Trolex Sentro 1 TX6351 User manual

P5536.1600 rev D 1
TX6351 • TX6352
Sentro 1 Universal Gas Detector
Leading safety technology
User Manual

TX6351 • TX6352 User Manual
P5536.1600 rev D 3
TX6351 • TX6352 Sentro 1 Universal Gas Detector
Contents
1. Product Overview 4
1.1 Operating Features 4
1.2 Application 5
1.3 Product Options 5
1.4 Dimensions 6
1.5 Technical Information 7
1.6 Electrical Details 9
1.7 Sentro eModules 11
2. Certification 18
2.1 Newer Sentro 1 Models with Red
Labels (designated .35) 18
2.2 Older Sentro 1 Models with
Yellow Labels (not designated
.35) 20
3. Installation 23
3.1 Safety Precautions 20
3.2 Tools and Test
Equipment Required 24
3.3 Siting Recommendations 25
3.4 Connections 26
3.4.1 0.4 to 2 V / 2 to 10 V Analogue
Output Signal 26
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
4. Setup and Calibration 31
4.1 Controls and Indicators 31
4.2 Main Display 33
4.3 Security Code Access 34
4.4 Main Menu 35
4.4.1 Calibrate 36
4.4.2 Sentro 1 Setup 39
4.4.3 Output Setup 41
4.4.4 Modbus 44
4.4.5 Module Setup 44
4.4.6 Support 47
5. Diagnostics and
Maintenance 48
5.1 Diagnostic Messages 48
5.2 Maintenance 49
5.3 Maintenance and
Calibration Log 52
5.4 Disposal 53
Disclaimers 53
Trademarks 54
Contact Details 54
Document History 54

4 P5536.1600 rev D
1. Product Overview
TX6351 3/4 wire device with separate output signal and power lines.
Can be used with any Sentro eModule
TX6352 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

TX6351 • TX6352 User Manual
P5536.1600 rev D 5
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
Supply Voltage: 12 V dc from an
approved power source
Type of protection:
Intrinsically safe. Ex ia
Category: I M1
General Purpose
TX6351.03
TX6352.03
Supply Voltage: 24 V dc
1.3 Product Options
Mining Ex ia
Certification Certification
Four-wire connection
(older models with yellow
labels)
(newer models with red
labels)
TX6351.01i
0.4 - 2.0 V dc .11 .35.05
4 - 20 mA .12 .35.19
Dual Relay NC .14
Dual Relay NO .17
IECEx (AUS) GrpI EAC GrpI ATEX/IECEx GrpI MASC GrpI
.06 MASC/IECEx GrpI
.14 ATEX/IECEx/UKEX GrpI .19
.05RS-485 .15
TX6352.01i Two-wire line powered
4 - 20 mA loop .12
General Purpose
Four-wire connection Button configuration
TX6351.03.00
4-20mA .12 Internal buttons .01
Dual Relay NC .14 External buttons .02
Dual Relay NO .17
RS-485 .15
2-10Vdc .16
TX6352.03.00 Two-wire line powered
4 - 20 mA .12

6 P5536.1600 rev D
1.4 Dimensions

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P5536.1600 rev D 7
1.5 Technical Information
Ambient temperature limits -20 to +40 °C
Storage temperature -20 to +60 °C
Ambient pressure 800 to 1100 mbar
Humidity 15 % to 90 % non-condensing
Protection classification Dust and waterproof to IP65. Gas Port: IP54.
Housing material Reinforced polymer with static charge dissipation
Nett weight 530 g
Cable entries 2 x M20
Electrical connections 4 mm barrier/clamp terminals
Conductors A maximum of two per terminal
Conductor size A maximum of 2.5 mm²
Terminal torque 2.4 Nm maximum
Information display 128 x 64 dot graphic backlit LCD
Vibration limits Vibration limits (IEC 60079-29-1):
• 10 to 30 Hz - 1.00 mm total excursion
• 31 to 150 Hz - 19.6 m/s2acceleration peak
Impact limits 20 joules (housing)
Calibration and setup Digitally controlled ZERO and SPAN pushbutton
setting
Signal fix The analogue output signal of the sensor is fixed
during calibration to prevent false alarms from
being initiated
Fault indication 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
Key coding Coding stops prevent insertion of a non-valid
sensing module.

