ESP PGU-P User manual

Part
Number:
10060-001
Rev:
03
Description:
SSS-903 TG-E
Install Guide
Date:
08/15/2017
Page: 1of 53
OPERATING MANUAL
SSS-903 Toxic Gas Detection System
Model SSS-903 Transmitter and Controller
Model PGU-IR Infrared Optical Gas Sensor
Model PGU-P Photo Ionization Gas Sensor
Model PGU-E Electrochemical Gas Sensor
Model PGU-C Catalytic Bead Gas Sensor
Date
Revision
Description
Approved
3/21/13
02
Addition; Appendix II
Warranty & Return Policy
A. Burgos
Revision History
Information and technical data disclosed in this document
may be used and distributed only for the purposes and to
the extent specifically authorized by ESP Safety Inc.
ESP Safety Inc. Reserves the right to change published
specifications and designs without prior notice

Part
Number:
10060-001
Rev:
03
Description:
SSS-903 TG-E
Install Guide
Date:
08/15/2017
Page: 2of 53
General Information.............................................................................................................. 3
Specifications of SSS-903 with PGU Sensors ........................................................................ 4
SSS-903 Theory of Operation .............................................................................................. 11
Data Communication ........................................................................................................... 17
IMPORTANT SAFETY INFORMATION................................................................................... 18
Physical Installation Procedure .......................................................................................... 19
Physical Installation Quick Guide........................................................................................ 20
Wiring Requirements .......................................................................................................... 24
Power up and Stand Alone Operation of the SSS-903 ........................................................ 31
RS-485 Modbus Digital Communication and Operation...................................................... 32
Calibration Procedures ........................................................................................................ 33
Non-Invasive Calibration Magnet Procedure ...................................................................... 33
Non-Invasive Calibration Procedure with HART Communicator……………………………..….33
Bench Test Calibration Procedure with ESP Commander ................................................. 438
Unpacking A New SSS-903.................................................................................................. 44
Appendix 1 Explosion Proof Design……………………………………………….............. …………45
Appendix 2 Warranty & Return Policy ..............……………………………………………………46

Part
Number:
10060-001
Rev:
03
Description:
SSS-903 TG-E
Install Guide
Date:
08/15/2017
Page: 3of 53
General Information
Applications
This instruction guide details the specification, application and operation of the ESP Safety Inc. SSS-903 with an included
sensor. The SSS-903 System consists of two components, a receiver and gas specific sensor that have been factory
configured and calibrated to provide detection of toxic, flammable and combustible gases in open or closed environments. The product
includes multiple features required to report alarms when the toxic gas concentrations in the environment
reach three independently programmed levels. Each alarm also triggers a relay that is provided as a standard feature,
which can be used to operate warning devices, sirens, valves or switches.
The SSS-903 receiver is a versatile product that can be used in a specific proximity or in a decoupled mode with the sensor
and receiver head located up to 500 feet apart. Furthermore, any SSS-903 can be reconfigured in the field to detect toxic
gases using optional sensor replacements.
The SSS-903 system is recommended for applications that require a gas detector with localized digital readout of detected
gas levels. It comes factory standard for with Analog 4-20mA output with embedded HART, an independent HART connector
that is conveniently located on the SSS-903 enclosure able, relay contacts, and Modbus RS485. The system is comprised of an
SSS-903 Receiver and plug-in universal PGU sensors for electrochemical (PGU-E) , infrared (PGU-IR) ,photo-ionized (PGU-P) and
catalytic bead (PGU-C)detection. Power is supplied from an external 24 VDC nominal power source (source can range 18-3VDC). In
operation the
SSS-903 system has been designed for operation in temperature ranges from minus 40 to 75 °С (without internal heated option
activation) and minus 60 to 75 °С (with activated internal heated option) and relative humidity of up to 100 % (non-condensing)
The SSS-903 receiver includes 5 LED annunciators plus an easily readable LCD display. On the display an operator can determine
information of alarm status, gas detected, current level detected and view a Time Weighted Average (TWA) run time graphic
showing each event and level detected during a user programmed time from 3 to 30 minutes. The design of the SSS-903 is an
approved product for use in control monitoring of gas contamination levels with flammable and toxic gases present in the
working area environment of oil, gas and chemical industries All electronics are enclosed in explosion-proof aluminum or
stainless steel housings that have been certified by FM-Approvals for use in explosive areas pertinent to classes 1 and 2 with the
potential hazard of forming explosive gas mixtures attributed to the subgroup IIС and to explosion hazard categories Т1–Т6,
inclusive of the following zones, premises and facilities:
Drilling and production platforms
Refineries
Bulk terminals and tank farms
Compressor stations
Pipelines
Transportation facilities
Petrochemical facilities
Paint Manufacturing
Fertilizer plants
Fuel loading facilities
Residential areas
Boiler stations
Non-invasive calibrations can be performed in the field using an included magnetic wand or a HART communicator.
A device descriptor file is available from ESP Safety for use with a HART communicator. Calibration can also be performed with an
included Windows PC application, ESP Commander. Both HART and ESP Commander applications can supply real time output of
current operational data plus access a non-volatile memory in the SSS-903 for further diagnostic analysis.

