Smoke Detectors Part II: Sounders

[Mike]

Well after the last informative thread I went to go after getting the smoke detectors for my new Elk...

and found one more decision. I had decided to go for the two wire detectors given the proximity of the bedrooms where the detectors are going (most of them at least) and decided my house isn't big enough to worry about multiple detectors for each room (on separate zones that is).

My question is: You can get detectors with and without an integral sounder. My first thought was to tie everything out with speakers and kill the sounder in the detector, but given I was only planning on one speaker in the hallway leading to the bedrooms I wondered if that was enough.

The first floor will have many in wall speakers that act as sounders (assuming I work that out).

Any opinions on integral sounders for smoke detectors?

 

[Spanky]

My opinion, if I have a fire, rock the neighborhood and the inside of the house. I would let the sounders sound.

Fire is the one good thing central station monitoring is good for.

 

[Mike]

Thanks Spanky. That was what I was thinking. It's not one of the 'cool automation things', its something people need to be woken up if it goes off. Since it was offered in two different ways it made me wonder about the alarm controlled version.

 

[jlehnert]

Yes, you can get detectors with or without sounders built in. Many jurisdictions (including all the ones in my area) require built in sounders. It's all how the AHJ (Authority Having Jurisdiction, aka the building inspector) interpretes the code.

4 wire smokes will also require a reversing relay to trigger the sounders. I never use 2-wire smokes, so I don't know if the same is true for them.

 

[pmonahan]

All Four wire smokes do not need a reversing relay to activate internal sounders, although they do require End of Line Relays in order to supervise power through to the last detector at the End of Line. For integral sounders, four wire detectors are a better choice. Some use a 5th or 5th & 6th Conductor.

Two wire detectors, if equipped with integral sounders can use the reverse polarity method to activate sounders, but you need to ensure that the detector model is listed for use with the control and that the control does in fact support the reverse polarity feature. Make a mistake here and you might experience a failure at a critical moment.

As stated previously most jurisdictions require integral sounders and require all of the sounders to be "linked".

Thanks

Peter

Edit: If the panel does not support polarity reversal of the powered circuit in a alarm, there are optional relays that can be added.

 

[upstatemike]

As stated previously most jurisdictions require integral sounders and require all of the sounders to be "linked".

I have never heard of ANY jurisdiction that required integral sounders, just power supervision on the audible circuit and adequate volume at all locations. For that matter I have never run across any place that required the 120VAC smoke detectors that have also been discussed so frequently. Where do you guys live that has all these weird rules (and have you thought about moving)?

 

[pmonahan]

As stated previously most jurisdictions require integral sounders and require all of the sounders to be "linked".

I have never heard of ANY jurisdiction that required integral sounders, just power supervision on the audible circuit and adequate volume at all locations. For that matter I have never run across any place that required the 120VAC smoke detectors that have also been discussed so frequently. Where do you guys live that has all these weird rules (and have you thought about moving)?

The weird rules are actually code requirements. The codes are only the minimun. The Authority Having Jurisdiction (usually Fire Marshal) is permitted to enforce any and all requirements above and beyond the code.

NFPA 1 (New)

NFPA 72 National Fire Alarm Code Section 2-2 (2-2.2.1 Covers integral sounders)

NFPA 101 Life Safety Code

ANSI S3.41

BOCA National Building Code

SBCCI Standard (Southern) Building Code

As with any other profession, The AHJ is also capable of poor performance, not enforcing the code, or not understanding it.

Thanks

Peter

 

[upstatemike]

Nobody enforces any codes like that around here. All we get is "Uncle Buckle the Safety Buffalo" who comes around to remind folks to wear safety belts and change the batteries in their smoke detectors!

If linked integral sounders are required by code, why do they make smoke detectors that do not have them? Why do panel manufacturers make panels with connections for separate audible devices? Do integral sounders in one smoke detector zone have to trigger the integral sounders in other zones? (I'm not challenging the codes, just trying to reconcile them with common sense).

 

[pmonahan]

I guess Because some people are absent of common sense, The codes permit No grey area; they are printed in black and white.

