Emerson Rosemount 6888A Reference Manual Download Page 114

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CAUTION!

EQUIPMENT DAMAGE

Do not remove the cell unless you are certain it needs to be replaced. Removal may damage the
cell and platinum pad. Follow the complete troubleshooting procedure to make sure the cell
needs to be replaced before removing it.

Cell Replacement Kit

Figure 5-4:

ANSI gasket

Wire and pad assembly

Anti-seize compound

22 gauge wire

Closed end connector

Set screws

Teflon tubing

Socket head cap screws

Cell and flange assembly

Corrugated seal

Probe (not included in kit)

Calibration gas passage

Maintenance and service

106

Rosemount 6888A

Summary of Contents for Rosemount 6888A

Page 1: ...Reference Manual 00809 0100 4890 Rev AA July 2018 Rosemount 6888A O2 Combustion Flue Gas Transmitter ...

Page 2: ...cement 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 peop...

Page 3: ...ilar design to the World Class and Oxymitter cells using the zirconium oxide sensing principle The cell is heated and maintained at 736 C 1357 F setpoint and generates a logarithmic MV signal proportional to the partial pressure difference of oxygen between the reference side of the cell usually instrument air at 20 95 O2 and the process side of the cell usually combustion flue gases For more info...

Page 4: ......

Page 5: ... System considerations 18 2 2 Mechanical installation 19 2 2 1 Install probe 20 2 2 2 Variable insertion 24 2 3 Electrical installation 26 2 3 1 Wiring for Rosemount 6888 Transmitter probe only no Rosemount 6888Xi Electronics 26 2 3 2 Standard housing transmitter probe plus Rosemount 6888Xi Electronics 28 2 3 3 Transmitter probe with single channel Xi and flame safety interlock 32 2 3 4 Transmitte...

Page 6: ...4 1 Overview 87 4 2 General 89 4 2 1 Grounding 89 4 2 2 Electrical noise 89 4 2 3 Electrostatic discharge 89 4 3 Alarm indications 90 4 4 Identifying and correcting fault indications 91 4 5 Calibration passes but still reads incorrectly 92 4 5 1 Probe passes calibration O2 still reads high 93 4 5 2 Probe passes calibration O2 still reads low 94 4 5 3 How do I detect a plugged diffuser 94 4 5 4 Can...

Page 7: ...ctive information 121 A 2 Ordinary location certification 121 A 3 Installing equipment in North America 121 A 4 Rosemount 6888A In Situ Oxygen Transmitter for General Purpose Locations 121 A 4 1 USA 121 A 4 2 Canada 122 A 4 3 Europe 122 A 5 Rosemount 6888Xi Digital Transmitter for General Purpose Locations 122 A 5 1 USA 122 A 5 2 Canada 122 A 6 Rosemount SPS4001B and IMPS4000 Autocalibration Devic...

Page 8: ...Contents iv Rosemount 6888A ...

Page 9: ...ver this manual describes the Rosemount 6888A Transmitter only Also use the product matrix Section 1 6 at the end of this section to compare your order number against your unit The first part of the matrix defines the model The last part defines the various options and features of the Rosemount 6888A Ensure the features and options specified by your order number are on or included with the unit De...

Page 10: ...libration gas accessories E 6888A integral autocal housing F 6888A probe with standard terminations electronics housing G Optional 6888Xi Advanced Electronics 1 2 Technical support hotline For assistance with technical problems please call the Customer Support Center CSC 1 RAI AND U 1 855 724 2638 1 440 914 1261 Description and specifications 2 Rosemount 6888A ...

Page 11: ...are several different arrangements of probes electronics and features that are explained below and in the wiring diagrams An optional Rosemount 6888Xi with HART communication provides a convenient operator interface for setup calibration and diagnostics HART communication is still present when using the Rosemount 6888Xi 1 4 System configurations 1 4 1 Transmitter probe only The Rosemount 6888 prob...

Page 12: ...enabled 1 4 3 Transmitter probe and Rosemount 6888Xi with flame safety interlock A flame safety interlock by Emerson is available for heater power disconnect whenever there is a loss of the process flame or a heater runaway condition heater over temperature in the O2 probe This input is internally powered by the Rosemount 6888Xi and is actuated via a dry contact output from your flame scanner A cl...

Page 13: ...lectronics World Class and Oxymitter as well as many competitive electronics 1 4 7 Wireless capability Both the transmitter electronics in the head of the probe and the Rosemount 6888Xi Electronics communicate over HART communications and can implement wireless communications via Emerson Wireless 775 THUM Adapter 1 4 8 Automatic calibration Calibrations consist of introducting bottled gases of kno...

Page 14: ...veraging System Data communications You can configure and diagnostically troubleshoot the Rosemount 6888A in one of two ways 1 Using the optional Rosemount 6888Xi Advanced Electronics allows local communication with the electronics The Rosemount 6888Xi also offers the following optional advanced features Fully automatic calibration Optional flame safety interface single probe version only High tem...

Page 15: ...Rosemount 6888A conduit port and converts the 4 20 mA signal to a wireless protocol All other HART information is also transmitted In addition to the wireless THUM Adapter a hard wire connection of the 4 20 mA signal to the DCS may be used at the same time More detailed information regarding the application of the THUM Adapter is available in Product Data Sheet 00813 0100 4075 Note The 375 field c...