Part
Number:
10060-001
Rev:
03
Description:
SSS-903 TG-E
Install Guide
Date:
08/15/2017
Page: 4of 53
Specifications of SSS-903 with PGU Sensors
Electrical Characteristics
Operational Characteristics
Mechanical Characteristics
Input Voltage
+24VDC Nominal (+18 to 32VDC)
Power Consumption
2 W-standby
5 W-during alarms
Output From SSS-903
+4-20mA industry standard analog with embedded HART
Digital RS-485 Modbus RTU
HART interface with easy access dedicated connector
4 “Dry Contact” relays (NO/Form-A)
All Relays Contact Rating 1Amp@125VAC/30VDC
Alarm Relays
3 User Programmed Alarm Relays
1 Fault Condition Relay
GT Sensor Interface to SSS-
903 Receiver
Digital RS-485 Modbus RTU
*Note All ESP Safety gas detector products can be interfaced with the SSS-903
Sensor Types / Model
Electrochemical: PGU-E
Infrared: PGU-IR
Photo Ionized: PGU-P
Humidity Range
Up to 100%, non-condensing
(Withstands up to 100% RH for short periods)
Operating Temperature
Standard Operation: -40oF to +167oF (-40oC to +75oC)
With Optic Heater Enabled: –76oF to +167oF (-60oC to +75oC)
Ingress Protection
IP66
RFI/EMI Protection
EN50081-1 / Class B E> 50270
*Operates with no interference from a 5 watt walkie talkie keyed (transmitting) at 1 meter
Annunciators (LED)
Tri-color status LED indicates operational mode, fault, and gas presence.
Three LED indicators for Alarms activation
A fourth LED indicates the unit is in calibration mode
Displayed Information
(Illuminated LCD Display)
Continuous sensor data
Gas Type
Measuring Units
Three Fixed Alarm Thresholds
Graphic display of trending data for Peak Readings and Time-Weighted Average (TWA) of gas
concentration 3-30 minutes
Explosion Proof Labels for SSS-
903 & PGU Sensors
Ex d [ia Ga] IIC T6 Gb
Ex d ia IIC T6
Dimensions of SSS-903
Receiver
270x150x120mm
10.63”x5.9”x4.73”
Dimensions of PGU Sensors
94x50mm
3.7”x1.97”
SSS-903 and PGU
Stainless Steel Grade-316
Cable Entry
2 Cable Entries ¾” NPT
Weight
5.5kg / 11lbs

Part
Number:
10060-001
Rev:
03
Description:
SSS-903 TG-E
Install Guide
Date:
08/15/2017
Page: 5of 53
Dimensions Diagram of SSS-903 Receiver
All dimensions are in mm

