3 wire 120VAC Smoke detectors possible to use?

[HighTest]

My home is already pre wired with the 120VAC 3 wire Firex smoke detectors. They all alarm as one and also run off of battery during a power outage.

Rather than remove them all and replace them with either 2 or 4 wire smokes, does anyone know of a method on how to interface them to a hardwired zone on a security panel? If I have to, I'll remove and replace them all, but the WAF will go down some if this is a requirement.

Thanks!

 

[jaysonc]

I am not as familiar with Firex, but I have USI 3-wire smoke alarms in my house that work the same as your Firex alarms.

USI sells a relay that activates when the alarms are tripped.

I would suggest giving Firex a call to see if they sell something similar....

I was actually going to get the phone number for you and found this URL...

http://www.icca.invensys.com/firex/accessories.htm

"Item 499, Firex Relay"

 

[Steve]

The only problem with a relay like that is it requires 120V to operate and therefore will not work in a power outage regardless of the battery backup in the detector.

If I have to, I'll remove and replace them all, but the WAF will go down some if this is a requirement.

Why would WAF go down if you take steps to protect your family? I usually put 12V detectors *in addition* to what the builder put in place. At least a few in key areas. Smoke detectors are a life safety system. Heaven forbid you ever need them you'll be glad you had them.

 

[HighTest]

Steve,

The WAF reduction is in that each smoke detector has it's own sounder. Currently I've had difficulty in finding smoke detectors that include individual sounders that are compatible with the Caddx NX-8 series of controll pannels.

For example the 2WTA-B from System Sensor does not list Caddx compatibility in it's list of UL 2 wire compatiblity. The 2WT-B and 2W-B detectors are listed as compatible, so it looks to be that the 2WTA-B requires too much current for support.

As for 4 wire, this may help eliminate that problem, but I've not located a 4-wire with internal sounder. If you have suggestions, then this would certainly be a way to replace the 120VAC alarms with 12V and get a sounder.

Besides the sounder issue, but a much less concern, is the worry that what if the panel is damaged first during a fire? Then the power/battery backup for the smokes are no longer working and there's no sounder activity. Would be interesting if someone developed 12V smokes that also have an internal battery backup for dual-redundancy on power. Again that extra battery really would only be of benefit if there were internal sounders.

So there's the reason the WAF factor is slightly lower. It may be that I'll have to simply add a couple 12V smokes in addition to the existing so there's a report to the monitoring company, but that's also less attractive in my view.

 

[HighTest]

I am not as familiar with Firex, but I have USI 3-wire smoke alarms in my house that work the same as your Firex alarms.

USI sells a relay that activates when the alarms are tripped.

I would suggest giving Firex a call to see if they sell something similar....

I was actually going to get the phone number for you and found this URL...

http://www.icca.invensys.com/firex/accessories.htm

"Item 499, Firex Relay"

When I read the instructions, they specifically point out that it is not recommended to use the relay with a security panel. Is this because there's no signalling during a power outage, or is it possible for it to fail in a maner that could send 120VAc to the input on the security panel?

Ouch.

 

[bmil]

HighTest,

You would still have to replace all your existing smokes but the GE ESL 350 series smokes are 120v based with battery backup and individual sounders. Two of the models have built-in relays that you can connect to a panel. One model's relay closes if any of the tandem wired smokes goes off while the other model's relay closes only if that particular smoke goes off. The relay's also work while on battery backup.

I used these when I was unable to complete my low-voltage wiring for smokes before the dry wall guys started. My electrician had already wired for 120v tandem smokes per code.

I used the ESL 350 model with no relay for all my smokes except one that happened to be right next to my wiring closet. For that one I used the 350cx whose relay closes if any of the tandem smokes goes off. I just had to put in a short 2 conductor run from that smoke to my Elk M1 in the wiring closet about 6' away.

This gives me all the benefits of the AC with battery backup, tandem connection, individual sounders independant of any panel, plus a zone connection on my panel for anything I want to do with that.

 

[HighTest]

bmil,

Thanks much, that's exactly what I was looking for. I'll look into these ESL 350 models that you recommend. This will get me my smoke reporting and meet the other concerns.

I really appreciate the knowledge and experience I find from yourself and other cocoontech members. Thanks again.

 

[BraveSirRobbin]

HighTest,

You would still have to replace all your existing smokes but the GE ESL 350 series smokes are 120v based with battery backup and individual sounders. Two of the models have built-in relays that you can connect to a panel. One model's relay closes if any of the tandem wired smokes goes off while the other model's relay closes only if that particular smoke goes off. The relay's also work while on battery backup.

I used these when I was unable to complete my low-voltage wiring for smokes before the dry wall guys started. My electrician had already wired for 120v tandem smokes per code.

I used the ESL 350 model with no relay for all my smokes except one that happened to be right next to my wiring closet. For that one I used the 350cx whose relay closes if any of the tandem smokes goes off. I just had to put in a short 2 conductor run from that smoke to my Elk M1 in the wiring closet about 6' away.

This gives me all the benefits of the AC with battery backup, tandem connection, individual sounders independant of any panel, plus a zone connection on my panel for anything I want to do with that.

bmil;

I have also been looking for a solution like this. Any suggestions as to where to purchase one!

