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9550-9142_5 - Scott Safety

1. WIRE NUT SHIELD silt RECEIVER z 4 20mA OUTPUT DCS PLC HOUSING GROUND SCREW ETC ge i 24 VDC f Ni 24VDC E COMMON x GROUND GREEN POWER j PPLY z S ff REFERENCE WHITE ro 40011600 OR 40009263 M TS COMBUSTIBLE DETECTOR GROUND J P a COMMON BLACK dd 00000 N d ACTIVE RED J i P1 y N out IO oo 0 SH EARTH GROUNDS 9 R l O PCB NEAR POWER SUPPLY Cy ey VW TB1 TB2 1234 BAL vous gt FJ FY s Fi JP1 STAND ALONE TRANSMITTER WIRING DIAGRAM SERIES 4888 NIC II CATALYTIC BEAD COMBUSTIBLE GAS NOTES GC TO CONVERT TO 12VDC 10 18 OPERATION INSTALL SOLDER IN JUMPER J04 27 SENSOR GAIN JUMPER JP1 MAY REQUIRE TO BE POSITIONED OTHER THAN SHOWN DEPENDING ON GAS TO BE MONITORED REFER TO MANUAL 9550 9142 FOR ADDITIONAL INFORMATION 9 VOLTS POTENTIOMETER IS TO BE ADJUSTED TO INDICATE 5 50 0 05VDC AT DETECTOR S IF DETECTOR IS ATTACHED TO TRANSMITTER ATTACH DVM TO TB1 R AND TB1 A TO MAKE ADJUSTMENT IF DETECTOR IS MORE THAN 18 457mm AWAY FROM TRANSMITTER REMOVE OUTER GUARD AND CONNECT DVM TO 2 TWO TEST POINTS LOCATED ADJACENT TO SENSOR AND ADJUST VOLTS POTENTIOMETER 4 REFER TO MANUAL 9550 9142 FOR OTHER INSTALLATION OPERATION AND CALIBRATION INSTRUCTIONS Instruction 9550 9142 R
2. 0 05 Vdc If the detector head is located more than 18 inches from the transmitter disassemble the detector head and install a Sensor Adapter Board 23 4027 between the sensor and the detector socket Attach the DVM to the adapter board terminals A and R and adjust the Volts potentiometer for a DVM indication of 6 00 0 05 Vdc Remove the Adapter Board and reassemble the detector head DETECTOR oo BODY SENSOR ADAPTER BOARD 23 4027 DQ COMBUSTILBES SENSOR c DVM Connection To Sensor Adapter Board GND COMMON CL C x SPARE JUMPERS PWR Glenn Sr amm Cy un ez SENSOR VOLTAGE ADJUST INPUT OUTPUT BOARD Page 38 Scott Health amp Safety Instruction 9550 9142 Rev 5 4800A NIC II LEL Transmitter Detectors 5 50 Vdc Scott stainless steel configuration Refer to Figure 5 4 Remove the detector outer guard Measure the voltage across the test points as indicated and adjust the Volts potentiometer for a DVM indication of 5 50 Vdc Replace the detector outer guard Figure 5 4 S COTT 5 5V Detector Test Points J SENSOR DRIVE VOLTAGE 5 50 1VDC TEST POINT NEGATIVE rr TEST POINT POSITIVE SENSOR TEST POINT SIGNAL USED TO MEASURE BRIDGE VOLTAGE TROUBLE SHOOTING PURPOSES CALIBRATION PORT 1 8 NPT Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 39 Calibration 4800A NIC II LEL T
3. Calibration Intervals ss 3 5 2 Preparine For C allt atl OM EE 31 5 3 Assembling the Calibration Fixture eege ee 32 SE SR E RE SE DID ote eo EEE NN TEEN co AL ott 33 Scb dopat voltasee Check re ee 33 5 4 2 Sensor Voltage Adjustment ccc cecceeceeceeceeceeceeceecceccseeeeees 34 5 4 3 Monitoring the VOUT Test Pont 36 5 4 4 Balance Adjustment Vee 36 545 Initial Fixed Gain JPL Semin Lue 37 5 4 6 Completing Initial Statt Up iei omia e prote pas earn tus 39 So ENN 39 Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 3 4800A NIC II LEL Transmitter 5 5 T Display Gdin Set VICE sed le 40 5 5 2 Set End of Service Life Indicator saa ses 40 5 6 Routine Calibration Non Intrusive ecsceecececseseeseseeseeerreseereseeseseeseseesese 41 S 7 EA Sit late Mode NS 43 6 COP OU AGI ON saeco cress secede ee 44 Dh Normal M de Operating 44 0 2 TSN Te EE 44 EM Ove 45 0d SATT TN se 45 REM PTS DR Mods 46 BIL Power Up Del ay aa 46 6 2 CAL Mode Ft E sake eee 46 6 5 3 Automatic CAL Mode Exit Tmer 46 6 5 4 Aborting the Delay OU egie eege deeg deeg 46 6 6 Calibration Values Back Up Power ree t i celeb east ahs 47 7 Mamntenanc b usage M P 48 JI ROE Ee 48 7 2 Replacing the Combustibles Sensor 2 SSE 48 7 3 Transmitter Circuit Board Replacement eese 51 7 4 LCD Full Scale Display Adjustment oroononnrnnrnnrnnrnnrvnrvnrnnrnnrnnrnnnnnnnnnnnnen 52 5 Replacement E
4. ISO BUTYLENE BUTYL ACETATE N BUTYL ALCOHOL CHLOROBENZENE CYCLOHEXANE CYCLOHEXANONE DIMETHYL FORMAMIDE DIETHYL ETHER N DECANE ETHANE ETHYL ACETATE ETHYL ACRYLATE ETHYL ALCOHOL ETHYL BENZENE ETHYLENE ETHYLENE OXIDE HEPTANE N HEXANE HEXANE ISOPROPYL ALCOHOL METHYL ETHYL KETONE METHYL ISO BUTYL KETONE N METHYL 2 PYRROLIDONE METHANOL METHYL STYRENE MINERAL SPIRITS MONOCHLOROBENZENE NAPTHA V M amp P NITRO PROPANE ISO OCTANE N OCTENE OCTENE PENTANE ISO PENTANE ISOPRENE PROPANE PROPYLENE STYRENE TETRAHYDROFURAN TOLUENE VINYL ACETATE VINYL CHLORIDE O XYLENE FOR 40011528 SENSOR FOR SENSOR 4888 2 FOR SENSOR 4888 3 P N 40011528 OPTION P N 40012111 OPTION 1 PROPANE 1 2 PROPANE 1 PROPANE 1 2 PROPANE 45 LFL 22 LFL 45 LFL 22 LFL P N 40009173 P N 40009614 P N 40009173 P N 40009614 XMIT GAS XMIT GAS XMIT GAS XMIT GAS VOLTS METER VOLTS METER VOLTS METER VOLTS METER 1 12 1 07 1 17 1 12 1 18 1 38 1 38 1 36 1 12 1 31 1 51 1 26 1 38 1 44 NO SPAN 1 22 1 22 51 1 25 1 23 1 18 1 31 1 31 1 41 HYDROGEN USE 1 HYDROGEN 25 LFL P N 40009171 METHANE USE 2 1 2 METHANE 50 LFL P N 40009061 Notes 1 Actual calibration field checks require use of factor shown on calibration gas cylinder to correct for actual Check gas readings include 10 positive correction for calibration port calibration at 2000 cc per mi
5. fa Detector Head bm J i Page 14 Scott Health amp Safety Instruction 9550 9142 Rev 5 4800A NIC II LEL Transmitter Wiring 4 Wiring 4 1 Wiring Overview WARNING Be sure to declassify the area to non hazardous before opening the transmitter or any other electrical enclosures Then check the area for the presence of combustibles with a portable gas detector Wire the 4888 A NIC II LEL Transmitter to e ts detector head A power source that will supply between 18 30 VDC at the input of the trans mitter The power source must be well filtered and regulated and of sufficient quality to provide a reasonable degree of protection 10 18 VDC operation is also possible Refer to Section 4 6 1 Equipment capable of receiving the transmitter s standard 4 20 mA output signal e g PLC DCS loop powered alarm data logger etc e Optional WARN ALARM and FAIL annunciators eg bells buzzers strobe lights etc which function to alert personnel of rising gas levels and transmitter electrical malfunctions Optional Modbus RS 485 master which functions to retrieve information from up to 128 transmitters using either 4 wire full duplex or 2 wire half duplex connec tions 4 2 Meeting Electrical Codes WARNING To avoid an explosion or electrical fire encase the cable connec tion to the transmitter in conduit The conduit must meet prevailing electrical codes for hazardous area installations which spec
6. 10 bit value representing the A2D value of 0 to 1023 for 20 to 103 FS 19720906 amp 1003 100 A2D ASCII 31010 6 bytes 3 amp 4 NA 6 bytes of data representing the scaled span value including the decimal point The first 5 bytes contain the value with the last byte being a space They are arranged with the first byte as the MSD with leading zero spacing For example with a span value of 1234 with I decimal point the correct value of 123 4 is returned for 100 of full scale as follows Byte 0 1 2 3 4 5 6 7 38 9 10 Response address 04 06 31 32 33 2E 34 20 Crcl Crch ASCII Char address Tel 4 1 2 3 L 4 sp Crcl Crch With the same settings a 50 of full scale reading of 617 would be Byte 0 1 2 3 4 5 6 7 8 9 10 Response address 04 06 20 36 31 2E 37 20 Crcl Crch ASCII Char address Tel sp 6 I L 7 sp Crcl Crch Page 30 Scott Health amp Safety Instruction 9550 9142 Rev 5 4800A NIC II LEL Transmitter Wiring TABLE 4 2 MODBUS REGISTER SUMMARY Cont VARIABLE ALIAS READFUNCTION WRITEFUNCTION CODE CODE EUNITS 40319 40324 3 6 6 ASCII characters assigned to the engineering units read as bytes Measurement Name 40325 40340 3 6 16 ASCII characters assigned to the unit identifier read as bytes Span 40343 3 6 An integer from 1 to 9999 used to scale the A2D ASCII value Alm1Setpoint 40345 3 6 Alm2Setpoint 40347 3 6 Integer compared to t
7. 5V Scott Poison Resistant Bead Stainless Steel Diffusion Head 4 5 5V Scott bead Stainless Steel Positive Flow Head 5 5 5V Scott Poison Resistant Bead Stainless Steel Positive Flow Head Detector Head I Diffusion attached to housing 2 Duct Adaptor 3 Flow Cell w aspirator 4 Remote Diffusion w calibration port 5 Flow Cell w o aspirator 6 Remote Diffusion 7 Round Duct Adaptor 4 or greater 8 No Option Power Options I 24VDC Standard 2 12VDC Transmitter Output I 420 mA Non Isolated 2 4 20 mA Non Isolated and Relays 3 RS 485 Modbus 4 4 20 mA Isolated All transmitter configurations are designed to be installed using explosion proof XP installation methods Page 6 Scott Health amp Safety Instruction 9550 9142 Rev 5 4800A NIC II LEL Transmitter Introduction 1 3 Features Continuous local LCD readout of combustible gas levels in the range of 0 100 LEL e Non intrusive calibration NIC using a magnet tool allowing the transmitter to be calibrated in hazardous areas without area declassification Three or four wire transmission providing a standard 4 to 20 mA output signal e One man calibration The ability of being operated as a stand alone unit or reporting to a host com puter through commercial input output processors ndicators that show when the transmitter is warming up in calibration or in a fault condition Diagnost
8. DETECTOR e CALIBRATION GAS CYLINDER See Section 8 2 Accessories for Part Number Regulator and Hose are part of 17 Liter Calibration Kit 23 7260 or 103 Liter Calibration Kits 51 2938 and 51 7339 Page 36 Scott Health amp Safety Instruction 9550 9142 Rev 5 4800A NIC II LEL Transmitter Calibration Figure 5 2 Input Voltage Measurement Points 5 4 Initial Start Up Perform these procedures after installing a new transmitter or after replacing the transmitter s Input Output printed circuit board or whenever a sensor detector is replaced For routine calibration skip to Section 5 6 Routine Calibration WARNING Declassify the area to non hazardous before opening the trans mitter housing or any other electrical enclosures Remove the cover from the transmitter enclosure To access the adjustment potentiometers and terminals on the Input Output board remove the front panel by loosening the two 2 thumbscrews located on the panel Pull the front LCD panel away from the enclosure The LCD panel is connected to the Input Output board with a ribbon cable that has sufficient length so that the panel can be placed to the side for access Do not disconnect the cable at either end After all power and signal connections have been made and checked apply power to the transmitter The current loop output will be held for approximately one 1 minute at 4 mA as indicated by the flashing delay arrow on the LCD
9. INSIDE HOUSING HOUSING GROUND SCREW e 4 20 mA Z RECEIVER DCS PLC etc GROUND GRN REFERENCE BLACK 24 VDC POWER TO SENSOR I COMMON WHITE weh Tomm TT uo SUPPLY ACTIVE RED EARTH GROUNDS NEAR POWER SUPPLY PW e IE EN Im EN oS Ju BE ET MES E E R OUT SIG SS E elle O n RAP SL fn CIC dn EH xem INPUT OUTPUT BOARD EN Note See Appendix C when using the 5 5V Scott Stainless B Steel Catalytic Bead ISOLATED 4 20mA OUTPUT CO ISOLATED 4 20 mA OUTPUT BOARD Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 23 Wiring 4800A NIC II LEL Transmitter Figure 4 4 Transmitter Wiring Diagram Stand Alone Operation Local Readout Only WIRE NUT INSIDE HOUSING HOUSING GROUND SCREW EARTH GROUNDS NEAR POWER SUPPLY GROUND GRN REFERENCE BLACK TO SENSOR COMMON WHITE GOLD BELL ACTIVE RED 6V TYPE JUMPERS SPARE Convert to 10 18 VDC operation by soldering a jumper wire at J04 Note See Appendix C when using the 5 5V Scott Stainless INPUT OUTPUT BOARD Steel Catalytic Bead Figure 4 5 Integrated Transmitter Wiring Diagram Bacharach System 130 WIRE NUT INSIDE HOUSING HOUSING GROUND nn 4 20 mA SCREW S STEM 130 ey p s TO INTERFACE BOARD REFERENCE BLACK COMBUSTIBLES 51 1797 51 1800 LL DET PWR COMMON WHITE
10. MODE exits back to NORMAL MODE by touching the UNITY key or automatically after 5 minutes without operator input Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 47 4800A NIC II LEL Transmitter 6 Operation 6 1 Normal Mode Operation The 4888 A NIC II LEL Transmitter is in its Normal Mode any time the LCD s left hand arrow is not visible and the Fault Keypad LED is not illuminated At this time the transmitter sends a standard 4 20 mA signal to the attached receiving unit where 4 mA corresponds to 0 LEL and 20 mA corresponds to 100 LEL full scale If connected to a Scott Health amp Safety Controller the controller s readout begins to indicate the level of combustible gas surrounding the transmit ter s detector head In addition to the transmitter s output signal an LCD display which is visible through the housing window shows the detected level of combustible gas in Gel EL 6 2 Fault Supervision e With the transmitter operating in its Normal Mode as described in Section 6 1 a fault condition is signaled if the transmitter s output drifts far enough nega tive to cause the output signal to drop to 2 4 mA 10 of full scale Note During Normal Mode operation both the transmitter s 4 20 mA output and LCD readout do not track input values below 0 of full scale This prevents erroneous and momentary negative noise signals from being transmitted and displayed but a 10 of