Part
Number:
10060-001
Rev:
03
Description:
SSS-903 TG-E
Install Guide
Date:
08/15/2017
Page: 6of 53
Table 1: SSS-903 with PGU-E Electrochemical Gas Sensor Range, Accuracy and
Response Times
Using Gas Specific Electrochemical Detectors
*Response Time is the time to reach a percentage of final reading when gas concentration is equal to full scale of the sensor
range of detection. (i.e. T50=50% 0f Range)
**Some sensors have multiple ranges one of which is determined by the user during setup or calibration
Gas
Formula
Range of Detection**
Accuracy
Response Time*
Hydrogen
(H2)
0 to 4 % vol (100%
LEL)
±2% full scale
T50 < 40 seconds
Т90 < 60 seconds
0 - 1% vol (0 - 100)
ppm
Carbon Monoxide
(CO)
(0 - 100) ppm
±2% full scale
T20 < 10 seconds
Т90 < 25 seconds
(0 - 500) ppm
(0 –1000)ppm
Ammonia
(NH3)
(0 - 1000) ppm
±2% full scale
Т90 < 90 seconds
Hydrogen Fluoride
(HF)
(0 - 10) ppm
±2% full scale
T50 < 30 seconds
Т90 < 90 seconds
Methanol
(CH3OH)
(0 –100)ppm
± 2% full scale
Т90 < 90 seconds
Oxygen
(O2)
(0 - 30) % vol
±2% full scale
Т90 < 11 seconds
Hydrogen Sulfide
(H2S)
(0 - 20) ppm
±2% full scale
T20 < 10 seconds
T50 < 12 seconds
Т90 < 25 seconds
(0 - 50) ppm
(0 - 100) ppm
Chlorine
(CI2)
(0 - 20) ppm
±2% full scale
Т90 < 25 seconds
Formaldehyde
(CH2O)
(0 - 10) ppm
± 2% full scale
Т50 < 20 seconds
Nitrogen Dioxide
(NO2)
(0 - 20) ppm
±2% full scale
T50 < 12 seconds
Т90 < 25 seconds
Sulfur Dioxide
(SO2)
(0 - 20) ppm
±2% full scale
T50 < 12 seconds
Т90 < 25 seconds
(0 - 100) ppm
Hydrogen Chloride
(HCI)
(0 - 30) ppm
±2% full scale
T50 < 30 seconds
Т90 < 90 seconds
Vinyl Acetate
(C4H6O2)
(0 - 100)ppm
± 2% full scale
Т90 < 90 seconds

Part
Number:
10060-001
Rev:
03
Description:
SSS-903 TG-E
Install Guide
Date:
08/15/2017
Page: 7of 53
Table 2: SSS-903 with PGU-P Photo Ionization Gas Sensor:
Range, Accuracy and Response Times
Using Gas Specific Photoionized Detectors
*Response Time is the time to reach a percentage of final reading when gas concentration is equal to full scale of the sensor
range of detection. (i.e. T50=50% 0f Range)
**Some sensors have multiple ranges one of which is determined by the user during setup or calibration
Note: All gases with ionization potential <10.6 eV
Gas
Formula
Range of
Detection**
Accuracy
Response Time*
Benzene
C6H6
(0 - 100) ppm
± 2% full scale
± 2% full scale
Т50 < 9 seconds
Т90 <25 seconds
Т90 <25 seconds
(0 - 1000) ppm
(0-10000) ppm
Ethylene
C2H4
(0 - 20) ppm
(0 - 2000) ppm
Isobutylene
C4H8
(0 - 20) ppm
(0 - 200) ppm
(0 - 2000) ppm
Methyl Mercaptan
СH3SH
(0 - 100) ppm
Other ranges per
request

