Posted 30 March 2012 - 06:09 AM
I believe I have finally reached the root of this issue. I will explain my findings, but in order to prevent this from becoming a really, really long post, I will summarize as much as possible and paraphrase the code a bit. If you want to look up the code reference for more detail, it will be in brackets.
First, I must define some terms.
Notification Appliance - A fire alarm system component such as a bell, horn, speaker, light, or text display that provides audible, tactile, or visible outputs, or any combination thereof. [NFPA 72 3.3.113] A sounder is an example of a commonly used notification appliance.
Single Station Alarm – A detector that incorporates a sensor and an alarm notification appliance in one unit [NFPA 72 section 3.3.175].
Multiple Station Alarm - A single station alarm capable of being interconnected to one or more additional alarms so that the actuation of one causes the appropriate alarm signal to operate in all interconnected alarms [NFPA 72 section 3.3.104]. These alarms are normally powered directly by 120VAC building wiring and are also commonly known as “builder smokes”. The GE 320A/350 series smoke alarms are examples of multiple station alarms.
System Smoke Detector - These detectors are connected to and powered by a control panel and may also have integral notification appliances, depending on the model and manufacturer.[NFPA 72 section 11.7.2] The term “system” smoke detector is defined in ANSI/UL 268. These are also known as 2-wire and 4-wire smokes. System Sensor models 4WTA-B and 2WTA-B are examples of “system smokes”.
Household Fire Alarm System - A system of devices that uses a fire alarm control unit (panel) to produce an alarm signal in the household for the purpose of notifying the occupants of the presence of a fire so that they will evacuate the premises. [NFPA 72 section 220.127.116.11] The Elk M1 with system smokes is an example of a combination panel (burglary/fire) and a Household Fire Alarm System.
Now I will get into some of the requirements for smoke alarms in residential occupancies. Please realize that I will be talking about requirements for new construction in jurisdictions that have adopted the 2009 version of the International Residential Code (IRC). I believe this is case in a large majority of the state-wide and local jurisdictions in the US, but local codes vary. Please check with your local AHJ for proper guidance. Most jurisdictions in the US do not require adherence to the latest codes unless major modifications are made to the residence.
The IRC requires that smoke alarms be listed in accordance with UL 217 and installed in accordance with NFPA 72. [IRC section R314.1] UL 217, entitled “Single and Multiple Station Smoke Alarms” specifies the requirements for “builder smokes”. It does not cover requirements for “system” smoke detectors.
As an alternate, the IRC permits Household Fire Alarm Systems which are installed in accordance with NFPA 72. [IRC section R314.2] UL 268, “Standard for Smoke Detectors for Fire Protective Signaling Systems” specifies requirements for “system smokes”.
NFPA 72 requires that a complete fire alarm system shall be installed with either a set of multiple station alarms or with system smokes. However, once a complete system is installed, detectors of either type may be added as supplemental to the system. [NFPA 72 section 11.3.2]
NFPA 72 requires that multiple station alarms comply with UL 217. [NFPA 72 section 11.7.2]
NFPA 72 requires that system smoke detectors comply with UL 268. [NFPA 72 section 11.7.2]
AVAILABLE HARDWARE COMPLIANCE
Manufacturers of smoke alarms and system smokes certify their products to meet either UL 217 or UL 268, but not both.
The GE 350CX smoke alarms, the Kidde SM120X relays, and First Alert (BRK) RM4 relays are certified to meet UL 217, “Single and Multiple Station Smoke Alarms”. They are not designed meet UL 268, “Standard for Smoke Detectors for Fire Protective Signaling Systems”.
UL 217 specifies requirements for stand-alone and interconnected smoke alarms not connected to an alarm panel. If a smoke is connected to an alarm panel it must meet UL 268 instead of UL 217. There are two key provisions in UL 268 which the GE 250CX does not meet. These are:
1. ANSI/UL 268 requires that a means be incorporated to identify the initiation of an alarm remain activated after the smoke has dissipated from within the detector. [NFPA 72 section 7.5.2]
2. NFPA72 requires that household fire alarm system smoke detectors, initiating devices, and notification appliances be monitored for integrity so that the occurrence of a single open or single ground fault in the interconnection, which prevents normal operation of the interconnected devices, is indicated by a distinctive trouble signal. [NFPA 72 section 18.104.22.168] Monitoring of the tandem relay coil in the GE350CX is not provided and therefore does it not meet this requirement.
Because of these two items, the 350CX cannot be listed per UL 268, and therefore it is not recommended to be connected to an alarm panel per UL Standards.
I find it interesting that while UL 268 requires these two features, UL 217, for “builder smokes”, does not. With this difference, UL is setting the standards of integrity higher for a “household fire alarm system” than for “builder smokes”.
To continue this discussion, and In order to prevent confusion, I need to define a couple more terms:
Supervised: In the context of the remainder of this discussion, “supervised” is a term applied to wiring, meaning that there is a mechanism to detect certain types of failures in the wiring. End-of-line resistors are used to supervise wiring circuits. This practice is also called “monitored for integrity”, which is different from “monitored” as defined next.
Monitored: In the context of the remainder of this discussion, “monitored” is a term applied to household alarm systems, meaning that such a system can report alarm and trouble signals to a central monitoring station.
MORE CODE REQUIREMENTS
You may find it surprising that the 2006 IRC essentially banned household fire alarm systems. Look it up. [2006 IRC section R313.1] However, even more surprising, the 2009 IRC permitted their use again, but with the requirement that they be monitored. [2009 IRC section R314.2]. The 2012 IRC, which is not yet been adopted by many states, continues with this requirement for monitoring.
Suppose I want to bring my 21 year old system up to current code under IRC 2009. Because the way the codes are written, and with available hardware, I am forced to choose between either of two system designs. The first is to use builder smokes which are not supervised and cannot be monitored. The second is to use the household fire alarm system which is required to be supervised and monitored.
Let’s suppose I pick the Household Fire Alarm System, an ELK M1 with System Sensor smokes. When the day comes to sell my house, I can visualize an inspector telling a prospective buyer this: “This house has a Household Fire Alarm System. Building code requires a lifetime monitoring contract with “ATD” in this house.” Well, that would be more than enough to scare me off from purchasing.
So the idea of a household fire alarm system and required monitoring is out. Now I’m forced to choose the builder smokes. But I still want monitoring, just not required monitoring. I know…..I’ll just run a wire from this smoke relay to the alarm panel. The NEC and NFPA 72 allow it, but there is this issue with the manufacturer and the UL. The smoke relay is not UL listed for connecting to a household fire alarm system. It seems like a little ol’ wire won’t hurt anything.
But now when inspector comes around and says,”Uh-oh you have monitoring…UL says that is a no-no”. I can take care of the issue in about 5 seconds with a pair of wire- snippers. Problem solved - no more monitoring. Now I, the home buyer, the inspector, and the UL…we are all happy.
With all that being said, I have five recommendations concerning this issue:
1. I say you should always follow the recommendations of your local fire marshal.
2. I say you should always follow the recommendations of your local building inspectors.
3. I say you should always follow the manufacturer’s recommendations for device installation.
4. I say you should always use components UL-listed for the particular installation.
5. I say you should always do what I say and not what I do.