How to Backup Power (UPS) an Insteon thermostat?

[apostolakisl]

My Insteon thermostats (heat pump model) work great when  letting ISY be the brains.  However, they suck at managing a power outage.  Every time the power goes out, several, if not all of them don't reboot properly.  I need to open them and push the secret reset button and then they come back up fine.  But this is very much less than ideal.  They are powered by the 24vac from the furnace, so . . . how to UPS this?  Obviously, they are rectifying and voltage regulating that down to something like 12vdc, or 3.6vdc or something.  I am wondering, what if I just used 12vdc to the line that powers the thermostat?  Do you suppose that this would just pass right through the rectifier and voltage regulator?  I have used these Talentcell 12v ups units for a bunch of stuff with really great success and I could easily have a couple of those that backup things.  Other ideas?

[apostolakisl]

It just occurred to me, maybe the issue is that the power outage/restore doesn't result in the 24ac transformer giving a clean on/off.  Maybe if I put a relay that kills the 24vac when power goes out and thus gives a clean on/off?  Obviously, don't actually need the thermostat to stay working when power is out, just need it to reboot when power comes back on.

[sjenkins]

I like your relay solution. Slow death power outages reek havok on electronics. Easy to test as well. 

[apostolakisl]

15 minutes ago, sjenkins said:

I like your relay solution. Slow death power outages reek havok on electronics. Easy to test as well. 

I would need to figure a way to shut down immediately (easy part) but have a delay for turning back on (hard part).  

[apostolakisl]

Maybe this

https://www.ebay.com/itm/175357094229?_trkparms=amclksrc%3DITM%26aid%3D1110002%26algo%3DSPLICE.SOI%26ao%3D1%26asc%3D241433%26meid%3D67e10adba1314f67925d679946c861dc%26pid%3D101196%26rk%3D4%26rkt%3D12%26sd%3D175304946248%26itm%3D175357094229%26pmt%3D1%26noa%3D0%26pg%3D2047675%26algv%3DPromotedSellersOtherItemsV2WithMLRv3%26brand%3DUnbranded&_trksid=p2047675.c101196.m2219&amdata=cksum%3A17535709422967e10adba1314f67925d679946c861dc|enc%3AAQAHAAABELB59iZaq6L1SxCGLGoiBqHdpPz8nqKyKuGL1QIa0H%2B47SsVltB%2Bw0rtaIhMqUN4rojJhp1wcQEr%2BAzUZqgK5SfqMmP1JjWjR%2B6il7Kc4Ode7h%2B8R0xDI1KNJWhgq%2FJ9auZYMiCmiHZpxLlEU3rzPq39ndKJXwoF%2FPjpzw%2BbIC5ggWXc5x240AGAFTLBp1U2LppX2uTi%2BpHvGx1XJNF5uG4cQIgvyfp95u4TNgqUHtl9OE4ORbFOaAfb7cIPT9w4mAyI7mdsNVd3M2nTuED6gzvaCXJSsRJX6LjuHtMcqLcBO%2FEishRmfkWIyujm1MjR9SEPctZ2aa2vXvCVXI4kLcISZgCBrYaP63PzWU4MJhBW|ampid%3APL_CLK|clp%3A2047675

Looks like I could use 120vac line to power the unit and use the relay to interrupt 24vac output from the transformer.  Should cut the 24vac almost immediately when the line voltage goes out, and if I understand correctly, when line voltage returns, it can be set to delay the relay closure for an adjustable amount of time.

 

EDIT: never mind, I would still need a 12vdc transformer and thus it would not shut down right away since those tend to bleed down over a few seconds.  Of course the shut down may not be the problem, it may be the restart.

Edited August 23, 2022 by apostolakisl

[sjenkins]

Yes a 120 control relay with delay on (some have a dial to set time). Instead of taking out the 24v mains just put the contact in line with the 24v to the thermostat. This could all be done down near the furnace still. 

[sjenkins]

This would work....

GAEYAELE GRT8-S Asymmetric Cycle Timer SPDT Relay 220V 16A AC/DC12V-240V Electronic Repeat Relay(GRT8-S1,A230) https://a.co/j4A5gkG

[apostolakisl]

38 minutes ago, sjenkins said:

This would work....

GAEYAELE GRT8-S Asymmetric Cycle Timer SPDT Relay 220V 16A AC/DC12V-240V Electronic Repeat Relay(GRT8-S1,A230) https://a.co/j4A5gkG

Yes, but I think this would be the one I would want.

https://smile.amazon.com/dp/B07CGCL5W6/ref=sspa_dk_detail_1?pd_rd_i=B07CGCL5W6&pd_rd_w=FNRoV&content-id=amzn1.sym.4d0fffec-3aba-4480-8fad-c6bd8f7f6b41&pf_rd_p=4d0fffec-3aba-4480-8fad-c6bd8f7f6b41&pf_rd_r=3EWZ336PTWAYJ9MVP74A&pd_rd_wg=RBdI0&pd_rd_r=3a7daec9-4002-4b91-b680-29231654d2a4&s=hi&sp_csd=d2lkZ2V0TmFtZT1zcF9kZXRhaWxfdGhlbWF0aWM&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyRFhMWlE5R1ZDTEM3JmVuY3J5cHRlZElkPUEwNDQ0NjA3MTIzRlpTVTZLS05COSZlbmNyeXB0ZWRBZElkPUEwOTE2MDk4MVMxQzE1UkgzODA3NiZ3aWRnZXROYW1lPXNwX2RldGFpbF90aGVtYXRpYyZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU&th=1

[MrBill]

Why don't you just power the 24v transformer via UPS?

