1、NEMA Standards PublicationNational Electrical Manufacturers AssociationNEMA SB 7-2013Applications Guide Carbon Monoxide Alarms and DetectorsNEMA SB 7-2013 Applications Guide Carbon Monoxide Alarms and Detectors Published by: National Electrical Manufacturers Association 1300 North 1 ih Street, Suite
2、 900 Rosslyn, Virginia 22209 www.nema.org 2013 National Electrical Manufacturers Association. All rights, including translation into other languages, reserved under the Universal Copyright Convention, the Berne Convention for the Protection of Literary and Artistic Works, and the International and P
3、an American copyright conventions. NOTICE AND DISCLAIMER The information in this publication was considered technically sound by a consensus among persons engaged in its development at the time it was approved. Consensus does not necessarily mean there was unanimous agreement among every person part
4、icipating in the development process. The National Electrical Manufacturers Association (NEMA) standards and guideline publications, of which the document herein is one, are developed through a voluntary standards development process. This process brings together volunteers and/or seeks out the view
5、s of persons who have an interest in the topic covered by this publication. Although NEMA administers the process and establishes rules to promote fairness in the development of consensus, it does not write the documents, nor does it independently test, evaluate, or venfy the accuracy or completenes
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7、he publication, use of, application, or reliance on this document. NEMA disclaims and makes no guaranty or warranty, express or implied, as to the accuracy or completeness of any information published herein, and disclaims and makes no warranty that the information in this document will fulfill any
8、particular purpose(s) or need(s). NEMA does not undertake to guarantee the performance of any individual manufacturers or sellers products or services by virtue of this standard or guide. In publishing and making this document available, NEMA is not undertaking to render professional or other servic
9、es for or on behalf of any person or entity, nor is NEMA undertaking to perform any duty owed by any person or entity to someone else. Anyone using this document should rely on his or her own independent judgment or, as appropriate, seek the advice of a competent professional in determining the exer
10、cise of reasonable care in any given circumstance. Information and other standards on the topic covered by this publication may be available from other sources, which the user may wish to consult for additional views or information not covered by this publication. NEMA has no power, nor does it unde
11、rtake to police or enforce compliance with the contents of this document. NEMA does not certify, test, or inspect products, designs, or installations for safety or health purposes. Any certification or other statement of compliance with any health- or safety-related information in this document shal
12、l not be attributable to NEMA and is solely the responsibility of the certifier or maker of the statement. Pagei CONTENTS Page FOREWORD . ,., . ,.,., . , “, ,.“ 111 1 2 3 4 5 6 7 8 1.1 1.2 2. t 2.2 4.1 4.2 4.3 4.4 4.5 4.6 5.1 5.2 5.3 5.4 5.5 5.6 5.7 6.1 6.2 6.3 6.4 7.1 7.2 7.3 8.1 8.2 8.3 8.4 8.5 SC
13、OPE AND PURPOSE , ,_,.“- 1 Scope 9 . . . . . . . . . . . . . . . . t . . 1 Purpose . 1 REFERENCED STAN DAR OS - 1 Installation Standards . . 1 Ptoduct Standards 1 GLO.SSARY OF TERMS , . . . . , 2 CO OVERVIEW, . . , , , , , , . ,.,., . H. 2 What Is CO? . . 2 Why Is CO a Concern? . 3 Where Is CO Produ
14、ced/Found? 4 Why Is Outdoor Fresh Alr Makeup So Important? 4 Is It Possible to Protect Against CO? 5 Model Buiding Codes 5 HOW CO AlARMS ANO, DETECTORS OPERATE: 5 BiOfn.inlelic co Sensor Operation . 5 Metal Oxide Semiconductor MOS) CO Sensof Operation . 5 Electrochemical (EC) co Sensor Operation . 7
15、 Limited ure of CO Sensors 8 Operational Differences Between Alarms and Detectors 6 5.5.1 co Alarm A. 0.0 . . . a . a . at. io4 “4 . 4 . . . . . . . o. 0 4 0 8 5.5.2 co DetectiOn . 9 5.5.3 Alarm Thresholds for CO Alarms and Detectors . 10 Combination Smoke/CO Alarms and Combination Smoke/CO Detector
16、s 1 o 5.6.1 Combination Smoke/CO Alarms 10 5.6.2 Combination Smoke/CO Detectors . 11 CODetection Technology Reliability and Effectiveness . 11 INSTAL.LATION AND PlACEMENT tHtH+HtH ,. . . . . . . . . . . _ _. 11 Placement and Spacing . 12 Interconnection ot co AJarms . 12 6.2.1 Sleeping Area Requirem
17、ents 12 PetformancBased Design 13 co Detectors for Controt of co Spread 13 INSPECTION. TESTING. AND MAINTENANCE . “.“ . .w w 13 CO AJanns . . . 13 Household co Systems . . 13 CO-Detection Systems 14 7 .3. 1 Notification . . . . . 14 7.3.2 VISUal lospectkln . 14 7.3.3 Reaooepta.nce Testing . . . . .
