Emerson ROSEMOUNT OCX8800C User manual

Manual
00809-0500-4881, Rev AA
December 2022
Rosemount™ OCX8800C
Oxygen and Combustibles Analyzer for Hazardous Areas

Essential instructions
Read this page before proceeding!
Emerson designs, manufactures, and tests its products to meet many national and international standards. Because
these instruments are sophisticated technical products, you must properly install, use, and maintain them to ensure
they continue to operate within their normal specifications. You must adhere to the following instructions and
integrate them into your safety program when installing, using, and maintaining Emerson's Rosemount products.
Failure to follow the proper instructions may cause any one of the following situations to occur: loss of life, personal
injury, property damage, damage to this instrument, and warranty invalidation.
•Read all instructions prior to installing, operating, and servicing the product.
•If you do not understand any of the instructions, contact your Emerson representative for clarification.
•Follow all warnings, cautions, and instructions marked on and supplied with the product.
•Follow all instructions during the installation, operation, and maintenance of this product.
•To prevent personal injury, ensure that all components are in place prior to and during operation of this product.
•Inform and educate your personnel in the proper installation, operation, and maintenance of the product.
•Install equipment as specified in the installation instructions of the appropriate Quick Start Guide and per
applicable local and national codes. Connect all products to the proper electrical and pressure sources.
•Ensure that all connections to pressure and electrical sources are secure prior to and during equipment operation.
•If this reference manual is not the correct one, call 1-800-854-8257 or 949-757-8500 to request the correct
reference manual. Save this reference manual for future reference.
•To ensure proper performance, use qualified personnel to install, operate, update, program, and maintain the
product.
•When replacement parts are required, ensure that qualified people use replacement parts specified by Emerson.
Unauthorized parts and procedures can affect the product's performance, place the safe operation of your
process at risk, and VOID YOUR WARRANTY. Look-alike substitutions may result in fire, electrical hazards, or
improper operation.
•Ensure that all equipment doors are closed and protective covers are in place, except when maintenance is being
performed by qualified people, to prevent electrical shock and personal injury.
Note
The information contained in this document is subject to change without notice.
NOTICE
If a Field Communicator is used with this unit, the software within the Field Communicator may require modification.
If a software modification is required, please contact your local Emerson Service Group or National Response Center
at 1-800-654-7768.
WARNING
Physical access
Unauthorized personnel may potentially cause significant damage to and/or misconfiguration of end users’
equipment. This could be intentional or unintentional and needs to be protected against.
Physical security is an important part of any security program and fundamental to protecting your system. Restrict
physical access by unauthorized personnel to protect end users’ assets. This is true for all systems used within the
facility.
Symbols
Earth (ground) terminal
Protective conducter terminal
2

Risk of electrical shock
Warning: Refer to Reference Manual.
Preface
The purpose of this manual is to provide information concerning the components, functions, installation, and
maintenance of the Rosemount OCX8800.
Emerson recommends that you thoroughly familiarize yourself with Description and specifications and Install before
installing your transmitter.
Description and specifications presents the basic principles of the transmitter along with its performance
characteristics and components. The remaining sections contain detailed procedures and information necessary to
install and service the transmitter.
Before contacting Emerson concerning any questions, first consult this manual. It describes most situations
encountered in your equipment's operation and details necessary action.
Definitions
The following definitions apply to warnings, cautions, and notes found throughout this publication.
WARNING
Highlights an operation or maintenance procedure, condition, statement, etc. that if not strictly observed, could result
in injury, death, or long-term health hazards of personnel.
CAUTION
Highlights an operation or maintenance procedure, practice, condition, statement, etc. that if not strictly observed,
could result in damage to or destruction of equipment or loss of effectiveness.
Note
Highlights an essential operating procedure, condition, or statement.
Notice
The contents of this publication are presented for informational purposes only, and while every effort has been made
to ensure their accuracy, they are not to be construed as warranties or guarantees, expressed or implied, regarding
the products or services described herein or their use or applicability. All sales are governed by Rosemount's terms
and conditions, which are available upon request. We reserve the right to modify or improve the designs or
specifications of such products at any time.
Rosemount does not assume responsibility for the selection, use, or maintenance of any product. Responsibility for
proper selection, use, and maintenance of any Rosemount product remains solely with the purchaser and end-user.
