INFRARED (IR) COMBUSTIBLE GAS TRANSMITTER INFRARED COMBUSTIBLE GAS TRANSMITTER
WARNING
Do not remove plugs. To reduce the risk of ignition of hazardous locations, all conduit runs must have a sealing fitting connected within 18 inches of the enclosure. C LA S S I FI E 36XO Classified by Underwriters Laboratories, Inc.® as explosion-proof in hazardous locations Class I, Div 1, Groups A,B,C,D; Class II, Div 1, Groups E,F,G when installed in accordance with Manual No. 7013285M. ISO 9001
Registered company NATIONAL ACCREDITATION OF CERTIFICATION BODIES Certificate No. 970084 C 16333 Bay Vista Dr. · Clearwater, FL 33760 · (800) 451-9444 · [FAX] (727) 539-0550 · www.sensidyne.com Revision B · Document No. 7013285M D LA S SIFIE D 36XO LETTER FROM THE PRESIDENT
Thank you for purchasing your new Sensidyne air monitoring product. We stand behind all of the products we sell . . . each Sensidyne product has been designed and manufactured to provide unparalleled service, day after day. Our professional staff has tested each unit under the strictest conditions possible to ensure successful, accurate results every time. With the minimal care and maintenance described in this Operation & Service Manual, the Sensidyne product you have purchased will give you many years of reliable service. Our only goal is that you are pleased with the quality, performance, and accuracy of your Sensidyne product. Be assured of our complete and prompt answers to any questions you may have about this product, since we are totally committed to providing you with fast, responsive customer service and technical support. If you ever have difficulty solving a problem with any Sensidyne product, or if you are not 100% satisfied with the service you receive from any level of our organization, please let me know about it. Call me at either of the numbers listed below, and I will personally research your problem to ensure that it is resolved in a manner that is satisfactory to you. Your satisfaction with our products and service is of the utmost importance to me. Sincerely, Carl Mazzuca President, Sensidyne, Inc. 800-451-9444 727-530-3602 Fax: 727-539-0550 PACKING LIST INFRARED (IR) COMBUSTIBLE GAS TRANSMITTER The items listed below are shipped with the IR Combustible Gas Transmitter: · · 4­20 mA electronics, housed in a heavy duty metal condulet with sensor Operation and Service Manual ALWAYS check to make certain you have received all of the items listed above. If you have any questions or need assistance, contact your Sensidyne Distributor, or call
(800) 451-9444 or (727) 530-3602 Sensidyne Document No. 7013285M (Rev B) PRELIMINARY 3 INFRARED (IR) COMBUSTIBLE GAS TRANSMITTER PROPRIETARY NOTICE This manual was prepared by Sensidyne, Inc. exclusively for the owner of the IR Combustible Gas Transmitter. The material within this manual is the proprietary information of Sensidyne, Inc. and is to be used only to understand, operate, and service the instrument. By receiving this document, the recipient agrees that neither this document nor the information disclosed within nor any part shall be reproduced or transferred, physically, electronically or in any form or used or disclosed to others for manufacturing or for any other purpose except as specifically authorized in writing by Sensidyne, Inc.
COPYRIGHT NOTICE © 1998, Sensidyne, Inc. ALL RIGHTS RESERVED. Information contained in this document is protected by copyright. No part of this document may be photocopied, reproduced, or translated to another program or system without prior written authorization from Sensidyne, Inc.
TRADEMARK NOTICE Sensidyne and the Sensidyne logo are registered trademarks of Sensidyne, Inc. The trademarks and service marks of Sensidyne, Inc. are protected through use and registration in the United States. DISCLAIMER SENSIDYNE, INC. ASSUMES NO RESPONSIBILITY WHATSOEVER, TO ANY PARTY WHOSOEVER, FOR ANY PROPERTY DAMAGE, PERSONAL INJURY, OR DEATH RECEIVED BY OR RESULTING FROM, IN WHOLE, OR IN PART, THE IMPROPER USE, INSTALLATION, OR STORAGE OF THIS PRODUCT BY THE USER, PERSON, FIRM, ENTITY, CORPORATION OR PARTY NOT ADHERING TO THE INSTRUCTIONS AND WARNINGS OR NOT ADHERING TO ALL FEDERAL, STATE, AND LOCAL ENVIRONMENTAL AND OCCUPATIONAL HEALTH AND SAFETY LAWS AND REGULATIONS. THE SELLER SHALL NOT BE LIABLE FOR DIRECT, INDIRECT, CONSEQUENTIAL, INCIDENTAL OR OTHER DAMAGES RESULTING FROM THE SALE AND USE OF ANY GOODS AND SELLER'S LIABILITY HEREUNDER SHALL BE LIMITED TO REPAIR OR REPLACEMENT OF ANY GOODS FOUND DEFECTIVE. THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR USE OR FOR A PARTICULAR PURPOSE WHICH ARE EXPRESSLY DISCLAIMED. 4 PRELIMINARY Sensidyne Document No. 7013285M (Rev B) INFRARED (IR) COMBUSTIBLE GAS TRANSMITTER TABLE OF CONTENTS
PREFACE · Packing List ........................................................................................................................... 3 · Notices ................................................................................................................................... 4 · WARNINGS ............................................................................................................................ 9 SECTION ONE: INTRODUCTION 1.1 1.2 1.3 Overview .................................................................................................................... 12 Method of Detection ................................................................................................ 12 Components .............................................................................................................. 14 1.3.1 1.3.2 1.3.3 1.4 Transmitter Housing ...................................................................................... 14 Electronics Module ........................................................................................ 14 Sensor Assembly ............................................................................................ 16 Accessories ............................................................................................................... 18 · · · · · · SensAlert Single Channel Controller ...................................................................... 18 SensAlert Four Channel Controller ......................................................................... 