11. Mount the transmitter with its detector head facing downward where it can be calibrated and maintained safely and easily Leave enough clearance for service personnel to make adjustments or repairs When planning the installation remem ber that 3 4 conduit will need to run from the transmitter to its receiving equip ment and if the optional relay board is installed from the transmitter to the WARN ALARM and FAIL annunciators and their power source See Figure 3 1 When in doubt about where to mount the transmitter we recommend that you consult a professional safety engineering firm Generally for accurate combustible gas detection install the 4888A NIC II LEL Transmitter and its attached detector head Where air currents contain high concentrations combustible gas Mount near the floor for heavier than air gases or near the ceiling or roofs for lighter than air gases In areas within the operating temperature range of the transmitter refer to Section 2 Technical Data lf the area 1s subject to temperature extremes protect the transmitter by choosing a friendly mounting location where natural protection is available to shade reduce or nullify the adverse temperature condition e Away from the direct destructive effects of corrosive agents moisture dust and dirt if possible Take precautions to prevent any blockage or freeze over of the gas diffusion path n an area where the transmitter can be calibrated an
12. This delay time upon initial power up is to allow the sensor time to stabilize thus reducing the possibility of an erroneous alarm condition Allow a new sensor to stabilize for one 1 hour before proceeding 5 4 1 Input Voltage Check Measure the inout voltage with a DVM as shown in Figure 5 2 across TB2 termi nals PWR and GND and verify that it is between 18 and 30 Vdc or 10 to 18 Vdc if a jumper has been installed in JO4 on the Inout Output board If the measured voltage is not correct check the power supply Also check that the powerwiring wire length and wire size is adequate as described in Section 3 ON EO O ia S a A iu LL Beet T a Sess COMMON INPUT OUTPUT BOARD Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 37 Calibration 4800A NIC II LEL Transmitter Figure 5 3 Sensor Voltage Measurement and Adjustment 5 4 2 Sensor Voltage Adjustment The sensor voltage will need to be adjusted to either 6 0 Vdc or 5 50 Vdc depending on which sensor detector is installed The voltage must be adjusted as measured at the detector location To check and adjust this voltage use one of the following procedures Detectors 6 0 Vdc Gold Bell configuration Refer to Figure 5 3 If the detector head is attached to the transmitter or located no more than 18 inches away connect a DVM to TB1 R and TBI A and adjust the Volts potenti ometer for a DVM indication of 6 00
13. amp Safety Page 51 4800A NIC II LE IMj riani emattee 7 Maintenance Figure 7 1 Sensor Replacement 6V Gold Bell Diffusi Head Assembly WARNING Before performing any maintenance procedures that require the transmitter housing detector head or any other electrical enclosure to be opened be sure to declassify the area to non hazardous It is advisable that spare transmitter circuit boards and sensors be on hand to facilitate maintenance The following sections describe how to Perform routine maintenance Replace the sensor Replace a transmitter circuit board Readjust the LCD s electrical SPAN R19 and ZERO R20 readings 7 1 Routine Maintenance Routine maintenance consists of simply calibrating the transmitter as described in section 5 6 Routine Calibration Non Intrusive on a periodic basis Check calibration of the transmitter once a week for the first month of operation monthly or as experience dictates thereafter 7 2 Replacing the Combustibles Sensor Remove power from the transmitter Then disassemble the detector head and replace the sensor as shown in either Figure 7 1 7 2 or 7 3 After replacing the sensor perform the procedures in Sections 5 4 2 Sensor Voltage Check 5 4 4 Balance Adjustment 5 5 Checking Sensor Output Signal Strength and 5 6 Routine Calibration dn E WEATHERGUARD 6 32 SET SCREW O RING 3 4 14 NPT og SENSOR Note See Appendix C for
14. associated wire size In this example 18 AWG wire can be used for wiring dis tances of up to 300 ft Page 18 Scott Health amp Safety Instruction 9550 9142 Rev 5 4800A NIC II LEL Transmitter Wiring Equation 4 1 Wiring Distance D V power Supa Nin Where D Maximum wire length in feet based on ir lu X Ry X 2 the wire s loop voltage IR drop V power Supply Power Supply output voltage V Minimum operating voltage of transmitter Imas Maximum current in amperes Rwire Resistance of wire in ohms foot Example 3 When wiring the 4888A NIC II LEL Transmitter that is configured for 10 18 VDC operation to a 16 VDC power supply the power supply leads cannot drop more than 6 VDC in order to provide at least 10 VDC at the transmitter Using Equation 4 1 the maximum wiring distance for 18 AWG wire 1s 16 10 D 890 ft 0 42 x 0 00802 x 2 SS 4 4 Removing Housing Cover and Front Panel To access the wiring terminal blocks inside the transmitter housing remove the housing cover and front panel as follows 1 Loosen locking screw on housing cover using a 1 64 hex wrench then unscrew and remove cover 2 Loosen the two captive thumb screws on the front panel assembly then lift out the front panel with its circuit boards attached as far as allowed by the ribbon cable 3 After wiring is complete replace the front panel assembly by aligning its two thumb screws with their mating standoffs and fi
15. develops an open or short circuit or its output drifts far enough negative to cause the 4 20 mA output signal to drop to 2 4 mA 1096 of full scale Over range mode Over range arrow flashes 3 4 times a second with the output held at 20 5 mA until the over range condition clears ESL ESL will flash on display every 10 seconds when trip point is exceeded during calibration ER E PROM device retains calibration settings during power interruptions TEE Transmitter electronics is housed in an HKB style explosion proof aluminum enclosure with watertight O ring Hazardous area rating Class I Div 1 Groups B C and D shane 0 1 of full scale 1 count 40 to 158 F 40 to 70 C Note that the transmitter s low end temperature performance is based on self heating of the electronics by having the cover in place and power applied for at least I hour prior to evaluating performance SE 40 to 200 F 40 to 93 C 6 Volt Detector 40 to 400 F 40 to 200 C 5 5 Volt Detector sd Less than 0 1 per C over ambient temperature range Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 9 Technical Data 4800A NIC II LEL Transmitter Sensor Catalyst Poisoning Hazardous Area Rating Relay Board Option Contact Rating Typical Alarm Settings Controls n
16. e CN 55 5 1 4888A NIC I LEL Transmitter EE 55 5 2 Detector Headsets ri ENE EE NER ET er aa 56 5 5 Flow Cell Detector Head ve 57 Sua Duet Adapter Detector Hedd EE 57 SD NCCES OM E T E 57 8 6 Scott Health amp Safety Sales Service Center 58 APPENDIX A Multiplying K Factors c c eee ee eee eee eee eese esee eee eee eee eeoeeoeeene 39 APPENDIX B Scott Health amp Safety Series 6004 6104 and 6800 Transmitter Wirio Sao 63 APPENDIX C 4888A NIC II LEL Transmitter with P N 40011600 P N 40009263 P N 096 2678 or P N 096 2679 5 5V Detector Assemblies 67 Page 4 Scott Health amp Safety Instruction 9550 9142 Rev 5 4800A NIC II LEL Transmitter Introduction 1 Introduction 1 1 Transmitter Assembly Description This manual describes how to install operate and maintain the Scott Health amp Safety 4888A NIC II LEL Transmitter Non Intrusive Calibration and associated detector head Figure 1 1 The transmitter consists of a Front Panel CPU assembly one option board if installed and an Input Output board all housed in an explosion proof aluminum housing with viewing window The transmitter operates from either 12 or 24 VDC and can drive virtually any configurable 4 20 mA receiving unit DCS PLC loop powered alarm data logger etc over three or four wires plus a conforming ground There are three basic detector heads diffusion duct adapter and flow
17. is required for installation areas that may contain combustible or flammable vapors TRANSMITTER VOLTAGE OUT TEST POINT ceoco d d O a 2 S a A mes s sesh TB2 SEW Mo illi JP1 SENSOR SENSOR BALANCE GAIN ADJUST INPUT OUTPUT BOARD Page 40 Scott Health amp Safety Instruction 9550 9142 Rev 5 4800A NIC II LEL Transmitter Calibration 5 4 5 Initial Fixed Gain JP1 Setting The transmitter has four fixed gain settings that select the range of sensitivity of the sensor The gain settings are selectable via the location of jumper s on JPI located on the I O board Figure 5 5 Each jumper position provides a different amount of sensor amplification Different gain settings are required for various combustible gas and solvent vapors to be detected The gain values for JP1 are as follows Jumper in Position 1 Gain of 51 Note Multiple jumpers are Jumper in Position 2 Gain of 26 additive in relation to gain Jumper in Position 3 Gain of 12 5 For example jumpers can be Jumper in Position 4 Gain 7 placed in positions 3 and 4 to No Jumper Gain of 1 provide a gain of 19 5 To determine the proper gain jumper position either the gas to be detected must be applied to the sensor or the surrogate gas to be used for calibration must be ap plied The jumper location is determined while measuring the voltage on the VOUT test point or by observing the LCD display when the UNITY mode is se
18. o II Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 27 Wiring 4800A NIC II LEL Transmitter 4 7 1 Latching Alarms When the FUNCTION DIP switches are set up for atching operation the WARN and ALARM annunciators must be manually reset acknowledged as follows Remote RESET ACKNOWLEDGE is accomplished by a momentary action pushbutton that is wired to Terminal Block TB4 per Figure 4 6 Local RESET ACKNOWLEDGE is accomplished without opening the enclosure by moving the magnet tool back and forth along the cover s ridge as shown in Figure 4 T Figure 4 7 Non Intrusive Relay Reset Acknowledge RELAY RESET AND ACKNOWLEDGE MOVE MAGNET TOOL BACK AND FORTH WITHIN THIS AREA AT THE COVER S RIDGE 4 7 2 Normally Energized Alarms The FUNCTION DIP switches allow the WARN and ALARM relays to operate normally energized when the transmitter is powered but when no alarm condition exists When an alarm condition occurs the relays then de energize The advan tage of this configuration is that a loss of power condition creates the same relay outputs as an alarm condition Note however that the annunciators must be powered by a backup power source if they are to activate during a power outage Also note that the FAIL relay should always be operated normally energized 4 7 3 Relay Trip Points Alarm 1 and Alarm 2 trip points are controlled by two 16 position rotary switches See Figure 4 6 for a definition of the sw
19. while the indication for 20 mA is set to 100 LEL Note When calibration of the LCD display is necessary it is important to understand that the only requirement is that the display must read 0 with a 4 mA output and 100 with a 20 mA output This adjustment has no affect on the transmitter s analog output 4800A Version Set meter span Hold the cal key until the word CAL disap pears approx 5 seconds and a value appears with the arrow flashing The Span up and down adjusts the reading from 20 to 1999 The Unity key sets the decimal point Touching the Cal key returns the unit to the cal mode Material Required 4800 Version Older Version Front Display does not say 4800A Digital milliampere meter DMM Cylinders of zero and span calibration gas normally used when calibrating the transmitter Several feet of 22 AWG hook up wire No 1 Phillips head screwdriver 1 64 socket head wrench Potentiometer adjustment tool Procedure 1 2 Figure 7 4 DMM Connection to TB2 for Measuring Transmitter Output Disarm any annunciators then switch off power to the transmitter Loosen socket head screw on housing cover then unscrew and remove cover Loosen the two captive thumb screws on the front panel assembly then lift out P Disconnect 4 20 mA OUT SIG Wire To DMM i 5 S A m Idee TB2 AH UON i enn INPUT OUTPUT BOARD Page 56 Scott Health amp Safety Instruction 9550
20. 1 Multiplying K Factors for Various Combustible Gases and Vapors for 6V Gold Bell Detector Combustibles Gas Vapor K Factor Based on Propane Acetone C H O 1 3 Acetylene CH 1 4 Acrylonitrile CHN 0 97 Ammonia 0 7 Benzene CH 1 5 Butadiene C H 1 5 Butane C H 1 1 Cyclohexane CH gt 1 3 Dichloromethane CH CL 1 5 1 2 Dichloropropane C H CL 1 5 Difluoromethane 0 9 Ethane CH 0 8 Ethyl Alcohol C H 0 1 1 Ethylene C H 0 9 Ethylene Oxide C H O 1 1 Heptane C H JP 4 gasoline 1 9 Hexane C H 4 1 7 Hydrogen H 0 8 Isopropyl Alcohol C H O 1 5 Methane CH 0 6 Methyl Alcohol CH O 1 1 Methyl Chloride CH Cl 0 7 Methylene Chloride CH CI 1 5 Methyl Ethyl Ketone C H O 1 8 Methyl Fluoride 1 1 Pentane C H 1 3 Propane CH 1 0 Propylene CH 1 2 Propylene Dichloride C H Cl 1 5 Propylene Oxide C H O 1 4 Styrene CH 3 95 Toluene CH 1 7 Vinyl Chloride C H Cl 1 2 O Xylene C H jo 3 0 K Factors applicable to Combustibles Sensor 6 VDC 8000 8050 Page 64 Scott Health amp Safety Instruction 9550 9142 Rev 5 4800A NIC II LEL Transmitter Appendix A Table A 2 Diffusion Detector Calibration Check Gas Readings Valid Only in Ambient Air with Oxygen Content Aproximately 21 For use with 5 5V Scott Stainless Steel Head GAS SOLVENT ACETALDEHYDE ACETONE ACRYLONITRILE ACETYLENE AMMONIA BENZENE 1 3 BUTADIENE N BUTANE ISO BUTANE
