2 wire smokes on Omni Pro II

[PaulD]

Got myself in a box (my fault) concerning use of smoke alarms with Omni Pro II system and am not sure how to get out. Builder wired the house for 2 wire smokes...with my approval since I saw 2 wire smokes supported in the Omni Pro II manual. However, I did not recognize that the Omni only supported the smokes as a sensor and did not provide sufficient power to drive smokes with audible alarm built in. Local building codes require an alarm in every bedroom and it is too late to add any more wire so I am now sitting here with 2 wire to each smoke sensor site and no solution which allows me to tie them to my Omni AND drive an alarm at each site.

Unless someone has an approach I have not discovered, I am facing a situation where I must drive the smokes (with alarm) from a seperate 12VDC source independent from my Omni. That defeates my ability to tie the system to my Omni unless I determine a method to monitor the independent smoke circuit. I don't really care which sensor has been triggered. I just what the ability for my Omni to know that a sensor on the circuit has been triggered so it can take what ever action I have programmed into the Omni.

Side note: The Omni has a load limit of 1 Amp for a group of devices which includes the smokes. Code required the ability to drive all alarms (6 in my case at 130ms ea = 780ma) at one time). That only leave room for 220ma to drive other devices such as consoles and that is not enough to cover all my components. With the new HAI Power Hub, I could offload the consols and create some additional reserve capacity which may allow me to wire the smokes directly to the Omni and that is the option I am looking at if I cannot come up with a less expensive solution.

HELP!!!!!!!!

 

[felixrosbergen]

Switch to wireless smokes?

 

[CollinR]

The only other thing I can think of is using a second panel just for fire and using it's outputs to alarm the HAI. Honeywell Vista15p should do it and you don't care if it's locked or not as it's wouldn't be doing any reporting. You can probably get one from a dumpster behind any alarm install shop, you would also need a 6160 keypad or better yet the red version used in commercial fire. Just mount the keypad right on the alarm can as all you can do with it is program the system or reset it.

 

[bphillips]

What brand 2-wire smokes with internal sounders are you intending to use? System Sensor (as do other smoke makers) offers a model RRS-MOD Reversing Relay/Sync module. It is designed to allow all detectors in the same loop to sound when one of the detectors goes into alarm. A side benefit is that it allows you to use your existing alarm panel which will power the smokes when not in alarm, but it has terminals to connect an external auxiliary power supply to power the smoke sounders ONLY during alarm. The only hitch is that you must ensure the aux. power supply is somehow supervised because during an alarm that would be the ONLY thing powering the smokes. No Power/No Sound! Do a search for System Sensor RRS-MOD and you will be able to download all the hookup options.

 

[nexus99]

My home had wired sounder smokes built in when I moved in. I just added additional sensors for the HAI panel. I hended up with two systems but it gets everything covered. Hopefully none of it ever gets used!

 

[PaulD]

Thanks all. The installer plan was to use System Sensor model 2WTA-B which is the same as the 2WT-B version called out by HAI except that the 2WTA-B has a sounder built in. Draws 130ma when sounding which would suggest that all 6 sounders would draw 6x130=780ma if all were in alarm mode at the same time. That would eat up the lions share of the 1000ma limit for the Omni Pro II and not leave me any room for other devices such as consols which must share the 1000ma limit. As a result, if I want to hook my smokes to my Omni, I must find a way to transfer enough load to a different 12VDC source such that my Omni can handle the smoke load along with items I must run thru the Omni.
After additional thought, I think I can deal with the issue by adding the new HAI Power Hub to my setup. That will let me off load my consols to the power hub and leave the Omni to power the smokes as well as several very low load items that must run thru the Omni. I can do that and stay within the 1000ma limit for devices connected to the Omni. Adding the power hub also provides me with a 12VDC source for some other widgets I have in my setup such as CATV distribution and allows me to cut down on a few wall warts.

For bphillips, I originally looked at the RRS-MOD Reversing Relay/Sync module as a possible way to deal with this but I cannot use it in my alarm setup because my smoke circuit also includes some passive (mechanical) heat alarms in the kitchen and garage. Language below is from System Sensor instructions.

"When using the RRS-MOD with model 2WTA-B, do not mix the 2WTA-B with other model smoke detectors and dry contact closure devices, including mechanical heat detectors, manual pull stations and waterflow switches. Such mixing can cause a direct short on the auxiliary power terminals, damaging the control panel’s internal circuitry and/or damage devices connected to the initiating device circuit."

 

[PaulD]

.......Dont forget the sirens you already have on the panel need to be included in the calculation.