Part
Number:
10060-001
Rev:
03
Description:
SSS-903 TG-E
Install Guide
Date:
08/15/2017
Page: 8of 53
Table 3: SSS-903 with PGU-IR Infrared Optical Detection:
Range Accuracy and Response Times
Using Gas Specific IR Detectors
*Response Time is the time to reach a percentage of final reading when gas concentration is equal to full scale of the sensor
range of detection. (i.e. T50=50% 0f Range)
Gas
Formula
Range of
Detection**
Accuracy
Response Time*
Methane
CН4
(0 -100) % LEL
± 3% to 50% LEL
± 5% from 51%
to 100% LEL
T20 < 5 seconds
Т90 < 25 seconds
Propane
C3Н8
Ethylene
C2Н8
Hexane
C6Н14
Butane
С4H10
Isobutane
l-С4Р10
Ethanol
C2H5OH
Cyclopentane
C5H10
Propylene
C3H6
Methanol
CH3OH
Gasoline Vapor
Diesel Vapor
JP4 Fuel Vapor
Carbon Dioxide
CO2
(0 to 2) % Vol
(0 to 5 ) % vol
( 1 –3000) ppm
± 2% full scale
Т90 <25 seconds

Part
Number:
10060-001
Rev:
03
Description:
SSS-903 TG-E
Install Guide
Date:
08/15/2017
Page: 9of 53
Table 4: SSS-903 with PGU-C Catalytic Bead Sensor:
Range Accuracy and Response Times
Using Catalytic Bead (pellisor) sensor specifically for detection of hydrogen
*Response Time is the time to reach a percentage of final reading when gas concentration is equal to full scale of the sensor
range of detection. (i.e. T50=50% 0f Range)
** All data refers to catalytic bead sensor as tested with H2 gas from an approved source. The sensor data listed is based on ideal test
environment with no interference from other gases
Gas
Formula
Range of
Detection**
Accuracy
Response Time*
Hydrogen
H2
0-100 % LEL
< ± 10% of
measured value
T 90 < 10 seconds

Part
Number:
10060-001
Rev:
03
Description:
SSS-903 TG-E
Install Guide
Date:
08/15/2017
Page: 10 of 53
Certifications
CE 0539 II 2 G
Ex d[ia] IIC T4 (Tamb 75°C)
IP 66
Ex d [ia] IIC T4
(Tamb 75°C)
IP 66
1 Ex d [ia] IIC T4 X T= -60°C....75°C
IP 66
EN Standards
EN 60079-0: 2006
EN 60079-1: 2007
EN 61779-1: 2000
EN 60529: 1991+A1: 2000
EN 50270: 2006.
94/9/EC ATEX:
IECEx:

Part
Number:
10060-001
Rev:
03
Description:
SSS-903 TG-E
Install Guide
Date:
08/15/2017
Page: 11 of 53
SSS-903 Receiver Operation
Figure 1 SSS-903 Receiver with PGU Sensor Installed
The SSS-903 is physically designed to perform in a wide range of hazardous environments and harsh weather conditions.
Employing a durable enclosure that can withstand these conditions and even explosion is key to the operation and function
of the device.
The SSS-903 is an elegant design that uses only two printed circuit board assemblies (PCBA) that have also been designed to
resist the effects of environmental challenges. The PCBAs are installed in a layered fashion with a single interconnection for easy
removal.
The Controller PCBA provides all information to the user via LED and LCD display. A micro controller with embedded software
performs all functions used in communication and control. As noted the controller card also functions as the driver for the
LCD display and performs all calculations used for the timed graphic HART. Event information displayed on the graphic cHART
is also stored in a Non-Volatile memory within the PGU sensor that can be accessed using ModBus or a HART communicator.
The second module is the Power PCBA. This PCBA accepts and regulates the externally supplied power source in addition to
all signal connections. Four solid state-sealed relays are also located on the Power PCBA eliminating the potential of electronic
discharge associated with mechanical relays.
All signals enter and exit the enclosure via ¾” threaded female attachments for conduit as required by the user application
and local regulations.
¾ Inch Inlet/Outlet Receptacles
For Explosion Proof Conduit and
Cabling
Dedicated HART Device
Communication Connector
with Protective Cover
Installed
.35” Diameter Surface
Mount (Left and Right)
Screw On Explosion Prove Housing Cover with
Shatter Proof Glass Window
Physical Earth
Ground Clamp
Housing Cover Lock
Screw
Removable PGU Sensor
Splash Guard and Gas Collector
Removable Detector Module Housing
cover with Lock Screw