18、14 7.3.4 Functional Tes1ing . 14 7.3.5 Chinese Drywall . . . 14 CQ.DETECTION SYSTEMS _,_ 15 Design Considerations . . 15 Distinctive Signals . 15 Types of CO,.Qetection Systems . 15 OCCupant Notiftcation 15 Secondary Power Requirements . . 16 201 3 Nationat Electrical Manuracturers Association Pagei
19、i ANNEX A N FP.A 720-2012 . a , , . , . 17 FIGURES Page Figure 1 CO in the Bloodstream . 3 Flgure 2 Cutaway View of a Biomimetlc Sensor . 5 Figur,e 3 Exploded View or ;a MOS Sensor . 6 Fure 4 Cutaway View or an EC CO Sensor Cell . . 7 Figure 5 Typical CO AJarm 9 Figure 6 Typical System-Coonected CO
20、Detector 10 TABLES Page Table, 1 General Effects of CO Exposure over Time 4 Table 2 Comparison or CO-Detection TechnolOgies 7 Table 3 CO Alarm Points per ANSIJUl2034 ( 2011 UL, used wi1h permission) . 10 2013 National Electrical Manufacturers Association Page iii FOREWORD The purpose of this guide i
21、s to provide information concerning the proper use of carbon monoxide (CO) alarms and detectors. It covers the major technologies used for CO detection; the differences between CO alarms and CO detectors; combination devices: and CO device reliability, effectiveness, and limited life. This guide was
22、 developed by NEMAs Signaling Protection and Communications Section (NEMA 3SB). Some material herein was extracted from NFPA 720-2012, Standard for the Installation of Carbon Monoxide (CO) Detection and Warning Equipment. NEMA extends its thanks to the National Fire Protection Association (NFPA) for
23、 granting permission to extract this material. About NEMA 358 The objective of NEMA 3SB is to serve as the primary source of technical, training, and educational materials essential for the specification, application, and manufacture of reliable life safety products, as well as their installation, p
24、erformance, and inspection. NEMA 358 currently represents 21 manufacturers in support of the automatic fire detection and alarm industry and the health care communications industry. Fire detection and alarm products include life safety/fire alarm systems and devices that provide early warning of an
25、impending or actual fire or gaseous hazard. The products detect, notify, and initiate control functions in case of hazard to life or property. For more information on life safety, go to wwwJifesafetvsolutionJ;online.org. About the National Electrical Manufacturers Association (NEMA) Founded in 1926
26、and headquartered near Washington, D.C., NEMA represents 400-plus member companies that manufacture products used in the generation, transmission and distribution, control, and end use of electricity. These products are used in utmty, industrial, commercial, institutional, and residential applicatio
27、ns. The associations Medical Imaging 54(02): 36-39, Vf!NW,qdc.aov/mmwrloreview/mmwrhtm_l/mm540_2_a2.hl r:n 201 3 National Electrical Manufacturers Association Page4 Table 1 General Effects of CO Exposure over Time Concentration Symptoms (ppm CO) 50 No adverse effects with 8 hours of exposure 200 Mil
28、d headache after 2-3 hours of exposure 400 Headache and nausea after 1-2 hours of exposure 800 Headache, nausea, and dizziness after 45 minutes of exposure; collapse and loss of consciousness after 2 hours of exposure 1,000 Loss of consciousness after 1 hour of exposure 1,600 Headache, nausea, and d
29、izziness after 20 minutes of exposure 3,200 Headache. nausea, and dizziness after 5-1 0 minutes of exposure; collapse and loss of consciousness after 30 minutes of exposure 6,400 Headache and dizziness after 1-2 minutes of exposure; loss of consciousness and danger of death after 10-15 minutes of ex
30、posure 12,800 (1.28% by Immediate physiological effects; unconsciousness and volume) danger of death after 13 minutes of exposure 4.3 WHERE IS CO PRODUCED/FOUND? CO is formed from the incomplete combustion of fossil fuels. Many common appliances, machinery, and heating equipment, if not working or v
31、ented properly, can produce dangerous CO build-up in a given environment. According to recent studies, the primary sources for CO fatalities are: a) Heating systems (HVAC: gas, oil-fired, central, and unitary equipment) b) Power tools c) Charcoal grills or other charcoal sources d) Gas ranges or ove
32、ns e) Camp stoves or lanterns f) Other or multiple appliances (gas-fired water heater, dryer, boiler) g) Internal combustion engines (running vehicles. generators, other equipment, etc.) h) “Fresh air“ makeup intakes in conjunction with internal combustion engines i) Fossil fuel-fired pre-heaters j)
33、 Suppression and extinguishing operations, internal and external (as they seek to make combustion less efficient until fire cessation) 4.4 WHY IS OUTDOOR FRESH AIR MAKEUP SO IMPORT ANT? Most modern buildings bring outdoor air into a building through a mechanical ventilation system for the purpose of