To the best of Rosemount's knowledge, the information herein is complete and accurate. Rosemount makes no
warranties, expressed or implied, including implied warranties of merchantability and fitness for a particular purpose,
with respect to this manual and, in no event, shall Rosemount be liable for any incidental, punitive, special, or
consequential damages including, but not limited to, loss of production, loss of profits, loss of revenue or use, and
costs incurred, including without limitation for capital, fuel and power, and claims of third parties.
Product names used herein are for manufacturer or supplier identification only and may be trademarks/registered
trademarks of these companies.
Rosemount and the Rosemount logo are registered trademarks of Rosemount. The Emerson logo is a trademark and
service mark of Emerson Electric Co.
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4

Contents
Chapter 1 Description and specifications................................................................................. 9
1.1 Component checklist...................................................................................................................9
1.2 System overview........................................................................................................................11
1.3 Specifications............................................................................................................................. 22
1.4 Ordering information............................................................................................................... 25
Chapter 2 Install.........................................................................................................................27
2.1 Product safety............................................................................................................................27
2.2 Mechanical installation............................................................................................................. 28
2.3 Electrical installation................................................................................................................. 33
2.4 Pneumatic installation.............................................................................................................. 40
2.5 Initial start-up............................................................................................................................ 49
Chapter 3 Configuration and start-up.....................................................................................51
3.1 Verify installation.......................................................................................................................51
3.2 Initial power up..........................................................................................................................54
3.3 Setting test gas values..............................................................................................................55
3.4 Reset........................................................................................................................................... 56
3.5 Calibration solenoids................................................................................................................ 57
3.6 Blowback feature.......................................................................................................................57
3.7 Calibration verify feature..........................................................................................................59
3.8 Calibration tolerance feature...................................................................................................61
3.9 COe purge/zero feature........................................................................................................... 62
Chapter 4 Using the local operator interface (LOI)............................................................... 67
4.1 Display orientation....................................................................................................................67
4.2 Local operator interface (LOI) controls...................................................................................68
4.3 Local operator interface (LOI) menu tree...............................................................................71
4.4 D/A trim procedures................................................................................................................. 76
Chapter 5 Using HART® communications...............................................................................79
5.1 Overview.....................................................................................................................................79
5.2 Field Communicator signal connections................................................................................ 79
5.3 Field Communicator PC connections......................................................................................81
5.4 HART® menu tree...................................................................................................................... 82
5.5 D/A trim procedures................................................................................................................. 86
Chapter 6 Calibration................................................................................................................ 89
6.1 Overview.....................................................................................................................................89
6.2 Fully automatic calibration.......................................................................................................89
6.3 Operator-initiated autocalibration..........................................................................................91
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6.4 Manual calibration.................................................................................................................... 91
Chapter 7 Field Communicator................................................................................................ 99
7.1 Overview.....................................................................................................................................99
7.2 Field Communicator connections............................................................................................99
7.3 Fieldbus menu tree................................................................................................................. 102
Chapter 8 FOUNDATION™ Fieldbus........................................................................................107
8.1 FOUNDATION™ Fieldbus technology......................................................................................... 107
8.2 Network communication........................................................................................................111
8.3 Rosemount OCX8800 function blocks.................................................................................. 113
8.4 Resource block.........................................................................................................................114
8.5 Configure PlantWeb alert (PWA) simulation with the Field Communicator.................... 122
8.6 Transducer block.....................................................................................................................124
8.7 Transducer block enumerations........................................................................................... 133
8.8 Analog input (AI) function block............................................................................................140
8.9 Proportional/integral/derivative (PID) function block........................................................ 160
8.10 Arithmetic (ARTHM) function block.....................................................................................188
8.11 Advanced topics.................................................................................................................... 197
8.12 Input selector (ISEL) function block.................................................................................... 197
8.13 Operation with Emerson DeltaV™........................................................................................205
Chapter 9 Troubleshoot.......................................................................................................... 207
9.1 Overview...................................................................................................................................207
9.2 Diagnostic alarms....................................................................................................................210
9.3 Fault isolation.......................................................................................................................... 210
9.4 Alarm relay events.................................................................................................................. 228
Chapter 10 Maintenance and service...................................................................................... 231
10.1 Overview.................................................................................................................................231
10.2 Removal and installation......................................................................................................231
10.3 Repair sensor housing..........................................................................................................257
10.4 Repair electronics housing.................................................................................................. 286
10.5 Replace tube fittings.............................................................................................................295
Chapter 11 Replacement parts.................................................................................................299
11.1 Sensor housing......................................................................................................................299
11.2 Electronics housing...............................................................................................................304
11.3 O2 cell and heater strut assembly.......................................................................................308
Appendix A Safety data..............................................................................................................311
A.1 Safety instructions.................................................................................................................. 311
A.2 Safety data sheet for ceramic fiber products...................................................................... 313
A.3 High pressure gas cylinders.................................................................................................. 319
Appendix B Product certifications............................................................................................321
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Appendix C SPA with HART® alarm.......................................................................................... 323
C.1 Description...............................................................................................................................323
C.2 Install........................................................................................................................................ 325
C.3 Setup.........................................................................................................................................326
Appendix D Returning material................................................................................................ 333
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Contents Manual
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1 Description and specifications
1.1 Component checklist
A typical Rosemount OCX8800 oxygen/combustibles transmitter package should
contain the items shown in Figure 1-1.