18 Other Controllers ..................................................................................................... 19 Power Supplies ........................................................................................................ 19 Calibration Equipment ............................................................................................ 19 Aspirator and Flow Block ....................................................................................... 19 SECTION TWO: INSTALLATION 2.1 2.2 2.3 Location ...................................................................................................................... 20 Transmitter Installation .......................................................................................... 20 Wiring ......................................................................................................................... 22 2.3.1 2.3.2 2.3.3 Overview ........................................................................................................ 22 Allowable Line Length .................................................................................. 23 Wiring Procedure .......................................................................................... 23 Sensidyne Document No. 7013285M (Rev B) PRELIMINARY 5 INFRARED (IR) COMBUSTIBLE GAS TRANSMITTER TABLE OF CONTENTS
SECTION THREE: START-UP & CALIBRATION 3.1 3.2 Start-Up ....................................................................................................................... 25 Calibration ................................................................................................................. 25 3.2.1 3.2.2 3.2.3 3.2.4 3.2.5 Calibration Equipment .................................................................................. 25 Calibration Procedure .................................................................................... 26 Zero Calibration ............................................................................................. 26 Span Calibration ............................................................................................ 28 Output Current Calculation ........................................................................... 28 SECTION FOUR: MAINTENANCE 4.1 4.2 4.3 Routine Maintenance ............................................................................................... 31 Electronics Module ................................................................................................... 31 IR Source / Optical Bench ....................................................................................... 33 4.3.1 4.3.2 4.4 Testing IR Source ........................................................................................... 33 IR Source Replacement ................................................................................. 33 Membrane Replacement ......................................................................................... 35 SECTION SIX: PARTS LIST · Parts & Accessories ........................................................................................................... 36 · Calibration Kits .................................................................................................................. 36 6 PRELIMINARY Sensidyne Document No. 7013285M (Rev B) INFRARED (IR) COMBUSTIBLE GAS TRANSMITTER TABLE OF CONTENTS
APPENDICES
· Appendix A: Specifications · · · · General Specifications ............................................................................................ 37 Classification ........................................................................................................... 37 Electrical/Electronic Specifications ........................................................................ 37 Sensor specifications .............................................................................................. 37 · Appendix B: Troubleshooting Guide · Troubleshooting Guide .......................................................................................... 38 · Appendix C: Returned Material Authorization · Returned Material Authorization ............................................................................ 39 · Service Options ...................................................................................................... 39 Sensidyne Document No. 7013285M (Rev B) PRELIMINARY 7 INFRARED (IR) COMBUSTIBLE GAS TRANSMITTER LIST OF FIGURES & TABLES
LIST OF FIGURES Section One: Introduction 1.1 1.2 1.3 1.4 Method of Detection ................................................................................................ 12 IR Combustible Gas Transmitter ............................................................................. 13 Electronics Module .................................................................................................. 15 Infrared Combustible Gas Sensor ............................................................................ 17 Section Two: Installation 2.1 2.2 Transmitter Installation ............................................................................................ 21 Transmitter Wiring ................................................................................................... 24 Section Three: Start-Up & Calibration 3.1 3.2 Calibration Procedure .............................................................................................. 27 Output Current Calculation ..................................................................................... 29 Section Four: Service & Maintenance 4.1 4.2 4.3 Electronics Module Replacement ............................................................................ 32 IR Source Replacement ............................................................................................ 34 Sensor Membrane Replacement .............................................................................. 35 LIST OF TABLES 3.1 Output Current vs Concentration ............................................................................ 30 8 PRELIMINARY Sensidyne Document No. 7013285M (Rev B) WARNINGS ! INFRARED (IR) COMBUSTIBLE GAS TRANSMITTER READ AND UNDERSTAND ALL WARNINGS BEFORE USE