8 P5536.1600 rev D
Alarms 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.
STEL and TWA 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
Output signals 0.4 to 2 V / 2 to 10 V
4 to 20 mA
Dual relay contacts. NO or NC to specification
RS485 Modbus datacomms

TX6351 • TX6352 User Manual
P5536.1600 rev D 9
1.6 Electrical Details
General Purpose
TX6351 3/4 wire. Remote powered
4 to 20 mA analogue output
Supply voltage: 18 to 28 V
Max. line load: 500 Ω at 24 V
Type of sensor: Toxic Flammable Infrared
Supply current: 40 mA 40 mA 60 mA
TX6351 3/4 wire. Remote powered
Dual output contacts NC/NO
Supply voltage: 20 to 28 V
Type of sensor: Toxic Flammable Infrared
Supply current: 35 mA 45 mA 60 mA
TX6351 3/4 wire. Remote powered
RS485 datacomms output
Supply voltage: 14 to 28 V
Line: Modbus protocol
Type of sensor: Toxic Flammable Infrared
Supply current: 40 mA 40 mA 60 mA
TX6352 2 wire. Line powered
4 to 20 mA analogue output
Supply voltage: 18 to 28 V
Max. Line Load: 300 Ω
Type of Sensor: Toxic only
TX6351 3/4 wire. Remote powered
2 to 10 V analogue output
Supply voltage: 14 to 28 V
Minimum line load: 10 KΩ
Type of sensor: Toxic Flammable Infrared
Supply current @ 24 V: 20 mA 60 mA 80 mA

10 P5536.1600 rev D
Mining and Tunnelling
TX6351 3/4 wire. Remote powered
4 to 20 mA analogue output
Supply voltage: 10 to 14 V
Max. line load: 220 Ω maximum @ 12 V dc
Type of sensor: Toxic Flammable Infrared
Supply current @ 12 V: 48 mA 70 mA 91 mA
TX6351 3/4 wire. Remote powered
Dual output contacts NC/NO
Supply voltage: 10 to 14 V
Type of sensor: Toxic Flammable Infrared
Supply current @ 12 V: 60 mA 85 mA 105 mA
TX6351 3/4 wire. Remote powered
RS485 datacomms output
Supply voltage: 10 to 14 V
Line: Modbus protocol
Type of sensor: Toxic Flammable Infrared
Supply current @ 12 V: 25 mA 60 mA 80 mA
TX6351 3/4 wire. Remote powered
0.4 to 2 V analogue output
Supply voltage: 10 to 14 V
Min. line load: 10 KΩ
Type of sensor: Toxic Flammable Infrared
Supply current @ 12 V: 20 mA 60 mA 80 mA
TX6352 2 wire. Line powered
4 to 20 mA analogue output
Supply voltage: 10 to 14 V
Max. line load: 90 Ω
Type of sensor: Toxic only

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P5536.1600 rev D 11
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:

12 P5536.1600 rev D
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.
TX6350 .240 .246 .244
Methane CH
4
Methane CH
4
Methane CH
4
Sensing element Poison resistant pellistor with active temperature compensation
Sensing range 0 to 100% LEL
based on 4.4%v/v
0 to 4% v/v 0 to 5% v/v
Linearity Linear up to 3% v/v 3% to 5% ±0.25%
Max. Drift @ 25°C ±0.25% CH4 v/v per month
*Response time t(63) <15 secs
*Response time t(90) <20 secs
Sensing element life >5 years in clean atmosphere
Warm up time <5 mins in air or 1% v/v CH4
Stabilisation time ≥15 mins
GENERAL alarm 10% LEL (.240) 0.40% (.246) 0.50% (.244)
HIGH alarm 25% LEL (.240) 1.00% (.246) 1.25% (.244)
* Response times are tested by owing 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.
Section 4.4.5

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P5536.1600 rev D 13
oxic 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.
TX6350 .250.50 .250.250 .250.300 .250.500 .251 .252
Carbon
Monoxide
CO
Carbon
Monoxide
CO
Carbon
Monoxide
CO
Carbon
Monoxide
CO
Hydrogen
Sulphide
H
2
S
Sulphur
Dioxide
SO
2
Sensing
element Electrochemical cell
Sensing range 0 to
50 ppm
0 to
250 ppm
0 to
300 ppm
0 to
500 ppm
0 to
50 ppm
0 to
20 ppm
Linearity ±2% FS
Drift 2% per month
Repeatability ±2%
*Response
time t(63) <20 secs <30 secs <20 secs
*Response
time t(90) <30 secs <45 secs <30 secs
Operating life 2 years
Relative
humidity 15 to 90% non-condensing
Operating
temperature -10 to +40°C
GENERAL
alarm 18 ppm 38 ppm 45 ppm 75 ppm 8 ppm 3 ppm
HIGH alarm 15 ppm 75ppm 90 ppm 150 ppm 15 ppm 6 ppm
STEL & TWA 200 ppm 200 ppm 200 ppm 200 ppm 10 ppm 1 ppm
30 ppm 30 ppm 30 ppm 30 ppm 5 ppm 0.5 ppm
* Response times are tested by owing test gas using the calibration kit referred to in section 5.2
Maintenance.
Section 4.4.5

