Newb GE 350 / 350CX smokes?

[windexh8er]

Good evening gentlemen,

Sorry if this has been beaten to death or it's total newb flame bait but...

I have a new building that's going up and have it mostly wired with LV for a security system - although what I asked to have done for the smokes wasn't. From what I gather (trying to do this from 200+ miles away through second hand information) the electrician did a single series loop. This should cover 12 smoke locations across the building. This is where it gets sloppy...

They want the building inspected and obviously I haven't ordered anything yet. Problem is the smokes were supposed to be tied to the non-existent security system. So now I'm thinking of getting 11 GE 350s and one 350CX. At that point I guess I'm still a little unclear on the wiring - and am wondering what it would look like if one was to do it right. Basically I'm fed up with the whole ordeal and just want all the smokes to sound when one is triggered. But does the CX placement matter? I'm guessing it's at the end of the line and then somehow use the Form A relay to loop it back through to make the circuit / break the circuit?

Help?

TIA!

 

[BraveSirRobbin]

Perform a search for GE350 and there are a lot of posts on this topic.

Basically if all you want is for an alarm to trigger your panel when ANY of the smokes go off, you only have to replace one existing smoke detector with a 350cx, then wire it's contacts to your panel. It does not matter where this one 350cx is replaced (any of the existing detectors).

If you want to be notified of the exact location of the smoke (i.e. determine zone) you will need to replace each detector with another model, can't remember the number. Then you have a pair of wires going to each detector.

Note that this is not the 'conventional' low voltage install which consists of other safety factors such as reversing relays (for power failure considerations). So you may want to take a close look at the type of code/install you want to follow.

 

[personalt]

Perform a search for GE350 and there are a lot of posts on this topic.

Basically if all you want is for an alarm to trigger your panel when ANY of the smokes go off, you only have to replace one existing smoke detector with a 350cx, then wire it's contacts to your panel. It does not matter where this one 350cx is replaced (any of the existing detectors).

If you want to be notified of the exact location of the smoke (i.e. determine zone) you will need to replace each detector with another model, can't remember the number. Then you have a pair of wires going to each detector.

Note that this is not the 'conventional' low voltage install which consists of other safety factors such as reversing relays (for power failure considerations). So you may want to take a close look at the type of code/install you want to follow.

You should be able to do the same thing with a kidde relay

http://appliances.pricegrabber.com/home-sa...m717623048.html

It will tell you when any of the zone is tripped but will not tell you location. I dont think that the GE 350CX does anything additional then to what this relay does. If someone can correct me on that I would be interested in learning what else the GE model does.

If you want to get fancier you can get 4 wire low voltage smokes but if you are required to put in 120v smokes then 4 wire smokes arent going to be much help as you would need to do both.

 

[russban]

Have you spoken with the local Authority Having Jurisdiction (AHJ) in the community where you are building? If not, before going any further I would suggest you contact them and find out what their requirements are for fire protection for your area and type of construction. Each AHJ can interpret the code their own way and what you may think meets code, often doesn't in their mind. I find that many AHJ's do not accept a low voltage system tied to a security panel as a primary fire alarm and still require you to have a 120v system in tandem with the low voltage system if residential and a separate fire panel or UL listed combo panel for commercial.

Please accept my apologies if I'm telling you something you already know but just in case, it could save you a lot of grief later if you didn't!

 

[windexh8er]

First and foremost thanks for all the replies. An electrician already ran the fire alarm "loop" according to what is feasible is what I'm told. I don't know if that means the 120v line *is* the loop itself or what - and basically that was my question.

I wouldn't think that it would be OK for all of the alarms to be on the same circuit, from a power perspective, but who knows. At this point I ordered 11x350s and 1x350CX in anticipation of eventually getting the status off of the CX to trigger the panel. Otherwise, for now, I'd just like one being triggered to sound all of them.

Would it be more typical of the electrician to have run a loop for the smokes in terms of the relay using the tandem bus (I'm guessing that wire is not actively powered) and then each smoke will have it's own hot and neutral?

Thanks for the insight! Much appreciated.

 

[personalt]

First and foremost thanks for all the replies. An electrician already ran the fire alarm "loop" according to what is feasible is what I'm told. I don't know if that means the 120v line *is* the loop itself or what - and basically that was my question.

I wouldn't think that it would be OK for all of the alarms to be on the same circuit, from a power perspective, but who knows. At this point I ordered 11x350s and 1x350CX in anticipation of eventually getting the status off of the CX to trigger the panel. Otherwise, for now, I'd just like one being triggered to sound all of them.

Would it be more typical of the electrician to have run a loop for the smokes in terms of the relay using the tandem bus (I'm guessing that wire is not actively powered) and then each smoke will have it's own hot and neutral?

Thanks for the insight! Much appreciated.

for 120v detectors you normally runa black and white for power and neurtral and then a red for interconnect. When any of the dectectors go off the red becomes hot and they all go off.

So the loop is most likely the 14/3 wire from the first detector to the last. It is isnt really a loop so much as a string.

I would ask him to run a 4 conductor alarm wire from the alarm panel area to the closest smoke detector before closing the walls up. With that you could tie in that GE unit or a relay.

 

[beelzerob]

Russban, that is a very good point, though it won't be an issue with these GE 350's since they are main power primary.

wind, I've got 9 GE 350 CC's and 1 GE 350 CX, and other than having to replace the smoke chambers occassionally, I've had no problems.

HOWEVER...I am almost positive that the 350 installation sheet says to not have more than 10 devices on the tandem line. Since you're talking 12 devices, I'm not sure what to do with that.

 

[windexh8er]

Thanks again for the info guys!

@personalt - I'm going to definitely have that done. That will be easy since the CX will be roughly 10 feet from where the panel is.

@beelzerob - Actually it's 12 devices on the tandem line for the 350 series which works out perfectly in my situation. The info is in the "ESL 320A/350 Installation Instructions" manual.

 

[plasman]

I've got 6 GE 350CX installed and running in my new home (I guess I could have used cheaper 350's for 5 of them?).

I now need to connect my Omnipro II to the 350CX that has the additional fire rated wire in the ceiling.

Can someone explain the difference between Form A and Form C relay contacts and which I should use for the Omnipro II connection?

Thanks....

 

[daxiang28]

Can someone explain the difference between Form A and Form C relay contacts and which I should use for the Omnipro II connection?

While looking for this clarification, I found this. Can somebody verify this and which one would I use to run back to my Elk M1 zone?

Relay Types
Relay forms are categorized by the number of poles and throws in addition to the default position of the relay. Form A is a single-pole single-throw (SPST) relay with an open default position. Form B is an SPST relay with a closed default position. Form C relays are single-pole double-throw relays and break the connection with one throw before making a connection to the other pole.

Read more: The Purpose of the Form C Relay in Smoke Detectors | eHow.com http://www.ehow.com/...l#ixzz1qbeGWqjp

I'm assuming the Form A is the simplest setup that would work for a zone.


Steve