Wednesday, June 19, 2013

Carbon Monoxide Detector Mounting

Carbon monoxide alarms and detection systems now have more direction on mounting and alerting thanks to NFPA 72 2022


NFPA 720: Standard for the Installation of Carbon Monoxide (CO) Detection and Warning Equipment (2015) currently does not have any requirements for the mounting height/location of a carbon monoxide detector.  However, NFPA 720 does specify that is a carbon monoxide detector is installed in a room with a fire fueled appliance such as a generator, hot water heater, furnace, etc., it is to be mounted on the ceiling.

The reason behind the NFPA 720 placement of carbon monoxide detectors on the ceiling in these areas is makes perfect sense. Continue below:  

Carbon Monoxide Poisoning with Fire Alarms

Carbon monoxide has a molar mass of 28.0, which makes it slightly lighter than air, whose average molar mass is 28.8. According to the ideal gas law, CO is therefore less dense than air.  With that said, the heat generated by these appliances will make the carbon monoxide (CO) more buoyant and present it to the carbon monoxide detector on the ceiling.

Another source for the mounting and installation of carbon monoxide detectors is found in NFPA 72 2019 section 17.12 "Carbon Monoxide Detectors"

NFPA 72 Carbon Monoxide Requirements per Chapter 17

NFPA 72 2022 Section 17.12.1 
Where required by other governing laws, codes, or standards, carbon monoxide defectors shall be installed in accordance with the following:
    1) On the ceiling in the same room as permanently installed fuel-burning appliances, and

    2) Centrally located on every habitable level and in every HVAC zone of the building, and

    3) Outside of each separate dwelling unit, guest rom, and guest suite sleeping area within 21 feet (6.4 m) of any door to a sleeping room, with the distance measured along the path of trave, and

    4) Other locations where required by appliance laws, codes, or standards or
    
NFPA 72 2022 Section 12.12.2 
Carbon monoxide detectors shall meet the following requirements:
    1) Carbon monoxide detectors shall be listed in accordance with applicable standards, such as ANSI/UL 2075, Gas and Vapor Detectors and Sensors.

    2) Carbon monoxide detectors shall be set to respond to the sensitivity limits specified in ANSI/UL 2034, Standard for Single and Multiple Stations Carbon Monoxide Alarms.

NFPA 72 2022 Section 17.12.4 
All carbon monoxide detectors shall be located and mounted so that accidental operation will not be caused by jarring or vibration. 

NFPA 72 2022 Section 17.12.5 
The location of carbon monoxide detectors shall be based on an evaluation of potential ambient sources and flows of carbon monoxide, moisture, temperature, dust, or fumes and of electrical or mechanical influences to minimize nuisance alarms. 

NFPA 72 Carbon Monoxide Requirements per Chapter 18

NFPA 72 2022 Section 18.4.3.1 
Where a carbon monoxide detector or alarm is required by other codes or standards or by the authority having jurisdiction and where an audible signal is required, a distinctive signal patter shall be required that is different from a fire evacuation signal.

We know this as Temporal Code 4

NFPA 72 2022 Section 18.4.3.2 
Where an audible signal is required, the carbon monoxide signal shall be four-pulse temporal pattern and comply with the following:
    1) Signals shall be a pattern consisting of four cycles of 100 milliseconds +/- 10 percent "on" and 100 milliseconds +/- percent "off" followed by 5 seconds +/- 10 percent "off" as demonstrated in figure 18.4.3.2

    2) After the initial 4 minutes of the carbon monoxide signal, the 5-second "off" time shall be permitted to be changed to 60 seconds +/- 10 percent.

    3) The alarm signal shall be repeated in compliance with 18.4.3.2(1) and 18.4.3.2 (2) until the alarm resets or the alarm signal is manually silenced.


temporal code 4 figure



NFPA 72 2022 Section 18.4.3.3
The signal shall be synchronized within a notification zone of a protected premises. 

NFPA 72 2019 Section 18.4.3.4 
The audible signal of carbon monoxide alarms and systems installed to meet the requirements of NFPA 72 chapter 29 shall NOT be required to be synchronized.

