I have a 5A lighting ring which I plug lamps into and which are controlled by wall switches. I plan to use Sonoff Basics between the lamp and the wall socket to control them. No problem so far…
What if the wall switches are dimmers? Is that a problem?
Yes, I know the pitfalls of this set up regarding the possibility of isolating the Sonoff by switching off the socket at the wall switch…
The Sonoff Basic is simply a relay. You can connect any load to it as long as you stay under the power rating (10-Amps for the Basic, I believe.)
However, as a former electrician, I would NEVER put 10 Amps through a Sonoff Basic. I find it hard to believe that the screw-connectors are rated at ten Amps, and if you have been using a Sonoff Basic for more than a few days, unplug everything and you will be able to tighten the screws by a half-turn or more. Repeat every few weeks. Loose terminal screws are a fire hazard.
Trust me, I’ve melted a couple of Sonof Basics testing this.
I do have a heater that draws 5 Amps controlled with a Sonoff Basic. I removed the screw terminals and soldered the power cord directly to the board. I am confident that I can tun this heater for hours without concern.
I did exactly the same thing, soldered the wires, skipping the connectors. But the weak spot was the fuse holder in my case. (Sonoff pow) The spot were the fuseholder is soldered to the pcb is burned. Be carefull .
Interesting, and slightly annoying as I have taken the cover off all of mine and put them in slightly larger plastic boxes (which are not deep enough to accommodate the original sonoff cover) so that I could add strain resistance to the cables to stop them being pulled out. I had to tape the box lids down using insulation tape because they just snap closed which I decided wasn’t good enough.
What mechanism is it that causes the screws to loosen? Mine are not subject to any movement and I would have thought that having the cables restrained a centimetre or so before they are screwed in might prevent this happening?
And yes, I would never load these basics, I only use them to control a table lamp.
Every time the joint conducts current there is a microscopic temperature change with some very tiny expansion and contraction. Over time this will loosen the screw. This is because the coefficient of expansion of the wire is different from the screw terminal.
Want to get really scared, turn off the power at the breaker and take a socket out of the wall that hasn’t been touched for years. You will be able to tighten the screws on the socket by 1/4 to 1/2 turn.
While I am on the soapbox, this is one of the factors that made aluminum wiring in homes illegal to install in most municipalities in the 1970’s. Aluminum expands faster than copper which exacerbates the problem with the screws backing out, added to the dissimilar metals and oxidation of the aluminum increases the contact resistance which in turn becomes a real fire hazard.
If you have aluminum wiring in your home, you should be checking these connections annually, especially on the high-current outlets, and use an oxidation barrier such as Noalox Anti-Oxidant on the joints. Or make sure your fire insurance is up to date.
If you don’t have aluminum wiring, then sleep well. If you have any high current devices like a space heater or washer/dryer, feel the wall above the outlet when they are running. If it’s slightly warm, then pop the outlet out of the box and retighten the screws. After turning off the breaker.
Likewise, if your Sonoff Basic is warm near the terminal screws cover- same thing. Tighten the screws.
Low current loads like lamps or small fans are much less of a hazard.