I'm going to get one and connect it to my HA system via a contact closure just like you did with your system.

Many thanks,

BSR

 

[opie]

I'll look into these ESL 350 models that you recommend.   This will get me my smoke reporting and meet the other concerns.

I had this same issue a few months ago with a client and went with the ESL 350 CX (also at the suggestion of Bmil; thanks by the way).

**Edit (I have only done the pre-wire so far, so I have not confirmed the following in practice but it was suggested to me by a 20 year veteran of the security industry.)**

If your walls and ceilings are still open, you may want to consider running Firewire to all smokes and using the ESL 350 CX in all locations. You can use lighter and cheaper 22 Ga Firewire since it will not be powering the smokes. Daisy Chain them and use an EOL. This way, you also get some supervision of all the smokes. For example, if one of the smokes was removed for some reason, the loop would be open and show a trouble indication and you would know there was some diminished monitoring. The NX-8 may not work this way but the ELK does so you may want to confirm how a fire zone works with your panel.

Scott

 

[bmil]

Glad I could help. I've gotten so much out of this board and it's members I'm glad to be able to give back.

I purchased my ESL 350's from Worthington. Their item #'s ESL350, ESL350CC, ESL350CX.

 

[beelzerob]

Is Worthington still the best/only place to get the 350xx models? And is it the worthington where I have to apply for an account, just to shop there? I'm trying to find a place to buy these smoke detectors, but geez they're tough.

 

[rrockoff]

My house came with USI-1204 3 wire smoke detectors. Per this thread, I replaced one of the smoke detectors with a GE ELS350CX. All I did was to run two wires from the NC / COM out on the smoke detector to an available zone on my ELK M1G (Don't forget to add the EOL resistor).

Worthington seems to have the best price on this item. All you need to do is call them during business hours. They setup a new account for me on the spot without having to apply for anything. I don't have a business. I'm just an end user.

Good luck

Rod

 

[George M]

Sorry to bring back an old thread but I just installed a 350CX and cannot get it to show faulted on my M1 when I test the smoke.

I replaced one of 10 original 3 wire smokes in my house with one 350CX. I ran two wires from this smoke to my M1 pannel and connected to a standard zone (Not zone 16). I used the NC / C of the form C relay (I believe it was Orange / Yellow wires). I set it up as Non Alarm - Normally Closed just to see what the zone reports before setting it to Fire Alarm.

There is no change to that zone when the smoke is tested.

So
1. Is the EOL reisistor neccessary?
2. Should I be using the form C or form A?
3. If it is Form C - should it be NC or NO?
4. Does the zone have to be set as Fire to work?


Thanks for you help

George M

 

[CORT]

Sorry to bring back an old thread but I just installed a 350CX and cannot get it to show faulted on my M1 when I test the smoke.

I replaced one of 10 original 3 wire smokes in my house with one 350CX. I ran two wires from this smoke to my M1 pannel and connected to a standard zone (Not zone 16). I used the NC / C of the form C relay (I believe it was Orange / Yellow wires). I set it up as Non Alarm - Normally Closed just to see what the zone reports before setting it to Fire Alarm.

There is no change to that zone when the smoke is tested.

So
1. Is the EOL reisistor neccessary?
2. Should I be using the form C or form A?
3. If it is Form C - should it be NC or NO?
4. Does the zone have to be set as Fire to work?


Thanks for you help

George M

1. No the EOL resistor is not necessary unless you have configured the zone in the M1 to expect an EOLR. However, many of Elk's fire zones require an EOLR.
2. You can use either the form A or the form C relay contacts. The form C gives you the option of normally closed contacts. Form A is a normally open contact.
3. NO or NC is your choice. Whatever you choose, make sure your M1 is configured to expect the configuration.
4. No, it needn't be set to fire.

Personally, I would use the normally open contacts of the form C relay (blue/orange) or the form A relay (violet/violet) with a 2200 ohm resistor across the contacts (blue/orange or violet/violet) at the 350CX. Then configure the zone in Elk RP on the M1 as definition 10=Fire Alarm, type 5.

Let us know how you do it.

 

[George M]

1. No the EOL resistor is not necessary unless you have configured the zone in the M1 to expect an EOLR. However, many of Elk's fire zones require an EOLR.
2. You can use either the form A or the form C relay contacts. The form C gives you the option of normally closed contacts. Form A is a normally open contact.
3. NO or NC is your choice. Whatever you choose, make sure your M1 is configured to expect the configuration.
4. No, it needn't be set to fire.

Personally, I would use the normally open contacts of the form C relay (blue/orange) or the form A relay (violet/violet) with a 2200 ohm resistor across the contacts (blue/orange or violet/violet) at the 350CX. Then configure the zone in Elk RP on the M1 as definition 10=Fire Alarm, type 5.

Let us know how you do it.
[/quote]

Thanks Cort,

I rewired it to use the NO relay. It will now show as "Violated" on the M1 zone when tested from this smoke. However when the other smokes are tested it does not trip the relay. I did confirm that I am using the 350CX which is supposed to notify when the tandem circuit trips.

GM