34、 maintaining acceptable indoor air quality. CO and/or other gases could be brought into the building if the outdoor fresh air makeup is located adjacent to a parking area where vehicles are routinely staged while running, or if several roof top units are located too close to each other or adjacent t
35、o other incomplete combustion exhaust stacks. The same holds true for CO produced from other outdoor transient incomplete combustion sources. 2013 National Electrical Manufacturers Association Page 5 4.5 IS IT POSSIBLE TO PROTECT AGAINST CO? By applying technology through the use of properly designe
36、d, installed, supervised, tested,maintained, and monitored automatic life safety CO alarms and detectors, it is possible to protect against CO. 4.6 MODEL BUILDING CODES The International Code Council (ICC) is a membership association that develops the codes used in the construction of residential an
37、d commercial buildings, including homes, hospitals, apartment buildings, hotels, and dormitories. The codes become law when adopted by local and state governments. The following 1-codes require the installation of CO-detection devices: a) The 2009 and 2012 editions of the International Residential C
38、ode (IRC): CO detection is required in newly constructed detached one- and two-family dwellings and townhouses not more than 3 stories within which fuel-fired appliances are installed and in dwelling units that have attached garages. b) The 2012 edition of the International Building Code (IBC) and I
39、nternational Fire Code (IFC): CO detection is required in Group-R and Group-1 occupancies such as hotels, dormitories, apartment buildings, hospitals, nursing homes, assisted living facilities containing a fuel-burning appliance, or a building which has an attached garage. 5 HOW CO ALARMS AND DETECT
40、ORS OPERATE CO-detection devices monitor the amount of CO in the air over a specific time period. Distinguished by their sensing technologies, three basic types of CO sensors are used today: biomimetic, metal oxide semiconductor, and electrochemical. 5.1 BIOMIMETIC CO SENSOR OPERATION Biomimetic sen
41、sors are designed to mimic how the hemoglobin in blood reacts to the presence of CO. The sensor monitors an infrared light source that is passed through a disc composed of synthetic hemoglobin which darkens in the presence of CO. Thus, as CO in the atmosphere increases, the light is obscured, trigge
42、ring an alarm signal. These sensors are inexpensive to produce and consume a small amount of energy to operate. However, research has shown that this type of sensor is prone to cause more nuisance alarms, has a shorter lifespan than do other types of CO sensors, and requires a long recovery time fol
43、lowing an alarm. Gel Plate Photo-optic CO Spot Figure 2 Cutaway View of a Biomimetic Sensor 5.2 METAL OXIDE SEMICONDUCTOR (MOS) CO SENSOR OPERATION MOS sensor technology utilizes a tin dioxide semiconductor, which is heated by an electrical current at specific intervals. When the tin dioxide reaches
44、 its operating temperature, its resistance will change in the 201 3 National Electrical Manufacturers Association Page6 presence of CO. Once the resistance changes, as a result of a specific amount of CO reaching the sensors threshold, the alarm signal is triggered. MOS sensors have a long lifespan
45、and can respond quickly to CO. MOS sensors utilize an electrical current to heat the semiconductor, which results in high current consumption. Also, MOS sensors have been shown to be more susceptible to nuisance alarms m the presence of some common household chemicals. Typical MOS Sensor Assembly I
46、“- _ / - -Filter Cap Sensing Oxide Sensor Electrodes with Substrate Heater Electrodes with Substrate Leads Base Connecting Pins Figure 3 Exploded View of a MOS Sensor 201 3 National Electrical Manufacturers Association Page7 5.3 ELECTROCHEMICAL (EC) CO SENSOR OPERATION EC sensors use a platinum elec
47、trode and acid combination to promote a reaction between CO and the oxygen in the air, which then produces an electrical current. When CO is present in the air, and the current increases beyond a specific threshold, an alarm signal is activated by the circuit. EC sensors have been in use in commerci
48、al and residential applications for many years. They have proven to be reliable, have relatively low current consumption, and respond quickly to CO. However, they may be susceptible to nuisance alarms in the presence of household cleaners that contain ammonia, such as glass cleaners. Filter -;:.-.-t
49、-Eieclrode Figure 4 Cutaway View of an EC CO Sensor Cell Table 2 Comparison of CO.Qetection Technologies Sensor Technology Advantages Disadvantages Typical Lifespan High false alarm rate Biomimetic Low cost Long recovery after 2-3 years alarm High current draw Non-selective; MOS Long lifespan sensit
