Critical Environment Technologies LPT-M Series User manual

Operation Manual
www.critical-environment.com
LPT-M Modbus®Digital Transmitter
Rev. B | 2022.03

2 © 2022 All rights reserved. Data subject to change without notice.
LPT-M - Operation Manual Rev. B | 2022.03
TABLE OF CONTENTS
1 POLICIES .......................................................................................................6
1.1 Important Note .................................................................................................6
1.2 Warranty Policy.................................................................................................7
1.3 Service Policy....................................................................................................7
1.4 Copyrights .........................................................................................................8
1.5 Disclaimer..........................................................................................................9
1.6 Revisions............................................................................................................9
2 INTRODUCTION ...........................................................................................10
2.1 General Description ...................................................................................... 10
2.2 Key Features .................................................................................................. 11
3 INSTRUMENT SPECIFICATIONS..................................................................12
3.1 Technical Specications.............................................................................. 12
3.2 Internal Sensor Gas Types .......................................................................... 15
3.3 ESH-A Remote Sensor Gas Types ............................................................. 16
3.4 Enclosure Dimensions ................................................................................. 17
4 INSTRUMENT FEATURES ............................................................................18
4.1 Exterior Enclosure......................................................................................... 18
4.2 Interior System Layout................................................................................. 20
5 INSTALLATION ............................................................................................21
5.1 Special Considerations for Different Types of Sensors......................... 22
5.2 General Safety Warnings ............................................................................. 23
5.3 Protection Against Electrical Risks............................................................ 23
5.4 Protection Against Mechanical Risks ....................................................... 23
5.5 Mounting the Transmitter............................................................................ 24
5.5.1 Wet Environment Considerations ................................................ 25
5.5.2 EMI and RF Interference Considerations ................................... 25

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5.5.3 Mounting Height (Sensor Dependent) ........................................ 26
5.6 Enclosure Mounting Components............................................................. 27
5.6.1 Enclosure Base................................................................................ 27
5.6.2 Enclosure Bottom ........................................................................... 28
5.7 Wiring Connections ...................................................................................... 28
5.7.1 Power & Output Connections ....................................................... 29
5.7.2 Relay Wiring Connection ............................................................... 31
5.7.3 ESH-A Remote Sensor Wiring Connection................................. 32
5.7.4 Modbus® Wire Gauge vs Run Length ........................................ 33
6 SYSTEM OPERATION & CONFIGURATION...................................................35
6.1 Navigating the Menu Structure .................................................................. 35
6.2 Accessing the Menu with Passcodes....................................................... 36
6.3 Power Up and Warm-up............................................................................... 38
6.4 Display Select................................................................................................. 38
6.5 Set LCD Display Contrast Level.................................................................. 40
6.6 Fault Detection .............................................................................................. 40
6.7 Modbus® Settings........................................................................................ 41
6.7.1 Change Modbus® ID...................................................................... 41
6.7.2 Change Baud Rate .......................................................................... 41
6.7.3 Modbus® Holding Registers ........................................................ 42
6.8 Alarm / Buzzer Operation............................................................................ 42
6.8.1 Enable / Disable Audible................................................................ 43
6.8.2 Audible ON Delay............................................................................. 43
6.8.3 Audible Alarm Level Assignment................................................. 44
6.9 Relay Operation ............................................................................................. 45
6.9.1 Enable / Disable Relay.................................................................... 45
6.9.2 Setting Relay ON / OFF Delay....................................................... 46
6.9.3 Relay Mode of Operation (Normal or FAILSAFE)...................... 47
6.9.4 Relay Alarm Level Assignment..................................................... 48