Page 16: ...s a larger diameter with grooves to accept packing material to seal out fly ash The snubber and ceramic diffusers may also be fitted with a flash arrestor to reduce the possibility of the probe igniting from flammable gases within the process WARNING FLAME AND EXPLOSION The diffusers fitted with flash arrestors have been tested to provide a measure of protection in preventing ignition of flammable...

Page 17: ...bly Figure 1 5 is the traditional design for the probe Used for over 25 years the ceramic diffusion assembly provides a greater filter surface area Ceramic Diffusion Assembly Figure 1 5 Cup type diffusion assembly The cup type diffusion assembly Figure 1 6 is typically used in high temperature applications where frequent diffusion element plugging is a problem The cup type difusion assembly is ava...

Page 18: ... below to the model number on the probe tag to confirm the features present in this specific probe Rosemount 6888A Product Matrix Table 1 2 Model Description 6888A O2 Transmitter Measurement 1OXY Oxygen standard sensing cell 2OXY Oxygen acid resistant stochiometric sensing cell Probe length 1 1 18 in probe standard probe tube 2 18 in probe standard probe tube with abrasive shield 3 18 in probe abr...

Page 19: ...ectronics 1HT Standard housing transmitter electronics HART communications 2HT Integral autocal transmitter electronics HART communications 4FF Integral autocal transmitter electronics Fieldbus communications 5DR Standard housing direct replacement no electronics 6DRY Standard housing direct replacement YEW electronics Mounting plate 00 None 04 New installation square weld plate with ANSI 2 in 150...

Page 20: ...reference function FOUNDATION Fieldbus only For HART versions order this feature with Rosemount 6888Xi Electronics 0 No 1 Yes Diffuser warning function FOUNDATION Fieldbus only For HART versions order this feature with Rosemount 6888Xi Electronics 0 No 1 Yes 1 Probes supplied with flanges with dual ANSI DIN hole pattern 1 7 Rosemount 6888Xi product matrix Compare the configuration matrix below to ...

Page 21: ...with traditional architecture probe only 15 45 m 150 ft cable use with traditional architecture probe only 16 60 m 200 ft cable use with traditional architecture probe only Stoichiometer function for O2 00 No 01 Single channel 02 Dual channel Programmable reference function for O2 00 None 01 Single channel 02 Dual channel Extended Temperature Function for O2 00 None 01 Single channel 02 Dual chann...

Page 22: ...tem response in reducing conditions requires stoichi ometer feature Going from oxidizing to reducing T90 in 120 seconds Going from reducing to oxidizing T90 in 30 seconds Environmental specifications Table 1 4 Transmitter probe Process wetted materials are 316L or 304 stainless Process temperature limits 0 to 705 C 32 to 1300 F 550 to 825 C 1022 to 1517 F with Xi heaterless operation feature 1 Tra...

Page 23: ... adapter flanges are available to mate to existing flanges Probe lengths and approximate shipping weights 457 mm 18 in package 7 3 kg 16 lb 0 91 m 3 ft package 9 5 kg 21 lb 1 83 m 6 ft package 12 2 kg 27 lb 2 74 m 9 ft package 15 0 kg 33 lb 3 66 m 12 ft package 17 7 kg 39 lb Reference air optional 2 scfh 1 L min clean dry instrument quality air 20 95 O2 regulated to 5 psi 34 kPa Calibration Semi a...

Page 24: ...er 12 42 Vdc loop powered from the control room or from the Xi box Installation Specifications for Traditional Architecture Rosemount 6888Xi for use with DR or other Probe Table 1 7 Electrical power for Xi 120 240 V 10 50 60 Hz Power consumption of Xi 12 VA maximum or 1020 VA maximum with traditional ar chitecture 120 V probes 450 VA maximum with traditional architecture 44 V probes Alarm relay ou...

Page 25: ...d safety ground leads after installation Failure to install covers and ground leads could result in serious injury or death WARNING HAZARDOUS AREAS The Rosemount 6888A O2 Transmitter can be installed in general purpose areas only Do not install the transmitter in hazardous areas or in the vicinity of flammable liquids CAUTION EQUIPMENT DAMAGE If external loop power is used the power supply must be...

Page 26: ...r plate and flange D Instrument air supply reference air E Pressure regulator F Flowmeter G Calibration gas H Line voltage I 4 to 20 mA signal J Rosemount 6888Xi Advanced Electronics optional K Stack A source of instrument air is required at the transmitter for reference air flow 2 0 scfh 1 0 L min Since the unit is equipped with an in place calibration feature you can make provisions to permanent...

Page 27: ...cting the 375 475 Field Communicator between the transmitter and Rosemount 6888Xi will cause communication errors and affect system operation NOTICE The transmitter electronics is rated Type 4X and IP66 and is capable of operation at temperatures from 40 to 85 C 40 to 185 F Retain the packaging in which the Rosemount 6888A arrived from the factory in case any components are to be shipped to anothe...

Page 28: ...ector must be correctly oriented 2 Before inserting the Rosemount 6888A probe check the direction of gas flow in the duct Orient the vee deflector so the apex points upstream toward the flow See Figure 2 2 Orienting the Optional Vee Deflector Figure 2 2 A Gas flow direction B Vee deflector C Diffusion element D Setscrew E Vee deflector F Filter G Apex 3 If using the standard square weld plate or a...