14 P5536.1600 rev D
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.
TX6350 .254 .254.10 .257 .259 .261
Nitrogen
Dioxide
NO
2
Nitrogen
Dioxide
NO
2
Oxygen
O
2
Nitric Oxide
NO Hydrogen H
2
Sensing element Electrochemical Cell
Sensing range 0 to 20 ppm 0 to 10
ppm 0 to 25% 0 to 50 ppm 0 to 1000 ppm
Linearity ±2% FS ±0.3% vol ±5% FS ±2% FS
Drift 2% per month 10%
per year 2% per month
Repeatability ±2%
*Response time
t(63) <20 secs N/A <20 secs <30 secs
*Response time
t(90) <30 secs <60 secs <30 secs <40 secs
Operating life 2 years 2 years 2 years
Relative humidity 15 to 90% non-condensing
Operating
temperature -10 to +40°C
GENERAL
alarm 3 ppm 1.5 ppm 19% (under) 8 ppm 150 ppm
HIGH alarm 6 ppm 3 ppm 23% (over) 15 ppm 300 ppm
STEL & TWA 1 ppm 1 ppm N/A 10 ppm N/A
0.5 ppm 0.5 ppm N/A 25 ppm N/A
* Response times are tested by owing test gas using the calibration kit referred to in section 5.2
Maintenance.
Section 4.4.5

TX6351 • TX6352 User Manual
P5536.1600 rev D 15
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 aect 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 eect 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.

16 P5536.1600 rev D
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 .243 .245 .242 .278.2 .278 .279
Methane
CH
4
Methane
CH
4
Methane
CH
4
Carbon
Dioxide
CO
2
Carbon
Dioxide
CO
2
Carbon
Dioxide
CO
2
Sensing element Infrared
Sensing range
0 to
5% v/v
0 to
100% LEL
0 to
100% v/v
0 to
2% v/v
0 to
5% v/v
0 to
100% v/v
Zero drift
±0.05% v/v
per month
±1% LEL
per month
±0.5% v/v
per month ±0.05% v/v per month ±1% v/v per month
Repeatability ±0.1% v/v ±2% LEL ±2% v/v ±0.05% v/v ±2% v/v
*Response time
t(63)
<15 secs
*Response time
t(90)
<30 secs
Operating life <5 years
Relative humidity 15 to 90% non-condensing
Operating
temperature
-10 to +40°C
GENERAL
alarm
0.5% v/v 10% LEL 10% v/v 0.3% v/v 0.75% v/v 15% v/v
HIGH alarm 1.25% v/v 25% LEL 25% v/v 0.6% v/v 1.5% v/v 30% v/v
* Response times are tested by owing test gas using the calibration kit referred to in section 5.2
Maintenance.

TX6351 • TX6352 User Manual
P5536.1600 rev D 17
Checkpoint - Carbon Dioxide Sensors
Normal atmosphere contains carbon dioxide which will aect 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.

18 P5536.1600 rev D
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

TX6351 • TX6352 User Manual
P5536.1600 rev D 19
Product Code:
Ex Certificate Number:
Ex Certification Code:
TX6351.01i.xx.35.19
Sentro 1 CML 20ATEX2271X
IECEx CML 20.0158X
CML 21UKEX2323X
I M1
Ex ia I Ma
-20 °C ≤ Ta ≤ +40 °C
TX6352.01i.12.35.19
Sentro 1
TX6351.01i.xx.35.05
Sentro 1
MASC M/21-8496 X
IECEx CML 20.0158X
Ex ia I Ma
-20 °C ≤ Ta ≤ +40 °C
TX6352.01i.12.35.05
Sentro 1
The following Safety Description applies to the equipment listed above:
Model No.
Power Input
Output type
Output
TX6351.01i.11.35
Terminal 5 w.r.t. 6
Ui = 14.4V
Ci = 0
Li = 0
0.4V – 2V
Terminal 1 w.r.t. 2 or 3
Ui = 14.4V
Uo = 14.4V
Io = 40mA
Po = 0.135W
Ci = 0
Li = 0
TX6351.01i.12.35 4mA – 20mA
Terminal 1 w.r.t. 2 or 3
Ui = 14.4V
Uo = 14.4V
Io = 0.477A
Po = 1.72W
Ci = 0
Li = 0
TX6351.01i.15.35 RS485
Terminal 1 w.r.t. 3 (RS485 A)
Terminal 2 w.r.t. 3 (RS485 B)
Parameters for each output:
Ui = 6.88 V
Ci = 0
Li = 0
Uo = 5.88 V
Io = 66 mA
Po = 97 mW
TX6351.01i.14.35 Relays NC
Terminal 1 w.r.t. 2 (Relay 1)
Terminal 3 w.r.t. 4 (Relay 2)
Ui = 30 V
Ci = 0
Li = 0
Uo = 0
Io = 0
Po = 0
TX6351.01i.17.35 Relays NO
Terminal 1 w.r.t. 2 (Relay 1)
Terminal 3 w.r.t. 4 (Relay 2)
Ui = 30 V
Ci = 0
Li = 0
Uo = 0
Io = 0
Po = 0
TX6352.01i.12.35
Terminal 1 w.r.t. 2
Ui = 14.4V
Ci = 0
Li = 0
Loop powered N/A

20 P5536.1600 rev D
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:
ГОСТ 31610.0-2014 (IEC 60079-0:2011)
ГОСТ IEC 60079-1:2013
ГОСТ 31610.11-2014 (IEC 60079-11:2011)
ГОСТ МЭК 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