Check the model number of your Rosemount OCX8800 against the transmitter
features and options, making sure options specified by this number are on or
included with the unit. Use this complete model number for any correspondence
with Emerson.
Optional accessories provides a list of accessories for use with the Rosemount
OCX8800.
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Figure 1-1: Typical System Package
A. Quick Start Guide
B. Adapter plate with mounting hardware and gasket
C. Reference air and calibration set (optional)
D. Blowback hardware (optional)
E. Rosemount OCX8800 with remote electronics
F. Rosemount OCX8800 with integral electronics
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1.2 System overview
1.2.1 Scope
This Reference Manual supplies details needed to install, start up, operate, and
maintain the Rosemount OCX8800.
Signal conditioning electronics outputs separate 4-20 mA signals representing
oxygen (O2) and combustibles (COe) values. You can access this information, plus
additional details, with the HART® Field Communicator or Emerson AMS software.
The local operator interface (LOI) also provides a communications interface with
the electronics.
1.2.2 System description
Emerson has designed the Rosemount OCX8800 to measure oxygen and
combustible concentrations in flue gas temperatures up to 2600 °F (1427 °C).
Electrical connections, power, and communications are made through two ¾
national pipe thread (NPT) ports in the flameproof electronics enclosure using
fittings and cables provided by the customer. Cable installation must meet NEC,
IEC, and/or other applicable national or local codes for Class I, Zone 1, Group IIB
+H2 T3/T6 permanently mounted equipment. The transmitter is close coupled to
the process and requires minimum sample conditioning requirements.
The equipment measures oxygen percentage by reading the voltage developed
across a heated electrochemical cell, which consists of a small yttria-stabilized,
zirconia disc. Both sides of the disc are coated with porous metal electrodes.
When operating at the proper temperature, the following Nernst equation gives
the millivolt output of the cell.
EMF = KT log10 (P1/P2) + C
where:
1. P2 is the partial pressure of the oxygen in the measured gas on one side of
the cell.
2. P1 is the partial pressure of the oxygen in the reference air on the opposite
side of the cell.
3. T is the absolute temperature.
4. C is the cell constant.
5. K is an arithmetic constant.
Note
For best results, use clean, dry instrument air (20.95 percent oxygen) as the
reference air.
When the cell is at operating temperature and there are unequal oxygen
concentrations across the cell, oxygen ions travel from the high oxygen partial
pressure side to the low oxygen partial pressure side of the cell. The resulting
logarithmic output voltage is approximately 50 mV per decade. The output is
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Rosemount OCX8800C 11

proportional to the inverse lograrithm of the oxygen concentration. Therefore,
the output signal increases as the oxygen concentration of the sample decreases.
This characteristic enables the transmitter to provide exceptional sensitivity at low
oxygen concentrations.
The Rosemount OCX8800 oxygen sensor measures net oxygen concentration in
the presence of all the products of combustion, including water vapor. Therefore,
it may be considered an analysis on a wet basis. In comparison with older
methods, such as the portable apparatus, which provides an analysis on a dry gas
basis, the wet analysis will, in general, indicate a lower percentage of oxygen.
The combustibles sensor is a catalytic sensor consisting of two resistance
temperature devices (RTDs). One RTD is the reference element covered with an
inert coating. The other RTD element is active, coated with a catalyst. As the
sample gases flow by the sensor, the combustible gases oxidize on the surface of
the active element. The oxidation that occurs produces heat and a temperature
rise in the active element. The temperature difference produces a resistance
relationship between the two elements that is directly proportional to the
concentration of combustibles in the sample gases.