Part
Number:
10060-001
Rev:
03
Description:
SSS-903 TG-E
Install Guide
Date:
08/15/2017
Page: 12 of 53
Figure 2- SSS-903 LED
Indicators
Figure 3 -
SSS-903 LCD Display
Detected Gas
Current Value
Alarm Preset
Values
Time Value of
Graphic Display
Graphic Display
Green
Calibration
Mode
Red
Alarm
1 2 3
Operational Status
Green –Normal Operation
Yellow –Alarm Active
Red –Fault Condition

Part
Number:
10060-001
Rev:
03
Description:
SSS-903 TG-E
Install Guide
Date:
08/15/2017
Page: 13 of 53
PGU-P Photo Ionization Gas Sensor Theory of Operation
Figure-4 PGU-P Detector
PGU-IR Infrared Optical Gas SensorTheory of
Operation
The PGU-P performs selective detection of hydrocarbon molecules using infrared light and
photo ionization detectors (PID). Air containing molecules of the selected combustible gas
passes into a collection chamber that has an IR source and detector. The molecules containing
the combustible gas absorb the IR photons and become ionized. Ionized molecules create an
electric current that is measured by the detector. The electric current increases as the amount
of gas molecules in the chamber increases. The current is measured and processed by the
PGU-P sensor, generating the signals that are passed to the SSS-903 receiver via RS-485. Each
detector is factor programmed for the gas requested by the customer at the time of purchase.
Operation the PGU-IR is based on selective signal disruption by hydrocarbon molecules when an
infrared light source is projected to an optical detector. Measurement for a specific gas is
determined by passing the IR energy through a filter placed between the source and a chamber
where the gas is collected. If nogas is present, the detector will receive all of the energy
radiated by the IR source and generating an electrical current. When gas molecules enter the
collection chamber, each molecule of the gas blocks the IR energy reducing the output of the
detector, which is then processed by the PGU-IR sensor. Each detector is delivered preset for a
specific gas, in the example shown, the gas is Methane (CH4), which ionizes at two points on the
light spectrum, one for each Atomic Element, and are measured as wave numbers (cm-1).
Figure -5 TG-IR Detector

Part
Number:
10060-001
Rev:
03
Description:
SSS-903 TG-E
Install Guide
Date:
08/15/2017
Page: 14 of 53
PGU-E Electrochemical Gas Sensor Theory of Operation
The PGU-P sensor contains electrode in contact with an electrolyte. The target gas
diffuses into the sensor through a membrane and comes into contact with electrodes
where it is oxidized. The electrochemical reaction results in an electric current that passes
to PGE-P microcontroller and from there to the SSS-903 receiver. The magnitude of the
current is controlled by how much of the target gas is oxidized by the electrode. Output
current from the sensor is also linearly proportional to the gas concentration. A linear
output allows for more precise measurement of low concentrations and much simpler
calibration.
Figure6 –TG-E Detector

Part
Number:
10060-001
Rev:
03
Description:
SSS-903 TG-E
Install Guide
Date:
08/15/2017
Page: 15 of 53
PGU-C Catalytic Bead Gas Sensor Theory of Operation
The PGU-C catalytic bead sensor oxidizes the target gas on the surface of a heated
alumina bead. The resulting heat of combustion results in a change in resistivity of the
element that is directly proportional to the concentration of the gas. A precious metal
catalyst is embedded onto the surface of the alumina bead to lower the oxidation
temperature. Two platinum wire leads are embedded in the alumina bead and connected
electrically in a Wheatstone bridge circuit. Heat is generated by passing current through
the leads.
Figure7 –TG-C Detector

