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July 18, 2004

                               ET NEWS                                
====================================================================== 
             NEWS AND INFORMATION FOR THE ENGINEERING TEAM             
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Issue No. 160   http://etnews.org   mailto:mike@etnews.org   7-18-2004 
====================================================================== 

Contents
--------
- News
- ET News Journal
- Job Opportunities
- Fire Alarm Class Schedule
- Comments & Acknowledgements

======================================================================
NEWS 
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AFSA Pacific NW Chapter meeting.
When: August 10, 2004 at 6:30 PM
Where: 13 Coins @ SeaTac

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VEGAS Notes: Fire Shuts Strip, Offers Safety Lesson
KTVU.com - San Francisco,CA,USA
... The moral of this story is "don't be stupid." If you hear a fire alarm,
leave. If you smell smoke, leave. If you wait until someone ... 
http://www.ktvu.com/travelgetaways/3511926/detail.html

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RAULAND-BORG Addresses Patient Safety Concern Over Pillow Speakers ... PR Web
(press release) - Ferndale,WA,USA ... approved pillow speakers in an oxygen-
enriched environment is a fire hazard ... current manufacturer of healthcare
communications products to obtain this UL approval ... 
http://www.prweb.com/releases/2004/7/prweb140796.htm

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EVAC Panel splits 50 W of audio power to 8 zones.
Industrial News Room - New York,NY,USA
... Model ACC-25/50ZS activates via reverse polarity or contact closure,
allowing unit to stand alone or be added to fire alarm control panel. ... 
http://www.industrialnewsroom.com/fullstory/453378

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INDUSTRY Roundup: Siemens Lands Patent
Consulting-Specifying Engineer - Oak Brook,IL,United States
... an entire loop of up to 252 devices, indicating shorts, ground faults and
proper communication with all devices before connecting to an active fire alarm
panel ... 
http://www.csemag.com/news_stories/news131.asp

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I'll see you in Happyrock this week.

Have fun!

Mike
mailto:mike@etnews.org

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ET NEWS JOURNAL 
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TO GROUND OR NOT TO GROUND
--------------------------

Is a power-limited fire alarm system required to be connected to ground? As
Wayne Moore would say, "It depends".

760.9 Fire Alarm Circuit and Equipment Grounding.
Fire alarm circuits and equipment shall be grounded in accordance with Article 250

250.112 Fastened in Place or Connected by Permanent Wiring Methods
(Fixed)  Specific.
(I) Power-Limited Remote-Control, Signaling, and Fire Alarm Circuits. Equipment
supplied by Class 1 power-limited circuits and Class 1, Class 2, and Class 3
remote-control and signaling circuits, and by fire alarm circuits, shall be
grounded where system grounding is required by Part II or Part VIII of this
article.

II. Circuit and System Grounding
250.20 Alternating-Current Circuits and Systems to Be Grounded.
(A) Alternating-Current Circuits of Less Than 50 Volts. Alternating-current
circuits of less than 50 volts shall be grounded under any of the following
conditions:  
(1) Where supplied by transformers, if the transformer supply system exceeds 150
volts to ground
(2) Where supplied by transformers, if the transformer supply system is
ungrounded
(3) Where installed as overhead conductors outside of buildings 

VIII. Direct-Current Systems
250.162 Direct-Current Circuits and Systems to Be Grounded.
Direct-current circuits and systems shall be grounded as provided for in
250.162(A) and (B).
(A) Two-Wire, Direct-Current Systems. A 2-wire, dc system supplying premises
wiring and operating at greater than 50 volts but not greater than 300 volts
shall be grounded.
Exception No. 1: A system equipped with a ground detector and supplying only
industrial equipment in limited areas shall not be required to be grounded.
Exception No. 2: A rectifier-derived dc system supplied from an ac system
complying with 250.20 shall not be required to be grounded. 
Exception No. 3: Direct-current fire alarm circuits having a maximum current of
0.030 amperes as specified in Article 760, Part III, shall not be required to be
grounded.