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LPT-M - Operation Manual Rev. B | 2022.03
6.10 Test Functions............................................................................................. 49
6.10.1 Test Audible / Buzzer................................................................... 49
6.10.2 Test Relay....................................................................................... 49
6.10.3 Test Gas Reading Response / Send Test Reading to
Controller .................................................................................................... 50
6.11 Setting Channel Alarm Setpoints............................................................. 52
6.11.1 Setting the Low Alarm Setpoint................................................. 52
6.11.2 Setting the Mid Alarm Setpoint.................................................. 53
6.11.3 Setting the High Alarm Setpoint ................................................ 53
6.11.4 Setting Hysteresis......................................................................... 54
6.12 Enable / Disable Channels ........................................................................ 55
7 CALIBRATION ..............................................................................................55
7.1 Calibration Specications............................................................................ 55
7.1.1 Gas..................................................................................................... 55
7.1.2 Regulators & Flow........................................................................... 56
7.1.3 Adapters ........................................................................................... 56
7.1.4 Calibration Frequency .................................................................... 56
7.1.5 Gas Testing Frequency (Bump Testing) ..................................... 57
7.1.6 Sticky Gases..................................................................................... 57
7.1.7 Non-Intrusive Calibration............................................................... 57
7.2 Calibrating the Internal Sensor(s) .............................................................. 58
7.3 Troubleshooting Calibration........................................................................ 61
7.3.1 Calibration Adapter Plug................................................................ 61
7.3.2 Zero Calibration Shift...................................................................... 61
7.3.3 Zero - Requires Override................................................................ 61
7.3.4 Span - Requires Override............................................................... 62
7.3.5 Fault Reading................................................................................... 62
7.3.6 Calibration Failure ........................................................................... 62

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7.4 Calibrating an ESH-A Remote Sensor Connected to an LPT-M ........... 63
7.4.1 Zero and Span Calibration of a Responsive ESH-A Remote
Sensor ......................................................................................................... 63
7.4.2 Zero Calibration of a New or Replacement ESH-A Remote
Sensor ......................................................................................................... 63
7.5 Calibrating an Oxygen Sensor .................................................................... 64
8 ACCESSORIES .............................................................................................66
8.1 Splash Guard.................................................................................................. 66
8.2 Calibration Adapter Clip “Cal Clip”.............................................................. 67
8.3 Magnetic Wand ............................................................................................. 67
8.4 Metal Protective Guards.............................................................................. 68
8.5 Calibration Kit................................................................................................. 68
9 MAINTENANCE............................................................................................69
10 TROUBLE SHOOTING.................................................................................70

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LPT-M - Operation Manual Rev. B | 2022.03
1 POLICIES
1.1 Important Note
Read and understand this manual prior to using this instrument. Carefully read
the warranty policy, service policy, notices, disclaimers and revisions on the
following pages.
This product must be installed by a qualied electrician or factory trained
technician and according to instructions indicated in this manual. This
instrument should be inspected and calibrated regularly by a qualied and
trained technician. For more information, refer to Section 7 Calibration and
Section 9 Maintenance of this manual.
This instrument has not been designed to be intrinsically safe. For your safety,
do not use it in classied hazardous areas (explosion-rated environments).
INSTRUMENT SERIAL NUMBER:
______________________________________________________
PURCHASE DATE:
______________________________________________________
PURCHASED FROM:
______________________________________________________

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1.2 Warranty Policy
Critical Environment Technologies Canada Inc. warrants the products we
manufacture (excluding sensors, battery packs, batteries, pumps, and lters)
to be free from defects in materials and workmanship for a period of two
years from the date of purchase from our facility. As a reminder, sensors are
consumable items and once they leave our factory, we cannot reuse or resell
them. As such, all sensor sales are nal. Should the sensor itself be faulty, there
is a one-year pro-rated warranty that would apply from the date of purchase
from our facility.
The warranty status may be affected if the instrument has not been used and
maintained as per the instructions in the manual or has been abused, damaged,
or modied in any way. The product is only to be used for the purposes stated
in the manual. Critical Environment Technologies is not liable for auxiliary
interfaced equipment or consequential damage.
All returned goods must be pre-authorized by obtaining a Returned
Merchandise Authorization (RMA) number. All goods must be shipped to
Critical Environment Technologies freight prepaid.Contact the manufacturer for
an RMA number and procedures required for product transport.
Due to ongoing research, development, and product testing, the manufacturer
reserves the right to change specications without notice. The information
contained herein is based on data considered accurate. However, no warranty is
expressed or implied regarding the accuracy of this data.
1.3 Service Policy
CETCI maintains an instrument service facility at the factory. Some CETCI
distributors / agents may also have repair facilities; however, CETCI assumes
no liability for service performed by anyone other than CETCI personnel.
Repairs are warranted for 90 days after date of shipment (sensors have