I forgot to mention. This issue is independed from driving internal or external sirens. The Omni Pro II has a seperate circuit (1 Amp max) for sirens. I have a Elk module that allows me to trigger the sirens while the sirens are driven from a different 12VDC power source ...... which will now be my my HAI Power Hub (5A of total power)

 

[PaulD]

Any 2 wire smoke detectors with internal sounders cannot have thermal detectors on the same zone. If the thermal detector goes into alarm you will have a dead short on the same circuit as the sirens.

When you say sirens, are you refering to the sounder in each individual smoke or external sirens? If you are refering to external sirens, they are on a different circuit than the smokes and are not driven from the smoke zone.

In the case of the Omni Pro II, it requires that all 2 wire smoke circuits be connected to Zone 1 thru 4. Meanwhile, the internal and external sirens are driven by a seperate connection dedicate to sirens.

 

[Lagerhead]

All 6 sounders would draw 6x130=780ma if all were in alarm mode at the same time.

Paul, please say again -- how are you going to trigger the sounders in all of the smokes when an alarm occurs?

 

[PaulD]

Paul, please say again -- how are you going to trigger the sounders in all of the smokes when an alarm occurs?

I don't really want all sounders to alarm at once. I will check but as far as I know, the only sounder that will trigger is the one in the smoke that is activated. I made the comment about all 6 because local code requires the power source to be capable of sounding all 6 if all 6 are triggered independently (worst case scenerio)

 

[PaulD]

Paul if the Thermal detectors are on the same 2 wires as the sirens in the detectors then if a thermal trips the panel and teh sirens in the detectors go on they will have a dead short against them and will not sound. IN addition anything on the same power source that you are using to drive the sirens in the detectors wil also have a dead short. That is what System Sensor is pointing out. The same would apply to anyones devices on this type of circuit as the thermal detector will not be isolated from the 2 wire loop.

If you move the thermal detectors to another zone you should be fine.

Whatever you do I suggest you test it well so you do not have a problem if (god forbid) it is needed.

Not sure how to answer your comment. The heat detector is System Sensor model 5603 and the alarm company installing the wiring and sensors do it routinely. The tech literature for this unit shows it wired just like a 2 wire smoke in series. That suggests to me that it is not a dead short when it is triggered but it must introduce some load to the system that can be used to trigger an alarm. I will ge tback with the alarm company and get a better understanding of what happens when it is triggered.

 

[felixrosbergen]

Doesn't code require the sounders of all smokes to sound when a single one is triggered?

If i understand correctly this is how my new home is wires. All the smokes are interconnected with each others and they all sound if any one gets triggers. I assume there is a light or something on the one that triggered so you can actually find it (in case of false alarm when there is no an obvious source of smoke).

I havent decide how to integrate my smokes yet. I believe there is only 1 on the ground floor wich is hard to get to. The others are all in the hallway and bedrooms on 2nd floor with attic access.

Worst case i go wireless for the one downstairs ( I don't like wireless much) and run 4 wires for the rest. I suppose I'll need 'Firewire' right ? 16/4 right ?

 

[PaulD]

From what I know of the 5603 it is a typical mecahinical thermal detector that when tripped becomes a dead short. It is basically a heat activated switch. They are fine for use on a 2 wire smoke zone only if there are no internal sounders in the detectors.

I am sure your alarm installer can verify this.

Thanks for your input. I am traveling right now but I intend to get back with my installer as soon as I get home. From what I saw when they pulled the wire, it looked like they intended to put 6 smokes and 2 heat on the same 2 wire zone. They have the wiring run in a daisy chain starting at my HA closet with the 2 heat units as the last in the string. I have been assuming that they would wire them just like a smoke but they may have an alternate wiring pattern with the 2 heats as a loop off of the main loop in such as way that it does not create the issue you have identified. I do know that I only have a single 2 wire running into my HA closet. I will find out how they intend to make it work when I get home.

 

[PaulD]

Doesn't code require the sounders of all smokes to sound when a single one is triggered?

I don't believe so but I will check. I think I could meet code by installing a bunch of independent smokes as long as I had a smoke alarm in each bedroom.

 

[jlehnert]

Condensed, the code says that if a smoke is tripped, the alarm must be audible throughout the house. If a smoke in the basement gets triggered, you need to be able to hear something in the second floor bedroom over the noise from window air-conditioner. Most tract homes do this by having sounders in every smoke, and then connecting all the smokes together so if one goes off, all go off. However, the requirement can also be met if the main siren/speaker goes off and it is audible throughout the house. The AHJ in your area will be the definitive source on what is okay.