Read and understand ALL warnings before using this product. Failure to read, understand, and comply with ALL warnings could result in property damage, severe personal injury, or death. Read and understand ALL applicable federal, state, and local environmental health and safety laws and regulations, including OSHA. Ensure complete compliance with ALL applicable laws and regulations before and during use of this product. UNDER NO CIRCUMSTANCES should this product be used except by qualified, trained, technically competent personnel and not until the warnings, Operation and Service Manual, labels, and other literature accompanying this product have been read and understood. Each user MUST READ AND UNDERSTAND the pertinent Material Safety Data Sheets (MSDS) and the Operation and Service Manual before operating this product or using its accessories, in order to ensure proper and safe use and installation of this product, and to ensure familiarity with the proper treatment and safety procedures in the event of an accident. Failure to read and understand the MSDS's and the Operation and Service Manual may result in preventable severe personal injury or death. Additional MSDS's and manuals are available from Sensidyne. Call (800) 451-9444, or (727) 530-3602. ALWAYS wash your hands thoroughly after handling, calibrating, or servicing this product, and before eating, drinking, smoking or applying cosmetics. If chemicals are ingested accidently, consult Material Safety Data Sheets and a physician IMMEDIATELY. Call Poison Control Center IMMEDIATELY. Consult the emergency section of your telephone directory for the telephone number of the Poison Control Center in your area. ALWAYS wear eye protection (such as safety goggles), face shield, chemical resistant gloves and chemical resistant clothing when handling chemicals, or calibration sources. DO NOT get chemicals, gases, fumes, or vapors in your eyes or on your skin, as they may cause severe burns to skin and eyes. If chemicals, gases, fumes, or vapors get in your eyes or on your skin, wash the affected area with copious amounts of water, consult MSDS's and call a physician immediately. ALWAYS calibrate in a well ventilated area by opening ALL doors and windows. Prevent the buildup of ANY calibration sources or vapors. Avoid breathing ANY calibration fumes or vapors as they are hazardous to your health. ALWAYS dispose of chemicals and calibration sources in compliance with ALL applicable safety laws, regulations, and guidelines for proper disposal. Failure to do so may result in environmental and property damage, personal injury or death. ALWAYS ensure that any compressed calibration substance sources are empty prior to disposal, should they be used. ALWAYS use clean, dry, inert materials to contain and transfer substances used for calibration. DO NOT remove, cover, or alter any label or tag on this product, its accessories, or related products. (Warnings continue on next page)
Sensidyne Document No. 7013285M (Rev B) PRELIMINARY 9 INFRARED (IR) COMBUSTIBLE GAS TRANSMITTER WARNINGS ! DO NOT operate this product should it malfunction or require repair. Operation of a malfunctioning product, or a product requiring repair may result in serious personal injury or death. SUBSTITUTION OF COMPONENTS NOT SUPPLIED BY SENSIDYNE MAY IMPAIR OR NULLIFY THE INTRINSICALLY SAFE DESIGN, AND PERSONS WHO RELY ON THIS PRODUCT FOR THEIR SAFETY COULD SUSTAIN SEVERE PERSONAL INJURY OR DEATH. SUBSTITUTION OF PARTS NOT APPROVED BY SENSIDYNE AND THE CERTIFYING APPROVAL AGENCY OR THE UNAUTHORIZED REPAIR OF THIS PRODUCT NOT APPROVED BY SENSIDYNE AND THE APPROVAL AGENCY SHALL VOID THE APPROVAL AGENCY'S CERTIFICATION. DO NOT attempt to repair or modify instrument, except as specified in the Operation and Service Manual. If repair is needed, contact the Sensidyne Service Dept. to arrange for a Returned Material Authorization (RMA). Use ONLY genuine SENSIDYNE® replacement parts when performing any maintenance procedures described in this manual. Failure to do so may seriously impair instrument performance. Repair or alteration of the product beyond the scope of these maintenance instructions, or by anyone other than an authorized SENSIDYNE® serviceman, could cause the product to fail to perform as designed and persons who rely on this product for their safety could sustain severe personal injury or death. DO NOT restrict the access of ambient air to the sensor. This product must be calibrated prior to initial use. Calibrate at regular intervals in strict accordance with the Operation and Service Manual. Failure to calibrate in accordance with the instructions in this manual and at the specified intervals may result in the product not operating properly or malfunctioning. Verify concentration of calibration substance before making calibration adjustments. Concentration can be altered by: · · · Deterioration of the concentration of compressed calibration substance sources during storage. Interaction of the calibration substance with materials used to contain and transfer the substance, as for example, absorption onto and permeation through certain plastics. Interaction of the calibration substance with materials with ambient contaminants, as for example, absorption into water. Sudden changes in pressure may cause temporary fluctuations in the sensor reading. To maintain the ex certification for the ir combustible-gas sensor, it must be screwed into a certified explosion proof junction box or enclosure. The rating for zone and gas group will be the lowest of any rating of the components. The cover of any junction box or enclosure into which the sensor unit is screwed must not be removed unless all power to it has been removed or the area has been tested and certified as free of combustible gas and continuous monitoring of the area is performed by suitable independent equipment until the cover is replaced. This IR combustible gas sensor has been certified as explosion proof (Class 1 zone 1 Group IIc T6), for normal atmospheres only. Use of this sensor input in an oxygen-enriched atmosphere is not included by this certification. 10 PRELIMINARY Sensidyne Document No. 7013285M (Rev B) INFRARED (IR) COMBUSTIBLE GAS TRANSMITTER THIS PAGE INTENTIONALLY LEFT BLANK Sensidyne Document No. 7013285M (Rev B) PRELIMINARY 11 INFRARED (IR) COMBUSTIBLE GAS TRANSMITTER SECTION ONE INTRODUCTION