Page 29: ... 3 Note All dimensions are in inches with millimeters in parentheses Rosemount 6888A Integral Autocal Housing Figure 2 4 A Dimension B Dimension C Hastelloy diffuser D Ceramic diffuser Note All dimensions are in inches with millimeters in parentheses Install Reference Manual 21 ...

Page 30: ...housing Dim B removal envelope accessory housing 457 mm 18 in probe 409 mm 16 1in 401 mm 15 77 in 490 mm 19 26 in 0 91 m 3 ft probe 826 mm 33 52 in 1182 mm 46 6 in 1271 mm 50 1 in 1 83 m 6 ft probe 1740 mm 68 52 in 2097 mm 82 6 in 2186 mm 86 1 in 2 74 m 9 ft probe 2655 mm 104 52 in 3011 mm 118 6 in 3100 mm 122 1 in 3 66 m 12 ft probe 3569 mm 140 52 in 3926 mm 154 6 in 4015 mm 158 1 in 1 Add 96 mm ...

Page 31: ... on C dia B C Mounting flange Table 2 2 ANSI DIN Flange diameter 7 28 185 Hole diameter 75 20 4 holes eq sp on BC 4 75 121 5 71 145 Installation Weld Plate Outline Table 2 3 Dimension ANSI DIN A 6 0 m 152 in 7 5 m 191 in B thread 625 m 11 in M16x2 C diameter 4 75 m 121 in 5 708 m 145 in Install Reference Manual 23 ...

Page 32: ... of a flue gas duct at infinitely variable depths This has several advantages over traditional mountings that fix the probe length with a flange at the time of installation One length of probe can be stocked for any length requirement The flue gas duct where the probe is mounted can be profiled with a single long probe while the flue gas levels are trended within the control system This informatio...

Page 33: ... pneumatic tubing must be able to travel with the probe Duct pressure Balanced draft and natural draft furnaces typically run at a slightly negative pressure so any small leaks in the packing material will draw air into the furnace When the probe is removed for service a flow of fresh air into the furnace also results A positive pressure duct however releases hot flue gases when the probe is remov...

Page 34: ...his circuit breaker should also include a mechanically operated isolating switch If not keep another external means of disconnecting the supply from the equipment located close by Circuit breakers or switches must comply with a recognized standard such as IEC 947 NOTICE To maintain proper earth grounding ensure a positive connection exists between the transmitter housing and earth The connecting g...

Page 35: ...Vdc from the DCS or an external power supply 4 Terminate the shield only at the transmitter electronics housing unless using a Rosemount 6888Xi When using the Rosemount 6888Xi Advanced Electronics terminate the shield at both ends NOTICE The 4 20 mA signal represents the O2 value and also powers the probe mounted electronics Superimposed on the 4 20 mA signal is HART information accessible through...

Page 36: ... of two channels serving two Rosemount 6888 probes 1 Remove cover screws from the front cover of the Rosemount 6888Xi Swing down the front cover of the interface box 2 Pull out the I O board on the right side of the card rack inside the Rosemount 6888Xi If your system is configured to operate two transmitter probes there are two I O interface boards See Figure 2 9 Install 28 Rosemount 6888A ...

Page 37: ... pins 2 3 external power Rosemount 6888Xi to Rosemount 6888 transmitter requires 2500 resistor across J4 PR to PR JP7 JP8 Pins 1 2 internal power Rosemount 6888Xi to DCS pins 2 3 external power Rosemount 6888Xi to DCS Compare the configuration matrix below to the model number on the probe tag to confirm the features present in this specific probe Remote Type Table 2 4 1OXY Single channel O2 2OXY S...

Page 38: ...Remote Type continued Table 2 4 4OXY Single channel O2 traditional architecture for 120 V probes Install 30 Rosemount 6888A ...

Page 39: ...wer supply board B Channel 2 IO board C Shield ground D Channel 1 IO board E AC input to P S F Plug G Channel 2 alarm relay SPS IMPS H Channel 2 4 20 mA HART output I Channel 1 alarm relay SPS IMPS J Channel 1 4 20 mA HART output Install Reference Manual 31 ...

Page 40: ...ck inside the Rosemount 6888Xi 9 Connect the line or L1 wire to the L1 terminal and the neutral or L2 wire to the N terminal 10 Reinstall the power supply connector in the power supply board 2 3 3 Transmitter probe with single channel Xi and flame safety interlock A flame safety interlock by Emerson is available for heater power disconnect whenever there is a loss of the process flame or a heater ...

Page 41: ... and switch settings are factory set and are shown for reference only D IO board 4 20 mA HART loop power settings JP5 Pins 1 2 internal power Rosemount 6888Xi to Rosemount 6888 Transmitter pins 2 3 external power Rosemount 6888Xi to Rosemount 6888 Transmitter requires 250 Ω resistor across J4 PR to PR JP7 JP8 Pins 1 2 internal power Rosemount 6888Xi to DCS pins 2 3 external power Rosemount 6888Xi ...

Page 42: ...Bottom View Figure 2 12 A Power supply board B AC relay board C Shield ground D IO board E Plug F AC input G Loss of flame output to burner management system H Alarm relay SPS IMPS I 4 20 mA HART output Install 34 Rosemount 6888A ...

