Model CX-IR Infrared Combustible Gas Sensors Operator’s Installation and Instruction Manual Covers all Model CX-IR Sensors DETCON, Inc. 4055 Technology Forest Blvd, Suite 100 The Woodlands, Texas 77381 Phone: 713.559.9200 • Fax: 281.292.2860 www.detcon.com May 29, 2014 • Document # 4428 • Revision 1.
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Model CX-IR Table of Contents 1. 2. 3. 4. 5. 6. 7. 8. Introduction ..................................................................................................................................................1 1.1 Description .......................................................................................................................................... 1 1.2 Modular Design ................................................................................................................
Model CX-IR Table of Figures Figure 1 Sensor Cell Construction ....................................................................................................................... 1 Figure 2 Principle of Operation ............................................................................................................................ 2 Figure 3 Sensor Assembly Breakaway .................................................................................................................
Model CX-IR 1. Introduction 1.1 Description Detcon Model CX-IR combustible gas sensors are non-intrusive “Smart” sensors designed to detect and monitor combustible hydrocarbon gases in the air with a detection range of 0-100% LEL (Lower Explosive Limit). The sensor features an LED display of current reading, fault and calibration status.
Model CX-IR Principle of Operation The target gas diffuses through a stainless steel screen and into the volume of the sample gas optical chamber. An alternating miniature lamp provides a cyclical IR radiation source, which reflects through the optical gas sample chamber and terminates at the two pyroelectric detectors. The active and reference pyroelectric detectors each give an output which measures the intensity of the radiation contacting their surface.
Model CX-IR CX-IR Bottom Housing Assembly Plug-in Replaceable Sensor 3 4" Rain Shield Ferrite Bead NPT Locking Nut Intelligent Transmitter Module (ITM) Micro-processor controlled circuit encapsulated in an Explosion proof housing. Magnetic Programming Switches Figure 3 Sensor Assembly Breakaway NOTE All metal components are constructed from electro polished 316 Stainless Steel to maximize corrosion resistance in harsh environments.
Model CX-IR 2. Installation 2.1 Hazardous Locations Installation Guidelines for Safe Use 1. Install the sensor only in areas with classifications matching the approval label. Follow all warnings listed on the label. Figure 6 Approval Label 2. Do not remove the junction box cover while in the classified are unless it is conformed the there is no explosive gas levels in the area. 3. A good ground connection should be verified between the sensor’s metal enclosure and the junction box.
Model CX-IR 2.2 Sensor Placement Sensor location is critical to the overall safe performance of the product. Confirm that the following five factors are verified during sensor placement. 1. 2. 3. 4. 5. Density of the gas to be detected Most probable leak sources within the industrial process Ventilation or prevailing wind conditions Personnel exposure Maintenance access Density Sensor placement should be relative to the density of the target gas.
Model CX-IR When possible mount in an area void of high wind, accumulating dust, rain, splashing from hose spray, direct steam releases, and continuous vibration. If the sensor cannot be mounted away from potentially damaging conditions then use the Detconꞌs Harsh Location Dust Guard accessory. Do not mount in locations where temperatures will exceed the operating temperature limits of the sensor. Use a sunshade to maintain correct operating temperature if mounted in direct sun light. 2.
Model CX-IR When mounting on a pole, secure the junction box to a suitable mounting plate and attach the mounting plate to the pole using U-Bolts. (Pole-Mounting brackets for Detcon junction boxes are available separately.) 2.4 Electrical Installation The sensor assembly wiring should be installed in accordance with local electrical codes. Proper electrical installation of the gas sensor is critical for conformance to electrical codes and to avoid damage due to water leakage.
Model CX-IR NOTE 1: Wiring table is based on stranded tinned copper wire and is designed to serve as a reference only. NOTE 2: Shielded cable is required for installations where cable trays or conduit runs include high voltage lines or other possible sources of induced interference. Separate conduit runs are highly recommended in these cases. NOTE 3: The supply of power should be from an isolated source with over-current protection as stipulated in table. 2.5.
Model CX-IR 2. Connect the incoming 24V to the terminal labeled "+" and 24V return to the terminal labeled "–". Connect the mA output to the “mA” terminal and the Modbus signals (if used) to the “A” and “B” terminals. Note: the “Y” terminal is not used. Green Blue White Black Red 3. Replace the junction box cover after Initial Start Up (Section 2.6).
Model CX-IR Initial Operational Tests After a warm up period of 1 hour (or when zero has stabilized), the sensor should be checked to verify sensitivity to the target gas.
