I want to buy a sauna and it comes with 9kW electric heating. The heating can be powered from single 230V, three phase 230V, or single 380V. I want to be able to control it remotely, and ideally track consumption.
9kW is 37.5A@240V or 24A@380V. It seems that Shelly 3EM supports up to 120A per single channel: Shelly 3EM - All Products - Products - Shelly , so it should handle it, is that right?
Is it also true that I could put there 380V by connecting another phase to N in 3EM and the other two phases just to LA and LB?
Can I just connect it to where the rest of my phases are on a DIN, and connect it to that?
Yup, but only the 1P+N 230V or the 3P+N 230V/400V case. It does not support 1P+N 380V.
No, absolutely not.
Yeah you can. Just make sure the CT clamps go around the wires connecting the sauna. Also if you use the contactor control, that should be close to the actual contactor. So usually in the panel on the DIN rail close to the breaker and RCD for the sauna circuit.
Yeah you can. Just make sure the CT clamps go around the wires connecting the sauna. Also if you use the contactor control, that should be close to the actual contactor. So usually in the panel on the DIN rail close to the breaker and RCD for the sauna circuit.
Can you please help me with this one?
I would like to use Shelly products. So my thoughts:
https://www.shelly.cloud/en/products/shop/shelly-3-em-1 has “Contactor control up to 10A” in the specs, but it seems to me that it’s only 10A combined and not per phase (I eyeballed that from the API - it has only one relay apparently). So I cannot use it without contactor.
Wait a second, you need to clarify one thing here. What is your phase to neutral voltage ? If it is 230V (phase to phase would be 400V), then the Shelly will work fine. If phase to neutral is 400V (phase to phase 690V), then the Shelly will not work.
I just finished building a sauna. My heater is an 8kw Tylo which runs off single phase 240V. I was considering having it controlled by a 40A solid state relay (expected load at full throttle was about 32A).
The wiring could have allowed me to run a single phase to each heater element - 3 elements - 3 separate controls for each one if I wanted to be more energy efficient - i.e I could run one element when solar is low output and then as solar inscreases i could have the other elements switch on ( I didn’t wire this way but was just considering this)
Anyway what i have done is put a wall mounted inline isolation switch. This will allow me to replace this with the previous mentioned 40A SSR if i want to start thinking about remote on. If I went this way i would also have to bypass the inbuilt timer unit on the Tylo heater.
Maybe in the future - as it is now we turn it on when solar is reallly cranking and it is ready in the evening for sauna.
Pat
The problem with the OP is that his diagram seems to indicate that each heater element runs on 400V, at least on the option 1 and 2 (wye and delta configuration). The option 3 is more like yours, the three elements are just connected in parallel to a single phase 240V supply. Which is a little confusing, because that doesn’t really match the other two options. Maybe it’s a different heater model.
Alex
definitely a different model however the image of possible connections that he posted showed the following
It shows a 240V - 1N connection that is just a live shared on the element connections 3,4 and 5.
Then wiring each element separately should be possible.
I wouldn’t be surprised if his also has an inbuilt timer.
Pat
Yeah but note how each element is supplied by 400V on the connection options number 1 (400V phase to neutral) and 2 (400V phase to phase), yet it is supplied by only 240V on the last number 3. That doesn’t really make sense. Either these are 400V rated heating elements (and they would be underpowered on the single phase 240V connection option) or there are two different heater models for his sauna (one for 400V per element and one for 240V per element).
and I basically will have the sauna heating plugged in a power socket in a garage. What I expect to do would be a 3P contactor and shelly controlling it. Here is my very naive way of how I think it could work:
I don’t know. When all the schematics you give and where people make their research on to find out compatibity turns out to be wasted time because it was just ‘inspiration’… If you don’t even know the details of what you will get how are people supposed to help you. I’d suggest getting an electrician for the setup. Good luck.
I appreciate your help and you are definitely totally free to setup conditions as you want and I am sorry you feel that your time was wasted. As a matter of fact, I think I am fairly close and this thread has helped me a lot to figure that out.
I am trying to understand what’s going on and not waste anyone’s time. My latest post is actually showing the detailed wiring and specific items that I would want to use. The schematics in my latest message should be what we are expecting to use and get (with the contactor being linked above).
If you don’t even know the details of what you will get how are people supposed to help you
I didn’t know what details were necessary… It is obvious to you, but not to me yet…
I’d suggest getting an electrician for the setup.
As I wrote in my latest message, I do plan to do that anyway. But want to give them some brief.
The passive aggressive quotes were IMHO unnecessary…