Page 43: ... Connect the 4 20 mA signal wires form the Rosemount 6888Xi to the connections in the side chamber of the transmitter Do not connect the signal wires to the terminals in the main chamber where the AC input wires are connected Use a shielded twisted wire pair Do not allow bare shield wires to contact the circuit boards Insulate the shield wires prior to termination The 24 Vdc loop power is sourced ...

Page 44: ...13 A Ferrite clamp B Signal C Test points D 8 pan htd scr internal ground E Power F Test point group NOTICE A Except for JP5 JP7 and JP8 on IO board jumper and switch settings are factory set and are shown for reference only Install 36 Rosemount 6888A ...

Page 45: ...ally via external dry contact HART communications or from the Rosemount 6888Xi local operator interface keypad The integral autocal feature can only be implemented when the probe is used with a Rosemount 6888Xi 1 Remove the two covers from the transmitter 2 Connect the line L1 wire to the L1 terminal the neutral L2 wire to the L2 N terminal and the ground wire to the ground lug The Rosemount 6888A...

Page 46: ...onium oxide O2 sensor are sent to a remote Rosemount 6888Xi electronics The Rosemount 6888Xi electronics also directly applies power to the probe heater in order to maintain the correct sensor temperature This arrangement calls for a 7 conductor cable to carry this power and the sensor signals Maximum length for this cable is 200 feet 1 Remove cover from probe 2 Feed all DR probe wiring through li...

Page 47: ...e Rosemount 6888Xi Instruction Manual for additional installation and operating instructions B All wiring marked with an asterisk is factory wiring inside the Rosemount 6888Xi C Except for JP7 and JP8 on IO board jumper and switch settings are factory set and are shown for reference only Install Reference Manual 39 ...

Page 48: ...aditional architecture cable connections A traditional architecture configuration is used to provide for remote location of the transmitter electronics All electronics are housed inside the Rosemount 6888Xi A multi conductor power signal cable connects between the probe and the Rosemount 6888Xi Use the following procedure to connect the traditional architecture probe to the Rosemount 6888Xi Instal...

Page 49: ...At the probe housing apply Teflon tape or similar sealing compound to the tapered pipe threads Thread the gland body into the probe housing until properly seated e At the Rosemount 6888Xi enclosure insert the gland body into the left front cable port from the inside of the enclosure Use the rubber O ring provided to seal the cable port f Ensure the cable shield braid is evenly formed over the gray...

Page 50: ...imum at 2 0 scfh 1 01 L min maximum less than 40 parts per million total hydrocarbons Regulator outlet pressure should be set at 5 psi 34 kPa Reference air can be supplied by the reference air set or the optional Rosemount SPS 4001B or Rosemount IMPS 4000 Plant Schematic Diagram Standard Housing Figure 2 15 A Vent B Calibration gas 1 4 in tube C Reference air flowmeter D 0 25 18 NPT female inlet c...

Page 51: ...igure 2 16 A Vent B Calibration gas 1 1 4 in tube C Calibration gas 2 1 4 in tube D Reference air flowmeter E 0 25 18 NPT female inlet connection F 0 25 or 6 mm O D tubing supplied by customer G Reference gas 1 4 in tube Install Reference Manual 43 ...

Page 52: ...illimeters in parentheses Reference air components are included in the optional manual calibration panel Figure 2 17 the Rosemount SPS 4001 Single Probe Autocalibration Sequencer and the Rosemount IMPS 4000 Intelligent Multiprobe Test Gas Sequencer Install 44 Rosemount 6888A ...

Page 53: ...rson suggests that gas for the low zero be between 0 4 and 2 0 O2 Do not use gases with hydrocarbon concentrations of more than 40 parts per million Failure to use proper gases will result in erroneous readings CAUTION EQUIPMENT DAMAGE If the ducts will be washed down during outage MAKE SURE to power down the Rosemount 6888A units and remove them from the wash areas NOTICE Upon completing installa...

Page 54: ...Rosemount 6888A Calibration Gas Connections Figure 2 18 A Cal gas in B Ref air vent C Ref air in Traditional Architecture Cable Gland Assembly Figure 2 19 Install 46 Rosemount 6888A ...

Page 55: ...mitter without connecting it to the Rosemount 6888Xi 1 Apply AC line power to the transmitter 2 Apply 24 Vdc loop power to the transmitter 3 Using either the DCS control or a Field Communicator verify communications to the transmitter The transmitter probe takes approximately 45 minutes to warm up to the 736 C 1357 F heater setpoint The 4 20 mA signal remains at a default value of 3 5 mA and the O...

Page 56: ...akes approximately 45 minutes to warm up to the 736 C 1357 F heater setpoint The 4 20 mA signal remains at a default value of 3 5 mA and the O2 reading remains at 0 through this warm up period After warm up the probe begins reading oxygen and the 4 20 mA output is based on the default range of 0 10 O2 If there is an error condition at startup an alarm message is displayed on the Rosemount 6888Xi 3...

Page 57: ...d Down keys to select the calibration method to be used The methods are defined as follows None Manual calibration with the standard probe housing configuration SPS Automatic calibration with the standard probe housing configuration using the Rosemount SPS 4001B IMPS Automatic calibration with the standard probe housing configuration using the Rosemount IMPS Integral Automatic calibration with the...