Model CX-IR 3. Operation The operator interface of the CX Series gas sensors is accomplished with two internal magnetic switches located to either side of the LED display (Figure 10). The two switches, labeled PGM1 and PGM2, allow for complete calibration and configuration, eliminating the need for area de-classification or the use of hot permits. Figure 10 Magnetic Programming Tool The magnetic programming tool (Figure 10) is used to operate the magnetic switches.
Model CX-IR 3.1 Operator Interface The operating interface is menu-driven via the two magnetic program switches located under the target marks of the sensor housing. The two switches are referred to as PGM1 and PGM2. The menu list consists of three menu items that include sub-menus: Normal Operation Concentration reading is displayed once every 10 seconds. Calibration Mode AutoZero AutoSpan Program Mode View Sensor Status CX-IR ##.
Model CX-IR Software Flowchart Normal Operation PGM1 (3) PGM2 (10) PGM1 (3) PGM2 (3) AutoZero AutoSpan View Sensor Status Auto Time-Out PGM1/2 (M) PGM1/2 (3) Set Gas Type Set Autospan Level AutoTime-out PGM1/2 (M) PGM1/2 (3) Auto Time-Out PGM1/2 (M) PGM1/2 (3) Set Gas Factor Auto Time-Out PGM1/2 (M) PGM1/2 (3) Status is CX-IR V Serial Number ## PGM2 (S) PGM1 (S) PGM1/2 (3) inc Range ### inc dec ## PGM2 (S) PGM1 (S) PGM1/2 (3) inc dec ## PGM2 (S) PGM1 (S) PGM1/2 (3) dec Auto Span Level ##
Model CX-IR calibration mode the display will scroll Pgm1=Zero Pgm2=Span twice before returning to normal mode (about 5 seconds). NOTE 3.3.1 Upon entering calibration mode, the Modbus™ status register bit 14 is set to signify the sensor is in-calibration mode. This bit will remain set until the program returns to normal operation. AutoZero The AutoZero function is used to zero the sensor. AutoZero should be performed periodically or as required.
Model CX-IR d) Remove the zero gas and calibration adapter, if applicable. 3.3.2 AutoSpan The AutoSpan function is used to span calibrate the sensor. AutoSpan should be performed periodically or as required. AutoSpan should be considered after periods of over-range target gas exposure. Unless otherwise specified, span adjustment is recommended at 50% of range.
Model CX-IR NOTE The "◄" prompt will show that the magnetic switch is activated during the 3 second hold period. c) The display will scroll ‘PGM1=Zero PGM2=Span’. Hold the programming magnet over PGM2 for 3 seconds to execute AutoSpan (or allow to timeout in 5 seconds if AutoSpan is not intended). The ITM will scroll ‘Apply XX % Gas’. d) Apply the span calibration test gas for combustible gas sensors at a flow rate of 200-500cc/min (500cc/min is the recommended flow rate).
Model CX-IR NOTE The arrow prompts (◄ and ►) will show that the magnetic switch is activated during the 3 second hold period. The ITM will enter program mode and the first menu item View Sensor Status will be displayed. Hold the magnet over PGM1 or PGM2 while the current menu text is scrolling to advance to the next menu item. At the conclusion of the text scroll the arrow prompt ("►" for PGM2 or "◄" for PGM1) will appear, immediately remove the magnet. The ITM will advance to the next menu item.
Model CX-IR The Set Gas Type menu function is a simple choice between these two gas type groupings. NOTE The default value for Gas Type is methane (%LEL). The menu item appears as: Set Gas Type. From the Set Gas Type and Range text scroll, hold the magnet over PGM1 or PGM2 until the arrow prompt appears and continue to hold the magnet in place for an additional 3 to 4 seconds (until the display starts to scroll %LEL / %VOL).
Model CX-IR The menu item appears as: Set Gas Factor. To calculate the correct Gas Factor (Table 2), take the Gas Factor of the target gas and divide by the Gas Factor of the cal gas. The calculated value is the correct number to enter into the menu as the Gas Factor. For example, if calibrating with methane when propane is the target gas, the correct Gas Factor to enter would be 0.63/1.0 = 0.63.
Model CX-IR Apply span gas to the sensor in accordance with Section 0. The sensor will respond to the gas testing the sensor response while the current Modbus gas reading (Modbus register 0002) remains unchanged. Remove the gas before the bump test time expires (2 minutes). The display will return to normal operation alternating between the live gas reading and showing Bump until 2 minutes expires or the execution of a momentary hold over PGM1 or PGM2, when the display will scroll Bump Test Ended. 3.4.