8 © 2022 All rights reserved. Data subject to change without notice.
LPT-M - Operation Manual Rev. B | 2022.03
individual warranties).
Should your instrument require non-warranty repair, you may contact the
distributor from whom it was purchased or you may contact CETCI directly.
Prior to shipping equipment to CETCI, contact our oce for an RMA #. All
returned goods must be accompanied with an RMA number.
If CETCI is to do the repair work, you may send the instrument, prepaid, to:
Attention: Service Department
Critical Environment Technologies Canada Inc.
Unit 145, 7391 Vantage Way
Delta, BC, V4G 1M3
You must include your Returned Merchandise Authorization (RMA) number,
address, telephone number, contact name, shipping / billing information, and
a description of the defect as you perceive it. You will be contacted with a cost
estimate for expected repairs, prior to the performance of any service work.
Pack the equipment well (in its original packing if possible), as we cannot be
held responsible for any damage incurred during shipping to our facility. All
incurred shipping charges, duties and taxes are your responsibility.
For liability reasons, CETCI has a policy of performing all needed repairs to
restore the instrument to full operating condition.
1.4 Copyrights
This manual is subject to copyright protection; all rights are reserved. Under
international and domestic copyright laws, this manual may not be copied or
translated, in whole or in part, in any manner or format, without the written
permission of CETCI.
Modbus® is a registered trademark of Gould Inc. Corporation.

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1.5 Disclaimer
Under no circumstances will CETCI be liable for any claims, losses or damages
resulting from or arising out of the repair or modication of this equipment
by a party other than CETCI service technicians, or by operation or use of the
equipment other than in accordance with the printed instructions contained
within this manual or if the equipment has been improperly maintained or
subjected to neglect or accident. Any of the forgoing will void the warranty.
Under most local electrical codes, low voltage wires cannot be run within the
same conduit as line voltage wires. It is CETCI policy that all wiring of our
products meet this requirement.
It is CETCI policy that all wiring be within properly grounded (earth or safety)
conduit.
1.6 Revisions
This manual was written and published by CETCI. The manufacturer makes
no warranty or representation, expressed or implied including any warranty of
merchantability or tness for purpose, with respect to this manual.
All information contained in this manual is believed to be true and accurate at
the time of printing. However, as part of its continuing efforts to improve its
products and their documentation, the manufacturer reserves the right to make
changes at any time without notice. In addition, due to improvements made to
our products, there may be information in this manual that does not exist in the
version of the product the user has. Should you detect any error or omission
in this manual, or should you want to inquire regarding upgrading the device’s
rmware, please contact CETCI at the following address:
Critical Environment Technologies Canada Inc.
Unit 145, 7391 Vantage Way, Delta, BC, V4G 1M3, Canada

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LPT-M - Operation Manual Rev. B | 2022.03
Toll Free: +1.877.940.8741
Telephone: [phone]
Email: [email protected]
Website: www.critical-environment.com
In no event will CETCI, its ocers or employees be liable for any direct, special,
incidental or consequential damages resulting from any defect in any manual,
even if advised of the possibility of such damages.
2 INTRODUCTION
2.1 General Description
Thank you for purchasing our LPT-M Modbus® Transmitter. The LPT-M is a
full-featured, digital gas detector for monitoring toxic and combustible gases
in non-hazardous (non-explosion rated) environments such as commercial
HVAC and light industrial applications. It is designed to communicate with a
Controller or Building Automation System (BAS) with Modbus® RTU RS-485
serial communication.
Sensor conguration options include one, two or three channel operation with a
comprehensive choice of sensors for many toxic gases (electrochemical) and
combustible (catalytic) gases, plus PID TVOCs. All LPT-M transmitters operate
by diffusion. The sensors utilized in this device are accurate enough to measure
to Occupational Health & Safety (OHS) hazardous levels for toxic gases.
Operating as a digital transmitter or as a standalone xed system, the LPT-M
offers an audible internal alarm, one dry contact relay, graphic LCD display
with user selectable functions, temperature compensation and an automatic
thermal resetting fuse all in a RoHS compliant package and standard water /
dust tight enclosure. With the optional splash guard installed, the enclosure is
IP54 rated and will be protected in water spray or wash down applications. An

