Thanks to Zemismart I received free of charge a SPM02 zigbee Flex device to install in my setup. This was a nice present and gave me some new opportunities to create new automations.
Automation goal: Make my dumb induction coocker integrate with Homey so I can control my previous dumb damper when coocking start. My damper is powered by the central ventilation unit. It was a very old fase shift engine in my attict. I replaced some time ago with a ComforFan unit controlled with a 10v controller unit (I had one from Qubino now Shelly) so I used that. It is controlled based on humidity sensors in my bathroom and motion sensors on my toilets since it is the suction power for all those rooms next to the damper. But since I had no way to detect when coocking commensed I was stuck with voice commands there. And that has been working fine for several years. So when I received this device it was a clear moment of enlightment. This would allow me to detect coocking and control this last vocie command piece of my house, improved WAF score.
The device: It is a zigbee based (mine, the manual states there are wifi versions) flex device that uses the CT concept to measure the power on the 3F coocking breaker. And its a 3F measurement device that can measure up to 64A. So thats actually really nice.
They made the housing of the unit a nice and compact whole with 3 holes to guide your fase wires through. This makes the CT concept much cleaner. In theorie you could place it on top of your coocking breaker and the wires go straight through into their clamps. The unit is about 1 cm thick and the same dimensions as the breaket of a 3F 4 slot unit that I have. So far the theorie.
Installation: When I received I was eager to install it so I pulled my breaker box open. But offcourse that is where my enthousiasm stopt. In my situation there where a lot of other breakers their wiring that where crossing above the coocking breaker. That meant clearly there was no way I could fit this, although compact still sizable, unit in there without a lot of rewiring. And since that was not on my schedule it went back on the shelve.
Installation attempt 2: I had a rework on my central breaker to move my heavy users (EV charger, home battery, solar panel, sauna etc) to a new breaker box in my basement. This should free up my ‘old’ breaker box with only the normal househould breakers left. And while this work was happening I had it ready to ask the electrician to place the Semismart while it was open anyway. However during this work the project went tails up, causing damage to my appliances etc, so since his attention got moved to solving that crisis, the Zemismart got forgotten and not installed by the time he left. But that is another story
Installation attempt 3: Once the dust settled on the problem caused by the work mentioned above the result was still a new breaker box in the basement and still lots more space in my old breaker box. One of the moved 3F breakers (EV charger) spots is right next to the coocking breaker and lots of the wires blocking the space above the coocking breaker where now gone, so I went for it myself.
Installation review: So even though it is designed to fit above the breaker, all drawings also show that as the example in the manual, in my case it would barely fit on top of my breaker. There are still some other breakers wires crossing above it, but all and all, my breaker is on the top din row of my breaer box (it has two). And if I would place this unit on top of the breaker there is no space between the breaker and the unit to put its own wiring properly into the breaker clamps. So I went for placing the unit left of my coocking breaker. The wires of my coocking unit come from that direction so I moved the fases through the holes while keeping the unit vertical instead of horizontal. This does mean the dimensions so stack on top of the din rail without it being to clamp into the din rail. There is a mounting version but it doesnt seem to solve this problem. The measuring wires are long enough to place it on the side, but my fase wires where not placed in such a way they fitted easilty and with that corner it was still a tough fit to get it all in. Next to that the device needs a nul from the same breaker.
Once I had the wire routing a bit figured out it came down to putting my wires back into their clamps but since the SPM02 needs measring wires you need to put those in the clamp also while screwing them tighlty again. This was the hardest part. Getting my fase solid core wires with the very thin flexible wires (thankfully properly fitted with a solid tip) was a challange. It was hard to get them in the clamp part without seeing the clamps due to the lack of top visibility. This din is high in my utitliy closet so I could not get my head higher in.
It took some effort and attempts to ensure they where properly fitted and firmly fixed. But then it was time to turn the breaker back on.
Pairing: The first power on turned the device in pairing mode. I forgot to have my phone near by so I went to grab it. Since its a powered Zigbee device it acts as a router and my Homey Pro is in the same unititly coloset so I did not expect problems. But when I got back and tried to add the device my using Homeys add zigbee device it did not find the device.
The device has a reset button and a status light (rather bright actually) so once I was sure the position I placed the device in actually allowed me to press that button without riscking my health and pressed it again for some seconds to ensure it was back in pairing mode.
This time my Homey did find the device and it offered me to install the Zemismart app and link the device next to the install without app. I choose for the install with the official app.
Measurements: With the deivce paired to Homey I could test the sensors it exposes, and those are impressive. It holds fase and total device values, specially in my coocking breaker that is a good concept. I can now see per part of the induction unit what fases are actually used but keep my flows clean by just stating the coocker is using more than 10W power so someone is coocking. And thurn on my damper.
But it also allows for:
Imported energy - Exported energy on totals
Voltage - Current - Power per Fase (labeled by X-Y-Z also on the device)
But additionally it even includes:
Power Factor - Forward Energy and Reverse Energy per fase
Reactive Power - Apparant Power per fase and totals
Active power and Frequency on totals.
These are very usefull for more advanced measuring of the health of your system. I probably wont be able to use them properly on my coocking breaker. Put in hindssight I should have placed a unit like this in the input side of the second breaker box in my basement. Since I build the Homey Smart EMS app I probably should figure out use cases for these measurements…
Conclusion: It is a nice device, the classival missery I have with CT clamps based systems they truly tried to solve. However it is still a difficult fit in my (and many others) breaker box. But once its in, the Zigbee is a good usecase for this type of device, it does bring a lot of usefull data to the table. I can not compare this with a certified measruments to know if they are accurate, but it seems clear that this treasure of data brings new oppurtunities to handle a households energy. RIght now I have to trust the battery reported values and the solar pabel reported values. I can imagin that adding these devices on their breaker level allow for proof of true value. If we are charging and decharging based on co2 emission on the grid or based on price levels, we know we are loosing power in the process. Not all batteries report this loss properly or trustworthy. This device can truly add that gap to the data set so we know it was worth it, if we lost more than money or emissions saved…
Wrap up: I also had to place the lid back on my breaker box, needed some pushing and moving the unit around, but it just about perfectly fits in there even though its a bit messy placed on the din behind a blind cover plate. the bright light of the status light shines a bit trhough the cracks of the blind slot plates it hides behind, so now my breaker box has internal lighting 
