More smoke questions

[dos46]

I have a 2 Floor house and a finished basement with a planned install of an OmniPro II. The basement does not have any bedrooms and is just a living space so I was planning on putting one smoke detector by the stairs, the first floor does not have any bedrooms and has living space and kitchen so I was planning on putting one smoke detector by the stairs and the third floor has 3 bedrooms so I was planning on putting one smoke detector in each bedroom and one in the hallway by the stairs.

1) That bring me to 6 smoke detectors, does that sound optimal for the current setup?

I want to use a two-wire system w audible alarm because I do not see any added benefit for me to go with the more complex and expensive 4 wire system so I will be purchasing the System Sensor 2WTA-B with audible alarm (compatible up to 10 perzone for the HAI OmniProII)

2) Do I need to purchase RSS-MOD with this setup?

 

[apostolakisl]

I'm not sure why you believe 4 wire to be more expensive, frequently they are cheaper when comparing like to like in 2 vs 4 wire. The wire is a bit pricier but assuming you only need a few hundred feet of wire it won't amount to much. I guess 2 wire is simpler strictly speaking, but again the complexity on either system is not a major issue.

You will need a reversing relay no matter 2 wire or 4 wire as this is how the sounders on all the units not directly detecting smoke/heat get turned on. With 2 wire you can not daisy chain in any non-2 wire detectors and generally speaking with 2 wire you should stick to the same units all around wheras 4 wire detectors can be mixed and matched without compatibility worries. With 2 wire you also have to be certain the model you choose is compatible with your system, 4 wire detectors aren't specific that way.

Your description of placement sounds consistent with code.

 

[Del91574]

Barring any compatibility considerations, wiring a 4 wire fire alarm does tend to add up quicker as far as pricing goes, in addition to other factors that need to be addressed when going this route. Wire cost is the last item to even think about on such a small scale. The real item is most people fail to consider is enough conductors to facilitate proper supervision, and in the case of 4 wire, a power supervision relay and, if the panel fails to provide a reset, then facilitate that.

The most prudent thing to do would be to wire as a continous 4 wire and then run a 2 wire loop IMHO.