Page 58: ...y for initial startup and operation but the most accurate measurement is gained by executing a calibration under normal operating conditions Emerson recommends using 0 4 O2 and 8 O2 as calibration gases with a balance of nitrogen in the gas bottles but other values can be used as long as the electronics are configured identically Do not use instrument air or pure nitrogen as calibration gas values...

Page 59: ...s a solenoid box for switching calibration gases or a larger intelligent multiprobe sequencer IMPS which can handle the autocal for up to four probes in one box The automatic calibration can be initiated in several ways Via a calibration recommended diagnostic that is periodically checking cell impedance Via push button on the Rosemount 6888Xi electronics Via HART communications from a 475 handhel...

Page 60: ...after the calibration is complete Push the Diagnostics button on the Rosemount 6888Xi to require an Accept Cal step so that the technician or operator can decide if they are ready to accept a potentially large change in calibration values 2 Plugged diffuser diagnostic This feature measures the return to process rate after calibration gases are removed and will alarm when this tiem exceeds 75 of th...

Page 61: ...Calibration Defaults Figure 3 1 Configuration startup and operation Reference Manual 53 ...

Page 62: ...HART Menu Trees Rosemount 6888Xi Figure 3 2 Configuration startup and operation 54 Rosemount 6888A ...

Page 63: ...Configuration startup and operation Reference Manual 55 ...

Page 64: ...Configuration startup and operation 56 Rosemount 6888A ...

Page 65: ...Configuration startup and operation Reference Manual 57 ...

Page 66: ...Configuration startup and operation 58 Rosemount 6888A ...

Page 67: ...Configuration startup and operation Reference Manual 59 ...

Page 68: ...Configuration startup and operation 60 Rosemount 6888A ...

Page 69: ...HART Menu Trees 375 475 Field Communicator Figure 3 3 Configuration startup and operation Reference Manual 61 ...

Page 70: ...Configuration startup and operation 62 Rosemount 6888A ...

Page 71: ...Configuration startup and operation Reference Manual 63 ...

Page 72: ...Configuration startup and operation 64 Rosemount 6888A ...

Page 73: ...FOUNDATION Fieldbus Menu Trees Rosemount 6888Xi Figure 3 4 Configuration startup and operation Reference Manual 65 ...

Page 74: ...Configuration startup and operation 66 Rosemount 6888A ...

Page 75: ...Configuration startup and operation Reference Manual 67 ...

Page 76: ...Configuration startup and operation 68 Rosemount 6888A ...

Page 77: ...Configuration startup and operation Reference Manual 69 ...

Page 78: ...FOUNDATION Fieldbus Menu Trees 375 475 Field Communicator Figure 3 5 Configuration startup and operation 70 Rosemount 6888A ...

Page 79: ...Configuration startup and operation Reference Manual 71 ...

Page 80: ...Configuration startup and operation 72 Rosemount 6888A ...

Page 81: ...Configuration startup and operation Reference Manual 73 ...

Page 82: ...Configuration startup and operation 74 Rosemount 6888A ...

Page 83: ... 1357 F heater setpoint The 4 20 mA signal remains at a default value of 3 5 mA through this warmup period Once warm the O2 reads oxygen and the 4 20 mA signal s reading is based on the default range of 0 10 O2 3 7 1 Error conditions If there is an error condition at startup an alarm message is displayed Refer to Chapter 4 to determine the cause of the error Clear the error and cycle power The O2 ...

Page 84: ...et O2 Temp Max Time Days ago Time stamp of the highest O2 sensor temperature reached since last reset Temperature CJC Max C This is the highest temperature reached at the cold junc tion since last reset Temperature CJC Max Time Days ago Time stamp of the highest temperature reached at the cold junction since last reset Voltage Heater Max C This is the highest heater voltage reached since last rese...

Page 85: ... C per second Operating Status Device configuration On Off Factory Mode Flame Status IO Board DIP Switch setting Auto Cal Device Relay 1 Device Re lay 2 Device AO Device Xmtr EE Val Transmitter board nonvolatile memory diagnostic Xmtr Restart Software restart count for the transmitter HART Device Rev HART device revision number Transmitter Version Software version number for the transmitter Tag De...

Page 86: ...was calculated as a result of the last successful calibra tion Impedance ohm Cell impedance This is the sensor resistance that was cal culated as a result of the last successful calibration Time Days ago Time stamp of the last successful calibration Cal Logs Slope mV Dec Previous calibration slope There are ten calibration results 1 is the most recent and 10 is the least recent calibration slope C...

Page 87: ...gh set to 0 4 and 8 0 respectively Perform this same process any time a transmitter board is replaced 1 Use the 375 475 Field Communicator to access the main HART menu 2 From the main menu select CONFIGURE 3 From the CONFIGURE menu select MANUAL SETUP 4 From the MANUAL SETUP menu select CALIBRATION 5 From the CALIBRATION menu select GAS 1 6 Press the Right key to edit the gas value 7 Use the stylu...

Page 88: ...pdate the Rosemount 6888A 3 9 3 Track output during calibration Use a Field Communicator to set how the analog output value will function during calibration A Rosemount 6888A shipped from the factory has output tracking set to No i e the analog output holds the last value during the calibration cycle You must perform this same process any time a transmitter board is replaced Procedure 1 Use the 37...