NFPA 72 2022 Section 23.8.4.9
Unless otherwise permitted by 23.8.4.9.1 signals form carbon monoxide detectors and carbon monoxide detection systems transmitted to a fire alarm system shall be indicated as a carbon monoxide alarm signal. No more general supervisory signals for carbon monoxide alarms or detection system. 

NFPA 72 2022 Section 23.8.6.1.2
Except as permitted in 23.8.61.3 occupant notification of carbon monoxide systems shall be throughout the protected premises. 

NFPA 72 2022 Section 23,8.6.1.3
Where carbon monoxide alarm signals are transmitted to a constantly attended on-site location or off-premises location in accordance with this chapter, selective public mode occupant notification zone encompassing the area where the carbon monoxide alarm signal was initiated. 

NFPA 72 2022 Section 23.8.6.3.3
The boundaries of carbon monoxide alarm notification zones shall be coincident with the area where the alarm initiation originated and other signaling zones in accordance with the building's emergency response plan. 

On another note, make sure that when you place your carbon monoxide detector outside of the sleeping area you still achieve a sound level of 75dB at the pillow with the door closed.

Read more hear about the new laws and state legislation for carbon monoxide detection in California.


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Drywall Dust Problems with System Sensor Smoke Detector

If any packaged air conditioning units are run during the drywall installation phase of building construction to assist in the drying of joint compound, the fine dust created by sanding of those drywall joints may compromise the System Sensor smoke detector sensor heads within the duct housing. The 2D51 System Sensor Head in the InnovairFlex Duct Smoke Detector models D4120, D4120W and D4S may display a “maintenance” condition that will require replacement or cleaning of the sensing chambers on the smoke detector head. The “maintenance” condition will be indicated on the fire alarm control panel, on the sensor itself or power board of the duct smoke detector (the sensor LED will blink “red” every five seconds and the power board LED will blink “amber” every five seconds).

To avoid this condition, it is recommended that the System Sensor smoke detector heads be removed during the construction phase and replaced once construction is completed and the Certificate of Occupancy is issued. The sensor heads twist out for removal and twist in for insertion.

Below is an extracted image of the System Sensor duct smoke detector sensor head:


Cleaning the sensing chamber on the sensor head

If the System Sensor smoke detector heads are not removed during the construction phase and the sensor chamber becomes dirty causing a maintenance condition (it will not always be visible on the exterior black screen on the sensor head), the sensor head must be cleaned with compressed air. To clean the sensor head chamber, follow these step-by-step instructions see the video demonstration below:

1. Remove the System Sensor smoke detector head to be cleaned from the duct smoke detector housing by twisting it in a counterclockwise direction.
2. Remove the smoke sensor cover by pulling outward on each of the four removal tabs that hold the cover in place.
3. Vacuum the screen carefully without removing it. If further cleaning is required continue with Step 4. Otherwise, skip to Step 7.
4. Remove the chamber cover/screen assembly by pulling it straight out.
5. Use a vacuum cleaner or compressed air to remove dust and debris from the sensing chamber.
6. Reinstall the chamber cover/screen assembly by sliding the edge over the sensing chamber. Turn until it is firmly in place.
7. Replace the cover using the holes for the LEDs for alignment and then gently push it until it locks into place.
8. Reinstall the System Sensor smoke detector head in the duct smoke detector housing by aligning it in the housing and twisting it in a clockwise direction.

Note: Cleaning only the sensor head’s exterior black screen will not remove any drywall dust in the smoke sensing chamber.
Note: Should the System Sensor duct smoke detector remain in a “maintenance” condition after cleaning, then it may require the complete replacement of the sensor head. The replacement sensor head is model 2D51.



It is Illegal to Tamper with Fire Alarm Systems

Today I rode along with some of our technicians to perform an annual fire alarm inspection of a three story apartment complex with approximately 140 units. The system comprised of a Gamewell IF610-252 addressable fire alarm control panel with Wheelock notification devices. On the first floor there were 20 handicap units with addressable system smoke detectors (Apollo XP95-P) which activated a signal module for the notification appliance circuit within its designated unit.

