Ohm Assistant - Home energy monitor

They said that the replacement was shipped yesterday ie May 13th, next day of raising the issue. So from a customer service point of view they are pretty good so far. I haven't got the tracking info though, as they said the logistics team is on holiday today due to Eid. They haven't said anything about what to do with the dead device yet, probably they'll arrange a reverse pickup once the replacement is delivered.

Got the tracking info today, it appears the package was picked up only today. Probably due to the holidays I guess. Should have it by Tuesday hopefully.

wonder why its not on Amazon would have given them more publicity, the ui and ux of the app leaves much to be desired, and if there was a way to get the data out and make custom charts with graphana it would be more cool

i understand that you can label devices based on its power signature( the voltage drop and watts being pulled) along with a timed user prompt for which device was turned on which they use to label the signature of an appliance, but how do they monitor the energy consumed per device ?,do they have enough resolution to detect both a signature of the device starting and it turning off ?, even then do they assume that these devices don't vary their energy usage ?, also what if they are a lot of noisy cheap smps phone charger connected on the house circuit, does all that switching noise hinder its resolution?, would be interesting to note how accurate the per device estimation really is with perhaps one of the appliance connected to a physical energy meter on the socket and comparing with the apps estimation

I had seen it on Amazon and Flipkart @Massivesiege (not fulfilled by Amazon though). Just checked and its still on Amazon with a 25% off coupon as well.

@varkey


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thought you might find this video interesting, the sense monitor(similar device sold in usa) uses the home lan to sense connected devices on the network to figure out the consumption, the video illustrates how the individual unplugs the tv from the network,the sense app can no longer detect the signature of the TV being turned on and only records the higher consumption of the mains,the video is a good illustration on the limitation on per device monitoring that these units claim that they can do

But network based detection are bound to have these issues.
The device Ohm is selling works on the fact that each device alters the waveform of the source current in a slightly different (as from the demo that I was given for a college project) and unique way. Which is what it uses to detect the number and type of appliance running.

sense works in the same way, they claim a 1mhz sample rate on the (hall effect sensors) for measuring current on each of the three phases and perhaps on the voltage wires of the phases as well
The point is the resolution or ability still isn't there to detect a signature for light load devices like the tv, it needs the network to detect this reliably, while this is a clever trick, it still illustrates the fundemental limiation of this approach,

a.c said:

But network based detection are bound to have these issues.
The device Ohm is selling works on the fact that each device alters the waveform of the source current in a slightly different (as from the demo that I was given for a college project) and unique way. Which is what it uses to detect the number and type of appliance running.

Click to expand...

nothing unqiue in what they are doing, the sense package does the same and has more bells and whistle strapped along for a wider detection of networked devices

Yep, I initially wanted to try Sense itself, but then that is more catered towards a 120V/60Hz system. I perfectly understand that any similar product wouldn't be as accurate as having individual CT or meter for each circuit or plug point. I think at a price point of around 7k (post discount) for a 3 phase system, Ohm Assistant is pretty decent (well, I haven't got my replacement yet, some mixup with the package. Delhivery misrouted it to a nearby town 15km away and now it has gone all the way to Bangalore from Kerala to correct the mix up and send it back to Kerala 🤦‍)

I had also seen IoTaWatt™ Open WiFi Electric Power Monitor, which lets you use additional CTs as necessary if you want to monitor individual circuits more accurately. You get access to all the data but would be more DIY.

I just noticed that there is Shelly 3EM | Shelly Cloud and Shelly EM | Shelly Cloud as well, but without the smart detection features, just shows whatever is tracked by the CTs.

@varkey


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another good video from the same uploader showing how appliances with variable current draw(pwm or ac inverter motor) that don't rely on the typlical bang bang feedback loop works

Finally received my replacement unit today, however it looks like there is some QC issue with a connector. The holes are not aligned properly so the connector wouldn't go in fully, I guess I will need to make a small cut on the plastic.



Also, they only sent the meter this time, and not the complete kit like last time, which kinda makes sense.

I managed to cut away a small portion of the plastic with a small paper cutter blade so that the green connector fits properly. Tested the device from a plug point, and it does power on and registered/activated the device. Now would need to install the device inside the electrical panel board. I am thinking of installing it myself, the electrician had done the re-arrangement of the MCBs etc to make room for this unit, so I would just need to open the panel and connect.

Will give it a try. 🤞

Having tried the app now, based on the initial impression I didn't like it much, its sluggish, not much info. Anyway will have the device installed and see how it goes.

@varkey any updates regarding how many devices and the per device tracking of the device?

I had written a long message earlier for this thread, looks like I never completed and posted it. 🤦‍♂️

So I had got it installed on May 25th (there were some un-related hiccups during installation, nothing to do with the Ohm Assistant) and I could see the live consumption. TL;DR Do not go for this product at this point cause the app is definitely not ready.

The device itself is probably doing its job, but lot of shortcomings with the app and the lack of options to get the data out.

1. It only shows the total consumption in watts across all phases. I would have liked the voltage, current, and power draw on each phase to be available. They are probably collecting all this data already but no way to get it out.
2. The app itself is buggy, I have to clear the app cache each time to get the graphs updated.
3. Analysis feature is pretty basic and offers no valuable insight to me. It just shows the time at which a heavy appliance was powered on, so far it could identify only heater, ac and fridge. Even then it doesn't identify it correctly always. Sometimes it confuses the AC with the heater and vice versa. Also, just the start time is not really helpful, would need the time it ran, consumption for each run. If there are multiple AC or fridge or heater then all gets clubbed into one in each category which makes it useless.
4. Also you can see the hourly usage graph only for the last 24 hours after that you can only drill down on a per day basis.

To be honest, if there was an option to get the raw data out of the device, I would have been really happy. But without that I am restricted by their not-so-ready app. I have a ticket open with these issues and all they say is that the feature would be ready soon (not sure how soon though).