Model CX-IR From the Set Modbus ID scroll, hold the programming magnet over PGM1 or PGM2 until the "►" prompt appears and continue to hold the magnet in place for an additional 3 to 4 seconds (until the display starts to scroll Set ID). The display will then switch to XX (where XX is the current ID address). Swipe the magnet over PGM2 to increase or PGM1 to decrease the hexadecimal number until the desired ID is displayed. Hold the magnet over PGM2 for 3 to 4 seconds to accept the new value.
Model CX-IR 4. Modbus™ Communications Model CX-IR sensors feature Modbus™ compatible communications protocol and are addressable via the operator interface. Communication is two wire, half duplex 485, 9600 baud, 8 data bits, 1 stop bit, and no parity. If a multi-point system is being utilized, each sensor should be set for a different address. Typical address settings are: 01, 02, 03, 04, 05, 06, 07, 08, 09, 0A, 0B, 0C, 0D, 0E, 0F, 10, 11…etc.
Model CX-IR Table 3 CX-IR Register Map Register 40000 40001 40002 40003 40004 40005 40006 40007 40008 40009 40010 40011 40012 40013 40014 40015 40016 40017 40018 40019 40020 40021 4.2.
Model CX-IR Bit 2 Bit 1 Bit 0 – Temperature Fault – Auto Span Fault – Global Fault CX-IR Instruction Manual Rev. 1.
Model CX-IR 5. Service and Maintenance Calibration Frequency In most applications, monthly to quarterly span calibration intervals will assure reliable detection. With industrial environments varying, after initial installation and commissioning close frequency tests should be performed, weekly to monthly. Test results should be recorded and reviewed to determine a suitable calibration interval.
Model CX-IR 1. Use a 1/ 16 " Allen wrench to release the locking setscrew that locks the ITM and splashguard adapter assembly together. NOTE One turn of the setscrew will suffice - Do not remove setscrew completely. 2. Remove the splashguard. Unthread and remove the splashguard adapter assembly from the ITM. 3. Gently pull the plug-in sensor out of the ITM. Verify that the gas type and range of the new sensor cell is correct.
Model CX-IR 1. Disconnect the sensor wire connections from the terminal board, taking note of the wire connections. 2. Use a wrench at the top section of the ITM and unthread the ITM until it can be removed. 3. Use a 1/ 8 " Allen wrench to release the locking cap head screw that locks the ITM and splashguard adapter assembly together. NOTE One turn of the setscrew will suffice - Do not remove setscrew completely. 4. Unthread and remove the splashguard adapter assembly and splash guard from the ITM.
Model CX-IR 6. Troubleshooting Guide If the ITM detects any functional errors the ITM will display the fault. If the sensor is experiencing a fault condition a momentary swipe of the magnet will cause the ITM to scroll the fault condition(s) across the display before the "◄" or "►" prompt will appear.
Model CX-IR • • Check for obstructions affecting cal gas hitting sensor face (including being wet, blocked, or corroded). H2S sensors assemblies use CX_DM Series Splashguard Adapter Assembly with integral filter. Clean or replace if necessary. Replace the plug-in toxic sensor. 6.
Model CX-IR 7. Customer Support and Service Policy Detcon Headquarters Shipping Address: 4055 Technology Forest Blvd, The Woodlands, Texas 77381 Mailing Address: P.O. Box 8067, The Woodlands Texas 77387-8067 Phone: 713.559.9200 Fax: 281.298.2868 • www.detcon.com • service@detcon.com • sales@detcon.com All Technical Service and Repair activities should be handled by the Detcon Service Department via phone, fax or email (contact information given above).
Model CX-IR 7.2 CX-IR Sensor Warranty Plug-in Sensor Warranty Detcon, Inc., as the manufacturer, warrants under intended normal use each new CX-IR sensor to be free from defects in material and workmanship for a period of one year from the date of shipment to the original purchaser. Should the sensor fail to perform in accordance with published specifications within the warranty period, return to Detcon, Inc., for necessary repair or replacement.
Model CX-IR 8. Appendix 8.
Model CX-IR 8.
Model CX-IR 8.3 Revision Log Revision 1.0 1.1 1.2 Date 3/27/2013 01/29/14 05/29/14 Changes made Release Update wiring, calibration and other corrections Added Section 2.1, Updated Approvals Label Approval LBU LBU BM Shipping Address: 4055 Technology Forest, Suite 100, The Woodlands, Texas 77381 Mailing Address: P.O. Box 8067, The Woodlands Texas 77387-8067 Phone: 713.559.9200 • Fax: 281.292.2860 •www.detcon.com • sales@detcon.com CX-IR Instruction Manual Rev. 1.