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Rev. B | 2022.03 LPT-M - Operation Manual
optional internal heater for is available for cold environment applications.
If after reading through the manual, you have any questions, please do not
hesitate to contact our Technical Service Department for technical support.
2.2 Key Features
• Up to 3 sensor congurations: single or dual internal electrochemical
sensor and/or one remote catalytic combustible or PID TVOC sensor
• Modbus® RTU RS-485 serial communication
• Graphic LCD display (user selectable function)
• Internal audible alarm
• 1 dry contact relay, 30 volts, 2 amps maximum
• 4-conductor shielded network wiring (daisy-chain)
• 24 volt DC or AC power (ground referenced)
• Optional heater for cold environment applications
• Standard water / dust tight, corrosion resistant enclosure (drip proof).
With optional splash guard installed, the enclosure is IP54 rated.
• RoHS compliant circuit boards
• Auto resetting fuses

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LPT-M - Operation Manual Rev. B | 2022.03
3 INSTRUMENT SPECIFICATIONS
3.1 Technical Specications
MECHANICAL
Enclosure
ABS / Polycarbonate, IP54 rating with splash guard
installed. Copper coated interior to reduce RF
interference.
Weight 400 g / 14 oz
Size 127 mm x 127 mm x 71 mm
5.0 in x 5.0 in x 2.8 in
ELECTRICAL
Power Requirement 16 - 30 VDC, 3 W, Class 2
12 - 27 VAC, 50-60 Hz, 3 VA, Class 2
24V recommended. See Section 5.7 Wiring
Connections.
Current Draw 30 mA (buzzer & relay energized, 2 sensors)
Wiring (4-wire)
VDC or VAC (ground referenced) four-conductor
shielded 16 AWG stranded within conduit, network
wiring (daisy-chain), Modbus® RTU (version 1.1b3)
RS-485
Fuses Automatic resetting thermal

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USER INTERFACE
Display
Graphic LCD, green border. Text prompting for
calibration operation and fault indications. Installer
congurable to suppress all other displays.
Magnetic Sensors Use a magnetic wand to access menu options and
initiate calibration without opening the enclosure.
Audible Alarm Standard internal buzzer, rated 90 dB @ 10 cm,
enable/disable
INPUT/OUTPUT
Communication
Modbus® RTU over
RS-485
Modbus® ID: 100 (default, congurable)
Baud rate: 19,200 (default, congurable)
Data bits: 8
Start bits: 1
Stop bits: 1
Parity: none
Analog signal 4-20 mA input signal from ESH-A Remote Sensor
Relay One SPDT dry contact relay, 30 volts, 2 Amps
maximum

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LPT-M - Operation Manual Rev. B | 2022.03
ENVIRONMENTAL
Operating
Temperature
-20°C to 40°C / -4°F to 104°F
NOTE: Low temperature option available to -40°C
/ -40°F) (Sensor dependent, some extremely cold
applications may require a small internal silicone
heater to maintain temperature stability for sensor.
Contact CETCI for details)
Operating Humidity 15 - 90% RH non-condensing
CERTIFICATION
Model: LPT-M-XXX
S/N: LPTM1603B00001
Rating: 16-30 VDC, 3W, Class 2
12-27 VAC, 50-60 Hz, 3VA, Class 2
CERTIFIED FOR ELECTRIC SHOCK & ELECTRICAL FIRE HAZARD ONLY. LA
CERTIFICATION ACNOR COUVRE UNIQUEMENT LES RISQUES DE CHOC
ELECTRIQUE ET D’INCENDIE D’ORIGINE ELECTRIQUE.
Conforms to: CSA-C22.2 No. 205-12, UL508 (Edition 17):2007
Conforms to: EMC Directive 2004/108/EC, EN 50270:2006, Type 1, EN61010
Conforms to: FCC. This device complies with part 15 of the FCC Rules,
Operation is subject to the following two conditions: (1) This device may not
cause harmful interference, and (2) this device must accept any interference
received, including interference that may cause undesired operation.