1.1 OVERVIEW
IMPORTANT 1.2 METHOD OF DETECTION You must read this manual in its entirety to ensure proper operation of the transmitter. This manual provides specific information concerning the installation, operation, calibration, and maintenance of the Sensidyne Infrared (IR) Combustible Gas Transmitter. The transmitter is capable of detecting the presence of potentially hazardous concentrations of a target gas. The Sensidyne Infrared Combustible Gas Transmitter (Figure 1.2) is a highly reliable infrared (IR) absorption type sensor designed to give extended service under extreme conditions. The sensor is used to detect the presence of combustible gases (methane, ethane, propane, butane, and similar gases). In a typical application, the sensor unit is electrically connected to a system capable of providing readouts indicating the percentage of Lower Explosion Limit (%LEL) of the gas detected by the sensor along with audible and/or visual alarms when the %LEL reaches a predetermined level. The IR Combustible Gas Sensor is used for diffusion sensing applications. These are applications in which the sensor continuously monitors that part of the environment with which it is in contact and the gas diffuses through the sensor's optical path. This manual covers the use of the Infrared Combustible Gas Transmitter as a diffusion type detection system. Detection of combustible gases is accomplished by measuring the absorption of IR energy by the gas being monitored. This measurement is made over a fixed distance within a part of the sensor assembly called the Optical Bench (see Figure 1.1, below). A miniature filament lamp mounted, at one end of the optical bench, acts as an IR source. The lamp illuminates an IR detector at the opposite end of the optical bench. The IR detector is designed to detect IR energy only at the hydrocarbon absorption wavelength. The introduction of a hydrocarbon gas into the optical path between the IR source and the IR detector causes the detector output to reduce by an amount that can be calibrated for the gas present. The filament lamp IR source is switched between two levels at a 1.5 second rate, and is controlled by a precision circuit which provides high stability operation and reduces thermal drift. Through several stages, this signal is amplified to a 4-20 mA signal for local or remote indication. The optical bench is enclosed in a UNS31803 Stainless Steel guard and a Teflon-coated 316 Sintered Stainless Steel flame arrector. The stainless steel ensures high corrosion resistance. The Gortex® covering on the flame arrestor resists the accumulation of dirt and dust and allows the sensor to resist water while letting gas pass through to the sensor. Detector and Spectral Filter Flame Arrestor Transmitter IR Source (Lamp) Optical Bench Assembly
Figure 1.1 Method of Detection 12 PRELIMINARY Sensidyne Document No. 7013285M (Rev B) INFRARED (IR) COMBUSTIBLE GAS TRANSMITTER Hexagon Head Screw Condulet INFRARED COMBUSTIBLE GAS TRANSMITTER
WARNING
Do not remove plugs. To reduce the risk of ignition of hazardous locations, all conduit runs must have a sealing fitting connected within 18 inches of the enclosure. C LA S S I FI E
D 36XO Classified by Underwriters Laboratories, Inc.® as explosion-proof in hazardous locations Class I, Div 1, Groups A,B,C,D; Class II, Div 1, Groups E,F,G when installed in accordance with Manual No. 7013285M. 3/4" NPT Thread Set Screw Sensor (inside guard) Stainless Steel Sensor Guard Figure 1.2 IR Combustible Gas Transmitter Sensidyne Document No. 7013285M (Rev B) PRELIMINARY 13 INFRARED (IR) COMBUSTIBLE GAS TRANSMITTER 1.3
1.3.1 COMPONENTS
Transmitter Housing · Controls The transmitter housing (metal condulet) provides an explosion-proof, weather-resistant, watertight barrier between the electronics module and the ambient environment. The condulet is explosion-proof to protect the electronics module from damage due to an external explosion and to prevent any electrical malfunction of the electronics module from triggering an external explosion.
1.3.2 Electronics Module There are 2 screwdriver adjustable controls located on the printed circuit board (PCB) of the electronics module (refer to Figure 1.3): Span Control The span control is a 23-turn potentiometer used during calibration to set the 4-20 mA output current to correspond to a known concentration of the target gas. Zero Control The zero control is a 23-turn potentiometer used to adjust the 4-20 mA output current to achieve a zero concentration level. The electronics module (Figure 1.2), housed within the explosion-proof condulet, operates the sensor, monitors sensor response, and converts the IR detector's absorption signals into a 4-20 mA current, linearly proportional to the concentration of the combustible gas present at the sensor. The circuit board is mounted on studs within the explosion-proof condulet and secured with two slotted screws.
· Terminals · Test Points There are three terminal blocks located on the electronics module. The upper strip is used to connect input and output wiring to the transmitter. The lower terminal blocks (2-pin and 5-pin keyed connectors) are used to connect the sensor assembly wiring to the electronics module. There are 2 check points located on the electronics module (refer to Figure 1.3). The check points are used to monitor the output current during calibration. The positive test point (red) is labeled "TP7," while the negative test point (black) is labeled "TP9." NOTE An ammeter (preferably digital), with a full scale capability of 20 mA and a resolution of ± 0.1 mA, is required to monitor current at the test points. 