Page 89: ...g output value 0 at 4 mA non configurable O2 URV O2 value at upper analog output value 50 max at 20 mA Output Range Range of analog output 4 20 mA non configurable Alarm level O2 alarm level 3 5 mA or 21 1 mA Xi Mode Selects whether or not the Rosemount 6888A is used with a Rosemount 6888Xi should always be set to NO for a stand alone Rosemount 6888A 6 Use the stylus to enter the value then press ...

Page 90: ... 6 6 In the first screen a Loop should be removed from automatic control warning occurs Remove the Rosemount 6888A from any automatic loop controls to avoid a potentially dangerous operating condition Press OK when ready 7 At the next screen when the step shows APPLY GAS 1 press OK to continue 8 When Flow Gas 1 and Read Gas 1 are complete and the step shows APPLY GAS 2 press OK to continue 9 When ...

Page 91: ...res the current and 10 previous calibrations The stored data includes the slope constant cell impendance and time in days since that calibration The log can be accessed as follows Using the Field Communicator Configure Calibration Calibration Constants Calibration Logs When first entering the log the screen displays Calibration 1 This is the most recent previous calibration not the current calibra...

Page 92: ... select SERVICE TOOLS 3 From the SERVICE TOOLS menu select MAINTENANCE 4 From the MAINTENANCE menu select ANALOG OUTPUT 5 From the ANALOG OUTPUT menu select TRIM mA OUTPUT In the first screen a Loop should be removed from automatic control warning occurs WARNING Failure to remove the Rosemount 6888A from automatic control loops prior to performing this procedure may result in a dangerous operating...

Page 93: ...D A Trim Method Simplified Figure 3 7 Configuration startup and operation Reference Manual 85 ...

Page 94: ...Configuration startup and operation 86 Rosemount 6888A ...

Page 95: ... difference between the process O2 and the reference O2 inside the probe 20 95 O2 instrument or ambient air When flowing calibration gases the raw cell millivolt value should represent the levels on the chart in Figure 4 1 Note that the raw cell millivolt value increases logarithmically as the O2 concentration decreases Troubleshooting Reference Manual 87 ...

Page 96: ...ading vs O2 at 736 C 1357 F Reference Air 20 95 O2 Figure 4 1 O2 EMF mV 100 34 20 1 0 15 7 25 10 16 1 9 18 4 8 21 1 7 23 8 6 27 2 5 31 2 4 36 0 3 42 3 2 51 1 1 66 1 0 8 71 0 0 6 77 5 Troubleshooting 88 Rosemount 6888A ...

Page 97: ...ity has not degraded during fault finding The system provides facilities for 100 effective grounding and total elimination of ground loops 4 2 2 Electrical noise The transmitter has been designed to operate in the type of environment normally found in a boiler room or control room Noise suppression circuits are employed on all field terminations and main inputs When fault finding evaluate the elec...

Page 98: ...ading over range Example range is 0 10 Current reading is 12 21 mA Critical alarm transmitter reading is unusable you can choose this alarm level instead of the factory default level of 3 5 to 3 6 mA NOTICE To ensure correct operation you should make sure that the Digital Control System is configured to interpret these signal levels correctly Once an alarm condition is identified the Rosemount 688...

Page 99: ...s turned on Default values have been loa ded Check to see that your configurations have not been changed Cycle the power to clear alarm Failed No Yes Board Temp High The electronics board reading is above the threshold The board may not function correct ly The predefined temperature threshold is 86 C 187 F for IO board or 126 C 259 F for transmitter board Failed No Yes O2 Sensor Open The cell impe...

Page 100: ...r alarm Maint Yes No Cell Imp High The O2 sensor impedance cell resistance value measurement is greater than 2000 Ohms indi cating the cell may be beyond its useful life Maint Yes No Xi Disconnect It indicates using transmitter s AO when con nected to Rosemount 6888Xi and Rosemount 6888Xi is disconnected Maint Yes Yes Htr Voltage Low The heater voltage for the O2 heater is below 30 volts Check hea...

Page 101: ... 2 There may be a leak inside the O2 probe itself permitting the reference air 20 95 O2 to mix with the process gases at the cell To confirm this leak condition pressurize the inside reference side of the probe by plugging the reference air exhaust port with your finger for one minute The conduit ports where the signal and power wires pass may also need to be sealed The O2 reading should decrease ...

Page 102: ...d diffuser Always use a two stage regulator for setting calibration gas pressure Calibration flow rates should be set only when a new diffuser is installed As the diffuser plugs do not adjust the flow rates upward 4 5 3 How do I detect a plugged diffuser The O2 cell s speed of response will degrade The O2 trend in the control room will become smoother When calibrating the calibration gas flow rate...

Page 103: ...ate from 8 to lower values indicating that the process gases are now mixing with the calibration gases Adjust the flow rate back up until this mixing is just eliminated Calibrate at this flow rate Replace the diffuser at the first opportunity WARNING ELECTRIC SHOCK Install all protective equipment covers and safety ground leads after troubleshooting Failure to install covers and ground leads could...

Page 104: ...Troubleshooting 96 Rosemount 6888A ...