21. 2 Transmitter Te ek ee e WEE 2 LTE er 3 Ore NL EAN dotes ai sl c D M epiac ML ee SING 4 2 Technical Data m M 5 3 Mistalatio m 7 SEN Dad heel e EE 7 9 2 uU M TIOUDEUT the T nsnes NE 10 a Wee E 11 Ap Ove Le 11 a2 Meeting bleetrical ee 11 25 SEIS CIID NES Eve ene 12 4 35 1 4 20 Signal Loop Resistance austen toes ee 12 4 3 2 Power Supply Wire Length Losvar 12 4 4 Removing Housing Cover and Front Panel rronnnnnernernnrnnrnnrnnrnnrnnrnnennennenn 15 2 5 Detector Mead Wie ven 16 4 6 Power Supply and Receiver Wiring rrnrnnnnnennennennernennernernnrnernnrnnennennennennenn 18 4 6 1 Setting the Transmitter s Operating Voltage 18 2 022 P wer Supply WINS ge 18 4 6 3 Isolated and Non Isolated 4 20 mA Oumut 18 264 Receiver WV WING ict ob ces Lacu echtes NN 18 4 6 5 Grounding and Shielding eese 21 4 7 Relay Board Wiring and Setup Lae SANGER 21 2c do SSAC MINS ANS eee 24 2 7 2 Normally BEuergtzed Alarm EE 24 Eeo Relay ITP e E 24 4 8 Modbus RS 485 Board Wiring and Setup 25 201 TEN e 2 4 8 2 Modbus Data Registers and Function Codes 25 4 8 3 MODBUS Configuration Software esee 28 E E e Ee 28 4 8 5 R4 47 End of Line Terminating Reststor ess 28 S acris ii E 31 SJ
22. 4800A NIC II LEL Transmitter HEALTH amp SAFETY INSTRUCTION 9550 9142 4888A NIC II LEL COMBUSTIBLE GAS DETECTION TRANSMITTER Non Intrusive Calibration e US Installation Operation Maintenance Rev 5 April 2008 ECN 129031 Faut a Delay Keypad ry Over range 0 100 LEL CAL Mode PES SCOTT HEALTH amp SAFETY 4320 Goldmine Road Monroe NC 28110 Phone 800 247 7257 FAX 704 291 8340 Web www scotthealthsafety com Printed in U S A Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 1 4800A NIC II LEL Transmitter WARRANTY Scott Health amp Safety warrants to Buyer that at the time of delivery this Product will be free from defects in material and manufacture and will conform substantially to Scott Health amp Safety applicable specifications Scott Health amp Safety s liability and Buyer s remedy under this warranty are limited to the repair or replacement at Scott Health amp Safety s option of this Product or parts thereof returned to Seller at the factory of manufacture and shown to Scott Health amp Safety s reasonable satisfaction to have been defective provided that written notice of the defect shall have been given by Buyer to Scott Health amp Safety within two 2 years after the date of delivery of this Product by Scott Health amp Safety Scott Health amp Safety warrants to Buyer that it will convey good title to this Product Scott Health amp Safety s li
23. 6191 gt N EARTH GROUNDS NEAR RECEIVING EQUIPMENT Ei El el TB2 SERIES 4800 NIC II TOXIC GAS TRANSMITTER or SERIES 4888 NIC II COMBUSTIBLE GAS TRANSMITTER NON ISOLATED 4 20mA 3 WIRE INSTALLATION J EARTH GROUNDS CUSTOMER SUPPLIED 4 C CABLE SEE NOTE 1 i z S fe 2 e z INPUT OUTPUT BOARD NIC II TOXIC GAS TRANSMITTER NEAR RECEIVING EQUIPMENT VE han a Sie E ISOLATED 4 20mA OUTPUT BOARD SERIES 4800 or SERIES 4888 NIC II COMBUSTIBLE GAS TRANSMITTER ISOLATED 4 20mA 4 WIRE INSTALLATION Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 67 Appendix B 4800A NIC II LEL Transmitter Figure B 2 Transmitter Wiring Diagram Scott Health amp Safety Series 6104 Panel Mount Quad Scan CUSTOMER SUPPLIED 4 C CABLE SEE NOTE 1 INPUT OUTPUT BOARD GND COMMON OUT SIG J EARTH GROUNDS NEAR RECEIVING EQUIPMENT ISOLATED 4 20mA OUTPUT BOARD gig SERIES 4800 NIC II TOXIC GAS TRANSMITTER or SERIES 4888 NIC II COMBUSTIBLE GAS TRANSMITTER ISOLATED 4 20mA 4 WIRE INSTALLATION CUSTOMER SUPPLIED 3 C CABLE SEE NOTE 1 INPUT OUTPUT BOARD FN GND COMMON SERIES 4800 NIC II TOXIC GAS TRANSMITTER or SERIES 4888 NIC II COMBUSTIBLE GAS TRANSMITTER NON ISOLATED 4 20mA 3 WIR
24. 9142 Rev 5 N80 mAeN AG dd LEL Transmitter the front panel with its circuit board s attached as far as allowed by the ribbon cable This step exposes the wiring connected to TB2 on the Input Output board 4 Remove the 4 20 mA signal lead from TB2 terminal OUT SIG Then connect a DMM to TB2 terminals OUT SIG and GND COMMON using 22 AWG hook up wire Figure 7 4 The DMM ts used to display the transmitter s milliam pere output signal 5 Reapply power to transmitter 6 Force transmitter to produce a 4 mA output as shown on the DMM when zero air is applied to the detector This can be accomplished by placing the transmitter into its CAL mode and then adjusting the magnetic TY Zero controls to produce a 4 mA output when the transmitter is placed back into its normal operation mode Remember that the transmitter s output is held at 1 5 mA while in the CAL mode therefore no DMM movement will be seen while adjusting the magnetic T Zero controls while in this mode 7 Adjust LCD ZERO control R20 Figure 7 5 until the LCD shows 0 LEL at 4 mA 8 Force transmitter to produce a 20 mA output as shown on the DMM This can be accomplished by exposing the sensor to an appropriate level of calibration gas and then adjusting the magnetic TV Span controls while in the CAL mode to produce a 20 mA output when the transmitter 1s placed back into its normal operation mode 9 Adjust LCD SPAN control R19 until the L
25. BODY 5 5V Scott Stainless Steel 6V GOLD BELL CONFIGURATION Detector view Figure C 6 Page 52 Scott Health amp Safety Instruction 9550 9142 Rev 5 N80 mAeN AG dd LEL Transmitter Figure 7 2 Sensor Replacement 6V Gold Bell Flow Cell Assembly NOTE Detailed installation instructions are contained in Instruction 51 9098 PLASTIC THREAD PROTECTOR BODY O RING fllnllf SENSOR E 6 32 SETSCREW WEATHERGUARD 8 32 SETSCREW O RING COMPRESSED AIR IN SEALING CAP ASPIRATOR ASSY MALE CONNECTOR EXHAUST TO SAFE AREA Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 53 4800A NIC II LE IMj riani emattee Figure 7 3 Sensor Replacement 6V Gold Bell Duct Adapter Assembly HUBBER GASKET THUMB SCREWS 2 O RING SENSOR BODY 3 4 14 NPT PLATE ASSEMBLY NOT FURNISHED JUNCTION BOX Page 54 Scott Health amp Safety Instruction 9550 9142 Rev 5 N80 mAeN AG dd LEL Transmitter 7 3 Transmitter Circuit Board Replacement Material Required No I Phillips head screwdriver e Small flat blade screwdriver e 7 64 socket head wrench Method of tagging wires e Replacement boards as needed Front Panel CPU Board Assembly Input Output Board Relay Board Modbus RS 485 Board or Isolated 4 20 mA Board Procedure 1 Disarm any annunciators then switch off power to the transmitter 2 Loosen socket head screw on housin
26. CD reads 100 LEL at 20 mA 10 Remove transmitter power remove test equipment and 22 AWG test leads reconnect 4 20 mA signal lead to TB2 terminal OUT SIG and then reassemble transmitter WARNING If any alarm circuits were disabled during this procedure reactivate them now otherwise hazardous combustible gas levels may go undetected 11 Calibrate the transmitter per Section 5 Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 57 4800A NIC HRehbHlcefirane nPi t s Figure 7 5 Jumper Placement and Potentiom eter Adjustments on CPU Board 4800 Version only not 4800A J1 Decimal Point Placement Decimal Points are Not Required on LEL Transmitters Therefore No jumpers are Used J2 Full Scale Reading 100 LEL Position B 2 Places LCD ZERO R20 LCD SPAN R19 Page 58 Scott Health amp Safety Instruction 9550 9142 Rev 5 4800A NIC II LEL Transmitter 8 Replacement Parts 8 1 4888A NIC Il LEL Transmitter Description Part No Complete Transmitter Assembly with Detector Head and Option Board Refer to Section 1 2 Ordering Information Housing Aluminum Explosion Proof 9505 0038 Cover w Window Housing 51 2745 O Ring Housing 05 5042 Front Panel CPU Board Ass y 9550 2083 nput Output Board 9550 2086 Relay Board Option 9550 2079 Modbus RS 485 Board Option 9550 2084 Isolated 4 20 mA Board Option 9550 2085 Magnet Tool 9550 0068 In
27. CLASS I DIV 1 GROUPS A B C amp D EXPLODED VIEW USING 5 5V SCOTT BEAD ASSEMBLY P N 40011600 OR 5 5V SCOTT POISON RESISTANT BEAD ASSEMBLY P N 096 2678 Figure C 3 Positive Flow Detector Assembly Ll TOP OF TRANSMITTER i a HOUSING 3 4 14 NPT DETECTOR BODY ASSEMBLY O RING STAINLESS STEEL HEX SOCKET HEAD PIPE PLUG 10 00 REF 254 0mm COMBUSTIBLE SENSOR 8 9 16 REF 21 7 cm GAS CALIBRATION PORT FOR CALIBRATION Il POSITIVE FLOW CAP CHECKS ACCEPTS 1 8 NPT MALE FITTING 1 4 O D COPPER TUBING RECOMMENDED EE IF REMOTE CALIBRATION IS USED 96 0mm E LABEL ol Je FLAME ARRESTOR ij PIPE PLUG E a POSITIVE FLOW DETECTOR ASSEMBLY CLASS I DIV 1 GROUPS A B C amp D POSITIVE FLOW DETECTOR ASSEMBLY EXPLODED VIEW USING 5 5V SCOTT BEAD ASSEMBLY P N 40009263 USING 5 5V SCOTT POISON RESISTANT BEAD ASSEMBLY P N 096 2679 Scott Health amp Safety Instruction 9550 9142 Rev 5 Page 72 4800A NIC II LEL Transmitter Appendix C Figure C 4 4888A NIC II LEL Transmitter Customer Wiring Connections
28. DC Both graphs are based on a temperature of 85 C and take into consideration that the wiring distance consists of two wires both hot and return The graphs are invalid however if the wire being used has a different ohms foot value from that listed If your wiring requirements fall outside the boundaries of the graph then use Equation 4 1 to calculate the maximum wire length Page 16 Scott Health amp Safety Instruction 9550 9142 Rev 5 4800A NIC II LEL Transmitter Calibration Wiring Distance Feet Between Power Supply and Transmitter 9000 8000 7000 6000 5000 4000 3000 2000 1000 Graph 1 Voltage Drop vs Wiring Distance 234 mA 18 VDC OREMUS Y 14AWG 16AWG 18AWG Ohms Foot Values 14 AWG 0 00314 16 AWG 0 00591 18 AWG 0 00802 tt jer cune mut A Eun Neri ps0 SS SS cum 1 2 3 4 5 6 7 8 9 10 11 12 Power Supply Lead Voltage Drop Example 1 When wiring the 4888A NIC II LEL Transmitter to a 24 VDC power supply transmitter setup for 18 30 VDC operation per Section 4 6 1 the power supply leads cannot drop more than 6 VDC in order to provide at least 18 VDC at the transmitter Using Graph 1 note that a power supply lead voltage drop of 6 vo
29. DETECTOR or 511906 DET PWR HEAD N ou ACTIVE RED GOLD BELL 6V TYPE EARTH GROUNDS NEAR SYSTEM 130 ENCLOSURE SPARE JUMPERS Note See Appendix C when To operate transmitter from the 16 VDC power using the 5 5V Scott Stainless SUPP YOA System oed Steel Catalytic Bead connect a jumper wire i to J04 INPUT OUTPUT BOARD Page 24 Scott Health amp Safety Instruction 9550 9142 Rev 5 4800A NIC II LEL Transmitter Wiring For transmitters being connected to an Scott Health amp Safety Series 6004 Quad Scan Series 6104 Panel Mount Quad Scan or Series 6800 Gas Receiver refer to Appendix B 4 6 5 Grounding and Shielding Following all wiring methods previously described for hazardous area installations connect a conforming safety ground wire per local code from the transmitter s ground screw to an earth ground near the power supply receiving equipment The ground wire must be no smaller than the largest current carrying transmitter wire Shielding the ground wire is optional Connect the shield of the transmitter wires to an earth ground near the power supply receiving equipment Do not ground both ends of the shield 4 7 Relay Board Wiring and Setup The optional relay board provides contact closures for the activation of local annun ciators e g horns bells buzzers or lights for the purpose of alerting personnel of ALARM 1 ALARM 2 and ALARM 3 WARN ALARM FAIL conditions ALAR
30. E INSTALLATION 6 19K RESISTOR ACROSS ALL UNUSED CHANNELS 088 6191 24V IN 4 20mA H EARTH GROUNDS NEAR RECEIVING EQUIPMENT NOTES 1 REFER TO TRANSMITTER MANUAL FOR CABLE SIZE CH1 CH2 CH3 CH4 TRANSMITTER INPUTS AND DISTANCE REQUIREMENTS Page 68 Scott Health amp Safety Instruction 9550 9142 Rev 5 4800A NIC II LEL Transmitter Appendix B Figure B 3 Transmitter Wiring Diagram Scott Health amp Safety Series 6500 Gas Receiver 24 INPUT INPUT GND JUMPER 7 0 1V Vor or 0 5V lout 4 20MA SERIES 6800 BACK PLANE CUSTOMER SUPPLIED 3 C CABLE 4 SEE NOTE 1 Z gt gt o H tr NE e 353 INPUT OUTPUT BOARD IO F GI SERIES 4800 NIC II TOXIC GAS TRANSMITTER or SERIES 4888 NIC II COMBUSTIBLE GAS TRANSMITTER NON ISOLATED 4 20mA 3 WIRE INSTALLATION NOTES EQUIPMENT MODULE 1 CH2 CH1 24 INPUT INPUT ND JUMPER SS lout 20mA SERIES 6800 BACK PLANE j _ EARTH GROUNDS NEAR RECEIVING CUSTOMER SUPPLIED EARTH GROUNDS NEAR RECEIVING EQUIPMENT AC CABLE SEE NOTE 1 INPUT OUTPUT BOARD GND COMMON ISOLATED 4 20mA OUTPUT BOARD SERIES 4800 NIC II TOXIC GAS TRANSMITTER 1 or S
31. ERIES 4888 NIC II COMBUSTIBLE GAS TRANSMITTER 1 REFER TO TRANSMITTER MANUAL FOR CABLE SIZE AND DISTANCE REQUIREMENTS ISOLATED 4 20mA 4 WIRE INSTALLATION Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 69 4800A NIC II LEL Transmitter Page 70 Scott Health amp Safety Instruction 9550 9142 Rev 5 4800A NIC II LEL Transmitter Appendix C APPENDIX C 4888A NIC Il LEL Transmitter with P N 40011600 40009263 096 2678 or 096 2679 Detectors Figure C 1 Series 4888A NIC II Catalytic Bead Combustible Gas Transmitter Detector 5 1 2 REF 4 1 2 REF 14 0cm E 11 5cm S 4 3 4 REF 12 1 cm L1 JL CAL Mode 5 1 4 REF Uny Span 13 3 cm y o9 N N HEALTH amp SAFETY SEE DIMENSION NOS ds WITH APPLICABLE Kei DETECTOR ASSEMBLY DETAIL 3 4 14 NPT CONDUIT ENTRY BOTH SIDES Zero A Series 4800 NICI Z v Ce DIFFUSION OR POSITIVE FLOW DETECTOR ASSY SEE FIGURES C 2 amp C 3 N SK ON A NC Ki jFault Keypad N X HOLE CLEARANCE FOR 10 FASTENER 2 PLACES TRANSMITTER HOUSING HKB STYLE EXPLOSIONPROOF ALUMINUM ENCLOSURE WITH WATERTIGHT O RING HAZARDOUS AREA RATING CLASS I DI