14 PRELIMINARY Sensidyne Document No. 7013285M (Rev B) INFRARED (IR) COMBUSTIBLE GAS TRANSMITTER Negative Test Point (TP9) [Black] Span Control Positive Test Point (TP7) [Red] Zero Control Mounting Screw 5-pin Sensor Connector 4­20 mA Output Common Ground +24 Vdc 2-pin Sensor Connector Mounting Screw TP13 Note: Electronics Module is oriented in unit as shown above Figure 1.3 Electronics Module Sensidyne Document No. 7013285M (Rev B) PRELIMINARY 15 INFRARED (IR) COMBUSTIBLE GAS TRANSMITTER 1.3.3 Sensor Assembly · Gases Monitored The sensor assembly consists of a Flame Arrestor surrounding an Optical Bench Assembly. The entire Sensor Assembly is surrounded by a protective stainless steel Guard (see Figure 1.4). Flame Arrestor The Flame Arrestor is made of 316 Sintered Stainless Steel. The stainless steel ensures high corrosion resistance. The arrestor has a sheet of Gortex® fixed around the outside to stop the ingress of dust, dirt and moisture. Optical Bench Assembly The Optical Bench Assembly is concentrically enclosed within the Flame Arrestor and the Guard. The miniature filament lamp is mounted in the IR Light Source Board at one end of the Optical Bench Assembly. The IR Light Source Board Assembly is designed for easy replacement in the event of a burnt-out miniature lamp. Guard The Guard, which is made of UNS31803 Stainless Steel, provides physical protection to the Flame Arrestor and the Optical Bench Assembly. In sensor calibration operations, a calibration cup can be installed over the Guard to provide for adequate flow of calibration gas to the sensor. The sensor is designed to monitor hydrocarbon gases and vapors from C1­C10 except that, in practice, the sensor typically detects C1­C6. Also, the sensor can detect any compound with an absorption band in the spectral range of 3.33 microns. The following are typical gases detected by the sensor: · · · · · · Methane Ethane Propane Butane Pentane Hexane Certain other combustible gases, such as Hydrogen and Hydrogen Sulphide, are not detected by the sensor. 16 PRELIMINARY Sensidyne Document No. 7013285M (Rev B) INFRARED (IR) COMBUSTIBLE GAS TRANSMITTER 2-pin Keyed Sensor Connector 5-pin Keyed Sensor Connector 3/4" NPT Thread M3 Locking Set Screw Stainless Stell Guard (UNS31803) Flame Arrestor Assembly Silicone Sealing Washer Figure 1.4 Infrared Combustible Gas Sensor Sensidyne Document No. 7013285M (Rev B) PRELIMINARY 17 INFRARED (IR) COMBUSTIBLE GAS TRANSMITTER 1.4 ACCESSORIES
· SensAlert Four Channel Controller · SensAlert Single Channel Controller The Sensidyne SensAlert Controller is an integral part of the SensAlert Gas Monitoring System. The SensAlert Controller provides 3 levels of alarm/relay outputs and a system fault alarm and relay, all housed in a General Purpose enclosure. It also serves as an interface when an event needs to be relayed to a peripheral device, such as a building fire alarm system. The SensAlert Controller displays the gas levels in %LEL. The power supply for the controller has been designed to operate at 115/230 VAC, with the capability of adding a 24 Vdc battery backup. Some of the features of SensAlert Single Channel Controller include: · · · · · · · Automatic sensor identification Lo, Hi, HiHi, & Fault alarms User-selectable alarm levels Four relay contacts Lock/tag out designed case RS-485 serial output Password protection The SensAlert Four Channel Controller is an integral part of the SensAlert Gas Monitoring System. The SensAlert Controller provides 3 levels of alarm/relay outputs and a system fault alarm and relay, all housed in a General Purpose enclosure. It also serves as an interface when an event needs to be relayed to a peripheral device, such as a building fire alarm system. The SensAlert Controller displays the gas levels in %LEL. The power supply for the controller has been designed to operate at 115/230 VAC, with the capability of adding a 24 Vdc battery backup. Some of the features of SensAlert Four Channel Controller include: · · · · · · · Automatic sensor identification Lo, Hi, HiHi, & Fault alarms User-selectable alarm levels Four relay contacts per transmitter Lock/tag out designed case RS-485 serial output Password protection 18 PRELIMINARY Sensidyne Document No. 7013285M (Rev B) INFRARED (IR) COMBUSTIBLE GAS TRANSMITTER · Other Controllers · Power Supplies
IMPORTANT In order to operate the SensAlert Transmitter with a nonSensAlert Controller, you must install a 10 µf capacitor between the Power Return and 4­20 mA Output. A 24 Vdc power supply is built into the SensAlert Controller. On Single Channel Controllers, the power supply provides output to the transmitter. However, any 15­30 Vdc power supply will suffice to operate the transmitter.
· Calibration Equipment Model 1000 & Model 2000 The Sensidyne Model 1000 Controller (Single Channel), and the Model 2000 Controller (Dual Channel) are combination power supply and readout devices that provide a 24 Vdc power supply and 250 termination resistance using 110 or 220 VAC input power. Both models display the gas concentration from the transmitter via an LED digital display. In addition, The Model 1000 and Model 2000 feature adjustable alarms, a mode select switch, and recorder output. Controllers may be wall, rack, or panel mounted. Special enclosures are also available. Model 3000 The Sensidyne Model 3000 Controller is capable of monitoring up to 16 channels simultaneously. The controller also provides simultaneous display and alarm functions for both toxic and combustible gases. The display consists of a 240 X 128 dot graphic LCD Flat Panel with LED backlighting. The unit offers a full range of alarm, operating, and printing options which can be field-implemented at the touch of the keypad. A variety of user-centered features and options are available in the Model 3000. For example, visual low, high, and fault alarms are completely user-adjustable. Users can display results as digital output, in the form of bar graphs, as a trend. Multiple channels also may be displayed simultaneously for comparative purposes. Other options include on-demand programmed printing. The Model 3000 is equipped with both RS-232 and RS485 serial interfaces with Modbus® to interact with a variety of other graphics, including Wonderware®. Power may be supplied as either 115 VAC or 11-28 Vdc at a maximum of 25 watts. Housing options include panel, rack, and surface mounting, as well as General Purpose enclosures. Sensidyne offers a full line of equipment for properly calibrating the IR Combustible Gas Transmitter. This calibration equipment allows the operator to produce a low concentration supply of the target gas, simply and with minimal risk. See Section Four­Calibration for a description of available calibration equipment.