[apostolakisl]

4 hours ago, MrBill said:

Why don't you just power the 24v transformer via UPS?

Crossed my mind, but 10 of them adds up and then I have to deal with 10 batteries going bad every few years.  And I don't know about you, but those stupid small UPS units tend to cause me more problems than they solve.  

[ase]

1 hour ago, apostolakisl said:

Crossed my mind, but 10 of them adds up and then I have to deal with 10 batteries going bad every few years.  And I don't know about you, but those stupid small UPS units tend to cause me more problems than they solve.  

You have 10 of them being powered separately? Are these attached to mini split systems, zone controllers or central?

[larryllix]

After a complete power outage, what difference would the slow death of the power supply be? I doubt an Insteon thermostat would remember how it died that a simple linking button would solve. If a factory reset was necessary, I could see that, possibly.

 

Depending on your HVAC zoning configuration, 1 x ecobee stat with 9 remote sensors may do your job but then you would be faced with 9 x CR2032 batteries to replace every 2-3 years.

[MrBill]

8 hours ago, apostolakisl said:

Crossed my mind, but 10 of them adds up and then I have to deal with 10 batteries going bad every few years.  And I don't know about you, but those stupid small UPS units tend to cause me more problems than they solve.  

Yea that would be a problem, unless they all happen to be on a single control circuit. unlikely tho.

[apostolakisl]

2 hours ago, larryllix said:

After a complete power outage, what difference would the slow death of the power supply be? I doubt an Insteon thermostat would remember how it died that a simple linking button would solve. If a factory reset was necessary, I could see that, possibly.

 

Depending on your HVAC zoning configuration, 1 x ecobee stat with 9 remote sensors may do your job but then you would be faced with 9 x CR2032 batteries to replace every 2-3 years.

It is either how it died or how it powered on.  Every time we have a power outage, at least half of them need the secret button pressed.  When they boot up, the screen stays blank.  You would assume they are completely dead, except you can sort of communicate with them from ISY . . .you can query and set the temp for example, but it won't report temp and it won't turn the units on.  If you power them down by cutting the 24v (pop them off the wall bracket) and then pop them back, they always work fine.  So it must have something to do with partial voltages during the transformer power up/down.  To the best of my knowledge, the secret button is not a factory reset but rather a memory dump?  I don't know, but you don't lose your settings, so it can't be a factory reset.

[apostolakisl]

1 hour ago, MrBill said:

Yea that would be a problem, unless they all happen to be on a single control circuit. unlikely tho.

2 different buildings.  Some of the units are all located in the same equipment room, so I could put those together on the same UPS.

[apostolakisl]

8 hours ago, ase said:

You have 10 of them being powered separately? Are these attached to mini split systems, zone controllers or central?

Two buildings, one with 4 units and one with 6.  They are just regular 5 ton split-system heat-pumps each running independently.  The only thing that makes these guys different than a standard residential unit is that the compressors are 3 phase.  It is not the way I would have designed a big commercial building, but it is what it is and changing it would be quite the challenge.  The upside is that they use standard residential thermostats, so lots of HA options available.  I suppose I could just switch them all over to one of the other brands that now work with ISY because we have node servers.  When I installed these, it was Insteon only.

[apostolakisl]

I just looked at the wiring diagram, and there is just a single 24vac power input and that is used to power the unit as well as to switch 24vac back to the hvac unit on the various heat/coo/fan/etc conductors.  Obviously, the electronics don't run on 24vac, so perhaps I could look at the board and figure out where it is converting 24vac to low level dc voltage and splice in a different power supply (ie 5vdc) there might be possible, but tricky.

[jwagner010]

If you have so many power outages perhaps go bigger and go with a Tesla Powerwall + or other whole home backup system.  Depending where you live you can get tax rebates to offset the cost, not to mention it will keep other items alive in the house during these outages. 

[apostolakisl]

1 hour ago, jwagner010 said:

If you have so many power outages perhaps go bigger and go with a Tesla Powerwall + or other whole home backup system.  Depending where you live you can get tax rebates to offset the cost, not to mention it will keep other items alive in the house during these outages. 

This is a church, they would never spend that kind of money just to keep electronics from needing to be reset.  Plus it is 3 phase.  Tesla doesn't do 3 phase.  It isn't that big of deal to not have power, it is just having things come back online all by themselves when power is restored.

