Wednesday, May 23, 2018

True 3-way occupancy / vacancy motion sensing wall switches

Simple problem:  Want motion detection (occupancy) at both ends of a hallway or stairwell.

Solution:  an amazingly large steaming hot mess!

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[Update]:  OK, so I've realized that the main reason why there are relatively few residential application for motion switches is: they don't save you money.

You can read the details here.  The original reviewer makes the mistake of confusing a 40W LED bulb (320 mA draw) with a 40W equivalent LED bulb (actually 9W, 72 mA draw), but otherwise the concept is sound.

The reality is that unless you are switching large lighting loads (150W-ish or more) and/or in a commercial environment where lights might get left on 24/7, adding a motion sensor makes no sense.  The "smart, energy-saving switches" will consume MORE energy than if you accidentally left the bathroom lights on an extra 15-20 hours per week, which seems rather unlikely for most situations.

This also means there is no payback period for smart switches.  They end up costing you when you buy them, and costing more every year in the energy they consume.  

There are still tons of reasons to buy motion sensors for the home.  There is no need to struggle carrying loads, or tripping down dark stairs.  Those things may easily be worth $5-$10 per year in energy costs, especially when compared to medical costs owing to an accident.  It's cheap insurance.  Ditto dimmers, which are just as much for comfort rather than energy saving.

But if you really want to save energy - after upgrading to LED bulbs, of course - the best way is to get up and turn off those LED lights whenever convenient, using a good old-fashioned $2 mechanical switch.  Everything will be off - totally off - and consuming zero energy, rather than consuming small amounts continuously to be "smart".

This rather puts California's Title 24 in doubt, at least when it comes to residential applications.  But whatever.

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As one reviewer commented, I have difficulty visualizing a situation where you don't want two motion sensors (at the end of a hallway, opposite sides of an L-shaped room, etc.)  Yet the solution is surprisingly hard to find.

Note:  "Occupancy" means lights turn ON and OFF automatically.  "Vacancy" means lights turn OFF automatically, but have to be manually turned on first.

Lutron:  Lutron advertises various "multi-location" Maestro Sensor switches.  Most models start with "MS", and most do not need a neutral wire.  Awesome, right?

The problem here is that you can only install ONE motion sensor, and the rest have to be "ordinary" 3-way switches.  Not what we want.

One enterprising soul did manage to make two Lutron MS motion switches work together in a "3-way" application, but it does not function 100% normally.  In a normal 3-way, ONE switch must be off to turn off the lights - in his setup, BOTH switches must be off to turn off the lights.

This is not a big deal (perhaps) since both lights are automatic, but may not suit everyone.  If it does, this may be the only no-neutral-wire installation that is possible.

You also must have a ground wire, and the switch is reportedly relatively loud.



Leviton:  Use the IPS15-1LZ (switch) and IPV0R-1LZ (remote sensor) together.  The remote sensor works with the main motion sensing switch to do true 3-way motion sensing.

The problem here is that both of these units need a neutral wire in the wall box in order to function.  Which not everyone will have.

It may be possible to substitute the green / bare ground wire for the required white neutral wire.  I don't recommend this because the ground wire is not supposed to be used in this manner, but it will likely work.  (The Maestro series actually does this on purpose.)

The other available Leviton switches seem to require one of the switches to be a "regular" 3-way mechanical switch.


Enerlites:  The DWOS-3R is the only multi-location switch.  It does not seem to be rated for use with LEDs, and it is unclear if you can actually use two switches controlling the same load.


Eaton:  The OS310U-W-K is not rated for LEDs, and there is no indication you can use two.


HubbellAccording to the instructions, you can use two ATP2000 series or two WS2000 series motion-sensing wall switches in tandem, and they will work properly.

Of course, they have high cost, limited availability, and non-standard wiring.  Other than that, they're perfect!

There are neutral-wire and no-neutral-required versions, and versions with and without a built-in nightlight.  Assuming no nightlight and no neutral, the model number is ATP2000W or WS2000W.


For reference, the "ATP" switches have some kind of auto-adjustment technology that lets them adjust their timeout period.  The "WS" series have an "ordinary", manually-set timeout period.  Both types are 3-way capable.

These switches are rated for "most" LED and CFL bulbs, and it does use a triac instead of a relay, so YMMV.

It is also not clear if the wiring is one-to-one with existing 3-way wiring.  Ordinary 3-way has line-hot to one switch, plus two travelers, while the Hubbel diagram shows line-hot going to both switches with one traveler.  You could re-purpose a traveler to a hot, if you know how.


This has already taken an amazing amount of time for what it is - doing motion in a stairwell - and I haven't even looked at my existing wiring yet.  I will update this if I learn anything more.


Friday, February 23, 2018

How to figure out which program is stealing Windows focus

I recently ran into an issue with losing focus while working.  An incredibly annoying problem for anyone that has experienced it.

Alt-Tab did not show anything useful and Alt-Space didn't either. 

Fortunately, I found the Adminscope Windows Focus Logger, which identified my problem in about 60 seconds. 