Now, the addressable system smoke detectors in the handicap units were programmed to supervisory events for the purpose of central station monitoring and common area notification of the facility. However, the individual notification devices within the unit were supposed to activate if the photoelectric smoke detector was activated. Needless to say, this system was messed up. Some of the smoke detectors failed to activate the NACs and other actually activated the common corridor devices. We also found that the installing fire alarm company did not design the system with SYNC modules.

How this facility passed it original acceptance test is beyond me.

Tampering with Fire Alarms is illegal

On top of all of this we came across 4 units where the occupant had tampered with the fire alarm system mini horn within their living room. We had to remove the tape, cotton, plastic and whatever else they could find to suppress the sound from the devices and warn the occupants that it is a crime to tamper with fire alarm equipment. For your reference, the California Penal Code section for this is 148.4

It reads:

a) Any person who does any of the following is guilty of a misdemeanor and upon conviction is punishable by imprisonment in a
county jail, not exceeding one year, or by a fine, not exceeding one thousand dollars ($1,000), or by both that fine and imprisonment:

(1) Willfully and maliciously tampers with, molests, injures, or breaks any fire protection equipment, fire protection installation,
fire alarm apparatus, wire, or signal.

(2) Willfully and maliciously sends, gives, transmits, or sounds any false alarm of fire, by means of any fire alarm system or signal
or by any other means or methods.

(b) Any person who willfully and maliciously sends, gives, transmits, or sounds any false alarm of fire, by means of any fire
alarm system or signal, or by any other means or methods, is guilty of a felony and upon conviction is punishable by imprisonment in the state prison or by a fine of not less than five hundred dollars ($500) nor more than ten thousand dollars ($10,000), or by both that fine and imprisonment, if any person sustains as a result thereof, any of the following:

(1) Great bodily injury.

(2) Death.


If you are interested in taking the NICET CBT exam for fire alarms, then we have you covered!  We are now selling our CBT Levels 1 - 3 practice exam DVDs.  These DVDs are packed with tons of NICET CBT practice exams along with all code references as to where to find the answers.  We have also supplied the DVDs with all of the necessary NICET applications, CBT calculator demonstrations, links and more.  If you need more information, feel free to send an email.  You can find the link to purchase our DVDs on the top left section of each page on this site.

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SLC Circuit for Duct Detectors Done the Easy Way

Okay we are back to the amazing installation practices that some fire alarm and security companies will perform to lower their labor time and land the job. However, after you will see in this amazing video you will wonder how some of these companies get away with it. And if they are doing these installs after the acceptance test, then how are they living with themselves? Better yet, how does the customer not make themselves aware of what they are paying for? Words cannot express the frustration that myself and other competent contractors feel when they see installs like this.

Here is what we have for you today. This video shows a quick clip of some conventional System Sensor duct smoke detectors installed within the rooftop HVAC unit. However, the previous fire alarm contractor thought it would be a good idea to run a standard 18 awg (American wire gauge) 2 conductor PVC cable open wire across the rooftop from unit to unit. They drilled a hole in the side of each HVAC roof top unit and proceeded to run this PVC cable across the roof and tied them directly to the addressable module for each System Sensor duct smoke detector. This was obviously done because the contractor was one of two things: 1 he was to lazy to get a scissor lift below the deck and find the problem, or 2 he was just not competent enough to resolve the issue without pulling off this nightmare. You be the judge!




Friday, June 14, 2013

Gamewell IF610 vs. Lightning. Got Surge Protection?

We just pulled out a Gamewell IF610-504 at a military base in California. Now they claim that lightning is the cause of the damage and from the looks of the board I could definitely agree. The fuse located directly to the left of the incoming 24VDC from the transformer was not blown which is a good indication that the surge was extremely powerful and quick. This power surge blew out the main board, the CPU, the display and the 4 SLC loop card even though the only visible damage was on the main board. It appears that the power surge was so powerful that it burned a hole through the Gamewell IF610 board. This is why it is so important to have Transient Surge Protection for your fire alarm systems.

Unfortunately for our customer these boards are not readily available from the Gamewell factory so the down time is about two weeks.Check out these pictures.



Gamewell IF610 FACP Board Hit by Lightning
Gamewell IF610 FACP Board Hit by Lightning