Computers behind sine-wave UPS will never be found?

Based on my reading it appears that anything behind a UPS is never going to be found. Not all of the outlets, just the line-interactive ones. Sense has found the laser printer that is plugged into a surge only outlet. My computer is automated via Good Night/Good Morning Google Home routines. Our son’s is almost always on. The mac is often off (used for graphic arts by our daughter and school paperwork by my wife). It wouldn’t even bother me if the entire backed up side of the UPS identified as a single device (computer, monitor, anything else plugged in those spaces). If it’s in those slots it’s related in some way.

I am very disappointed in how little Sense has found of the ‘Always On’ at 90 days. Most of those devices have clear patterns of on and off (automated house plant lighting 5 fixtures total to keep clear air so I don’t have to use inhaler so much) / Overnight landscaping lighting). It found my old upstairs AC, but it never found the larger heat pump. The new upstairs AC has only been running 5 days so I understand why it isn’t found yet.

I also found that the “link” to IFTTT is exceptionally misleading. As devices are composed of multiple identified devices, then the triggers are worthless until all are found (and we don’t know how many there will be - we don’t even know when they are all found). I’m know they can be merged, but it has to find the all first. I don’t want to know when the heat stopped in my dryer. I want to know when it’s done (tumbling, heat, and whatever else) so the next load can go in, or the work clothes can be hung immediately.

Most devices you’re likely to be plugging in to the backed-up outlets on a UPS are probably not going to be detected by Sense even if the UPS wasn’t part of the equation.

My advice would be to get a single smartplug (HS110 or Wemo Insight) and use that: plug all the low-power devices that are on the UPS into a power strip and then plug the strip into the smarplug and then the smartplug into a UPS backup-outlet. Alternately you could use an HS300 power strip in the same way but you’d get per-device information.

I have things like a combo washer/dryer on a smartplug (it’s 120V and relatively low power so within the smartplug tolerance); likewise a fridge & OLED TV.

I put an HS110 on a multi-speed vent hood so when it goes on (at any speed) it can trigger a room-to-room fan (also on a smartplug) to switch off via IFTTT.


I have tons of smart plugs already of various manufacturers and sizes. Some are multi-outlet, and some even support energy monitoring. However they are all Chinese Tuya based clones and so aren’t supported.

Having said that if I buy more plugs they will not be wifi. Not that I have a better hub, any plugs are going to be zigbee or z-wave. Not only do I get more control in the hub for rules and scenes, but they work even if the internet is down (which happens more than I like here in the middle of a National Forest). Also it shifts all those devices and their bandwidth off of my wifi network.

Rather than ask Sense to support Tuya clones (KMC, gosund, hasbell, smartlife, etc). I’d like to see Sense provide an open API for our hubs to feed the power consumption data. It’s unrealistic to expect them to write a driver for each hub that exists, but if they provide the endpoint then that hub’s community can write the code to feed it.

A few thoughts:

  • I second @ixu’s suggestion to put a smartplug on the input to your UPS
  • I think you are misusing the “Always On” definition if you apply it to devices that switch between a standby, to active, then off again. Those devices are not “Always On” devices, but instead have “Always On” components to them. Sense has a way of figuring out the sum of the Always On components of all the devices in your house. But the Always On component will never be “detected” by Sense using on and off signatures, since that is the component that never turns on and off.
  • Sense also has a way to break out the Always On component of specific devices (or a outlet strip/UPS full of devices) on a smartplug
  • You are right about the challenges of IFTTT and different device components. At the same time, Sense has got to identify individual components before it puts together the combined device.
  • Not that it helps, but there is a good blog article on why heat pumps and variable speed AC systems are more difficult for Sense to “detect”
1 Like

Same. I’ve got two different APC UPSes, neither with 5-15 plugs that can go in a smart outlet. Behind them I have Raritan PX3 PDUs that provide per-outlet monitoring and lots of really great APIs. It would be simple to adapt them if Sense provided more APIs to feed data into their system.

When we have threads about “King of Always On” I look at my servers and know I’m King of usage and would love to break things down better.

Without burrowing too deep into what you have, with 240V APCs and the Raritan PX3 you are probably asking for Sense monitoring of quite a few outlets … given the expense of that setup I would suggest getting an additional Sense and dedicate the Main CTs to one of the APCs and the Solar CTs to the other … and then stick smartplugs on any individual devices you want to go deeper on. Those smartplugs can be monitored by the secondary Sense. You’ll get reliable ground-truth data for your cluster(s) and can choose to drill down if needed.

Just because the Sense motherbrain has significant processing resources doesn’t mean your local monitor does. Sounds to me like what you really want will force your Sense monitor into dodgy (read: unreliable) processing territory.

Any idea about the sampling or update frequencies for the PX3 PDU power data ? Most systems that monitor per plug have both lower sampling and update frequencies vs. the supported TP-Link and Wemo smartplugs.

Wish I could remember the name of the guy here with the bitcoin mining operation, his Always On was in double digit KW’s

Here is a screenshot, it’s @peter that wins this one

They’re actually both 120V UPSes, just one is 20A and one is 30A and thus don’t fit the supported smart plugs.

It looks like the PX3’s monitoring is 1Hz, but the manual isn’t super clear. What’s the frequency for the supported smart plugs?

Oh, and it’s not nearly as interesting as bitcoin. Just a homelab for a compiler engineer that likes fast build times.

Your amperage to be supported will kit be determined by the 20 and 30 amp output ratings of the UPS. It would be determined by the breaker size along with the input of the UPS.

I mean that the plug on the UPS isn’t physically compatible with an HS110 which is NEMA 5-15. One is NEMA 5-20, the other is 5-30.

It’s not just plus physical configuration. The reason for different plugs is usually (but not always) the current draw. The smart plugs don’t want to see 20 or 30 amp draws….fire and other such behavior ((-:wink:

Correct, and there’s no supported smart plug for those uses.

Hence, leave them plugged in and put Sense CTs on the dedicated (I assume) circuits back in the panel. When all is said and done that will give you the highest resolution data with the fewest dropouts. I would gang up a bunch of HS110s on the PDU, or use 3 HS300s, and link them to the dedicated Sense.

The early versions of the HS110 and Wemo Insight sampled at 2520Hz and update Sense at 0.5Hz (every 2 secs). The HS300 and newer versions of the HS110 sample faster.

One other thought - if the PX3’s produce a log of monitored readings, then you could blend Sense hourly export data and PX3 data.