Part
Number:
10060-001
Rev:
03
Description:
SSS-903 TG-E
Install Guide
Date:
08/15/2017
Page: 16 of 53
Each PGU sensor consists of PGU module with imbedded processing and a single gas specific plug-in
electrochemical, infrared (optical) or photo-ionized detector. There is a filter located between the
collection chamber and the detector to minimize potential contamination from dust or moisture. The
collection chamber is covered by a splashguard, which also serves as the gas collector. The
splashguard also has an inlet nipple for calibration purposes.
Each PGU detector internally stores the data reported to the SSS-903, HART, or Modbus. All
calibration information is also stored in the PGU module processor, thus any PGU module can be
moved to another SSS-903 receiver and resume data collection from the time of removal.
The detector module may be replaced in the field with a one that is intended for use to detect the
same gas. If a different gas is required a replacement PGU module must be ordered from ESP Safety
or their representative. Aside from detector or filter replacement there are no user serviceable parts
in the PGU sensor.
Figure 7 –PGU Detector Module
Field Replaceable Detector
Module
Housing Label Must
Match with Detector
Gas.
Removable Housing
Cover with Filter

Part
Number:
10060-001
Rev:
03
Description:
SSS-903 TG-E
Install Guide
Date:
08/15/2017
Page: 17 of 53
Digital Data Communication
HART Dedicated Connector
Digital RS-485 Modbus
UPES Controller
Explosion Proof Integrity
The SSS-903 provides three digital communication methods:
HART (Highway Addressable Remote Transducer) accessible via a dedicated connector that is located on the SSS-903 housing.
Digital RS-485 ModBus-RTU (Remote Terminal Unit)
HART over +4 to 20 mA output
HART is a bi-directional communication protocol that provides data access between
Intelligent field instruments and host systems. In most applications for the
SSS-903 the host is an ESP-Safety specific software application available from
the HART Foundation for use on a technician's hand-held HART communicator
device.A HART system in considered non-invasive in that the SSS-903 does not
have to be opened or removed from a field installed location.
HART communicators and RS-485 devices can access:
Information detected gas type
The measuring range in PPM or LEL%
Value of current gas concentration
State and programming of fixed alarm thresholds
Calibration Zero Cal Address of the SSS-903 as used by RS-485
Download of Non-Volatile Memory of event occurrence from a 60 day history
Modbus is an interface structure that is used for communication to control devices (PLC) or computers. Modbus is a similar
to HART but has been adapted as the industry standard for communication to multiple devices with a single cable run.
(Series or “Daisy Chain” connection) Unlike HART, RS-485 must be considered and designed into the installation of the SSS-903.
All of the same functions available with HART can also be accessed remotely with this system.
Modbus is available for use as a dedicated communication system with High Speed data communication.
ESP-Safety provides a Windows compatible computer application, ESP Commander, that provides all access to the
SSS-903 functions, and is often used for bench calibration of units removed from the field or prior to new installations.
ESP-Commander may require a customer provided translation device. All ESP Safety gas detector models have the ability
to interface with ESP Commander in RS-485 “daisy chain” networked installations. Modbus is also available in a single
point to point interface (one SSS-903 to One port of a control system as a data signal
that is imbedded in the +4 to 20mA analog output. In this application the data rate is significantly slower at 1200kb/s.
ESP-Safety has an available rack mounted control system that can
be used with all ESP devices along with those of other manufacturers.
Explosion proof integrity of SSS-903 units installed and in operation it is must not be modified in any form. All labeling must be
intact and visible. All surfaces that are subject to disassembly or removal during installation or maintenance must be installed as
detailed in Appendix I (Explosion Proof Diagram)
Emerson 475 Shown
Figure 8 - SSS-903 with
HART Communicator
Figure 9 - UPES Controller