· Aspirator and Flow Block An aspirator is available which uses factory air pressure to create a vacuum for drawing an air sample through an optional flow block assembly. This allows the unit to detect toxic substances in a remote area or duct. The exhaust of the aspirator may be routed to an external duct, or back to the sampling area, if desired. Sensidyne Document No. 7013285M (Rev B) PRELIMINARY 19 INFRARED (IR) COMBUSTIBLE GAS TRANSMITTER SECTION TWO INSTALLATION
2.1 LOCATION 2.2 TRANSMITTER INSTALLATION The Infrared (IR) Combustible Gas Transmitter is a local area gas monitor and must be mounted as close as possible to any potential leak sources. This allows the transmitter to detect a gas leak as soon as possible after it occurs. Expert consultation may be necessary to determine the most strategic location for optimum monitoring. In all circumstances, the plant safety officer or other appropriate personnel should be consulted before installation. Site determination, at a minimum, must consider the following factors: · · · · · most probable location of a leak physical properties of the target gas air convection in the area due to ventilation or ambient conditions operational environment presence of interferent gases Refer to all NEC and local electrical codes to ensure compliance for proper installation. The transmitter mounts to 3/4" wiring conduit via 3/4" (19 mm) NPT female connection. It is strongly suggested that you install conduit seals within 2" of the condulet to provide an environmental seal for the electronics. Shielded cable must be used to achieve maximum RFI/EMI immunity. The transmitter must be mounted vertically (± 90° from center in ANY direction) with the sensor assembly pointing down. INSTALLATION GUIDELINES To ensure continued reliable operation of the IR Combustible Gas Transmitter, the following installation guidelines should be observed: · For monitoring of heavier than air gases, mount the sensor unit as close as practical to the floor or ground. For monitoring of lighter than air gases, install the sensor unit as high as practical. The sensor unit should be installed in a location where it is easily accessible for repairs, adjustments and calibration. Calibration Cup (PNº 7013289) is available for applying calibration gas without removing the external guard. Calibration from remote points can be achieved by fitting the Weather Guard Calibration Adapter (PNº 7017227-4) and a suitable length of tubing to a convenient point to apply calibration gas. Mount the sensor unit in a position which minimizes the risk of mechanical damage. Prevent water and dust accumulation from affecting operation by mounting the sensor unit with the guard pointing downward (± 90° in any direction). Whenever practical, avoid mounting the sensor unit in direct sunlight. If it is necessary to install the sensor unit in a sunlit area, provide a shade to minimize heat absorption from direct sunlight. Ultimately, monitoring efficiency will depend upon how carefully this survey is made. · · · · 20 PRELIMINARY Sensidyne Document No. 7013285M (Rev B) INFRARED (IR) COMBUSTIBLE GAS TRANSMITTER Negative Test Point (TP9) [Black] Span Control Positive Test Point (TP7) [Red] Zero Control Mounting Screw 5-pin Sensor Connector 4­20 mA Output Common Ground +24 Vdc 2-pin Sensor Connector Mounting Screw TP13 Note: Electronics Module is oriented in unit as shown above Figure 2.1 Transmitter Installation Sensidyne Document No. 7013285M (Rev B) PRELIMINARY 21 INFRARED (IR) COMBUSTIBLE GAS TRANSMITTER 2.3 Refer to Figures 1.2 and 1.3 and mount the transmitter as follows: 1) Get confirmation from the safety officer that the area is free of hazardous atmospheres. 2) Loosen the hex head screw. 3) Unscrew and remove the condulet cover. 4) Confirm that the input and output wires are not energized, and thread them through the upper opening of the condulet. 5) Hold the wires out of the way and screw the condulet firmly into the conduit.
2.3.1 WIRING
Overview Refer to all NEC and local electrical codes to ensure proper wiring compliance. The use of twisted, shielded wire is recommended. The electronics module supplies a 4 - 20 mA output signal which is a current source only; an external common ground return must be provided. Total circuit load and cable resistance should be less than 600 Ohms for the 4 - 20 mA loop. The +24 Vdc and common ground leads must be of sufficiently low resistance to ensure the correct operation voltage at the PCB. NOTE 6) Cap the wires and replace the condulet cover if you are not going to wire the transmitter at this time. (You need not tighten the hex head screw at this time.) The power supply must have a power source return isolated from earth ground. Shielded cable is recommended with shield terminated to earth ground (at the power source only) to ensure maximum RFI/EMI immunity. The following sections provide specific information necessary to wire the transmitter to a power supply. A wiring diagram is provided to aid in wiring the transmitter. The diagram (see Figure 2.2) shows the wiring configuration when using the Sensidyne SensAlert Controller. Three wires are required to connect the transmitter to a Sensidyne controller or a customer supplied 15­30 Vdc power supply (see Figure 2.2) and readout device. Any supplemental readout device used must have a termination resistance of 250 or less. Sensidyne SensAlert Controllers have a termination resistance of 100 . 22 PRELIMINARY Sensidyne Document No. 7013285M (Rev B) INFRARED (IR) COMBUSTIBLE GAS TRANSMITTER 2.3.2 Allowable Line Length 2.3.3 Wiring Procedure The maximum distance between the power supply and the transmitter is known as the "allowable line length." It is a function of the power supply voltage and termination resistance, which in turn determine allowable loop resistance and wire size. The maximum allowable line length for 250 termination resistance and for wire sizes larger than 24 AWG is 2000' (610 m). The allowable voltage range for the power supply is 15­30 Vdc. The transmitter terminals will not accept wire gauges larger than 14 AWG. In all cases, the connections must be clean, tight and protected from the weather. They must meet all required electrical codes. Refer to Figure 2.2 for the transmitter-to-controller wiring diagram. Follow the steps below: 1) Get confirmation from the safety officer, or appropriate personnel, that the area is safe. 2) Verify that the conduit and the transmitter are properly connected. 3) Verify that the input and output wires are not energized. Remove the transmitter cover. 4) Verify that the total resistance of the wiring does not exceed the allowable loop resistance. 5) Connect the positive lead from the +24 Vdc input wire to the +24 Vdc terminal of the transmitter. 6) Connect the 4-20 mA output wire to the 4-20 mA terminal of the transmitter. 7) Connect the power return wire to the common ground terminal of the transmitter. 8) Replace the transmitter cover. Tighten the hex head screw to secure the condulet cover. 9) Proceed to Section Three to perform the Start-Up Procedure. Sensidyne Document No. 7013285M (Rev B) PRELIMINARY 23 INFRARED (IR) COMBUSTIBLE GAS TRANSMITTER WIRING DIAGRAM (3-Wire)
