contractorselectricalsmoke-detectors
I recently purchased a 2001 built condominium unit with original battery powered smoke and CO2 alarms. Since I have to replace all the alarms at this point anyway, I'm curious how invasive a procedure it would be to get wiring run for these in a traditional wood frame / drywall construction.
Can I expect someone marketing themselves / licensed as an electrician to be able to do a job like this or do I need to seek help from a more general contractor for the drywall / etc. work on the ceilings?
I take it the detector is mounted in the ceiling, and a cut-in 3-O or 4-O (plastic) boxes have a 2 hour fire rating. If this is not enough then you can use metal ceiling octagon box (2 hour fire rating) and use something like a 3M Fire Barrier Moldable Putty Pads. Most companies that deal with fire related caulks and putty make these. A lot of states require these in fire walls and ceilings, especially in multi-family units.
These pads are intumescent, which means that it swells as a result of heat exposure, thus increasing in volume, and decreasing in density. Wikipedia.
If I were you I would take it a step further and install a 120V with a battery back-up smoke/carbon monoxide combo units. You can also pay more for the detector and get either optical or ionization styles. Ionization detectors are more sensitive to flaming fires than optical detectors, while optical detectors are more sensitive to smouldering fires. Wikipedia again. Electrical supply stores should have all this or Amazon. I suggested 3M only because that is what I am used to.
Also, since the electrical boxes are fire rated, you might just use a fire caulk around the box. Caulks are intumescent also.
Yes, with it being cat-5e cable, you could repurpose it as network cable by installing rj-45 jacks. Early Ethernet (10mBit & 100mBit) used two pairs (4 wires) and Gigabit typically uses all 4 pairs (all 8). Your Cat-5 link is referring to 10/100 Ethernet, so only two pairs are used. The other two pairs could carry a phone line each or another Ethernet connection (we used this on IP phones, the computer was on one half and the VOIP on the other half, figure out the color diagrams yourself for your RJ-45s on the second half). My preference is to not muck around with this as the first time you plug in a Gigabit equipped computer, you face getting full ring voltage into its RX/TX for the second set of pairs. Wire it for Gigabit using all pairs and be done with it.
In the good old days of 25 wire straight cable, daisy chain was common installation technique, with the advent of CAT-4 and above phone installations I have worked with have all been star to a central patch panel.
Best Answer
I would first consult your local fire inspector and get what is and is not required ie, locations, how many, and what brands they recommend. They may even know a decent electrician to install them
Also, the current locations of your smoke alarms may be improperly placed and doesn't make sense to spend the money to just do it wrong.
I would keep the alarms on their own AFCI breaker/circuit too, even though the NEC does not require this. Just smarter that way because less chance of interference from other AFCI and GFCI if shared with existing lights and outlets.
The extent of the project could be very high since you did mentioned you're in a condo. Some condos have no attic and basically have a concrete slab for a ceiling. Others may have a drop ceiling grid, so it is hard to give a fair estimate without knowing for sure.
And yes, a licensed electrician would be required since the type of smoke detection we are talking about uses high voltage. If it were low voltage then most of the time the alarm company handles their own installation.