[larryllix]

It is either how it died or how it powered on.  Every time we have a power outage, at least half of them need the secret button pressed.  When they boot up, the screen stays blank.  You would assume they are completely dead, except you can sort of communicate with them from ISY . . .you can query and set the temp for example, but it won't report temp and it won't turn the units on.  If you power them down by cutting the 24v (pop them off the wall bracket) and then pop them back, they always work fine.  So it must have something to do with partial voltages during the transformer power up/down.  To the best of my knowledge, the secret button is not a factory reset but rather a memory dump?  I don't know, but you don't lose your settings, so it can't be a factory reset.

I had two of the 2441ZTH units and found those units were bad news.

My oldest one worked fine but when I got a newer model ISY could not ever control it. The newer unit always reported status changes but after an online support call from Michel, he pointed out the stat was reporting changes sent by ISY as confirmed each time without actually changing anything in the stat. The newer stat had an actual engineering design defect built in. Of course they wanted me to pay for return shipping to get warranty repairs honoured. That was one of the 3 for 3 items they sent me in that order that turned out to be defective on arrival. Another item was the iRLinc with a reverse wired iR sensor.

In each case the return shipping costs were higher than the devices were worth.

I never ordered directly from SmartLabs again.

I digress but to be short..I wouldn't trust Insteon stats to control my doghouse.

Sent from my SM-G781W using Tapatalk

[apostolakisl]

1 hour ago, larryllix said:

I had two of the 2441ZTH units and found those units were bad news.

My oldest one worked fine but when I got a newer model ISY could not ever control it. The newer unit always reported status changes but after an online support call from Michel, he pointed out the stat was reporting changes sent by ISY as confirmed each time without actually changing anything in the stat. The newer stat had an actual engineering design defect built in. Of course they wanted me to pay for return shipping to get warranty repairs honoured. That was one of the 3 for 3 items they sent me in that order that turned out to be defective on arrival. Another item was the iRLinc with a reverse wired iR sensor.

In each case the return shipping costs were higher than the devices were worth.

I never ordered directly from SmartLabs again.

I digress but to be short..I wouldn't trust Insteon stats to control my doghouse.

Sent from my SM-G781W using Tapatalk
 

Sorry for your issues.  I have not had any issues with these 10 thermostats except for power outage reboot issue.  They aren't the fanciest thermostats in the world, but that is fine because ISY does everything, they fulfill my needs completely and have done so now for maybe 10 years.  I also got them for a song, I think maybe $30/ea?.  I am also able to lock them out so only people I've allowed access from the app can adjust them.  I can't tell you how often people would set the AC and then put it on "hold" and the AC would just run for days with no one in the building.  I don't need a smart thermostat, I need a thermostat that ISY can control, that is about it.

I wonder if they had made these thermostats with a battery backup if that would have prevented this issue.  My office thermostats have 2 AA batteries for that purpose.  

[sjenkins]

I do think it is the power on cycle. Those power supplies are often not of the switching variety and don't forget the 24vac going back to the furnace. I bet the voltage comes up slow and non linear. 

[larryllix]

8 minutes ago, sjenkins said:

I do think it is the power on cycle. Those power supplies are often not of the switching variety and don't forget the 24vac going back to the furnace. I bet the voltage comes up slow and non linear. 

Most electronic devices have a circuit that keeps individual circuits from running or causes a general reset after power is fully restored to all circuits at functioning levels. With SmartHome's horrible reputation of cutting out components until the prototype won't run with even one less component, my opinion is that you are totally correct.

I doubt any Insteon thermostat had enough "brains" to remember bad things from a poor power down sequence or cause a polite power up reset to ensure proper quiescent state. While voltage is quickly waning you don't have time to write cycle data to an EPROM memory.

[apostolakisl]

It 100% has to be either the transformer bleeding down or coming on weird.  You can disconnect the 24vac and reconnect all day long and no probs, the thermostat boots up fine each time.  It is only when power is cut to the transformer while it is running the thermostat, not when power is cut between the transformer and the thermostat.  So, it seems the obviously solution is to open the circuit between the transformer and the switch upon power failure and delay the reconnection until the transformer has fully powered up.

I found these 5 for $10 relays on ebay that are designed for cars where when 12v is applied, the relay will turn on after a user specified delay.  The intention is that you start your car and then a few seconds later your electronics turn on.  Assuming it is a power up problem, this would fix it.  And it is dirt cheap.  So I will give it a shot. 

 

 

[PinchRoller]

I am late to the discussion and, despite larryllix negative attitude towards…well, the whole world; there is a super capacitor on the wired-in thermostats that keep the MCU running (like the clock and status) when power is lost. 

C21 shown in the image is a .22uF/3.3V super capacitor that can be replaced to maintain settings during a power outage.  Perhaps there is a Li-Po battery that can be used in place of the S-cap.  I expect that one can remove the thermostat and place a voltmeter across the cap and observe the discharge.  The circuit shows signs that when the power is lost, the MCU switches to the super capacitor circuit to maintain status and probably goes to deep-sleep mode.