Part
Number:
10060-001
Rev:
03
Description:
SSS-903 TG-E
Install Guide
Date:
08/15/2017
Page: 18 of 53
IMPORTANT SAFETY INFORMATION
Caution: The installation of SSS-903 must comply with relevant requirements of the latest edition
of the national Electri Code (ANSI/NFPA 70)
Caution: Connection Conduit, Barrier Glands, and Epoxy Sealants are to meet
EN-50018/IEC 60079-1 Standards
Caution: ESP Safety Inc. Recommends use of shielded cable with 14AWG conductors reaching a span
no greater than 3,900 ft. (1200 meter)
Be sure to read and understand the entire instruction manual before installing or operating the gas detection system. The products
described in this document can be used with a variety of ESP-Safety gas detector models to provide earlywarning of the presence of a
toxic or explosive gas mixture. Proper device installation, operation, and maintenance is required to ensure safe and effective
operation. If this equipment is used in a manner not specified in this manual, safety protection may be impaired.
Caution: The installation of SSS-903 must comply with relevant requirements of the latest edition of the national
Electric Code (ANSI/NFPA 70)
Caution: Connection Conduit, Barrier Glands, and Epoxy Sealants are to meet EN-50018/IEC
60079-1 Standards
Caution: ESP Safety Inc. Recommends use of shielded cable with 14AWG conductors reaching a span no greater
than 3,900 ft. (1200 meter)
Cautions and Warnings
This user guide includes numerous cautions and warnings that are specifically included to prevent injury to
personnel and prevent damage to equipment. Care is also taken to include notation of all applicable
standards and best practices as appropriate information that may apply to any use or procedure associated
with the product.
WARNING: TOXIC, COMBUSTIBLE, AND FLAMMABLE GASES OR VAPORS ARE VERY
DANGEROUS. USE EXTREME CAUTION WHEN THESE HAZARDS ARE PRESENT.
WARNING: Take appropriate precautions, including wearing and use of protective clothing and
devices when servicing the SSS-903 as they may have remnants of corrosive solutions.

Part
Number:
10060-001
Rev:
03
Description:
SSS-903 TG-E
Install Guide
Date:
08/15/2017
Page: 19 of 53
Physical Installation Procedure
Preparing For
Installation
The SSS-903 has unique installation procedures for either local or remote hardware
configurations. Before installation, evaluate the gas leak locations and other
conditions at the test site and configure the unit for that particular need.
PGU sensor Location
Selection of PGU sensor location is critical to the overall performance of the product.
Five factors play an important role in the selection of PGU sensor locations:
Density of the gas to be detected
Most probable leak sources within the industrial process
Ventilation and prevailing wind conditions
Personnel exposure
Maintenance access
*Note the PGU Sensor must be pointed down.
Density of detected
gas
If the target gas is heavier than air, the sensor should be located within 4 feet of
grade. Heavier than air gases will tend to settle in low-lying areas. For gases lighter
than air, PGU sensor placement should be 4-8 feet above grade in open areas or in
pitched areas of enclosed spaces.
Probable leak
sources
Leak sources include flanges, valves, and tubing. Connections of the sealed type
where seals may either fail or wear. All potential leak sources and SSS-903 mounting
locations are best determined by facility engineers with experience in similar
processes.
Ventilation and
Prevailing Winds
Normal ventilation or prevailing wind conditions can dictate efficient location of gas
PGU sensors so that migration of potential gas clouds is quickly detected.
Personnel exposure
If an undetected migration of gas clouds should approach concentrated personnel
areas such as control rooms, maintenance or warehouse buildings. Selection of PGU
sensor location should include the potential leak source and perimeter of personnel.
Use of ESP Safety PGUAES open field detectors should be considered for these areas.
Maintenance Access
Consideration should be given to providing easy access for maintenance personnel.
PGU sensor location should also take into account the proximity to contaminants that
may foul the PGU sensor prematurely.
SSS-903 Receiver
and PGU Sensor
Location Guidelines
There are no standard rules for placement since the optimum PGU sensor location is
unique for each application. Before installing the SSS-903, check the conditions at the
installation site to make a placement determination. The following guidelines can
assist in determining the best possible placement of the SSS-903:
Locate the SSS-903 near potential gas leak sources and away from excessive heat,
light, wind, dust, water, vibration, shock, and radio frequency interference (RFI).
Ensure the installation location has sufficient space to accommodate the SSS-903
housing, PGU sensor, and all necessary cabling.
Mount the SSS-903 with the PGU sensor pointing down.
Mount the SSS-903 housing in an easily accessible location for reading the digital
display and calibration checks

Part
Number:
10060-001
Rev:
03
Description:
SSS-903 TG-E
Install Guide
Date:
08/15/2017
Page: 20 of 53
Physical Installation Quick Guide