Page 105: ...ng levels of O2 are very low below 1 O2 A calibration check is generally recommended on a quarterly basis every three months by flowing bottled gas to the probe Make sure the operations personnel are notified when doing this and also make sure that the O2 control loop is placed in manual mode If the probe readings vary significantly from the bottle values conduct a formal calibration as noted in C...

Page 106: ...osemount SPS4001B one per probe or Rosemount IMPS4000 up to four probes provides the ability to manually initiate a calibration at any time from the control room The Rosemount 6888Xi interface must be used with the Rosemount SPS4001B or Rosemount IMPS4000 in order to perform an auto semi auto calibration Refer to the Rosemount SPS4001B or Rosemount IMPS4000 instruction manual for further details o...

Page 107: ...1 Bolt the transmitter to the stack and install the insulation 2 Connect all signal and power leads at the probe Refer to Chapter 2 for detailed wiring instructions 3 Connect the calibration gas and instrument air lines to the probe 4 Install the housing cover 5 Turn on instrument air 6 Restore power to the system Refer to Chapter 3 NOTICE Recalibration is required whenever the electronic cards or...

Page 108: ...ll be used as default to calculate the O2 measurement Transmitter board mounting Figure 5 1 A Cover B Plastic cover C Transmitter board D Mounting plate E Screws F Thermal pad G Screws Procedure 1 Remove cover A from the transmitter housing 2 Disconnect the power and signals from the transmitter board C 3 Remove the three screws E securing the plastic cover B and transmitter board C to mounting pl...

Page 109: ...he mounting pad is being replaced remove the four screws H securing the plate to the housing Install the new mounting plate using four screws Replacement screws are provided if any become lost or damaged 9 Reconnect the two wire harness connectors to the back of the transmitter board The connectors are different and individually keyed to prevent misconnection 10 Carefully push the wire harnesses t...

Page 110: ...d This section covers replacement of the DR board The board is not repairable and must be replaced if any component fails See Figure 5 2 for letter references The DR board is available as a standalone kit or with the plastic cover and mounting plate WARNING ELECTRIC SHOCK Disconnect and lock out power before working on any electrical components DR terminal board mounting Figure 5 2 A Cover B Plast...

Page 111: ...revent misconnection 7 Carefully push the wire harnesses through the hole in the mounting plate and align the DR terminal board with plastic cover over the three standoffs on the mounting plate 8 Install the three screws to secure the board to the mounting plate Replacement screws are provided if any become lost or damaged 9 Reconnect the power and signal wires to the transmitter board 10 Reinstal...

Page 112: ...or Section 5 4 3 to remove the electronics from the housing 3 Remove four screws E Remove housing from probe using care not to damage the strut wire harnesses or O ring I 4 Remove the strut clamp H from inside the finned housing on the probe 5 Remove tube clamps L and Viton tubes K from the CAL and REF gas ports and the CAL and REF gas lines Leave the clamps in place on the hoses for later reassem...

Page 113: ...de of the probe and position the housing on the probe 14 Install and tighten the four screws J 15 Follow the instructions in Section 5 4 2 to install the electronics into the housing 16 Follow the instructions in Section 5 4 1 to install the transmitter into the stack or duct 5 4 5 Cell replacement This section covers oxygen sensing cell replacement Do not attempt to replace the cell until all oth...

Page 114: ...o make sure the cell needs to be replaced before removing it Cell Replacement Kit Figure 5 4 A ANSI gasket B Wire and pad assembly C Anti seize compound D 22 gauge wire E Closed end connector F Set screws G Teflon tubing H Socket head cap screws I Cell and flange assembly J Corrugated seal K Probe not included in kit L Calibration gas passage Maintenance and service 106 Rosemount 6888A ...

Page 115: ...ions for replacing the contact pad provided in the cell replacement kit 6 Remove and discard the corrugated seal Clean the mating faces of the probe tube and retainer Remove burrs and raised surfaces with a block of wood and crocus cloth Clean the threads on the retainer and hub 7 Rub a small amount of anti seize compound on both sides of the new corrugated seal 8 Assemble the cell and flange asse...

Page 116: ...element whenever removing the probe for any purpose Replace if damaged Damage to the diffusion element may become apparent during calibration Compare probe response with previous response A broken diffusion element will cause an inadequate response to calibration gas Hex wrenches needed to remove setscrews and socket head screws in the following procedure are available as part of a probe disassemb...

Page 117: ...structions in Section 5 4 1 to remove the probe from the stack or duct 2 Loosen set screws D using the hex wrench from the probe disassembly kit and remove the vee deflector E Inspect sets crews If damaged replace with stainless sets crews coated with anti seize compound 3 Follow the instructions in Section 5 4 1 to install the probe into the stack or duct Maintenance and service Reference Manual ...

Page 118: ...ld wiring label NOTICE Field wiring labels are supplied for each product configuration Ensure the correct label is applied to the inside of the cover that matches your configuration Field wiring labels Figure 5 6 A Label for full transmitter B Label for DR probe C Label for DR YEW probe Maintenance and service 110 Rosemount 6888A ...

Page 119: ...el that matches the existing label on the inside of the old cover A graphic of each label and its application is shown in Figure 5 6 3 Peel off the backing and attach the new label to the inside of the new cover 4 Install the new cover onto the housing Maintenance and service Reference Manual 111 ...

