Questions about dimmer switches

(Nathan Z) #1

I want to start down the home automation road, but don’t understand a few aspects of switches and dimmers (and maybe Z-Wave and ST) well enough to know how to procede. I am hoping this enlightened community can bring me up to speed…

My primary concern is replacing a large number of wall switches (2-, 3-, and 4-way, with and without dimmers). My house is nicely wired with respect to having switches (with neutrals) almost everywhere you would want them, and while I do want smartphone-/remote- (and maybe sensor-) based control I expect wall switches to stay heavily used. I also already have (dumb) LEDs everywhere. Based on my research so far I understand that I could replace my switches with something like Linear WD500Zs (and the accessory switches for 3-/4-ways), but certain things about that solution aren’t clear to me:

  1. Can I opperate (my lights) with these switches without a ST hub, given that there’s a lot of reason to wait for the 2.0 hub? (I’m pretty sure the short answer is yes, but does the long answer involve something like a remote?)
  2. How do these dimmer switches (the Linear and other popular brands/models) function: I know that a short ramp-up is when turning on is typical (is this configurable, with or without ST?), but is there any way to control (from the switch) the brightness when the light first comes on? For example, when I went to bed and I turned off my hall light it was at 100%. At 3am my baby wakes up; I want to be able to turn the light on at something much less than 100%. Can I do this by holding the “on” down to get the power to go from 0% up to what I want? Or would I have to turn it on then lower the power?
  3. I’m pretty sure the Linear dimmers, and probably most brands, work this way: when turned on, the power level is set to X where X is the last power level set prior to turning off (assuming nothing else happened in the meantime, like ST told the dimmer to turn on at power level Y). I might like a setup where that is the normal functioning, but from the hours of 12am to 5am (for example) the lights will turn on at 15% when switched on (i.e. regardless of their last power level). Ideally, if the lights aren’t turned on during a night in that window, the next time they are turned on the next day they will go on at power level X. Is this something that can be accomplished?
  4. Is the previous bullet something that could only be achieved with accessory switches + a line dimmer? If so, can such a configuration opperate without a ST hub? (I certainly require operation without the cloud, but it sounds like 2.0 will handle that.)
  5. Does the accessory switch(es) + line dimmer configuration opperate any differently than actual Z-Wave dimmer switches with respect to button-pressing features? E.g. can you dim by pressing and holding, etc.?

I am a software developer and have a computer engineering degree (hybrid of computer science and electrical engineering) so I don’t expect any of this stuff to ultimately be beyond me; I just want to make sure that I can end up with a system that meets my admittedly picky desires.

(Bruce) #2

Some answers to your questions:

  1. Yes, any z-wave dimmer or switch you put in will always operate independently of the ST hub. If the internet is down, your switches and dimmers still work the old fashioned way.
  2. Every dimmer that I know of will turn on at the last level the dimmer was set to. That has nothing to do with ST, just a function of the design of these devices. So from that point it will operate such that when you turn it on it may be bright, and you can dim it over a few seconds to a low setting. Yes, you have to turn it on and then lower it, UNLESS you use a SmartAPP.
  3. Yes, this can be accomplished through a SmartApp.
  4. Not sure what you’re referring to, but if 3-way and 4-way switching situations, these still work without ST.
  5. Operates the same with or without ST, unless an ST SmartApp intercepts an event and does something with it.

Hey, it’s a Turing Machine. You can get it to do anything you want. It’s a bit of a puzzle at first, and asynchronous parallel event driven software has it’s own issues to be aware of. Overall, within the constraints of the devices themselves, ST can do anything you can dream up.


^^^ what @bravenel said… I personally use GE devices, including dimmers. They work great, and the new dimmers are even better from what some members have experienced.

(Nathan Z) #4

Thank you both for your helpful responses.

I don’t think I understand (or am aware of) the concept of an ST SmartApp “intercepting” the event, unless you are just referring to having the the accessory switches “wired” (metaphorically) to the hub instead of to the in-line dimmer. Along the same lines, is it possible to take a standard Z-Wave dimmer switch (e.g. the Linear WD500Z) and have the ST hub act on its button activations rather than the dimmer itself? For example, could I make it so that pressing the buttons on dimmer A doesn’t actually affect the line that dimmer A is wired (physically) to, and instead have ST do something else with those signals, while making dimmer B not affect its own line but have (via a SmartApp) ST send signals to dimmer A? Not that this particular example is something that one would likely want to do, but hopefully it illustrates the idea. (Maybe this is something that varies with the brand/model of switch?)

The older versions of the GE switches didn’t look like they were a great option for me, but I did just recently see some favorable posts about the newest generation, so I will definitely give them a good look.

This is reason I am expecting to go with SmartThings. (This, and the strong community, and the apparent potential for future existence/relevance.)