32. GASES NEAR VALVES em GLANDS IN COLLECTOR HOOD LOW INSTALLATIONS FOR HEAVIER THAN AIR GASES CONDUIT TUNNEL INSTALLATION INDOOR OR OUTDOOR WITH DRIP SHIELD Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 13 Installation 4800A NIC II LEL Transmitter Figure 3 4 Transmitter and Detector Head Outline and Mounting Dimensions 3 4 NPT Conduit Connection 8 Places Unity o DI Ze Over range CAL Mode 3 2 Mounting the Transmitter Mount the transmitter on a vertical surface in the area determined from Section 3 1 Transmitter Location Choose appropriate 10 hardware that will safely secure the transmitter and its two 1 14 standoffs P N 51 1329 on the mounting surface Note that if the detector head is being located separate from the housing then the standoffs are not re quired Refer to Section 2 Technical Data to determine the combined weight of the transmitter and detector head Mounting dimensions are shown in Figure 3 4 The general mounting procedure is to place the transmitter where it will be mounted mark the positions of its two mounting holes predrill the mounting holes then use 10 hardware to secure the transmitter and its standoffs 1f used to the supporting structure Fault Keypad Zero t STANDOFF 5 e 51 1329 e 2 supplied 0 25 6 35 mm Mounting esi Hole Accepts 10 Hardware TI 2 places NE RN e Gold Bell
33. Health amp Safety Page 33 Wiring 4800A NIC II LEL Transmitter Notes Page 34 Scott Health amp Safety Instruction 9550 9142 Rev 5 4800A NIC II LEL Transmitter Calibration 5 Calibration WARNING Before performing any calibration procedures that require the removal of the transmitter cover be sure to declassify the area to non hazardous before opening the transmitter or any other electrical enclosures 5 1 Calibration Intervals e Calibrate after initial installation Calibrate after replacing the transmitter the sensor detector or any circuit assemblies Calibration frequency is to be determined by the user however as a general rule check calibration once a week for the first month of operation then monthly or as experience dictates thereafter 5 2 Preparing for Calibration Calibrate the transmitter and detector preferably on the gas that 1t will be monitor ing If more than one gas or vapor will be monitored calibrate the instrument on the gas solvent vapor that requires the highest gain setting on the transmitter Contact Scott Health amp Safety for additional information if necessary Refer to Appendix A for additional calibration details and a chart with recommended calibration gas to be used for most common combustible vapors Equipment required for calibration Digital Volt Meter DVM with a minimum accuracy of 0 5 and a 2 00 Vdc range e Small flat blade screwdriver Calibration
34. Kit See Appendix A and Section 8 5 Accessories Calibration Cup 23 4098 for Diffusion 6 Volt detector Gold Bell configuration 3470 9500 for Diffusion 6 Volt detector with Duct Adapter Note 5 5 Volt detectors do not require a calibration cup Scott stainless steel configuration e Sensor Adapter Board 23 4027 Only required for a 6 Volt detector mounted more than 18 away from the transmitter e Zero Gas Cylinder See Section 8 5 Accessories e Combustible gas cylinder s See Appendix A and Section 8 5 Accessories Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 35 Calibration 4800A NIC II LEL Transmitter 5 3 Assembling the Calibration Equipment Assemble the calibration fixture as shown in Figure 5 1 using the appropriate calibration kits that is listed in Section 8 5 Accessories Note 6 Volt detectors require a nominal gas flow of I liter per minute The 5 5 Volt detectors require a nominal gas flow of 2 liters per minute Be sure that the proper gas bottle regulator is used FOR CALIBRATING THE SCOTT 5 5V CATALYTIC BEAD SENSOR REFER TO APPENDIX C FIGURE C 5 Figure 5 1 Calibration Fixture Showing 6V Gold Bell Catalytic Bead CALIBRATION CUP DETECTOR FROM DUCT 3470 9500 FOR ADAPTER REMOVED FROM DUCT ADAPTER ITS MOUNTING PLATE HOSE REGULATOR 1 LPM For 108 Liter Tanks REGULATOR m CALIBRATION CUP 23 4098 FOR For LU DIFFUSION Tanks
35. M 3 is typically a fail safe FAIL relay and is tripped by a defective sensor or if the 4 20 mA output has drifted below 10 of full scale Since a FAIL relay is normally energized relay de energizes under a fault condition this alarm also indicates loss of power to the transmitter If the FAIL relay is not required it is possible to configure the ALARM 3 relay to trip with ALARM 2 This configuration is useful if ALARM 2 is to drive an audible device which needs to be acknowledgeable but another ALARM 2 relay is needed for driving another non acknowledgeable device such as a fan The ALARM 1 and ALARM 2 relays activate their associated annunciators when the gas level rises above predetermined trip points These trip points are set by each relay s associated 16 position rotary switch The ALARM 1 and ALARM 2 relays can be made to function in the following manner as determined by the FUNCTION DIP switch e Increasing Trip Action occurs when the gas level rises above the trip point e Decreasing Trip Action occurs when the gas level falls below the trip point e Non Latch Annunciator automatically turns off then the gas level falls below the trip point e Latch Annunciator remains on even if the gas level falls below the trip point Once activated the annunciator must be manually reset by either closing a remote switch connected to TB4 on the relay board as shown in Figure 4 6 or by holding a magnet near the transmitter enclosure p
36. Replacement Kit Poison Resistant Combustible Sensor 40012125 Positive Flow Cap Assy Std Sensor 40009329 Positive Flow Cap Assy Poison 096 2649 Resistant Sensor O Ring 40009264 8 2a Diffusion Detector Head 8 2b 5 5V SCOTT Diffusion Detector 8 2c 5 5V SCOTT Positive Flow Detector Page 60 Scott Health amp Safety Instruction 9550 9142 Rev 5 4800A NIC II LEL Transmitter Replacement Parts 8 3 Flow Cell Detector Head 6V Gold Bell Type See Figure 7 2 Description Part No Complete Assembly 23 4017 115 32 Setscrew 02 0788 116 32 Setscrew 02 0789 Male Connector 03 1822 Plastic Thread Protector 05 3243 O Ring Body 05 5007 O Ring Sealing Cap 05 5012 Body 23 4019 Aspirator Assembly 23 4092 Sealing Cap 23 4099 Weatherguard 23 4693 Sensor Combustibles 8000 8050 See Figure 7 3 Description Part No Complete Assembly 23 4014 O Ring Body 05 5007 O Ring Hub Assembly 05 5038 Body 23 4019 Plate Assembly 23 4020 Hub Assembly 23 4021 Rubber Gasket 23 4067 Elbow 3301 0900 Sensor Combustibles 8000 8050 8 5 Accessories 8 4 Duct Adapter Diffusion Head 6V Gold Bell Type Item Part No Description Calibration Cup 23 4098 For use with 6V Gold Bell type Diffusion Detector Calibration Cup 3470 9500 For use with 6V Duct Adapter Detector Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 61 Replacement Pa
37. V 1 GROUPS B C AND D FINISH HYBRID EPOXY POLYESTER PAINTED FOR CHEMICAL RESISTANCE SERIES 4888 NIC II CATALYTIC BEAD COMBUSTIBLE GAS TRANSMITTER DETECTOR NOTES 1 TRANSMITTER DETECTOR ASSEMBLY MUST BE INSTALLED XP OPERATES ON NOM 24 VDC INPUT 18 30 VDC 2 TRANSMITTER HOUSING IS CERTIFIED XP FOR CLASS I DIV 1 GROUP B C amp D DETECTOR HOUSING IS SUITABLE FOR CLASS I DIVISION 1 GROUPS A B C amp D AND MAY BE REMOTED FROM TRANSMITTER HOUSING IF REQUIRED BY APPLICATION OR AREA CLASSIFICATION Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 71 Appendix C 4800A NIC II LEL Transmitter HenryH Bacharach Inc com Figure C 2 Diffusion Detection Assembly TOP OF TRANSMITTER i HOUSING FI 10 00 REF 254 0mm 3 4 14 NPT Re EN 7 9 16 REF SSS 19 2cm STAINLESS STEEL i HEX SOCKET HEAD PIPE PLUG DETECTOR BODY GAS CALIBRATION PORT FOR CALIBRATION Il ASSEMBLY CHECKS ACCEPTS 1 8 NPT MALE FITTING 50 6 pen ae 1 4 O D COPPER TUBING RECOMMENDED SC Seca IF REMOTE CALIBRATION IS USED gO eee LABEL OUTER GUARD Er 1 30 DIA REF 33 0mm DIFFUSION DETECTOR ASSEMBLY DIFFUSION DETECTOR ASSEMBLY
38. ability and Buyer s remedy under this warranty of title are limited to the removal of any title defects or at the election of Scott Health amp Safety to the replacement of this Product or parts thereof that are defective in title The warranty set forth in paragraph 1 does not apply to parts the Operating Instructions designate as having a limited shelf life or as being expended in normal use THE FOREGOING WARRANTIES ARE EXCLUSIVE AND ARE GIVEN AND ACCEPTED IN LIEU OF I ANY AND ALL OTHER WARRANTIES EXPRESS OR IMPLIED INCLUDING WITHOUT LIMITATION THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE AND II ANY OBLIGATION LIABILITY RIGHT CLAIM OR REMEDY IN CONTRACT OR TORT WHETHER OR NOT ARISING FROM SCOTT HEALTH amp SAFETY S NEGLIGENCE ACTUAL OR IMPLIED The remedies of the Buyer shall be limited to those provided herein to the exclusion of any and all other remedies including without limitation incidental or consequential damages No agreement varying or extending the foregoing warranties remedies or this limitation will be binding upon Scott Health amp Safety unless in writing signed by a duly authorized officer of Scott Health amp Safety WARNING Because this instrument is used to detect and monitor materials and conditions which are listed by OSHA or others as potentially hazardous to personnel and property the information in this manual must be fully understood and utilized to ensure that the i
39. ade through the housing s transparent window using a magnet tool that is supplied with the transmitter Routine calibration consists of first applying a zero gas to the sensor and adjusting the magnetic Zero controls for a zero indication on the transmitter s LCD display An appropriate span gas is then applied and the magnetic Span controls are adjusted for the correct span value Note While in the calibration mode the transmitter s output is held at 1 5 mA to prevent alarms from being tripped by the span gas that will be applied later in the calibration procedure However transmitters integrated into CEI30 Systems will cause the system s FAIL relay to drop out Zero Adjustment Attach a zero gas cylinder to the regulator of the calibration fixture 2 Place transmitter into its calibration mode by briefly holding the magnet tool over the CAL dot on the front cover plate The transmitter responds by displaying a left hand arrow on the LCD display See Figure 5 6 The calibration mode is indicated by a steady arrow It is important that this arrow is not flashing during calibration since a fast flash rate of 3 4 times per second indicates a saturated A D converter If the arrow is flashing ensure that jumper JP1 on the Input Output board is correctly installed per Section 5 4 5 3 Open regulator on calibration fixture and allow zero gas to flow over sensor until LCD readout stabilizes 4 Zero readout by holding magnet tool ov
40. alibrated using the specific gas vapor to be measured If your instrument has an agency approved certification e g Factory Mutual CSA etc failure to calibrate on the specific gas hazard to be monitored may void the certification When in doubt as to proper calibration gas or procedure contact your Bacharach Inc Sales Representative or factory applications engineer The multiplying K factors in Table A 1 may be used to calibrate a 4800 NIC II LEL Transmitter fitted with the 6 0 volt Gold Bell housing P N 8000 8050 with propane when gases other than propane are to be detected For example to use Scott Health amp Safety standard Propane gas cylinder 077 0241 42 9 LEL to calibrate a transmitter for Hexane Multiply 42 9 LEL Propane by the Hexane multiplying K factor of 1 7 as given in Table A 1 to obtain 73 LEL Hexane Adjust the transmitter s span control to indicate 73 LEL with 42 9 LEL Propane being applied to the detector The results obtained when using the K factors are approximate and must not be construed as representing highly accurate LEL percentages They are usually considered to be adequate for general detection of combustible gases but are not adequate for accurate gas analysis The calibration factors for Scott stainless steel head P N 40011528 and 40012111 are found in Table A 2 Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 63 Appendix A 4800A NIC II LEL Transmitter Table A
41. ating The relays are capable of switching loads of up to 5 A resistive at 250 VAC 30 VDC Important The relay contacts are rated for resistive loads Appropriate surge suppressors should be installed across loads to prevent arcing on the contacts Arcing generates high levels of RFI which may interfere with the measurement signals Figure 4 6 shows a typical wiring scheme that has the ALARM 1 and ALARM 2 relays wired for normally de energized operation and the ALARM 3 relay wired for FAIL operation Page 26 Scott Health amp Safety Instruction 9550 9142 Rev 5 4800A NIC II LEL Transmitter Wiring Figure 4 6 Relay Board Wiring and Switch Settings FUSED INDEPENDENT POWER SOURCE AC or DC power conforming to annunciator and relay ratings WARN ALARM FUNCTION DIP SWITCHES SWA MAGNETIC RESET SWITCH See Figure 4 7 REMOTE RESET ACKNOWLEDGE SWITCH OPTIONAL FAIL ALARM 1 amp 2 ROTARY SWITCH TRIP POINTS OF FULL SCALE POSITION z TRIP POINT POSITION ON OFF POSITION z TRIP POINT ALARM 1 1 INCREASING TRIP DECREASING TRIP 0 INACTIVE 2 NON LATCH LATCH 1 e 59 3 DE ENERGIZED ENERGIZED 2 10 3 15 ALARM 2 4 20 4 INCREASING TRIP DECREASING TRIP 5 259 5 NON LATCH LATCH 6 30 6 DE ENERGIZED ENERGIZED 7 35 7 NO ACKNOWLEDGE ACKNOWLEDGE ALARM 3 8 A3 FAIL TRIPS WITH A2 40 45 50 55 60 65 10 78 CH rm O OD Po
