Minimum Acceptable Gauge Wire

Hi all, I am back at it and ready to change out my old PS1832 for the new 1864 panel.  I notice that the installation manual calls for a minimum 22AWG wire however the current system is using 24AWG CAT3 cable to all sensors (incl. the smokes).  I am not certain that running new wire to all sensors is a viable solution though certainly for the new sensors I am adding it is.  At least it is solid copper.  I guess I have two main questions:

1. How concerned should I be in this scenario? and
2. Is there an issue with mixing gauge (i.e. should the new sensors use min 22AWG or should I stick with 24)?

Thx,

Personally don't think its an issue.  That said wondering what other folks will post.
 
Here have mostly stranded 22/2 or 22/4 but some stragglers of 22/4 22/2 solid core wires around.   Older home (neighbors) used all solid core (from a 1970's installation?)

There are many a retrofits out there that have less than desirable wiring but work fine. I wouldn't lose sleep over it.
 
That being said I never pull anything less than 22 for most sensors and would never use CAT(x) for a new sensor install.

I wouldn't be concerned about replacing all the old wire...with one MAJOR exception.
 
Get those smokes wired to code using Fire-wire.  ASAP.  It just might save your life.  
 
NFPA put the requirement in after finding cases where a fire in the ceiling disabled the smoke detectors before they went off.  It's one of those cases where the $25 you saved reusing the cat-3 since it was already hanging around, could cost you immeasurably more in the long run.

Yes, noted re the fire-wire, I will see if this is possible.  That said, I suppose it is somewhat less of a concern as the LV smokes are a redundant system really designed to trigger the alarm panel vice alert the occupants.  There are interconnected 110V smokes installed per local building code.  Regardless, I will see if I can find a way to pull the new wire.
 
As for the wire gauge, I will use 22 AWG 4 conductor wire for any new sensors, replace where practical but leave as is for the finished areas.
 
Thx

The AWG for the fire alarm is the same whether or not it's a primary or redundant system. Granted, the code is somewhat ambigious (it conflicts) but the actual interpretation is the lesser AWG is only acceptable for a factory harness or interconnect cable, not field cabling.

I'm wired my motion sensors (Z-Wave) using Cat6.
 
I only run 5vDC over 1 pair of the wires to provide mains powered.
 
I have one run where current I'm drawing is 12v over Cat5 for a 19" LCD bathroom TV (using all 4 pairs).  I think it's about 10 watts.
 
Am I causing a fire hazard by using cat5 for mains power?
 
 
 
 
PS - Smoke Alarms has wiring to code.

If you are using Cat6 to provide 5VDC to your motion sensors, that should be ok.
 
Most 19" LCD TVs draw 50 to 60W, or about 5 Amps at 12V.   I don't know of any that draw just 10W.   Even if you are using all 4 pairs for power, at 1.25A per conductor, you are exceeding the current that Cat6 wire is spec'd for.  So yes, that is a potential fire hazard.

Thanks RAL!  I think I'm OK based on your info.
 
My 19" is only 6 watts (I put 10w as buffer):
http://www.amazon.com/Samsung-UN19F4000-19-Inch-720p-60Hz/dp/B00BCGRZ04 
 
I just replaced an 55" LCD conventional backlit...with a LED backlit...the power dropped from 280 watts to 45watts average watts. This LED stuff saves a lot of energy

The 6W number is the sound output.  They don't make this very clear on Amazon, so it's understandable why you misunderstood.
 
I was able to track down the specs for that TV here.  Click on "Specs" and then "See Full Specs."
 
The maximum power consumption is listed as 35W, so it's less than the typical 19" set.    At that level, using all 4 pairs in the Cat6 cable, it would draw 0.73 A per conductor, which is right at the maximum for what a Cat6 conductor is spec'd for.   Since the typical power consumption is listed at just 15W,  you might have some additional margin.  It's hard to say what conditions require maximum power.  It could just be momentary inrush current when the set is turned on.
 
There is still some risk if one or more of the conductors fails, then the others would be overloaded.   My preference would be to use a 16-2 cable to supply power rather than Cat6.

@RAL Thank you sir.  Will look into replacing that proto.