HAZARDOUS AREA SAFE AREA Maximum Cable Length Transmitter (3-Wire) SensAlert Controller
TB5 + +24V 4-20 ­ RTN +24V 4-20 RTN ­ + CABLE PARAMETERS Maximum Length = 2000 ft
NOTE: All intrinsically safe wiring shall be kept separate from all other wiring. Use of conduit required for installation. Refer to Article 504 of the National Electrical Code. Must not be connected to equipment which uses or generates more than 250 V RMS with respect to Earth ground. WIRING DIAGRAM (3-Wire Standalone)
HAZARDOUS AREA
Transmitter (3-Wire) SAFE AREA
Maximum Cable Length = 2000 ft
Power Supply +24V nom 4-20 mA PWR RTN Termination Resistance < 250 + 15­30 Vdc ­ EARTH GROUND Figure 2.2 Transmitter Wiring 24 PRELIMINARY Sensidyne Document No. 7013285M (Rev B) INFRARED (IR) COMBUSTIBLE GAS TRANSMITTER SECTION THREE START UP & CALIBRATION
3.1 START UP 3.2
3.2.1 CALIBRATION
Calibration Equipment Prior to connecting power to the sensor, the following preliminary checks should be made. 1) Ensure the Sensor Assembly is screwed tightly into its junction box/enclosure. 2) Ensure the Sensor Assembly is correctly wired to its PCB. Sensidyne offers a full line of equipment for properly calibrating the IR Combustible Gas Transmitter. Calibration equipment available for the IR Combustible Gas Transmitter is described below. Refer to Appendix A-- Parts List for ordering information, and for a complete listing of available calibration equipment and accessories.
· Methane Calibration Kit (Recommended) CAUTION To avoid damage to the equipment, make certain the voltage applied to the PCB does not exceed 30 volts. The calibration kit includes one disposable cylinder of methane at 50 %LEL (2.5 %vol) concentration, cylinder regulator (1 LPM), calibration cup, and tubing. For information on ordering accessories or other items not normally included with the basic kit (e.g., verification detector tubes, pumps, etc.) see Appendix A-- Parts List, or call Sensidyne. 3) Make certain the unit is oriented vertically (within ± 90°) with sensor facing down. 4) Inspect the unit for signs of damage or corrosion to the sensor assembly or its enclosure. 5) Check that the voltage applied to the PCB is between 15 and 28 Vdc. After power has been applied, let the sensor unit function for 60 minutes prior to calibration (a 24-hour "burn in" is recommended). Sensidyne Document No. 7013285M (Rev B) PRELIMINARY 25 INFRARED (IR) COMBUSTIBLE GAS TRANSMITTER 3.2.2 Calibration Procedure 3.2.3 Zero Calibration Although it is likely that this device will remain stable at its initial calibration settings for long periods (1­2 years), Sensidyne recommends calibrating the sensor every 6 months. If the following tests reveal only minor variations in settings, the factory Zero and Span settings should not be changed. Use of the Calibration Cup is more effective than the Weather Protection Shield in some circumstances (such as high wind conditions); in such cases increasing the flow rate to 2­3 LPM may be necessary using the Weather Protection Shield, but is not necessary with the Calibration Cup. Calibration of the sensor requires two steps: Zero Calibration and Span Calibration. Adjustments, if required, are made using the ZERO and SPAN potentiometers on the Amplifier PCB; see Figure 2.1 for location of the potentiometers. Potentiometer adjustments are somewhat interactive; therefore changing either potentiometer setting may require a repetitive sequence of adjustment of both potentiometers until the correct output current is achieved. For this reason, the calibration potentiometers should not be adjusted unless absolutely necessary and adjustment should be made only after thoroughly reading and understanding this Instruction Manual. Perform Zero Calibration as follows: 1) Use a milliammeter set on a suitable scale to read 4 mA . Connect the positive test lead to TP7 and the negative test lead to TP9 on the PCB (See Figure 2.1) and ensure the 4-20mA loop is connected. 2) Apply a zero gas such as Nitrogen or instrument air at a flow rate of 0.8 to 1.2 LPM for calibration cup, 2­3 LPM with weather shield. If a zero gas is unavailable, ensure a gas-free environment before performing Zero Calibration. 3) Adjust the potentiometer on the PCB to set the output current at 4.0 mA. Perform adjustments slowly to allow for the sensor unit's settling time (up to 30 seconds). 4) Leave the milliammeter connected until SPAN Calibration is completed. 26 PRELIMINARY Sensidyne Document No. 7013285M (Rev B) INFRARED (IR) COMBUSTIBLE GAS TRANSMITTER INFRARED COMBUSTIBLE GAS TRANSMITTER
WARNING
Do not remove plugs. To reduce the risk of ignition of hazardous locations, all conduit runs must have a sealing fitting connected within 18 inches of the enclosure. C LA S S I FI E
D 36XO Classified by Underwriters Laboratories, Inc.® as explosion-proof in hazardous locations Class I, Div 1, Groups A,B,C,D; Class II, Div 1, Groups E,F,G when installed in accordance with Manual No. 7013285M. 500 0 1000 PSI USE NO OIL CALIBRATION GAS Figure 3.1 Calibration Procedure Sensidyne Document No. 7013285M (Rev B) PRELIMINARY 27 INFRARED (IR) COMBUSTIBLE GAS TRANSMITTER 3.2.4 Span Calibration 3.2.5 Output Current Calculation Perform Span Calibration as follows: 1) Ensure the Zero Calibration is correct. 2) Check the concentration of calibration gas and calculate the corresponding output current. To calculate the output current (refer to Section 3.2.5). 3) Apply calibration gas (for example 50% LEL Methane) using the same flow rate settings for Zero Calibration, 0.8­1.2 LPM using calibration cup, 2­3 LPM using weather shield. 4) If necessary, change the milliammeter scale setting and adjust the SPAN potentiometer on the PCB to achieve the calculated output current. Allow 30 seconds stabilization time with calibration gas flowing before making this adjustment. 5) Repeat Zero and Span adjustments as necessary. When adjustments are completed disconnect the milliammeter and close the unit. The sensor is designed to provide specific values of amplifier output current over the normal operating range for various concentrations of Methane and other gases. Figure 3.2 is a graph showing the amplifier output current values for various concentration levels of six different gases. The X (horizontal) axis of Figure 3.2 represents gas concentration levels from 0% to 100% LEL. The Y (vertical) axis of Figure 3.2 represents the amplifier output current from 4 mA to 20 mA. The following examples explain how to calculate output current values using the Figure 3.2 graph.