42. ble Modbus is the protocol or language used by the transmitter to communicate with other devices The transmitter 1s a Modbus slave that requires a Modbus master to interrogate it and retrieve information made available in specific register locations Modbus master devices are typically PLCs or PCs running HMI or GUI software equipped with a Modbus driver 4 8 1 RTU Address The 8 position switch SW1 allows a different RTU address to be assigned to each transmitter The 8 switches represent an 8 bit binary number with LSB and 8 MSB For example OFF ON ON OFF ON OFF OFF OFF 0110 1000 RTU address 104 A unique RTU address must be assigned to each transmitter communicating on the same RS 485 port 4 8 2 Modbus Data Registers and Function Codes Table 4 2 identifies the transmitter s Modbus register locations and function codes that are available Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 29 Wiring 4800A NIC II LEL Transmitter TABLE 4 2 MODBUS REGISTER SUMMARY VARIABLE ALIAS READ FUNCTION WRITE FUNCTION CODE CODE Fail Bit 12000 2 NA 0 OK Fault Alarms 12008 2 NA Returned as 8 discrete bits packed in the low byte of the response data 12008 bit O 2 Fault tracks 12000 12008 bit I Alarml 12008 bit 2 Alarm2 12008 bit 3 2 Not Used 12008 bit 4 2 Not Used 12008 bit 5 2 Not Used 12008 bit 6 2 Alarm2 Acknowledgeable 12008 bit 7 2 Not Used A2D Raw 33000 3 amp 4 NA
43. cell Varia tions of these heads include diffusion with calibration port and flow cells with and without an aspirator Each of these detector heads contain a catalytic bead com bustible gas sensor Figure 1 1 LCD DISPLAY 4800 NIC LEL PROVIDES LOCAL Transmitter with Magnet ae READOUT OF GAS Tool and Associated LEVELS Fautt a Delay Keypad eru Over range 0 100 LEL CAL Mode SE Detector Heads IN 9550 0068 O O Q MAGNETIC CONTROL PANEL ALLOWS E NON INTRUSIVE TRANSMITTER CALIBRATION HOUSING DIFFUSION DUCT ADAPTER FLOW CELL Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 5 Introduction 4800A NIC II LEL Transmitter 1 2 Transmitter Identification A transmitter is identified by its model number which in turn is determined by what type of sensor detector head and output option board are installed at the time of manufacture The transmitter s model number is located on a label that is attached to the side of the enclosure The diagram below shows how the transmitter s model number is used to specify its configuration For example The model number 4888 1 1 1 2 denotes a transmitter with a combus tibles sensor an intergal diffusion detector head and a 4 20 mA output with an optional relay board 4888 X X X X Sensor Type Combustibles 6V Gold Bell sensor 2 5 5V Scott bead Stainless Steel Diffusion Head 3 5
44. ctivity 11 Disassemble the calibration fixture Figure 5 6 Front Panel Indicators and Magnetic Adjustments as seen through the Front Cover Window Steady State Arrow Indicates FAULT KEYPAD LED the Calibration Mode Lights under fault conditions and when Slow Flashing Arrow Indicates the magnet tool is held a Power On or CAL Exit Delay over a magnetic keypad control Flast Flashing Arrow Indicates an Over range Condition Five rapid flashes indicate entry into the Unity Gain Mode LCD DISPLAY Shows combustible gas level in LEL UNITY GAIN MODE ENTER ZERO UP ADJ SPAN DOWN ADJ SPAN UP ADJ ZERO DOWN ADJ CALIBRATION MODE ENTER EXIT RESET amp ACKNOWLEDGE ALARM MAGNETIC SWITCH Hold magnet tool near base of housing cover at this location Refer to Section 4 7 1 Page 46 Scott Health amp Safety Instruction 9550 9142 Rev 5 4800A NIC II LEL Transmitter 5 7 4 20mA Simulate Mode During NORMAL MODE operation holding the magnet over the DOWN ZERO key for at least 10 seconds places the unit into a 4 20mA SOURCE MODE The LCD indicates directly in milliamps the actual value of the 4 20mA output and is irregardless of gas on the sensor The UP DOWN SPAN keys are used to set this value between 4mA and 20mA This feature is provided to make it easier to test display and alarm devices connected to the 4800A s 4 20mA output without expos ing the sensor to test gas 4 20mA SOURCE
45. d maintained in a safe and easy manner Leave enough clearance for service personnel to make adjustments or repairs 9 4 NPT Conduit he used for power 4 20 mA signal and optional relay board sop Fas Keypa or modbus wiring 111 Over range 0 100 LEL CAL Mode If second conduit opening is not required seal unused opening with pipe plug supplied with transmitter Diffusion Detector Head Gold Bell Type Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 11 Installation 4800A NIC II LEL Transmitter Figure 3 2 shows typical mounting of the flow cell and duct adapter detector heads detailed mounting instructions of the flow cell detector are supplied in Instruction 51 9098 Figure 3 2 Typical Flow Cell and Duct Adapter Detector Head Locations COMPRESSED AIR IN Ta 3 Za WASTE DAL ec Ru Her nO kr 7 p did FLOWMETER FLOW CELL w ASPIRATOR N DUCT ADAPTER Page 12 Scott Health amp Safety Instruction 9550 9142 Rev 5 4800A NIC II LEL Transmitter Installation Figure 3 3 shows installation of a diffusion detector head mounted separate from the transmitter 106 foot maximum separation in areas where it is not convenient to have both units together Figure 5 3 Typical Diffusion Head Mounting Locations when Separated from the Transmitter Housing CEILING HOLE IN FALSE CEILING HIGH INSTALLATIONS FOR LIGHTER HAN AIR
46. e optional relay board or a Scott Health amp Safety Controller turn on and remain activated or immediately turn off Don t attempt to reset alarms until the combustible gas or vapor is cleared Let qualified personnel reset alarms only after the area is known to be free of combustibles If the relays in the alarm circuit are set up for non latching operation then in the case of sensor flooding as previously described the annunciators will turn on and then quickly turn off even though combustible gas is still present at the detector Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 49 4800A NIC II LEL TQpenaition e The transmitter won t respond to new combustible gas concentrations at the sensor until the atmosphere clears and adequate Oxygen levels return For safety reasons check calibration per Section 5 6 Routine Calibration Non Intrusive after the combustible gas or vapor flooding has cleared 6 5 Delay Modes 6 5 1 Power Up Delay The 4 20 mA output is held at 4 mA for 1 minute after power is first applied to the transmitter This delay is to allow the combustibles sensor time to stabilize and reduce the possibility of causing an erroneous alarm condition within the gas detection system 6 5 2 CAL Mode Exit Delay Span gas is typically the last gas applied during a routine calibration If the CAL mode is exited too quickly after removing span gas from the sensor the reading may still corresp
47. er Figure 4 7 Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 25 Wiring 4800A NIC II LEL Transmitter De energized The relay is de energized under normal operating conditions and becomes energized when the gas level exceeds the trip point Energized The relay is energized under normal operating conditions and becomes de energized when the gas level exceeds the trip point The normally energized operating mode may also be referred to as fail safe Acknowledge The ALARM 2 ALARM level annunciator can be turned off by activating the local magnetic or remote RESET switch Alarm 2 condition acknowledged horn silenced when the gas level is still above its trip point No Acknowledge The ALARM 2 annunciator cannot be reset until the gas level drops below its trip point A3 FAIL Operate the ALARM 3 relay in its FAIL mode normally energized For gas detection applications A3 should always be operated as a FAIL relay Trips with A2 Operate the ALARM 3 relay in conjunction with ALARM 2 Connect the annunciators to their own power source DO NOT use the transmitter s power supply to power the annunciators Also make certain that the annunciator s power source is properly fused Run wires of a suitable AWG size according to NEC and any appropriate local electrical codes from each annunciator to Terminal Blocks Al A2 and A3 Use the annunciator s power consumption rating to determine wire size and fuse r
48. er the appropriate Zero TY symbol until the LCD display shows zero 5 Shut off regulator and remove zero gas cylinder SPAN Adjustment 6 Attach an appropriate span gas cylinder to the calibration fixture s regulator 7 Open regulator and allow span gas to flow over sensor until the LCD readout stabilizes 8 Hold magnet tool over the appropriate Span TV symbol until the correct span indication is observed on the LCD display Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 45 Calibration 4800A NIC II LEL Transmitter If a flashing left hand arrow appears on the LCD during calibration the calibration procedure should be halted since the analog voltage being applied to the A D converter is too high Either the span gas concentration is incor rect or the fixed gain jumper on the Input Output board is set incorrectly refer to Section 5 4 5 9 Shut off regulator and remove calibration cup Then before proceeding with Step 10 wait until the transmitter s LCD readout drops below the system s alarm trip points otherwise alarms may sound when the transmitter is placed back into its normal mode of operation 10 Exit the calibration mode by again briefly holding the magnet tool over the front panel s CAL dot The left hand arrow should now start slow flashing and then turn off after a 1 minute delay If the calibration mode is not exited manually it will automatically exit after 5 minutes of keypad ina
49. ev 5 Scott Health amp Safety Page 73 4800A NIC II LEL Transmitter Appendix C Figure C 5 4888A NIC II LEL Transmitter Calibration Test Set Up for SCOTT 5 5V Detector 1 8 NPT CALIBRATION pa BRED TIBET OR CHECK PORT ACCEPTS TUBE FITTINGS BARBED INSERTOR TUBE FITTING a CYLINDER VALVE 1 gt H x FLOW METER ei ES G d WITH VALVE TT TUBING MAY BE C TEMPORARY OR PERMANENTLY 1 i SCOTT 5 5V e DIFFUSION eme DETECTOR f GAS CYLINDER S MUST USE ONE OF THE FOLLOWING CALIBRATION TEST KITS 2 1 2 METHANE IN AIR P N 40009061 1 HYDROGEN IN AIR P N 40009171 196 PROPANE IN AIR P N 40009173 1 2 PROPANE IN AIR P N 40009614 Instruction 9550 9142 Rev 5 Page 74 Scott Health amp Safety
50. full scale drift will still cause a fault indication to occur e The transmitter is also equipped with fault detection circuitry that detects when the sensor s catalytic beads open or short circuit This fault condition will exist until the sensor is replaced The transmitter signals either of the above fault conditions by lighting the front panel Fault Keypad LED dropping out the ALARM 3 FAIL relay on the optional relay board and clamping the transmitter s output signal at O mA Note The ALARM 3 relay on the optional relay board should always be configured as a FAIL alarm causing this relay to de energize in the event of a fault condition If the transmitter is connected to a Scott Health amp Safety Controller the transmitter s O mA output signal will cause the controller s FAIL indicator to light and actuate its FAIL alarm circuit Page 48 Scott Health amp Safety Instruction 9550 9142 Rev 5 ATA tNIC II LEL Transmitter 6 3 Overrange The A D converter saturates at readings above 103 of full scale At this point an overrange condition is indicated by a fast flashing 3 4 times per minute left hand arrow on the transmitter s LCD display Note that if an overrange condition occurs during calibration check 1f either the span gas concentration is incorrect or the fixed gain jumper on the Input Output board is set incorrectly refer to Section 5 4 5 The transmitter identifies an overrange condition t
51. g cover then unscrew and remove cover 3 Referring to Figure 8 1 disassemble the transmitter as necessary to remove the circuit board being replaced If the board has external wires connected to its terminal block s be sure to first tag the wires before removing them 4 Install the new circuit board Then if necessary reconnect any wires that were removed in Step 3 If the Input Output board was replaced also be sure jumpers JO4 and JP1 are placed correctly Refer to Sections 4 6 1 and 5 4 5 for information on jumper placement In addition the board s VOLTS and BAL potentiometers will need to be adjusted per Sections 5 4 2 and 5 4 4 If the Relay board was replaced also be sure the ALARM 1 and ALARM 2 rotary switches and the FUNCTION DIP switch are set correctly Refer to Section 4 7 for information on switch positions If the Modbus RS 485 board was replaced also be sure the DIP switches and jumpers are set correctly Refer to Section 4 8 for information on switch and jumper positions 5 Replace housing cover and tighten its socket head screw 6 Calibrate transmitter per Section 5 Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 55 4800A NIC II LE IMf riani emattee 7 4 LCD Full Scale Display Adjustment This procedure is performed at the factory and need not be repeated unless the LCD indications for 4 and 20 mA need to be changed or verified The LCD indication for 4 mA is factory set to 0 LEL
