injecting a test gas

Gas Sensing Modules · The Sentro eModules should be changed at regular intervals to ensure the accuracy of response
· Service history is logged within the module and this data is used to periodically assess its condition whenever it is returned for servicing. Simply insert the new module into the instrument and return the original for checking and calibration.

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Gas Inlet Port
· Check the condition and clean with a small brush to remove dust and debris

Checkpoint If the gas inlet port has been exposed to water conditions that exceed the IPx4 rating, dry the sensor and check its response.
Ingress protection (IP) rating does not imply that the equipment will always detect

Annual Safety Check The main sensor unit will not normally require maintenance or calibration, but it is advisable to return it to the Trolex Product Support Department for an annual safety check.
Calibration The Sentro 1 performs an important safety function and periodic calibration is an essential part of maintaining safety integrity. Gas sensors have a known ZERO and SPAN movement related to time, level of exposure to gas, and the nature of the environment, so Trolex recommend that the sensors should be bump tested with a suitable test gas at regular intervals. This should be carried out in accordance with best practice for the industry where the gas sensor is being used.
Trolex Calibration Recommendation Statement · Methane and Hydrocarbon gas sensors often perform an important safety function and periodic calibration is an essential part of maintaining safety integrity. · Pellistor gas sensors have a known ZERO and SPAN movement related to time, level of exposure to gas, and the nature of the environment. · Trolex recommend that these sensors are `Bump Tested’ with a suitable test gas at regular intervals. This should be carried out in compliance with local requirements, or once per month will normally be adequate Calibrate the sensor if necessary, or as a minimum every 6 months, to ensure correct operation · All other gas sensor types should also be bump tested with a suitable test gas at an interval in line with the site I industry health and safety standards and calibrated as necessary, or as a minimum every 6 months, to ensure correct operation.

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Recommended Test Gas Concentration

Gas Sensor Type CH4 (Pellistor) 100% LEL CH4 (Infra Red) CO H2S NO NO2 SO2 CO2
O2

Zero Gas Zero Air Zero Air or Nitrogen 100% Zero Air Zero Air Zero Air Zero Air Zero Air Nitrogen 100%
Nitrogen 100%

Calibration Gas/ balance gas
2.2% v/v CH4 in air 50% to 100% of range CH4 in N2 50% to 100% of range CO in air
50% to 100% of range H2S in air 50% to 100% of range NO in air
50% to 100% of range NO2 in air 50% to 100% of range SO2 in air 50% to 100% of range CO2 in air Clean air, or 50% to 100% of range O2 in N2

Standard test gas canisters are available from our Product Support department and can be supplied in a range of capacities from 34 litres up to 110 litres.
Please call our sales engineers for advice regarding recommended test gas procedures and product support plans.
Test gas equipment may be ordered from Trolex using the order code: P5393.23. The kit is comprised of a 0.5 litre/min gas regulator, pipe-work and gassing hoods.

Checkpoint · CH4 test gas must be combined with balance air if being used to calibrate pellistor
based devices. · 25% O2 cannot be supplied. A maximum concentration of 23% can be supplied.

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5.3 Maintenance and Calibration Log

Order Reference: TX Serial Number: Gas Type:

Date

Scheduled Check

Fault

Date Purchased: Location:

Recalibrate

Change Modules

Return to Trolex

Comments

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5.4 Disposal
Part of the ethos of Trolex is sustainable design. Sentro 1 contains materials that can be recovered, recycled and reused. At the end of its useful life ensure that the Sentro 1 is recycled in accordance with local laws and bylaws for the geographic area where it is located. The end of its useful life is to be determined by the owner/operator of the equipment and not Trolex. Ensure that the Sentro 1 is recycled by licenced waste contractors with the appropriate licences for handling electronic waste in the geographic area where the Sentro 1 is located.
Checkpoint Consult your local Trolex service agent or the Trolex Product Support Department if you require assistance with disposal: service@trolex.com
Disclaimers
The information provided in this document contains general descriptions and technical characteristics of the performance of the product. It is not intended as a substitute for and is not to be used for determining suitability or reliability of this product for specific user applications. It is the duty of any user or installer to perform the appropriate and complete risk analysis, evaluation and testing of the products with respect to the relevant specific application or use. Trolex shall not be responsible or liable for misuse of the information contained herein. If you have any suggestions for improvements or amendments, or find errors in this publication, please notify us at marketing@trolex.com.
No part of this document may be reproduced in any form or by any means, electronic or mechanical, including photocopying, without express written permission of Trolex.
All pertinent state, regional, and local safety regulations must be observed when installing and using this product. For reasons of safety and to help ensure compliance with documented system data, only Trolex or its affiliates should perform repairs to components.
When devices are used for applications with technical safety requirements, the relevant instructions must be followed.
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Trademarks
© 2023 Trolex® Limited.
Trolex is a registered trademark of Trolex Limited. The use of all trademarks in this document is acknowledged.

Document History

Revision

Date

A

25 April 2017

B

29 March 2019

C

25 January 2023

D

06 February 2023

ECR
4483 4828 5416 5429

Contact Details
Trolex Ltd, Newby Road, Hazel Grove, Stockport, Cheshire, SK7 5DY, UK +44 (0) 161 483 1435 sales@trolex.com

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Trolex Ltd. Newby Road, Hazel Grove, Stockport, Cheshire SK7 5DY, UK

t: +44 (0)161 483 1435 e: Sales@trolex.com www.trolex.com

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References

• Trolex – At Trolex, we save lives. 60 years of our pioneering safety technology has helped keep workers protected in even the most challenging environments.

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