The catalyst is specifically designed to detect carbon monoxide (CO), but the
sensor responds to other combustible gases. The sensor is calibrated using CO;
thus the output should be expressed in terms of CO. However, as the sensor
detects other combustible gases, the output cannot just be labeled CO. The
response of the sensor to other combustible gases gives an output that is
equivalent to the sensor detecting CO.
The term COe is used in this Manual to describe the sensor output. This term
indicates that the sensor is calibrated in terms of CO and that the sensor output is
equivalent to CO but not specific to CO.
Dilution air is provided to the COe sensor to ensure that there is adequate oxygen
to fully oxidize any combustible gases regardless of the concentration of oxygen
in the process.
1.2.3 System configurations
Transmitters are available in four lengths, giving you the flexibility to use a
penetration appropriate to the size of the stack or duct. The length options are 18
in. (457 mm), 3 ft. (0.91 m), 6 ft. (1.83 m), or 9 ft. (2.7 m). Probes are available in
three material options: 316L stainless steel, Inconel 600, and ceramic to
accommodate higher temperatures.
The electronics are contained in a separate housing from the sensors. When the
transmitter is configured with the integral electronics option, the electronics and
sensor housings are mounted as a unit at the stack mounting flange. When the
transmitter is configured with the remote electronics option, the electronics
housing is separated from the sensor housing. The electronics housing may be
mounted up to 150 ft. (45.7 m) from the sensor housing.
The electronics control both sensor temperatures and provide output signals in
one of two ways:
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1. Individual 4-20 mA isolated outputs that are proportional to the measured
oxygen and combustibles concentrations. The oxygen output also contains
HART® communication.
2. Single FOUNDATION™ Fieldbus output.
The electronics control both sensor temperatures and provide individual 4-20 mA
isolated outputs that are proportional to the measured oxygen and combustibles
concentrations. The power supply can accept voltages of 100 to 240 Vac and 50 to
60 Hz. The electronics accepts millivolt signals generated by the sensors and
produces the outputs to be used by remotely connected devices. The outputs are
isolated 4-20 mA linearized currents. Refer to Configuration and start-up for
specific instructions upon initial power up.
1.2.4 System features
1. The O2 cell output voltage and sensitivity increase as the oxygen
concentration decreases.
2. HART® or FOUNDATION™ Fieldbus communication is standard. To use this
capability, you must have either:
a. Field Communicator
b. Asset Management Solutions (AMS) software for the PC
3. Oxygen cell and heater/thermocouple assembly are field replaceable.
4. Electronics are automatically configured for line voltages from 100 to 240
Vac.
5. An operator can calibrate and diagnostically troubleshoot the transmitter in
one of two ways:
a. Local operator interface (LOI): The LOI is mounted to the end of the
electronics module and allows local communications with the
electronics. Refer to Using the local operator interface (LOI) for more
information.
b. HART or FOUNDATION Fieldbus interface: The transmitter's output line
transmits a digital signal with the detected oxygen or combustible
levels encoded in a digital format. The HART output is superimposed
on the oxygen 4-20 mA output line only. This information can be
accessed through the following:
•Field Communicator: The handheld Field Communicator requires
Device Description (DD) software specific to the Rosemount
OCX8800. The DD software is supplied with many Field
Communicators, but can also be programmed into existing Field
Communicators at most Emerson service offices. Refer to Using
HART® communications for additional information.
•Personal computer (PC): The use of a personal computer requires
AMS software available from Emerson.
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•Selected distributed control systems: The use of distributed control
systems requires input/output (I/O) hardware and AMS software
which permit HART or FOUNDATION Fieldbus communications.
6. When the transmitter is configured without the LOI, you must calibrate and
diagnostically troubleshoot the transmitter using the HART or FOUNDATION
Fieldbus interface.
7. Optional blowback system: The blowback system periodically blows
instrument air back through the sample line filter and out the sample tube.
This clears out particulate and keeps the sample line filter from clogging.
1.2.5 System operation
Figure 1-2 shows the relationship between the components of the Rosemount
OCX8800.
The sensor housing and probe mount to a duct or process wall so that the probe
protrudes into the flue gas stream. An air powered eductor continuously pulls
samples of the process flue gas through the probe to a chamber in front of the
sensor housing where the sample passes the O2 sensor and continues on the COe
sensor. Dilution air is provided to the COe sensor and reference air to the O2
sensor. After the gas sample flows past the O2 sensor and through the COe
sensor, it is drawn through the eductor where it mixes with the eductor air and
exits through exhaust back into the system.