52. he A2D Raw value to determine alarm 1 or 2 status The 0 to 100 set point must be scaled from 197 to 1003 This is done by using Alarm 806 Offset Example A 40 set point would be computed as 0 4 806 197 D P Position 40349 3 6 Determines how many decimal positions return with the A2D ASCII value Valid range is O to 3 Alm1Trip 40351 3 6 Alm2Trip 40359 3 6 Set to 255 alarms on high set to O alarm on low Alm1Latch 40353 3 6 Alm2Latch 40355 3 6 Set to O causes alarm 1 or 2 to auto reset set to 255 causes alarms 1 or 2 to latch AlmZoneWord 40357 3 6 16 bit value which may be used as a zone alarm mask for the master AlarmReset 2000 NA 5 Setting to 255 causes any latched or acknowledgeable alarms to reset InitRtu 2010 NA 5 Setting to 255 causes a re start which applies updated configuration variables Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 31 Wiring 4800A NIC II LEL Transmitter 4 8 3 MODBUS Configuration Software All of the register values described in Section 4 8 2 must be configured via the serial port This is a one time only requirement unless changes within the appli cation necessitate adjustments after the initial installation This function is usually built into the Modbus master 4 8 4 RS 485 Wiring The RS 485 electrical standard allows cable lengths up to 4000 feet between Modbus master and slave Both 4 wire full duplex and 2 wire half duplex connec tions are s
53. ic output signals which distinguish between the transmitter s calibra tion 1 5 mA fault 0 mA and overrange 20 5 mA modes An approved explosion proof aluminum transmitter enclosure with watertight O ring The enclosure is coated with a hybrid epoxy powder polyester paint for superior chemical resistance The 4888 A NIC II LEL Transmitter and its detector assembly are suitable for installation in Class I Division 1 Group B C and D hazardous locations e Space is provided behind the Front Panel CPU assembly to add a single circuit board for adding one of the following optional functions Relay Board provides local activation of WARN ALARM and FAIL annun ciators for the purpose of alerting personnel of rising combustible gas levels or system electrical failures Modbus RS 485 Serial Interface Board allows up to 128 transmitters to communicate to a Modbus master device over a single 2 or 4 conductor cable Isolated 4 20 mA Output Board isolates the transmitter s output from its power supply and sensor circuits Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 7 Introduction 4800A NIC II LEL Transmitter 1 4 Operational Overview In operation when a mixture of air and combustible vapors or gases surrounds the detector head the combustibles around the surface of the sensor s active element are rapidly oxidized by catalytic oxidation thus raising the temperature of that element This rise in
54. ify conduit sealing explosion proof fittings and special wiring methods To meet prevailing electrical codes use conduit and all other materials required for electrical wiring in hazardous areas Install wiring according to National Electrical Code NEC Articles 501 517 As supplied the detector head s wiring 1s already sealed and requires no additional sealing to conform to NEC requirements for explosion proof installations as long as the detector is mounted no further than 18 457 mm from the transmitter NEC Article 501 5 a 1 Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 15 Wiring 4800A NIC II LEL Transmitter 4 3 Selecting Wire Size 4 3 1 4 20 Signal Loop Resistance The maximum signal loop resistance that can be connected to the transmitter s output is 800 ohms 24 VDC 400 ohms 12 VDC In almost all cases the wire size chosen for the power supply leads will be more than adequate for the 4 20 mA signal lead Note that 18 AWG wire provides a 4 20 mA signal lead wiring dis tance of approximately 34 000 feet Note Maximum signal loop resistance is defined as the sum of the 4 20 mA signal wire resistance the receiver s input resis tance normally 250 ohms and the resistance of the common ground wire between the transmitter and power supply 4 3 2 Power Supply Wire Length The transmitter requires an operating voltage of between either 10 18 or 18 30 VDC as determined by the in
55. ion This value represents the gain applied to the sensor output at the time it was last calibrated Each time the sensor is calibrated the gain setting may change to a higher value as additional gain is applied to the sensor output to compensate for the loss of sensitivity that 1s inherent in catalytic bead sensors 5 5 2 Set End of Service Life Indicator The 4888A NIC II will display ESL every ten seconds after a calibration results in the gain applied to the sensor output exceeding the trip point that has been set The gain range is 0 50 to 2 00 as described in section 5 4 5 The factory trip point is adjusted at 1 90 and is adjustable by the user as follows I In normal operation hold a magnet over the UNITY key for approximately 5 seconds until a value is displayed with the delay arrow flashing 2 The value displayed will be the Compared Gain Value and is adjustable from 0 50 to 2 01 3 Use the SPAN UP DOWN arrow keys to adjust this value Setting the value to 2 01 will disable the ESL feature 4 After the desired value is displayed hold the magnet over the UNITY key momentarily to return to normal operation Page 44 Scott Health amp Safety Instruction 9550 9142 Rev 5 4800A NIC II LEL Transmitter Calibration 5 6 Routine Calibration Non Intrusive Routine calibration does notrequire the area to be declassified as non hazardous since all adjustments are done with the transmitter s cover intact Adjustments are m
56. ion following a successful calibration that a particular sensor is nearing its end of service life This enables a user to plan sensor replacement during scheduled maintenance time while the sensor is still operational rather than after a sensor is found to be beyond its service life which is typically not known until a calibration 1s attempted unsuccessfully The gain value will display from 0 50 to 2 00 0 50 representing a low gain and 2 00 representing a high gain value This value represents the amount of gain applied to the sensor output signal to calibrate it The initial gain applied to a new sensor during the initial calibration will be dependent on the gas solvent vapor that the detector is being calibrated for as well as the position of JP1 It is normal for new sensors calibrated on the same cal gas to have initial gain settings vary by as much as 20 percent Sensors will also lose output signal strength at varying levels due to many factors regarding the application and operating environment Calibration frequency and how often how much gas is detected will also affect the loss of sensitivity of a given detector 5 5 1 Display Gain Setting In normal operation hold a magnet over the SPAN DOWN arrow key The gain will display as a number between 0 50 and 2 00 with the delay arrow flashing The gain will display so long as the magnet remains over the SPAN DOW N arrow key Remove the magnet and the display will go back to normal operat
57. itch positions Note that both alarm set points incorporate approximately 1 5 hysteresis In other words the signal must drop about 1 5 below the trip level to reset the alarm This prevents alarm chatter when the input signal equals the trip level Page 28 Scott Health amp Safety Instruction 9550 9142 Rev 5 4800A NIC II LEL Transmitter Operation 4 8 Modbus RS 485 Board Wiring and Setup Figure 4 8 Modbus RS 485 Board TX amp RX ARE TRANSMIT RECEIVE LED s USEFUL IN TROUBLESHOOTING JP1 HOLD HOLDS MODBUS VALUE AT 15 DURING CALIBRATIONS JP1 TRACK MODBUS VALUE TRACKS READING DURING CALIBRATIONS JP2 DETERMINES ZWEE OR 4 MRE RS 485 OPERATION JUMPERS SHOWN IN 2 MRE N3dO o CONFIGURATION T T 22 8 BIT RTU ADDRESS RA R8 am pe el Hil bc ac DIP SW 1 LSB TBI IS FOR RS 485 CABLE CONNECTION HD Q DIP SW 8 MSB IN2 MRE MODE 1 amp 2 MAY BE IN OQ i S S 9295T t2V q COMING CABLE AND 4 amp 5 EXITING R12 c6 SW CABLE 02 L3 R14 RS 485 TERMINATING RESISTOR Orme AW 0010 1092 REMOVE EXCEPT FORUNT AT END OF LINE The optional Modbus RS 485 Serial Interface board Figure 4 8 allows up to 128 transmitters to communicate to a Modbus master device on a single ca
58. lected Important JP7 must be configured only with a new sensor Configuring JP1 using a sensor that has been is use for any period of time may cause inaccurate gas readings Note JP7 is located to set the course span value by setting the gain of the sensor s bridge circuit JP1 is only a coarse setting The Span Up and Down arrow keys have an adjustment range equal to a minimum gain of 0 5 to a maximum gain of 2 For example when the gain jumper JP1 is located in position 4 a course gain of 7 is set The arrow keys can reduce the gain to 3 5 or raise it to 14 VOUT Test Point Method The VOUT test point has a total voltage swing of 1 6 volts between 0 4 and 2 0 Vdc This voltage swing is equivalent to O 100 LEL Therefore a voltage of 1 2 Vdc will correspond to 50 LEL Use Equation 5 1 Table 5 1 and Appendix A to determine the span voltage that is to be indicated on the VOUT test point for a given calibration The following examples show how to properly use the information contained in these sections Example 1 If Methane in air is the gas to be monitored apply an appropriate calibration gas to the detector preferably use 2 5 Methane which is 50 LEL The JP1 jumper is to be configured so that the voltage measured at VOUT corre sponds to the gas concentration applied If 2 5 Methane in air is used 50 LEL position JP1 so that the voltage at VOUT is approximately 1 2 Vdc or slightly higher When finished remove gas f
59. lts crosses the wire size lines at approximately the following wiring distances 14 AWG 4050 ft 16 AWG 2150 ft 18 AWG 1600 ft The power supply wiring distance should not exceed the value determined for its associated wire size In this example 18 AWG wire can be used for wiring dis tances of up to 1600 ft Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 17 Wiring 4800A NIC II LEL Transmitter Wiring Distance Feet Between Power Supply and Transmitter 3500 3000 2500 2000 1500 1000 500 Graph 2 Voltage Drop vs Wiring Distance 420 mA 10 VDC 16AWG 18AWG Ohms Foot Values 14 AWG 0 00314 16 AWG 0 00591 18 AWG 0 00802 1 2 3 4 5 6 7 8 Power Supply Lead Voltage Drop Example 2 When wiring the 4888A NIC II LEL Transmitter to a 12 VDC power supply transmitter setup for 10 18 VDC operation per Section 4 6 1 the power supply leads cannot drop more than 2 VDC in order to provide at least 10 VDC at the transmitter Using Graph note that a power supply lead voltage drop of 2 volts crosses the wire size lines at approximately the following wiring distances 14 AWG 760 ft 16 AWG 400 ft 18 AWG 300 ft The power supply wiring distance should not exceed the value determined for its
60. n wire serves as an earth ground that is connected to the ground screw inside the transmitter enclosure Page 20 Scott Health amp Safety Instruction 9550 9142 Rev 5 4800A NIC II LEL Transmitter Wiring Figure 4 1 Typical Explosion Proof Conduit Configurations from Transmitter Housing to Detector Head for Installation in Group B C NIC II and D Hazardous Areas TRANSMITTER DETECTOR HEAD CONDUIT 18 inches is the standard distance per NEC Articles For exceptions to this 18 distance read the label on Aug the transmitter housing EXAMPLE 1 Transmitter and Detector threaded together as a unit or mounted within 18 inches of each other NIC II JUNCTION BOX TRANSMITTER CONDUIT 51 1330 SEALS CONDUIT CONDUIT CONDUIT CONDUIT cu HEAD 18 18 18 max max max 106 max EXAMPLE 2 Connecting the Detector to the Transmitter Housing at a distance greater than 18 inches Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 21 Wiring 4800A NIC II LEL Transmitter 4 6 Power Supply and Receiver Wiring The transmitter can be connected to its power supply and receiver using individual wires but the recommended method is to use a multi conductor overall shielded cable It is strongly recommended that the transmitter wiring not be run in common conduit or raceways with AC power conductors or conductors servicing raceway equipment that may generate RFI 4 6 1 Setting
