Switches without common wires

[fman47]

I have encountered a wall switch without a common wire. It looks like the line side cable was brought to the receptacle box in ceiling with load line going down to the switch for turning light on & Off. Without re-wiring, I am looking for a smart switch that works without a common wire or controller i put in the ceiling box. I have the ISY994i controller with Zwave. The smart device has to work with that

[lilyoyo1]

What technology are you currently using? Insteon or zwave

[oberkc]

Well, if you are opposed (for whatever reason) to adding a device in the ceiling box, you are stuck with a limited selection of switches.  With insteon, there is the "2-wire" switch, but I suspect it is rated only for incandescent loads.  I am not sure how it would work with other types of loads.

[Derek Atkins]

There is an Insteon 2-wire dimmer module that you could try to use.  I've never actually used it myself.

[simplextech]

As was asked before.  What protocol are you wanting to use?  Z-Wave or Insteon?  There's a no-neutral wire Dimmer available for each.  GE makes one for Z-Wave and there's the Insteon 2-wire Dimmer as well.  Both work fine as long as you use an incandescent bulb.

[Brian H]

The Insteon one is a 2474D two wire dimmer. Incandescent loads only. Uses Insteon RF only. So another Dual Band Module has to communicate with it.

[kclenden]

Smarthome sells the Micro On/Off Module (2443-222) which you could put in the ceiling box and then use the wires running to the wall switch as "sense wires".  This allows the Micro On/Off Module to sense the position of the wall switch and act accordingly.  I use this for a couple of switches in my house - once because of the exact situation you describe, and once because there was a set of existing switches that I wanted to match.

The only real downside to the Micro On/Off Module is that there is a perceptible delay between the switch changing state and the device responding.  I haven't actually timed it, but my guess is that it's about a half second.  This manifests itself mostly when new people in the house try to turn on the guest bathroom light switch.  They flip it on, notice nothing happens, and switch it off before the light has come on.  Then they move to the next switch which turns on the fan, so they turn it off.  Finally they move to the third switch which turns on the shower light and they use that for illumination.  Once they know that the first switch does indeed turn on the bathroom light, they're good going forward.

[fman47]

Thanks -  I assume the Micro on/off would be wired in to what they refer as latching mode

[kclenden]

39 minutes ago, fman47 said:

Thanks -  I assume the Micro on/off would be wired in to what they refer as latching mode

That's how my switches are programmed.  They come programmed for latching mode by default.  They also come programmed for 3-way toggle mode by default whereby they act like they're in a multi-switch setup.  I turn the 3-way toggle mode off so that the switch being UP means ON and the switch being down means OFF.

[oberkc]

8 hours ago, kclenden said:

I turn the 3-way toggle mode off so that the switch being UP means ON and the switch being down means OFF.

But, if the switch is in the "OFF" position and something else (a program, a scene, etc) turns the light ON, would not your switch now be out of sync?

[kclenden]

38 minutes ago, oberkc said:

But, if the switch is in the "OFF" position and something else (a program, a scene, etc) turns the light ON, would not your switch now be out of sync?

Yep.  That scenario would require me to flip the switch UP and then DOWN again to actually turn the light OFF.  Both modes will result in the switch being out of sync if a program or scene acts on the device.  In the 3-way mode my switch will be out of sync until a program or scene again acts upon the device, nothing I do at the switch will get it back in synch, but with the 3-way mode disabled the switch is back in sync as soon as I use the physical switch again.  In the case of both switches, they are acted upon by a program or scene probably less than 2% of the time, so the way I have them set up means they'll be in sync the vast majority of the time whereas having them in 3-way mode would result in them being in sync for long periods of time followed by them being out of sync for long periods of time.

[oberkc]

3 hours ago, kclenden said:

That scenario would require me to flip the switch UP and then DOWN again to actually turn the light OFF.

I was wondering if that was the case.  I would find that more obnoxious than flipping the switch up to turn the lights off (aka being out of sync).

[oberkc]

3 hours ago, kclenden said:

  In the case of both switches, they are acted upon by a program or scene probably less than 2% of the time

In which case, I start to wonder if it is even worth automating.  Regardless, it would be worth the expense, to me, to replace the dumb switch with insteon so that nothing is ever out of sync and up is always ON and down is always OFF.

[simplextech]

I haven't been following this too closely but what's the issue with just using the 2-wire dimmer?  And running a neutral line if it's missing is like a $120'ish job for most electricians... kinda seems crazy to spend so much thought effort on how to solve a cheap problem.

[oberkc]

In my mind, the problem with the two-wire dimmer is concerns over how it would work with low-power loads (will they glow or flash) and how well it works with loads other than incandescent.  I also understand that they communicate via RF only, and my experience so far is that this is not as robust (at least, with insteon).  

yes, an electrician may only charge $120, but he is just as likely to leave you with with a couple of holes that I have to fix or hire done for another $120.  For me, at least, I find the cost (whether time or money) of a micro module to be less than the cost of running a wire.  Besides...I dont know how it is where you live, but it takes almost as much effort getting an electrician to come than it takes to do it yourself.  

[simplextech]

6 minutes ago, oberkc said:

how well it works with loads other than incandescent.

They don't work that well.  Which is why they state incandescent as required.

6 minutes ago, oberkc said:

I also understand that they communicate via RF only, and my experience so far is that this is not as robust (at least, with insteon).  

Never had a problem myself.

6 minutes ago, oberkc said:

leave you with with a couple of holes that I have to fix or hire done for another $120.  

Never had this issue.  If they cause damage that wasn't there before then they don't get paid until the damage is fixed and they only get paid for the work I asked for not the damage they caused.  Yeah most of the time it's faster to run the wire myself but sometimes I'm lazy and I just call someone to do it for me

 

[hart2hart]

I’ve seen this come up many times. I’ve speculated that one could:

1. Install regular dimmer in wall without load control from step 2
2. Use wires running to box from ceiling to create full time power to dimmer in box
3. Install micro dimmer/relay in ceiling to control light without direct control circuit to switch
4. Put micro module and dimmer in a scene


I haven’t drawn this out or thought it all the way through but submit for consideration.

[kclenden]

10 hours ago, oberkc said:

14 hours ago, kclenden said:

  In the case of both switches, they are acted upon by a program or scene probably less than 2% of the time

In which case, I start to wonder if it is even worth automating.

I might argue that it's the rare case that is most worth automating because you are most likely to not check for it manually.  Both of my switches are only acted upon by my "All Off" keypad button that we hit on the way out the door.  So programs will only change the state of these switches if they are in the ON state when the "All Off" button is pushed.  That doesn't happen very often because my wife and I are very good at turning the lights OFF when we leave those rooms.  It generally only happens when we have guests over and they venture into one of these rooms and exit without turning the light OFF.

[oberkc]

46 minutes ago, kclenden said:

I might argue that it's the rare case that is most worth automating because you are most likely to not check for it manually. 

Fair enough.  For me, though, I automate things so that I don't have to manually go through the house and turn off lights.  I guess, on the other hand, if the automation is viewed as backup to manual control then, yes, the harder-to-see and easier-to-forget switches are the most valuable automation candidates.