I'm getting ready to prewire everything and I may have some cat5e left over. I'm thinking about prewiring for ALC. What would be the constraints that I should look out for? The house isn't big (I do not yet know how many switches there will be) but we are looking at a combined 2400 sq ft (main floor and basement). I was just going to homerun a single cat5 from each switch to my location in the basement and will buy switches/panels as money permits throughout the years. Will that be mostly sufficient for prewiring? What pitfalls might I encounter that way? I'm not up to speed on the req's for ALC yet.
ALC / ONQ
- Thread starter lewisjd
- Start date
AceCannon
Active Member
I agree with reading thoroughly.
I just finished my new house and pre-wired for ALC but only bought switches for the kitchen and keeping room. So it sounds like we have a similar situation. If you run a single cat5e to every switch, you are definitely fine. That may, in fact, be overkill. The most conductors any switch will use is 5. I ran a single cat5e to each switch LOCATION. So basically, each gang box has a single run. Some of my switch locations have 3 switches with a single cat5e.
Rationale: The ALC communication bus is 2 conductors, so a 3-gang switch cluster can share those two conductors. That leaves 6 more for aux switch use. Some switches will not be "3-way" or "4-way" and as such will only need to be on the ALC bus (i.e. no aux connection need to be made). Trouble shooting may be compromised, however, since one bad switch in the cluster may make them all lose communication. So if you are doing a separate cat5e to each switch, you are set.
Make sure the wire is easily accessible, taking into consideration the future drywall.
I think 1 cat5e wire to every switch junction box will be good enough for 80% of the needs. However, if you are going to be using scene switches, then I would add an additional wire to every scene SWITCH location. So if you have a junction box with 2 regular ALC switches, I would run 1 wire. If it has 2 regular ALC switches and 1 scene switch then I would run 2 wires. If it has 1 regular ALC switch and 2 scene switches then I would run 3 wires, etc.
How should I handle the 3 way switches? Since I am just going to prewire, (and I haven't gotten to do my electrical walkthrough yet) I assume the sparky is just going to put in a handful of 3 ways (hallway, stairway, kitchen/greatroom, etc) Since ALC may not actually happen, i don't want them to change the initial wiring. Is that a problem to install alc later on 3 ways? my understanding is that 3way is not allowed, but can it be done by rewiring at the switch location?
felixrosbergen
Senior Member
ALC takes some pretty carefull planning IMHO and there's several threads covering it.
One thing easily overlooked is that the scene switches MUST be on Branch1, but i believe this is only a restriction when controlling the lights via ELK.
Like others said, do the match for the number of conductors needed to a location.
Multiple switches share a singe communication pair (Blue/Blue-White on cat5). Each switch that is part of a multiway (3 way, 4 way, whatever) will need 3 more conductors. Brown / Green / Orange for the first and WhiteBrown / WhiteGreen / WhiteOrange for the 2nd.
If you plan to have any scene switches count on another pair to be safe.
If you're in a hurry and don't want to do the match take a single cat5 to any place that has 2 switches or less and 2 cat5's for each additional 2 switches. That should roughly get you there.
One thing easily overlooked is that the scene switches MUST be on Branch1, but i believe this is only a restriction when controlling the lights via ELK.
Like others said, do the match for the number of conductors needed to a location.
Multiple switches share a singe communication pair (Blue/Blue-White on cat5). Each switch that is part of a multiway (3 way, 4 way, whatever) will need 3 more conductors. Brown / Green / Orange for the first and WhiteBrown / WhiteGreen / WhiteOrange for the 2nd.
If you plan to have any scene switches count on another pair to be safe.
If you're in a hurry and don't want to do the match take a single cat5 to any place that has 2 switches or less and 2 cat5's for each additional 2 switches. That should roughly get you there.
Wait a second... if you have a CAT5 to a multi-way and then have traveller wires from that switch off to the other switches in the multi-way setup, can you not just wire-nut the 3 conductors to each of the other switches together? In effect, using your colors... you use blue/blue-white as the communication pair to the main switch and then wire nut together the brown/green/orange from each of the traveller wires and the main switch? Therefore, the additional 3 conductors are not used at all. Or am I missing something (a distinct possibility since I'm about to embark on the installation myself in the next month or so)?
AceCannon
Active Member
I don't think a standard installation is going to have enough traveler wires to do the ALC aux switches.
But, yes, the aux switches on/off/com conductors are directly connected to the main switch on/off/com wires. Either locally or back at the central wiring location.
Maybe I'm not really explaining myself clearly, or I'm really confused and in trouble with the way we pre-wired
With a multi-way in our home we have the following pre-wired... a single CAT5 to the box which contains what will be the main 'control' switch for the multi-way, and then individual CAT5s to each of the other switches from this main 'control'. Therefore, I was thinking that I simply wirenut the on/off/com (brown/green/orange in your example) from EACH of the individual CAT5 'runners' with the main control switch on/off/com wires (so for 1 control and 2 aux switches, I have 3 sets of brown/green/orange wires wire-nutted). Then the main control switch has the regular blue/blue-white communication pair that is connected to the next switch in the daisy-chain (or back to the homerun location).
Edit... upon re-reading your response Ace, I think that's what you're saying actually, but if not, can you let me know