61. nnm 4 20 mA Output Board Option RS 458 Serial Board Option lt 10 seconds to 50 full scale 30 seconds to 90 full scale See Figure 3 4 Transmitter Assembly 3 lb 8 oz 1 6 kg Diffusion Detector 8 oz 0 2 kg Flow Cell Detector 14 oz 0 4 kg Duct Adapter Detector 1 Ib 9 oz 0 7 kg Catalytic platinum bead 6 volt operation year normal service when intermittently exposed to combustible gas in air mixtures Do not expose catalytic sensor to silicone vapor or silicone compounds that outgas before fully curing Consult factory for further details CSA Explosion proof installation Class I Division 1 Groups B C and D Hazardous Location C22 2 No 152 CSA US CSA has accreditation in U S from Occupational Safety and Health Administration OSHA as a nationally recognized testing laboratory Relay contacts are SPDT Form C rated for SA 250 VAC 30 VDC resistive 20 LEL WARN level Alarm 1 40 LEL ALARM level Alarm 2 DIP switch determines setting of eight board functions Two rotary switches set the WARN and ALARM trip points 1500 V isolation between the 4 20 mA output signal and the transmitter s power supply Modbus protocol Page 10 Scott Health amp Safety Instruction 9550 9142 Rev 5 4800A NIC II LEL Transmitter Installation 3 Installation Figure 3 1 Typical Transmitter showing a Diffusion Detector Head 3 1 Transmitter Location
62. nstrument is operating properly and is both used and maintained in the proper manner by qualified personnel An instrument that is not properly calibrated operated and maintained by qualified personnel is likely to provide erroneous information which could prevent user awareness of a potentially hazardous situation for the instrument user other personnel and property If after reading the information in this manual the user has questions regarding the operation application or maintenance of the instrument supervisory or training assistance should be obtained before use Factory assistance is available by calling 704 291 8300 Declaration of Conformity Manufacturer s name Scott Health amp Safety Manufacturers address 4320 Goldmine Road Monroe NC 28110 Product name 4888A NIC Il Combustible Gas Transmitter conforms to the following specifications European Directive 89 336 EEC EMC EN 50081 1 Emissions EN 50082 2 Immunity Copyright 1999 by Scott Health amp Safety All rights reserved amp SCOTT HEALTH amp SAFETY is a registered trademark of Scott Health amp Safety All other brand or product names are trademarks or registered trademarks of their respective holders Page 2 Scott Health amp Safety Instruction 9550 9142 Rev 5 A 4800A NIC II LEL Transmitter Contents 1 Introduction me 1 1 1 Transmitter Assembly Description 222 e sah eb to e ERU EI Po usse tabe tes l 1
63. nute concentration variations in calibration gas lots Calibration check gas readings using conventional diffusion techniques plastic bag filled with calibration gas and placed over detector should be reduced by 10 multiply table gas reading by 0 91 96 gas meter readings are the flammable gas concentration expressed as 96 lower flammable limits in air Instrument must be above flash point of the vapor to be detected Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 65 Appendix A 4800A NIC II LEL Transmitter Page 66 Scott Health amp Safety Instruction 9550 9142 Rev 5 4800A NIC II LEL Transmitter Appendix B APPENDIX B Scott Instrumennts Series 6004 6104 and 6800 Transmitter Wiring Refer to Figure B 1 B 2 or B 3 when wiring a 4800 NIC II LEL Transmitter to an Scott Health amp Safety 6004 Quad Scan 6104 Panel Mount Quad Scan or Series 6800 Gas Receiver Figure B 1 Transmitter Wiring Diagram Scott Health amp Safety Series 6004 Quad Scan CUSTOMER SUPPLIED lt P 3 C CABLE a SEE NOTE 1 gt gt o H MI INPUT OUTPUT 5 a BOARD o QUAD SCAN POWER SUPPLY PC BOARD TRANSMITTER INPUTS CH3 CH4 BCABC NOTES 1 REFER TO TRANSMITTER MANUAL FOR CABLE SIZE AND DISTANCE REQUIREMENTS br ped RE RR z FI Bz aT lt x 2 Es E E R 6 19K RESISTOR ACROSS amp 9 amp 38 53 ALL UNUSED CHANNELS Z 088
64. o the receiving equipment by locking its output signal at 20 5 mA until the overrange condition clears 6 4 Sensor Flooding WARNING Explosion hazard The sensor could become damaged if the detector becomes flooded or samples high combustible gas concentrations over 100 LEL for long periods of tim e Always recalibrate the transmitter as per Section 5 6 Routine Calibration Non Intrusive after sampling a high gas concen tration If the sensor cannot be calibrated replace it per Section 7 2 Replacing the Sensor and then recalibrate the transmit ter If the atmosphere around the transmitter s sensor becomes flooded with a high concentration of combustible gas or vapor The gas indication at the receiving unit and on the transmitter s faceplate will quickly jump above 60 LEL and then rapidly fall to 076 LEL This indicates that a high possibly explosive concentration of combustible gas is surrounding the detector Even a concentration too rich to be explosive should be considered dangerous The rapid increase of the gas reading was caused by the high concentration of combustible gas combining with the air already inside the detector and being oxidized by the sensor The now flooded sensor can no longer oxidize the gas due to a lack of Oxygen in turn causing the gas reading to return to zero even though combustible gas is still present at the detector The WARN and ALARM annunciators either activated by th
65. on settings during power interruptions Page 8 Scott Health amp Safety Instruction 9550 9142 Rev 5 4800A NIC II LEL Transmitter Technical Data 2 echnical Data Readout ern Power Requirements Signal Output Magnetic Calibration Adjustment Range Calibration Resolution Diagnostics uusses Memory Backup PA OUST ensem Sheesh Accuracy electronics Ambient Temperature Transmitter electronics Combustibles Sensor Temperature Drift ns 3 14 digit LCD 96 LEL NN 18 0 to 30 0 VDC 4 2 watts maximum steady state 24 VDC nominal input with relay option board installed relays energized NE 4 20 mA into 800 ohms with 24 VDC power standard Range of operation is O to 20 5 mA een ZERO 15 of full scale SPAN Turn up to gain of 2 down to gain of 0 5 The sensor can lose up to 50 of its signal strength and the magnetic SPAN adjustment can still be used to properly calibrate the transmitter without having to open the enclosure poer 0 1 of full scale NG CAL mode Lighted CAL Mode arrow with the output held at 1 5 mA FAULT mode Lighted Fault Keypad LED with the output held at O mA A fault condition is detected if the sensor
66. ond to the span gas value and trip alarms For this reason the transmitter s 4 20 mA output is held at 4 mA for 1 minute after exiting the CAL mode 6 5 3 Automatic CAL Mode Exit Timer The transmitter s 4 20 mA output is held at 1 5 mA during calibration This alerts any loop monitoring devices that a special condition is present Since it is possible for an operator to forget to return the transmitter to its normal operating mode the transmitter s microprocessor monitors the magnetic keypad while in the CAL mode and if no key stroke is made during a 5 minute interval the CAL mode is automatically exited 6 5 4 Aborting the Delay Modes Troubleshooting or other testing procedures may be easier to perform without the power up and CAL mode exit delays active These delays can therefore be tempo rarily turned off by first removing power holding the magnet tool over the Zero T control and then reapplying power Note that the transmitter must not be in a fault condition when power is reapplied Any subsequent power up without holding the magnet tool over the Zero control reactivates both delay periods Page 50 Scott Health amp Safety Instruction 9550 9142 Rev 5 ATA tNIC II LEL Transmitter 6 6 Calibration Values Back Up Power An E PROM non volatile memory device provides unlimited periods of continuous storage of calibration values during power interruptions Instruction 9550 9142 Rev 5 Scott Health
67. onds after the power is turned on Remove the magnet from the display 3 The LCD will show a value with both the flashing arrow and steady arrow on for 1 minute 4 This will set the gain to unity no gain the meter span to 100 and the End of Service Life value to 1 9 Page 42 Scott Health amp Safety Instruction 9550 9142 Rev 5 4800A NIC II LEL Transmitter Calibration The Unity feature has now been activated so that the LCD display can be used to position JPI Important Whenever the Unity feature is activated the transmitter must be recalibrated All previous calibration information will be erased when the Unity feature is accessed Use Equation 5 1 Table 5 1 and Appendix A to determine the level that is to be displayed on the LCD for a given calibration The following examples show how to properly use the information contained in these sections Example 1 If Methane in air is the gas to be monitored apply an appropriate calibration gas to the detector preferably use 2 5 Methane which is 50 LEL The JP1 jumper is to be configured so that the LCD display corresponds to the gas concen tration applied If 2 5 Methane in air is used 50 LEL position JP1 so that the display on the LCD is approximately 50 or slightly higher When finished remove gas from sensor and go to Section 5 4 6 Note Example 2 assumes 6V Gold Bell catalytic bead sensor Example 2 If Acetylene in air is the gas to be monitored Pr
68. opane in air will be used as a surrogate gas as detailed in Appendix A The LCD display is based on the K Factor of Acetylene Using the procedure detailed in Appendix A it is determined that 42 9 Propane in air is equivalent to 60 LEL Acetylene Therefore by applying 42 9 LEL Propane in air 0 94 96 Propane position JP1 so that the display on the LCD shows approximately 60 or slightly higher When finished remove gas from sensor and go to Section 5 4 6 5 4 6 Completing Initial Start Up After completing the initial start up procedures reinstall the front panel assembly by aligning the 2 thumbscrews with their mating standoffs and tightening firmly by hand Replace the housing cover and tighten its locking screw 5 5 End of Service Life The model 4888A NIC II Transmitter has a standard feature whereby the sensor gain level can be displayed after calibration and compared to a user adjusted level for the purpose of determining the remaining service life of the sensor Catalytic combustible sensors inherently lose output signal strength as they age Knowing the signal strength of a new sensor as defined by the gain applied during calibration when it is first installed allows a user to track its signal deterioration over time Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 43 Calibration 4800A NIC II LEL Transmitter A high gain level alert can be activated by the 4888A as a means of automatic notificat
69. put Output Board 096 2805 When using 5 5V Detectors only as referenced in Section 8 2b amp 8 2c Figure 8 1 Exploded View of the 4SSSA NIC II LEL Transmitter 7 64 SOCKET OPTION INPUT OUTPUT HOUSING y HEAD SCREW BOARD BOARD COVER FRONT PANEL CPU O RING BOARD ASSEMBLY Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 59 Replacement Parts 4800A NIC II LEL Transmitter 6V Gold Bell Type See Figure 7 1 Description Part No Complete Assembly Standard Rain Guard 23 4012 w Calibration Port 9550 1002 116 32 Setscrew 02 0789 O Ring 05 5007 Body 23 4019 Weatherguard 23 4692 Sensor Combustibles 8000 8050 Assembly See Appendix C Figure C 2 Description Part No Complete Assembly Standard 40011600 Complete Assembly w Poison 096 2678 Resistant Sensor Detector Body Assembly 40009065 Stainless Steel Pipe Plug 40002800 Combustible Sensor Standard 40011528 Replacement Kit Poison Resistant Combustible Sensor 40012111 Outer Guard Assy Standard Sensor 40009066 Outer Guard Poison Resistant Sensor 096 2648 Set Screw 33351 017 Assembly See Appendix C Figure C 3 Description Part No Complete Assembly Standard 40009263 Complete Assembly w Poison 096 2679 Resistant Sensor Detector Body Assembly 40009065 Stainless Steel Pipe Plug 40002800 Combustible Sensor Standard 40011528
70. ransmitter Figure 5 5 Test Point VOUT Balance Adjustment and JP1 Gain Setting 5 4 3 Monitoring the VOUT Test Point The V OUT test point on the Input Output board may be monitored during the remainder of this section to verify correct initial setup Connect the DVM to TB2 GND and V OUT as shown in Figure 5 5 V OUT has a total voltage swing of 1 6 volts with an active range of 0 4 to 2 0 volts corresponding to 0 to 100 LEL The Input Output board may be consid ered properly configured when V OUT is at or slightly above the desired value A V OUT voltage that is below the expected value may result in a shortened sensor life 5 4 4 Balance Adjustment The balance adjustment matches the resistance of a sensor to the transmitters input bridge circuit This adjustment is required whenever a new sensor is in stalled Adjust the BAL potentiometer as follows but only after the new sensor has stabilized for 1 hour minimum 1 Connect a DMM to the I O board as shown in Figure 5 5 2 With the detector exposed to combustible gas free air adjust the BAL potentiometer until the VOUT test point measures 0 4 Vdc This is an approximate adjustment Precision zero adjustment is made using the magnetic zero controls The Zero Up and Down arrow keys have an adjustment range of 15 of full scale that the sensor would have to drift beyond before the BAL potentiometer would require further adjustment Use of combustible gas free air