A Fire Marshal once said to me: "We make it easy for you. All that you have to undertstand is the black part". There is nothing to reconcile.

There are exceptions to integral sounders, but when they are used, they must be lnked; any one detector in alarm Must activate all of the others.

One of the exceptions requires general audibles that are audible above (10db higher than) any ambient noise with doors closed, and all household equipment running, including window air conditioners, etc....it's too subjective and most AHJ's favor the more stringent requirement.

Homeowners can perform electrical work in their own home with a "Homeowners permit"; passing inspection is another matter.

Thanks

Peter

 

[upstatemike]

So if I install an ELK M1 with 3 zones of 4-wire smokes that have integral sounders then activation of any smoke detector will activate the integral sounders of all detectors including those in the other 2 zones?

 

[pmonahan]

So if I install an ELK M1 with 3 zones of 4-wire smokes that have integral sounders then activation of any smoke detector will activate the integral sounders of all detectors including those in the other 2 zones?

Depends on the model you have selected.

with GE Models In order for all sounders to activate when the panel alarms, the panel must reverse the supply voltage polarity to the loop on alarm. If the panel does not implement polarity reversal, an ESL 405 PolarityReversal Relay Module must be used. (Refer to the installationinstructions for the ESL 405 Polarity Reversal Relay Module.)

Some models require a 5th or 5th & 6th Conductor.

Peter

 

[rocco]

When I remodeled my home in NJ this summer, the borough fire code was clear:

There had to be a smoke-detector on each floor (four, in my case). They had to be powered by their own 120 VAC, 15 amp circuit, and they all had to be linked together. If it was new construction, there would have to be a smoke-detector in each bedroom and a CO-detector on each floor, as well.

Inflexible? yes. Arbitrary? somewhat. Silly? maybe. Clear? very.

As far as being monitored from an alarm panel, we were allowed to do whatever we wanted, as long as it didn't interfere with the stated requirements.

 

[upstatemike]

rocco-

I think I understand the 120V smoke detector rules, I just haven't seen them applied locally. (Of course I don't get out much so that may have something to do with it).

What Peter is talking about however is completely new to me. I have never before heard about a requirement to have linked integral sounders on low voltage 2 or 4 wire smokes so I was really curious to learn more about that. I'm not sure how many people with smoke detectors tied to ELK or Caddx panels currently meet that requirement.

As for my comments about the rules being weird, it only seems that way to me because they are outside my experience and I never see them discussed in the catalogs selling smoke detectors and alarm panels.

 

[pmonahan]

Rocco is correct and although aware, probably forgot to mention that the 120V detectors must also have a backup battery (usually 9V).

The requirements I mentioned for low voltage are as they pertain to installations where the low voltage is the primary source of detection and code compliance.

If your detectors are supplemental to existing compliant detectors, then you can do virtually anything you want, because it is in excess of the code requirements.

In installations that I have supervised, the low voltage detectors take the place of the 120V detectors and are required as we previously discussed for both code compliance and occupancy. This is usually during new construction (everything is new here in Atlanta) and there is no point in duplicating fire protection.

"System" detectors also perform much better than the 120V detectors which are usually ionization types.

The question looms, if one is aware of the requirments (and they are requirements for good reasons), would one deviate to save money ?? In my years, I have marveled at homeowners sometimes; they won't install half a room of carpeting, laminated counters in the kitchen, or compromise other creature comforts, but they will look to compromise on Life Safety.

I'm sharing my knowledge and experiences here not to be critical; I've spent a good deal of my life in this industry and I am very passionate about Life Safety.

Regards,

Peter

 

[upstatemike]

I also am not trying to be critical with the nature of my questions. (Sometimes I just think I'm a lot funnier than I actually am). I also have a strong interest in life safety. I have around 30 photoelectric smoke detectors, a bunch of rate-of-rise detectors, and several motorized fire bells on supervised bell circuits.

I thought I was doing OK until the topic of integral sounders came up. As I mentioned, it was a surprise because I had not heard anything about it locally or really noticed it mentioned in any catalogs where I would normally shop for replacement smoke detectors. Now I may have to rethink things a bit before doing any further upgrades to the fire alarm system.