Page 120: ...Maintenance and service 112 Rosemount 6888A ...

Page 121: ...y diffuser with V deflector 6A00453G06 Kit Hastelloy diffuser with dust seal with V deflector 6A00454G01 Kit strut 18 inch 6A00454G02 Kit strut 3 foot 6A00454G03 Kit strut 6 foot 6A00454G04 Kit strut 9 foot 6A00454G05 Kit strut 12 foot 6A00455G01 Kit cell replacement 18 inch standard cell 6A00455G02 Kit cell replacement 3 foot standard cell 6A00455G03 Kit cell replacement 6 foot standard cell 6A00...

Page 122: ... Spare DR term board cover 6A00475G01 Tool kit 6888 1A99119G01 Calibration gas bottles 0 4 and 8 O2 balance nitrogen 550 liters each 1 1A99119G02 Two flow regulators for calibration gas bottles 1A99119G03 Bottle rack 1 Calibration gas bottles cannot be shipped via air freight Replacement parts 114 Rosemount 6888A ...

Page 123: ...76 7 2 By Pass Packages The specially designed Rosemount By Pass Package for oxygen analyzers has proven to withstand the high temperatures in process heaters while providing the same advantages offered by the in situ sensor Inconel steel tubes provide effective resistance to corrosion and the package uses no moving parts air pumps or other components common to other sampling systems For more info...

Page 124: ...e the ability to perform automatic or on demand calculations The Rosemount SPS 4001B is fully enclosed in a NEMA cabinet suitable for wall mounting This cabinet provides added protection against dust and minor impacts The Rosemount SPS 4001B works in conjunction with the Rosemount 6888Xi eliminating out of calibration occurrences and the need to send a technician to the installation site For more ...

Page 125: ...ion routines The sequencer works in conjunction with the CALIBRATION RECOMMENDED feature eliminating out of calibration occurrences and the need to send a technician to the installation site In addition the Rosemount IMPS 4000 provides a remote contact input to intiate a calibration from a remote location and relay outputs to alert when a calibration is in progress an O2 probe is out of calibratio...

Page 126: ... carefully designed to provide a more convenient and fully portable means of testing calibrating and servicing Rosemount s oxygen analyzers These lightweight disposable gas cylinders eliminate the need to rent gas bottles For more information call Rosemount at 1 800 433 6076 Optional accessories 118 Rosemount 6888A ...

Page 127: ... Averaging System receives up to eight 4 20 mA signals from individual probes trends individual outputs and calculates four programmable averages as additional 4 20 mA outputs For more information call Rosemount at 1 800 433 6076 Rosemount OxyBalance System Figure 7 5 Optional accessories Reference Manual 119 ...

Page 128: ...Optional accessories 120 Rosemount 6888A ...

Page 129: ...ty and Health Administration OSHA A 3 Installing equipment in North America The US National Electrical Code NEC and the Canadian Electrical Code CEC permit the use of Division marked equipment in Zones and Zone marked equipment in Divisions The marking must be suitable for the area classification gas and temperature class This information is clearly defined in the respective codes A 4 Rosemount 68...

Page 130: ...5 Rosemount 6888Xi Digital Transmitter for General Purpose Locations A 5 1 USA FM Certificate FM17NUS0009X Standards FM 3810 2005 ANSI IEC 2003 ANSI EC 60529 2004 Markings Type 4X Special conditions for use 1 Mounting option 01 was not certified to provide Type 4X ingress protection through the panel cut out opening The panel mount gasket has not been tested for Type 4X installation A 5 2 Canada C...

Page 131: ...cate 1640823 Standards CAN CSA C22 2 No 61010 1 04 ANSI UL 61010 1 2004 2nd Edition CSA C22 2 No 94 1 07 ANSI UL 50 12th Edition CSA C22 2 No 94 2 1st Edition ANSI UL 50 E First Edition CSA C22 2 No 60529 05 R2010 ANSI IEC 60529 2004 R2011 Markings Type 4X IP66 Rosemount 6888 product certifications Reference Manual 123 ...

Page 132: ...Rosemount 6888 product certifications 124 Rosemount 6888A ...

Page 133: ... equipment connection to the mains supply should only be made through a circuit breaker which will disconnect all circuits carrying conductors during a fault situation The circuit breaker may also include a mechanically operated isolating switch If it does not then another means of disconnecting the equipment from the supply must be provided and clearly marked as such Circuit breakers or switches ...

Page 134: ... Open While Energized or similar there is a danger of ignition in areas where an explosive atmosphere is present This equipment should only be opened when the power is removed and adequate time as specified in the label or in the intruction manual has been allowed for the equipment to cool down and then only by trained service personnel Safety data 126 Rosemount 6888A ...

Page 135: ...Safety data Reference Manual 127 ...

Page 136: ...utomation Solutions Emerson FZE Jebel Ali Free Zone Dubai United Arab Emirates P O Box 17033 971 4 811 8100 971 4 886 5465 gas csc emerson com ASIA PACIFIC Emerson Automation Solutions 1 Pandan Crescent Singapore 128461 Singapore 65 777 8211 65 777 0947 gas csc emerson com Linkedin com company Emerson Automation Solutions twitter com rosemount_news Facebook com Rosemount youtube com RosemountMeasu...

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