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3.2 Internal Sensor Gas Types
Internal Electrochemical
Sensors Part Number Range Lifespan
Ammonia (NH3) LPT-M-NH3 0 - 500 ppm ~2 years
Carbon Monoxide (CO) LPT-M-TCO 0 - 200 ppm ~6 years
Chlorine (Cl2) LPT-M-CL2 0 - 5.0 ppm ~3 years
Ethylene (C2H4) LPT-M-C2H4 0 - 200 ppm ~2 years
Formaldehyde (CH2O) LPT-M-CH2O 0 - 5.0 ppm ~2 years
Hydrogen (H2) LPT-M-EH2 0 - 2,000 ppm ~2 years
Hydrogen Cyanide (HCN) LPT-M-HCN 0 - 30 ppm ~2 years
Hydrogen Sulphide (H2S) LPT-M-H2S 0 - 50 ppm ~2 years
Hydrogen Sulphide (H2S) LPT-M-H2SB 0 - 50 ppm ~5 years
Nitric Oxide (NO) LPT-M-NO 0 - 100 ppm ~2 years
Internal Electrochemical
Sensors continued...
Part Number Range Lifespan
Nitrogen Dioxide (NO2) LPT-M-NO2A 0 - 10 ppm ~3 years
Nitrogen Dioxide (NO2) LPT-M-NO2B 0 - 10 ppm ~6 years
Oxygen (O2) LPT-M-O2 0 - 25% Vol ~3 years
Ozone (O3) LPT-M-O3 0 - 1.0 ppm ~2 years
Sulphur Dioxide (SO2) LPT-M-SO2 0 - 20 ppm ~2 years

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LPT-M - Operation Manual Rev. B | 2022.03
3.3 ESH-A Remote Sensor Gas Types
ESH-A Remote Sensors - Combustible
(Catalytic)
Hydrogen (H2) ESH-A-
CH2-100
0 - 100% LEL ~5 years
Methane (CH4) ESH-A-
CCH4-100
0 - 100% LEL ~5 years
Propane (C3H8) ESH-A-
CC3H8-100
0 - 100% LEL ~5 years
ESH-A Remote Sensors - PID TVOC
PID TVOC
ESH-A-SPL 0 - 30 ppm usage /
application
dependent
ESH-A-SPH 0 - 300 ppm

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3.4 Enclosure Dimensions
Above dimensions are shown with optional splash guard. Without splash guard,
thickness is 71 mm / 2.8 in. The area required for enclosure door to be open 90
degrees is 178 mm / 7.0 in or 254 mm / 10.0 in for fully open. With the optional
splash guard installed, the enclosure is IP54 rated.
NOTE: During calibration, the sensor response time will be slower with a splash
guard installed.
NOTE: The standard splash guard (Option -S) is optional for protecting non
sticky gas sensors in wash down applications. For sticky gas sensors such as
Chlorine (Cl2), Hydrogen Cyanide (HCN) and Ozone (O3) order the sticky gas
splash guard Option -SN).

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LPT-M - Operation Manual Rev. B | 2022.03
4 INSTRUMENT FEATURES
4.1 Exterior Enclosure






Side view of LPT-M showing
location of Magnetic Sensors.



ARROW
UP
ENTER
ARROW
DOWN

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Rev. B | 2022.03 LPT-M - Operation Manual
NUMBER FEATURE FUNCTION
Door Hinge Secures door to base and allows
easy opening and closing
Display with green
border
Graphic LCD display. Green
border indicates transmitter
operation is Modbus®

Magnetic Sensors
(arrow up, Enter,
arrow down)
Use a magnetic wand to access
menu options and program
functions without opening the
enclosure
Sensor Opening Allows gas diffusion into sensor
Door Screw Secures door shut
Padlock Opening For security padlock

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LPT-M - Operation Manual Rev. B | 2022.03
4.2 Interior System Layout







