*WARNING* SONOFF MINI DANGER !
Posted: 01 Nov 2019, 15:36
... the past few days I have built a court and garden lighting for a friend. There were also a total of 5 SONOFF MINI used.
I preferred the SONOFF to the SHELLY due to the outgoing antenna and the already for WLAN considerable distances. For many lamps, the SONOFF is housed in the lamp housing, with the antenna projecting upwards into the plastic lampshade and thus not being shielded from the stainless steel housing.
When mounting a SONOFF, it happened then that I had damaged the insulation of the antenna (the edges are very sharp inside) and this damaged area came into contact with the grounded housing ....
* BUMM *
After examining the now-dead SONOFF, I found that the developers somehow have one on the waffle (germany topic for an Idiot)!
How can one only come up with the idea, to place the connection for "phase" (over the bridge rectifier) on the internal equipment mass and to attach the "neutral" via condenser (not potential-free RC power supply)?
Had it been done the other way round, nothing would have happened, except maybe a burning of the protective resistor due to overload ...
So here's a haunting warning:
The lead-out antenna is directly at the potential of the connection "L in", ie directly to "phase" !!!!
Also the connection "S1" is also on internal ground and on "phase" potential
If I have the next week some time, I'll see if the circuit can be rebuilt without much stress, so that the internal mass is at "neutral" potential ...
I preferred the SONOFF to the SHELLY due to the outgoing antenna and the already for WLAN considerable distances. For many lamps, the SONOFF is housed in the lamp housing, with the antenna projecting upwards into the plastic lampshade and thus not being shielded from the stainless steel housing.
When mounting a SONOFF, it happened then that I had damaged the insulation of the antenna (the edges are very sharp inside) and this damaged area came into contact with the grounded housing ....
* BUMM *
After examining the now-dead SONOFF, I found that the developers somehow have one on the waffle (germany topic for an Idiot)!
How can one only come up with the idea, to place the connection for "phase" (over the bridge rectifier) on the internal equipment mass and to attach the "neutral" via condenser (not potential-free RC power supply)?
Had it been done the other way round, nothing would have happened, except maybe a burning of the protective resistor due to overload ...
So here's a haunting warning:
The lead-out antenna is directly at the potential of the connection "L in", ie directly to "phase" !!!!
Also the connection "S1" is also on internal ground and on "phase" potential
If I have the next week some time, I'll see if the circuit can be rebuilt without much stress, so that the internal mass is at "neutral" potential ...