· Example 1 Assuming the calibration gas is Methane, and the unit is linearized for Methane and the gas concentration is 50% LEL; draw a vertical line from the 50% LEL mark on the X-axis to the point where it intersects the METHANE curve. Read across to the Y-axis; the amplifier output current should be 12 mA
· Example 2 Assuming the calibration gas is Hexane and the gas concentration level is 35% LEL; draw a vertical line from the 35% LEL point on the X-axis to the point where it intersects the HEXANE curve. Read across to the Y-axis; the amplifier output current is between 10 mA and 12 mA. Interpolate between the two values; the output current should be approximately 10.1 mA. 28 PRELIMINARY Sensidyne Document No. 7013285M (Rev B) INFRARED (IR) COMBUSTIBLE GAS TRANSMITTER 20
TAN E
PRO PAN E BUTA ETH 18 OUTPUT CURRENT (mA) 16 14 12 mA
EXAMPLE 1 12 10.1 mA
EXAMPLE 2 PEN HEX T ME AN ANE HA NE E NE 10 Example 1 50 %LEL Methane = 12.0 mA Example 2 35 %LEL Hexane = 10.1 mA 8 NOTE: Calculations normalized for Methane 6 4 10 20 30 40 50 60 70 80 90 100 %LEL CONCENTRATION Figure 3.2 Output Current Calculation Sensidyne Document No. 7013285M (Rev B) PRELIMINARY 29 INFRARED (IR) COMBUSTIBLE GAS TRANSMITTER Gas Concentration 0­100 %LEL 0.0 1.3 2.5 3.8 5.0 6.3 7.5 8.8 10.0 11.3 12.5 13.8 15.0 16.3 17.5 18.8 20.0 21.3 22.5 23.8 25.0 26.3 27.5 28.8 30.0 31.3 32.5 33.8 35.0 36.3 37.5 38.8 40.0 41.3 42.5 43.8 45.0 46.3 47.5 48.8 Output Current (mA) 4.0 4.2 4.4 4.6 4.8 5.0 5.2 5.4 5.6 5.8 6.0 6.2 6.4 6.6 6.8 7.0 7.2 7.4 7.6 7.8 8.0 8.2 8.4 8.6 8.8 9.0 9.2 9.4 9.6 9.8 10.0 10.2 10.4 10.6 10.8 11.0 11.2 11.4 11.6 11.8 Gas Concentration 0­100 %LEL 50.0 51.3 52.5 53.8 55.0 56.3 57.5 58.8 60.0 61.3 62.5 63.8 65.0 66.3 67.5 68.8 70.0 71.3 72.5 73.8 75.0 76.3 77.5 78.8 80.0 81.3 82.5 83.8 85.0 86.3 87.5 88.8 90.0 91.3 92.5 93.8 95.0 96.3 97.5 98.8 100.0 Output Current (mA) 12.0 12.2 12.4 12.6 12.8 13.0 13.2 13.4 13.6 13.8 14.0 14.2 14.4 14.6 14.8 15.0 15.2 15.4 15.6 15.8 16.0 16.2 16.4 16.6 16.8 17.0 17.2 17.4 17.6 17.8 18.0 18.2 18.4 18.6 18.8 19.0 19.2 19.4 19.6 19.8 20.0 Table 3.1 Output Current vs Concentration 30 PRELIMINARY Sensidyne Document No. 7013285M (Rev B) INFRARED (IR) COMBUSTIBLE GAS TRANSMITTER SECTION FOUR MAINTENANCE
4.1 ROUTINE MAINTENANCE
IMPORTANT 4.2 ELECTRONICS MODULE The transmitter contains components that are electrostatically sensitive. Always wear a grounding wrist strap while performing the service and maintenance procedures described in this section. If the Zero and/or Span adjustments are not functioning as expected, the Electronics Module (PNº 7017227-1) may be faulty and should be replaced. Replace the Electronics Module as follows (refer to Figure 4.1). 1) Disconnect electrical power from the unit. 2) Remove the cover of the condulet. 3) Disconnect the 3-wire field connections. 4) Remove the two sensor connectors from the PCB. 5) Remove the two screws attaching the circuit board to the condulet. 6) Install the new Electronics Module in the reverse order of disassembly. 7) Apply power to the transmitter and let it stabilize at least 1 hour (24 hours recommended). Perform calibration in accordance with Section 3. The maintenance of the IR Combustible Transmitter Sensor is part of the overall system-level maintenance scheme. However, in addition to any required systemlevel maintenance, the sensor unit should be checked for proper operation using test gas every six months. NOTE The design