According to Parts II and VIII of article 250, it appears as though
power-limited fire alarm systems are not required to be connected to ground,
with exceptions. Another article that will impact this decision is 110.3(B):


760.52 Wiring Methods and Materials on Load Side of the PLFA Power Source.
(B) PLFA Wiring Methods and Materials. Power-limited fire alarm conductors and
cables described in 760.71 shall be installed as detailed ... Devices shall be
installed in accordance with 110.3(B), 300.11(A), and 300.15.

110.3 Examination, Identification, Installation, and Use of Equipment.
(B) Installation and Use. Listed or labeled equipment shall be installed and used
in accordance with any instructions included in the listing or labeling.


If the manufacturer's documentation requires the fire alarm control panel to be
connected to ground then you'll have to do so. The size of the equipment
grounding conductor will be in accordance with article 250:


Table 250.122 Equipment Grounding Conductor Size

Overcurrent Device  AWG Copper
------------------  ----------
     15 amp            14
     20 amp            12


Wiring methods on the supply side of the power-limited source limits the
overcurrent device to no more than 20 amps:


760.51 Wiring Methods on Supply Side of the PLFA Power Source.
Conductors and equipment on the supply side of the power source shall be
installed in accordance with the appropriate requirements of Part II and
Chapters 1 through 4. Transformers or other devices supplied from power-supply
conductors shall be protected by an overcurrent device rated not over 20 amperes.

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JOB OPPORTUNITIES 
======================================================================

Place your "job opportunity" or "seeking employment" ad here. 
mailto:jobs@etnews.org

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FIRE ALARM CLASS SCHEDULE 
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------------------
August 17-19, 2004 Cincinnati, OH
------------------
Basic Fire Alarm Seminar
Fire Alarm System Testing & Inspections Seminar
Fire Alarm Plan Review Seminar 
http://www.afaa.org/afaa/PDF/BasFA_TI_PR_Cincinnati_Aug2004.pdf

------------------
August 24-26, 2004 Indianapolis, IN
------------------
Fire Alarm Plan Review Seminar
Understanding IBC Fire Alarm Requirements 
http://www.afaa.org/afaa/PDF/PR_UCR-IBC_Indy_Aug2004.pdf

------------------
August 31 - September 2, 2004 Dallas, TX
------------------
Fire Alarm Plan Review Seminar
Understanding IBC Fire Alarm Requirements 
http://www.afaa.org/afaa/PDF/PR_UCR-IBC_Dallas_Aug2004.pdf

------------------
September 8-9, 2004 Keizer, OR
------------------
Understanding IBC Fire Alarm Requirements 
More information is forthcoming.

------------------
September 14-16, 2004 Spokane, WA
------------------
Fire Alarm Plan Review Seminar
Intermediate Fire Alarm Seminar (NICET I & II)
More information is forthcoming.

------------------
September 21-23, 2004 Lafayette, LA
------------------
Fire Alarm System Testing & Inspections Seminar
Understanding IBC Fire Alarm Requirements 
More information is forthcoming.

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COMMENTS AND ACKNOWLEDGEMENTS 
======================================================================

ET News is written nearly every week and almost always sent on Sunday.

Doug Hockinson built the PHP/MySQL ET News website -> http://phpvs.com

Purchase NICET Element Review Handbook online http://tinyurl.com/28ldd

Purchase NFPA, ICC, and more on line: http://www.etnews.org/index.php?s=461

Purchase new & used codes & standards on eBay http://tinyurl.com/36zzk

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Some information may be found within this email message that is reprinted with
permission from one or more of the following; NFPA 70 National Electrical Code(r),
NFPA 72(r) National Fire Alarm Code(r), NFPA 101(r) Life Safety Code(r),
Copyright(c) NFPA, Quincy, MA 02269. This reprinted material is not the complete
and official position of the NFPA on the referenced subject, which is represented
only by the standard in its entirety. 
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Some information may be found within this web site that is reprinted with permission from one or more of the following: NFPA 70 National Electrical Code®,NFPA 72® National Fire Alarm Code®, & NFPA 101® Life Safety Code®, Copyright© NFPA, Quincy, MA 02269.

This reprinted material is not the complete and official position of the NFPA on the referenced subject, which is represented only by the standard in its entirety.