I am trying to find 15 24 volt DC fire alarm horns that are an older metal style that have a high enough impedance to work on a modern fire alarm system (Firelite MS 9050). We are trying to match audibility with the older system in place which uses a series horn system and the wheelocks and system sensors of today just don’t do it.
Any suggestions of a type and where to readily purchase would be great. Price is not an issue.
Thanks for any help!!
Mark
These older style horns you desire are referred to as electromechanical horns. They are generally no longer produced as electronic horns have replaced them. It will be extremely difficult to find enough NOS horns of the same model to complete a whole system. I would make the case for you to go electronic with the horns, but I won’t go down that road if you are already settled on electromechanical horns.
If you follow the MS-9050 compatibility document, the only electromechanical horn that is listed for use on the MS-9050 is the Gentex GMH series of horns. This does not mean other horns will not work, it only means you will not be able to use the Special Application power calculations. I am not an expert in the NFPA fire alarm code, but you may also need to meet approvals to use them.
Straying away from the compatibility document, a good source of new fire alarm devices is buyfirealarmparts.com. This is a reputable dealer highly trusted and recommended by this site. It looks like most of their electromechanical horns they have listed are out of stock, but it is a good place to look around.
In all reality, electronic horns are really the way to go for a new installation. The Wheelock and System Sensor horns you mentioned do have a very high and shrill sound, but there are other brands available that offer horns that can reproduce the sound of older horns. If the elctromechanicals turn out to be unfeasible, that is a good option to look into.
For instance, the Gentex Commander series of horn-strobe signals have an “electromechanical” tone (they are multitone signals) that are fairly low-pitched compared to other signals made today, as well as being very durable signals.
You could try using 520 Hz sounders. From my own experience, the tone does penetrate pretty well through walls and floors, kind of like these old horns were capable of. If that’s still not enough you’ll have to run wiring and add additional signals.
Since we are on the topic of 520HZ sounders, MRELEC, what kind of installation is this? Residential, commercial, etc. What NFPA code revision does your AHJ follow? All of these are important information for making the decision on what kind of devices to use.
Also, if you using mechanical units with the intention of having each unit to cover more area than electronic devices, remember that there is also the issue of strobe coverage to deal with. It all depends on the exact codes your AHJ follows, as I mentioned earlier, but it is nearly certain all areas of the building will need to have strobe coverage. If it is a residential installation with sleeping units, then the strobes in the bedrooms must be increased to 110cD “at the pillow.”
Well if hes looking for mechanical horns, why not replace it with one from the guys who pioneered them?
Federal Signal manufactures the 450E (E meaning electronic.) a replacement for their Model 450 Vibertone Horn, it is rated for Fire, and General Notification systems, UL, cUL and ULC Listed.
Instructions:
If it was a series horn system, I’m guessing it probably used AC. In that case, your best bet is probably the Simplex TrueAlert series. Their frequency is 120 Hz, the same as an AC-powered buzzer. And unlike the similar-sounding 450E, they come with a built-in strobe.
Another good choice might be Edwards Integrity series horn/strobes. They are also low-frequency, but they sound more like a DC-powered horn (less like a dryer buzzer and more like a brass instrument).
However, none of these devices are listed in the MS-9050’s device compatibility document.
I think it would be best to let the OP listen to the different horns we recommended, then decide on his own. Bear in mind that the only signal that’s actually in the 9050’s compatibility sheet is the Commander series. The other devices (like the low-frequency sounders or Vibratone 450E) are either too new or too obscure to warrant being added to the sheet. However, below are the sounds each of these signals make, so you can decide for yourself which tone you think best fits the building. None of these videos belong to me, but I am simply using them for reference.
Another thing, since the 9050 outputs FWR rather than filtered DC, on the off-chance you install Truealerts, be aware that FWR has been known to fry Truealert signals, so I would not recommend using them.
What Wheelock does is make a retrofit strobe plate called the RSSP, in both red and white. What you could do is have Federal Vibratones on one signal circuit, coded to Temporal (Code 3) and have the RSSP plates on another signal circuit, with Wheelock sync, and the strobes should all sync up with each other. Of course, you’d probably have to use white RSSP plates so that the 450E doesn’t look silly sitting on it. It would provide FIRE lettering and strobe coverage, albeit in a rather strange-looking signal.
Again, this is my opinion, and since I’m not a tech or professional, it should be taken with a grain of salt.
I heard about the issue with the TrueAlerts. That’s why I checked to make sure. In the device compatibility document, it said that the MS-9050UD outputs filtered DC.
https://www.firelite.com/CatalogDocuments/15384.pdf
I did notice that it also said “(Special Application)”. I’m not sure what that refers to, though.
<URL url="Notifier & Fire-Lite: Filtered or Full Wave Rectified? text=“viewtopic.php?f=60&t=6616”>Notifier & Fire-Lite: Filtered or Full Wave Rectified?
It puts out FWR, that would fry the true alert very quickly.
Robert, they do have a red 450E cover plate that can be ordered instead of the white one, although I’m not sure how it would do with FWR. It says DC.
FWR is a very dirty DC. When the bridge rectifier converts AC to DC, instead of converting it to a steady flow of DC current, it converts it to DC cycling at 60hz. That’s why mechanical horns sound raspy; the rate at which the plate vibrates is being bottlenecked by the cycling current. Most modern horns (with the exception of TrueAlerts) have circuitry in them (diodes, capacitors) to compensate for this. I would imagine the 450E does, too.
Everyone, I have removed the unhelpful and argumentative posts / content from this topic. Please do not do this again.