It's freeware, and there is no install.  Run the GUI and watch what happens.  Soooooo awesome.....

In my case, Razer Synapse kept stealing the focus. 

I suppose I should have clued in when I saw an "Unacceptable character" message pop up a few times - the font used was subtly different than a standard Windows dialog.  But the message was right over my Word navigation pane, leading me to believe the Word nav pane was somehow stealing focus.

Shutting down Synapse and restarting appears to have fixed it.  I think the problem only happens when you pop up Synapse, record a new macro or something, and then close it.  Somehow, it doesn't fully close.

I have a multimonitor system with multiple desktops (via Dexpot) so perhaps this is contributing.

Monday, January 8, 2018

Wiring the ecobee3 AUX+ and AUX- inputs

Note: this post has nothing to do with the dreaded "C-wire" that is required to run an ecobee.  If you're looking for that, go elsewhere.


One of the more frustrating items for a heating/cooling system is the sheer number of possible ways to set it up.  Sure, there are "standard" ways, but there are also always other ways.

My previous post on a missing G (fan) wire was not my only issue; in fact, it wasn't even the hardest issue.  The actual problem I had - the one I called ecobee about - was that my humidifier wasn't working.

For anyone who may not know, a whole-home furnace-mounteded humidifier is de rigueur  in Canada and the northern parts of the USA.  The cheapest and most common kind is the "evaporative" kind which uses hot furnace air to work - hence, it only runs when the furnace runs.

There are undoubtedly many ways to wire such a system, most of which the ecobee3 will support.  But it sure helps to know what the ecobee3 does.

ecobee3 supports two types: a "one-wire" accessory, and a "two-wire" accessory.  According to ecobee support, the thermostat works thusly:

-  In "one wire" mode, the thermostat supplies +24V to ACC+.

-  In "two wire" mode, the thermostat presents a dry contact across ACC+ and ACC-.

If you put this information together with how your system is currently wired, I bet you can figure out of how to wire and configure the ecobee to run your humidifier (or other accessory). 

If, on the other hand, you don't know what a "dry contact" is, this job is likely not for you.  Best get a pro to help.

Wiring an ecobee3 without the G wire (G-wire, fan wire)

Note: this post has nothing to do with the dreaded "C-wire" that is required to run an ecobee.  If you're looking for that, go elsewhere.


One of the more frustrating items for a heating/cooling system is the sheer number of possible ways to set it up.  Sure, there are "standard" ways, but there are also always other ways.

We had a new furnace installed not long ago.  However, there were not enough wires run to the thermostat to support the additional A/C system.  The cable had only enough wires for heat-only operation.

To make it work, the installers should have run a new cable, but they didn't.  Instead, they disconnected the G (fan) wire, and used it for Y (cold call) instead.  This led to an atypical installation that lacked a G (fan) wire at the thermostat.

Note it still worked.  The thermostat sent the W (heat) and Y (cold) signals, and the furnace controlled its own fan.  No worries, thanks to them thar new-fangled furnace, y'all.

However, when I installed the ecobee3, it said "To use the Y1 wire you must install the G wire".  Since I didn't have one, that was a bit of a poser.


When I described this to to ecobee tech support, they could not wrap their head around the idea that the furnace controlled its own fan.  They actually told me to rewire the entire furnace to include a G wire, otherwise they wouldn't help. 

Note I said "wouldn't" there.  I don't know if they could have because - basically - they just gave up.  The tech support rep said - and I quote - "I have been instructed not to proceed further."

Now, I don't particularly blame ecobee for this, owing to the problems noted at the top, but the workaround is actually built into the ecobee.  There was no reason to tell me to go hang; it was rather disappointing and reflected a lack of understanding of their own product.

Fortunately, in the first 5 minutes of being on hold, I figured it out for myself.  The actual correct workaround is as follows:

-  Run the ecobee setup.
-  Tap "Configure" to set wiring manually.
-  Tap "G" to tell the ecobee the G wire is connected (though it is not).
-  Later on, it will ask if the fan is to be controlled by the ecobee or the HVAC equipment.  Select HVAC.

That's it, it should work as it did before.

Now, OBVIOUSLY, you do not have manual control over the furnace fan at the thermostat with this setup.  But I didn't have that before, did I?  So no change there.

Also, I would not recommend anyone switching existing wires around to get a C wire (or any other wire) by sacrificing the G wire.  My furnace works this was because it was originally set up and configured to operate in the absence of a thermostat fan wire.  A furnace that has been set up otherwise, only to have the fan wire removed, is highly unlikely to function correctly afterwards.

This workaround applies to furnaces that have a manual fan switch installed somewhere else.  This is sometimes called the "summer fan" configuration, and often involves putting a manual switch on the furnace to provide for fan control that is independent of the thermostat.  Not a "normal" situation - unless your installer was too lazy to run new wiring when you got your additional cooling/heating unit(s) installed.

So, if you're unlucky enough to be missing a G wire at your thermostat, you can still make the ecobee3 work.  Hope this saves someone a few hours of their life.