This device is currently distributed in Italy by EttroIT, it’s identified by Tuya as R3_WIFI3, it’s an electromechanical switch remotely controllable attached to a differential magnetothermal switch, in this case a C32 (32Amps, 6.6Kw).
I managed to disassembly it by removing the rivets, you can replace the rivets with a m2 bolt and nut, just ensure to enlarge holes by drilling them only on the surface with an 5.5 drill, then enlarge the central holes with a 2.5 drill.
The procedure is somewhat similar to any CBU - (generic-bk7231n-qfn32-tuya), you can take 3.3v and ground from there (red circles, check for ground by touching metal shell of cbu, the other pin is 3v3):
Config is really simple, down below, what you won’t find is the remote lock, commented out, since I haven’t found any way to communicate the lock with the apparatus, but AFAIC it’s not a functionality I would use anyway.
DP1 of the mcu is the reclosing motor switch. It’s already wrote in the configuration. mcu is controlling the reclosing, if any lock is active, it won’t start the reclosing motor.
I’ve pasted an ESPhome configuration example in the first post (I don’t know if you can’t see it), you have control on the reclosing by using the datapoint 1 of tuya mcu, while the datapoint 102 is for mechanical lock and 104 is for local lock. 103 is a remote lock switch, in original device it wouldn’t allow you to remotely control the device, but considering the nature of esphome you can provide such a lock in any other way (you could use a placeholder for that and prevent any control by using a virtual switch or sensor)
Yes, I can see your yaml.
Like you can see from my questions, I have (luckily) never configured Tuya devices, so the device slang is unfamiliar to me.
But I might try, since I actually need a RCD that I can freely configure for reclosing.
The “normal” ones try to reclose two times in few seconds and then give up. We have lot of interferences on mains lines and I need completely different timing pattern.
Thank’s.
The input is prior to output of the C32, so the device is still controllable in the case the thing has be put to off for whatever reason (reopened) but mains should be present of course, the switch can be controlled also within a yaml script inside the esphome configuration, and it’s possible to use a timing for those, but as you can imagine, you have to be extra cautious with what you automatically decide to do in those cases.
The device itself doesn’t do any ground or short-circuit check, so the magnetothermal differential will just reopen if the reclosing has any of those things (and the wifi module will get the DP1 switch immediately open after the reclosing, in this case); you can use any timings, but as an electrician, I would suggest extreme caution with anything you do when controlling such devices automatically or remotely.
If you turn on the local lock, anyway, the device wouldn’t rearm automatically (it’s a switch into the tuya module, visible and usable outside)
But, anyway, it’s possible, yes.
Thank’s for your advices. My plan is not to abuse safety device, opposite.
When we have those interferences on mains, the whole neighborhood suffers from ridiculous RCD problem, it’s not a problem of residual current . I have tried every possible class of RCDs but they all fail. So instead of reclosing after 2s and 5s, I prefer 2s, 5min for example. Flashed directly to device of course, I never do important automations out of the device.
For curiosity, did you ever ask EttroIT to provide certifications for that device?
I have always serious doubts when there is Tuya used, generally they are chinese stuff with no certifications/fake certifications…
BT-ESR3532 is probably a certified device (will confirm when I get the answer from ettroit), but it’s not intended to be used as an automatic recloser, but instead as a wifi controlled recloser, tuya in fact lacks the ability to do such a reclosing automatically.
The tuya module is only attached to the original certified module (they are kept together with two clips in plastic), the certification number and specifications are as below (in Italian, lacks CEI certs, will report when I get answer from ettroit):
Modello ESR3532
Tipologia Interruttore Magnetotermico Smart
Moduli 3
Poli 1P+N
Corrente In 32A
Tensione 230V/400 VAC
Consumo in Stand-by <3W
Tempo di intervento ≤0.1 sec
Tempo di cortocircuito ≤0.04 sec
Curva C
Metodo di Controllo Integrato manuale e automatico
Metodo di comunicazione WiFi, Contatto Pulito
Gestione Remota Si mediante App Tuya
WiFi Si
Potere d'interruzione Inc 4.500A
Indice di protezione IP IP20
Normativa GB/T10963.1-2020
Certificazione CE
I will ask anyway the ettroit people for the certificate for the EU (just out of curiosity), since this is what I did find on the specs module, will put an answer here when I get it
Just to inform, I have received absolutely no aswer from them, the device itself has the stamp that informs that it is compliant with the cei en 61009-1, but still, the fact that they never answered, is not a good sign.
EDIT:
BTW, since the stamp is on the recloser itself and not on the differential, assuming everything is good, doing any phisical modification will invalidate the certification, always assuming it’s good.
RCD is “differenziale”, circuit breaker for overcurrent is “magnetotermico”. Nothing about recloser.
Anyway, one should always be aware that the waters are gray when something happens. In this case at least there is local importer that might take some responsability.
But think, if you burn your house with a smart switch like this bought from amazon:
eh, you’re absolutely right, that recloser-RCDO is mounted, at least on my case, below an external fountain, but the recloser is already protected by another device in the main panel inside the house.
Considering the lack of answers and the way it is, I would not use it for protecting an electrical line inside an house, but only as a toy.
I wanted to add something to what I’ve said above, given that I haven’t yet received a definitive answer, supported by documentation certifying its validity as a surge and ground fault protection device.
I have a photovoltaic system with a storage battery (on-grid, I also sell the surplus to the grid), and I’m using this device, placed under an appropriate protection device, to disconnect from the grid when I don’t have any surplus to sell and if the battery is above 35%.
Below there is a configuration that takes into account the case study mentioned above by @Karosm, but without certification, we have no certainty of its validity. The instrument tests obviously confirm the device as valid (<30mA for the leakage protection part, and also good for the magnetic part), but we’re still waiting for some kind of valid certificate, given that the stamp on the device itself is invalid, as it’s placed on the reclosing system and not on the protection mechanism (but, even if not tested, this reclosing device could be attached to a compatible protection device, of course certified).
I finally have the corresponding certifications, valid for EU, can’t attach them here as they don’t allow PDF, and that’s pretty lame, will upload them to google drive.
Edit: at least I can consider this safe for my fountain and for the main entrance below grid connection. As said above anyway, any mod to the main software, unless done software only (and this can’t be done software only, you have to drill the old rivets and place new ones, unless you are very firm and good this will be noticied), would probably invalid any guarantee, so be careful, even if certified, an insurance company will search anything to not pay you.