The electronics housing contains the CPU and communication boards, which
convert the sensor inputs into 4-20 mA analog output signals. The CPU can also
initiate and perform calibrations. Solenoids can turn on and off three test gases
and instrument air. A flow meter between the electronics and sensor housings
regulates test gas flow to the sensors. Instrument air is separated into eductor
air, reference air, and dilution air. The instrument air solenoid does not allow air
flow until the heaters are up to temperature. This minimizes the amount of
sampled process flue gas being pulled into the cold sensors causing
condensation.
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Figure 1-2: System Operation Diagram
A. Sensor housing
B. COe combustibles sensor
C. Sample gas
D. Probe
E. O2 sensor
F. Eductor
G. Exhaust
H. Eductor air
I. Electronics housing
J. CPU
K. HART® board
L. Power supply
M. Optional test gas solenoids
N. Instrument air solenoid
O. Flow meter: 7 scfh
P. Eductor air
Q. Reference air
R. Low O2 test gas
S. High O2 test gas
T. CO test gas
U. Instrument air
V. Flow meter: 50 cc/min. (0.1 scfh)
W. Dilution air
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1.2.6 Handling the transmitter
CAUTION
Equipment damage
The Rosemount OCX8800 is designed for industrial applications. The probe may
contain components made from ceramics, which are susceptible to shock when
mishandled.
Treat each component of the system with care to avoid physical damage.
Only handle printed circuit boards and integrated circuits when adequate anti-
static precautions have been taken to prevent possible equipment damage.
1.2.7 System considerations
Prior to installing your transmitter, make sure you have all the components
necessary to make the system installation. Ensure that all components are
properly integrated to make the system functional.
After verifying that you have all the components, select mounting locations and
determine how each component will be placed in terms of available line voltage,
ambient temperatures, environmental considerations, convenience and
serviceability. Figure 1-4 shows a typical system wiring for a system with integral
electronics. Figure 1-5 shows a typical system wiring for a system with remote
electronics. Figure 1-6 shows the dimensions for the optional sample tube
support.
Figure 1-7 shows the dimensions for the optional in-situ filters. Figure 1-8 shows
the optional panel mounted blowback.
A source of instrument air is required at the transmitter for reference air, dilution
air, and eductor air. As the transmitter is equipped with an in-place calibration
feature, make provisions for connecting test gas tanks to the transmitter when
calibrating it.
Note
The electronics module is designed to meet Type 4X and IP66, and the electronic
components are rated to temperatures up to 185 °F (85 °C).
Retain packaging in which the transmitter arrived from the factory in case any
components are to be shipped to another site. This packaging haws been
designed to protect the product.
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Figure 1-3: Communications Connections and AMS Application - Rosemount
OCX8800 with Integral Electronics
A. Rosemount OCX8800 with integral electronics
B. Instrument air
C. Three calibration lines by customer (300 ft. [91 m] maximum)
D. Signal output (twisted pairs)
E. Termination in control room
F. Field Communicator
G. Customer's laptop with AMS
H. AMS
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Figure 1-4: Typical System Installation - Integral Electronics
A. Adapter plate
B. Signal outputs (twisted pairs)
C. Line voltage
D. Instrument air supply (reference gas)
E. High O2 test gas
F. Low O2 test gas
G. CO test gas
H. Gases
I. Duct
J. Stack
K. Test gas flow meter
L. Dilution air flow meter
M. Pressure regulator
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Figure 1-5: Typical System Installation - Remote Electronics
A. Gases
B. Duct
C. Stack
D. Heater power cable (up to 150 ft. [46 m])
E. Signal cable (up to 150 ft. [46 m])
F. Test gas flow meter
G. Dilution air flow meter
H. 4-20 mA outputs (two twisted pairs)
I. Line voltage
J. Instrument air supply (reference gas)
K. Pressure regulator
L. High O2 test gas
M. Low O2 test gas
N. CO test gas
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Figure 1-6: Optional Sample Tube Support
C. 0.75-in. (19 mm) diameter on 7.5-in. (190 mm) diameter B.C., eight places
D. 0.75-in. (19 mm) diameter on 4.75-in. (121 mm) diameter B.C., four places
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