71. rawings reference the National Semiconductor standard specification in regard to the polarity of terminals A amp B Some converter manufacturers e g B amp B have chosen to reverse this polarity Please note that reversing this polarity will cause the transmitter to not send the digital stream in a correct fashion and therefore the unit will not communicate properly Note that A is the positive or high side and B is the negative or low side of the input RS 485 2 WIRE NETWORK RS232 485 l RXB COMPUTER CONVERTER SET JP2 SET JP2 SET JP2 TO 2 WIRE TO 2 WIRE TO 2 WIRE SEE DETAILS SEE DETAILS SEE DETAILS BELOW BELOW BELOW MODBUS MODBUS MODBUS OPTION BOARD OPTION BOARD OPTION BOARD ADDRESS 1 ADDRESS 2 ADDRESS 3 pR aes Rev 0 amp Rev A Version Boards Boards shown are jumpered for 2 wire operation Move jumper JP2 to 4W for 4 wire operation TERMINIAL BLOCK TB1 TERMINATIONS TB1 1 RXA TB1 2 RXB TB1 3 SHLD J TB1 4 T RXA TB1 5 T RXB MODBUS RS 485 BOARD MODBUS RS 485 BOARD AW 0010 1092 REV 0 AW 0010 1092 REV A Instruction 9550 9142 Rev 5 Scott
72. rmly hand tighten 4 Replace the housing cover and tighten its locking screw Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 19 Wiring 4800A NIC II LEL Transmitter Note Table 4 1 only applies D E D MEM she ERN I to the Gold Bell 6 0V bead design The 5 5V Scott stainless steel head design can be seperated up to 600 feet using 18 AWG wire L 4 5 Detector Head Wiring Each 6 Volt detector head assembly is supplied with 18 of wire allowing it to be mounted on the transmitter housing either directly or by a short section of 34 conduit per Figure 4 1 Example 1 5 5 Volt detectors are supplied with 6 of wire for direct mounting to the transmitter housing Note that the wiring attached to the detector head is already sealed and requires no additional sealing to conform to NEC requirements for explosion proof installations as long as the detector head is mounted no further than 18 from the transmitter NEC Article 501 5 a 1 For exceptions to this distance read the label on the transmitter housing If the detector head is being mounted more than 18 from the transmitter 106 ft max as shown in Figure 4 1 Example 2 splice a three conductor cable prefer ably with black red and white wires onto the detector head s existing wiring as described below The maximum distances between the detector head and transmit ter for various wire sizes are listed in Table 4 1 The detector head s safet
73. rom sensor and go to Section 5 4 6 Instruction 9550 9142 Rev 5 Scott Health amp Safety Page 41 Calibration 4800A NIC II LEL Transmitter Note Example 2 assumes 6V Gold Bell catalytic bead sensor Example 2 If Acetylene in air is the gas to be monitored Propane in air will be used as a surrogate gas as detailed in Appendix A The voltage to be measured at VOUT is based on the K Factor of Acetylene Using the procedure detailed in Appendix A it is determined that 42 9 Propane in air is equivalent to 60 LEL Acetylene The VOUT that corresponds to 60 LEL is 1 36 Vdc see Table 5 1 Therefore by applying 42 9 LEL Propane in air 0 94 Propane position JP1 so that the voltage at VOUT is approximately 1 36 Vdc or slightly higher When finished remove gas from sensor and go to Section 5 4 6 Equation 5 1 VOUT 1 6 x LEL of calibration gas 100 0 40 Example VOUT for a 25 LEL calibration gas cylinder is VOUT 1 6 x 25 100 0 40 0 80 Vdc TABLE 5 1 CALIBRATION GAS vs VOUT Calibration Gas VOUT LEL VDC LCD Display Method using Unity Mode This method of configuring JP1 for the proper gain setting uses the LCD to display the sensor output The transmitter must first be placed into its Unity Gain Mode as follows 1 With power off to the transmitter hold a magnet over the UNITY symbol on the LCD module 2 Turn on the power to the transmitter The LCD will display cb a few sec
74. rts 4800A NIC II LEL Transmitter 8 6 Scott Health amp Safety Sales Service Scott Health amp Safety 4320 Goldmine Road Monroe NC 28110 Phone 800 247 7257 FAX 704 291 8340 Page 62 Scott Health amp Safety Instruction 9550 9142 Rev 5 4800A NIC II LEL Transmitter APPENDIX A Multiplying K Factors From time to time Scott Health amp Safety is requested to supply multiplying K factors that can be used to simulate response to a combustible in terms of a readily available compressed calibration gas such as propane in air It should be under stood that such conversion factors are calculated estimates only They are in tended to serve as a guide to show approximate typical response of an instrument to the particular gas needed for calibration The K factors shown in Table A 1 are based on test studies of related gases and a calculated comparison to standard theoretical values of pertinent gas parameters available to Bacharach Inc at the time of estimating For measurements critical to determining a health or explosive flammable hazard a particular instrument should always be calibrated using the specific gas or vapor to be measured There is no other way to ensure reliable readings Too many parameters are involved to make any single simple conversion factor accurate WARNING For maximum safety in determining existence of an explosive flammable or health hazard your particular instrument should be c
75. stallation of a jumper at JO4 on the Input Output board Use a power supply that provides a voltage within the appropriate range at the transmitter after taking into consideration the IR drop of the power supply leads as described below The transmitter s terminal block can accept wire sizes of up to 14 AWG however 16 or 18 AWG should be sufficient for most installations The minimum AWG wire size that can be used to connect the power supply to the transmitter is determined by the output voltage of the power supply the maximum current drawn by the transmitter and the voltage drop that occurs across the wiring When choosing the location of the transmitter and its power supply the size and length of the power supply wires become an issue if the wiring s voltage drop would cause the transmitter s input voltage to drop below its minimum operating voltage The following graphs are provided as an aid in determining maximum wiring distances for various power supply voltages and wire sizes To determine the maximum wiring distance first calculate the wiring s maximum allowable voltage drop by subtracting the transmitter minimum operating voltage either 10 or 18 VDC from the power supply s output voltage Then use the appropriate graph to determine the maximum wiring distance for 18 16 and 14 AWG wire Note that Graph 1 is based on a worse case transmitter current of 234 mA at 18 VDC while Graph 2 is based on a current of 420 mA at 10 V
76. temperature causes an increase in the resistance of the active element in relation to the sensor s inactive reference element The transmitter s electronics measure the sensor s change of resistance and generates an output current of between 4 and 20 mA that is proportional to the detected combustible gas level where 4 mA represents 0 LEL and 20 mA repre sents 100 LEL In addition to the transmitter s output signal the LCD on the unit s faceplate viewable through the explosion proof enclosure s transparent cover provides local display of the detected gas level in LEL Calibration is performed at the transmitter without removing its explosion proof viewing cover making area declassification unnecessary The only tool required for this non intrusive calibration is a small magnet which is provided with the transmitter ZERO and SPAN operations are performed by placing the transmitter into its calibration mode by briefly holding the magnet tool over the CAL dot on the face plate The transmitter responds by causing the CAL Mode arrow to light steadily The magnet serves as a pass key which makes it difficult for unauthorized personnel to tamper with the calibration settings Calibration of the system is then performed by applying calibration gas and holding the magnet over the TV Zero and TL Span symbols as required to obtain the correct readings Once calibration is complete an E PROM provides backup to retain calibrati
77. the Transmitter s Operating Voltage The transmitter is normally configured for an operating voltage of 18 30 VDC however 10 18 VDC operation is also possible by soldering a jumper at JO4 on the Input Output board The lower voltage setting is used when the transmitter is used as a stand alone unit with a 12 VDC power supply The location of jumper JO4 is shown in Figures 4 4 and 4 5 4 6 2 Power Supply Wiring Following all wiring methods previously described for hazardous area installations run wires of an appropriate AWG size as determined from Section 4 3 Selecting Wire Size from the remote power supply to the transmitter housing Connect the and power supply leads to TB2 terminals PWR and GND on the Input Output board per Figure 4 2 4 3 4 4 or 4 5 Or refer to Appendix B if the transmitter is being connected to an Sentinel VI Sentinel 16 or Series 6800 Gas Receiver 4 6 3 Isolated and Non Isolated 4 20 mA Output When the optional Isolated 4 20 mA Output board is installed the output signal is isolated from the transmitter s power supply and sensor leads Without this board installed the transmitter s circuit boards sensor and output signal all share a common power supply wire Use the Isolated 420 mA Output board option if your receiving equipment requires an isolated input Note that a transmitter with a non isolated output requires 3 wires while a transmitter with an isolated output requires 4
78. upported Place a jumper on JP2 to correspond to the number of wires being used See Figure 4 9 4 8 5 R4 R7 End of Line Terminating Resistor Note Current boards Rev A or later only have R7 resistor see Figures 4 8 and 4 9 Older boards Rev 0 have R4 and R7 resistors see Figure 4 9 R4 R7 are socketed plug in resistor positions for a 120 ohm End of Line terminat ing resistor All units are supplied with one 120 ohm resistor installed Remove the resistor from all transmitters except for the transmitter at the end of the serial communications Data Highway The unit furthest from the Host Computer or other master communications device such as a PLC or system controller MUST have one 120 ohm resistor installed Position R4 is used with a 2 wire half duples data communications highway while Position R7 is used with a 4 wire full duples highway See applicable Figures 4 8 and 4 9 Note On very short runs e g less than 20 feet no resistor 1s typically required Page 32 Scott Health amp Safety Instruction 9550 9142 Rev 5 4800A NIC II LEL Transmitter Figure 4 9 Typical RS 485 Wiring RS 485 4 WIRE NETWORK T RXB RS232 485 OTRA O RXA BI o COMPUTER CONVERTER RXA Po C MEER SET JP2 SET JP2 SET JP2 TO 4 WIRE TO 4 WIRE TO 4 WIRE SEE DETAILS SEE DETAILS SEE DETAILS BELOW BELOW BELOW MODBUS MODBUS MODBUS OPTION BOARD OPTION BOARD OPTION BOARD ADDRESS 1 ADDRESS 2 ADDRESS 3 IMPORTANT These d
79. wires In both cases a conforming safety ground wire is also required shielding the ground wire is optional 4 6 4 Receiver Wiring If the transmitter will be reporting to a remote receiving device e g PLC DCS loop powered alarm data logger etc then connect the transmitter s 420 mA output to the receiving device as follows For transmitter s requiring a non isolated output connect the receiver s 4 20 mA input to TB2 terminal OUT SIG on the Input Output board per Fig ure 4 2 For transmitters requiring an isolated output connect the receiver s 4 20 mA input to TB1 terminals and on the optional Isolated 4 20 mA Output board per Figure 4 3 Page 22 Scott Health amp Safety Instruction 9550 9142 Rev 5 4800A NIC II LEL Transmitter Wiring Figure 4 2 Transmitter Wiring Diagram Non Isolated 4 20 mA Output WIRE NUT INSIDE HOUSING HOUSING GROUND SCREW 4 20mA RECEIVER DCS PLC etc GROUND GRN TO REFERENCE BLACK COMBUSTIBLES COMMON WHITE DETECTOR HEAD GOLD BELL 6V TYPE c D mx DES Note See Appendix C when ACTIVE RED EARTH GROUNDS NEAR POWER SUPPLY T ee ER d using the 5 5V Scott Stainless mm ao TTT i J Bea SIE Steel Catalytic Bead SSS SSS 1234 TB2 JPifefe S NS In INPUT OUTPUT BOARD Figure 4 3 Transmitter Wiring Diagram Isolated 4 20 mA Output WIRE NUT gt
80. y ground wire must the same size as the other transmitter wires as determined from Section 4 3 Selecting Wire S ize The added detector head wiring must meet prevailing electrical codes for hazard ous area installations that specify conduit sealing explosion proof fittings and special wiring methods TABLE 4 1 MAXIMUM DISTANCE BETWEEN DETECTOR AND TRANSMITTER AWG Ohms Foot Maximum at 85 C 185 F Distance 12 0 0023 106 38m 14 0 0031 80 24 m 16 0 0059 42 13m J 18 0 0080 31 9 m Note Consult the factory if longer distances are required when the temperature between the transmitter and the detector head is relatively constant When installing conduit and wiring from the detector head to the transmitter housing see Figure 4 1 and follow the procedures listed below e If the detector head is mounted more than 18 from the transmitter encase all wire splices in a junction box Also place conduit seals Crouse Hinds EYS 216 or equivalent between the transmitter housing and the junction box Use AMP or equivalent parallel or butt type splices for all wire connections Ground the junction box After mounting the detector head either on the transmitter housing or at its remote location trim off any excess wire and connect the detector head s black white and red wires to terminal block TB1 terminals R C and A on the Input Output board per Figure 4 2 4 3 4 4 or 4 5 The gree

9550-9142_5 - Scott Safety

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