I assume that when you say “correctly” you mean operating the device within its rated limits of voltage and current. That’s the minimum expectation, namely does the device work as advertised? Ostensibly yes, this device can work “correctly”.
However, electrical appliances approved for residential or commercial use must conform to national electrical codes. Among other things, these standards specify the device should fail gracefully in the event it is NOT used “correctly”.
For example, accidentally dropping a hair-dryer into a sink full of water, shorting a light fixture, connecting a motorized appliance to a circuit controlled by a dimmer, drawing more current through a device than it is rated to handle, etc. In all of these situations, the device should fail gracefully and NOT become a fire hazard.
If you watch the video in my previous post, the Sonoff Basic has nothing to protect itself from an overload. Its internal temperature rises significantly when overloaded by merely 25%. At 50% overload its temperature is high enough (> 100 C) to cause burns (to skin). At that point, it’s acting like a heater within a plastic box. Operated this way, it’s only a matter of time before internal components degrade and fail or, even worse, smoulder and ignite.
What concerns me most is that some people conceal these devices in walls and ceilings where they cannot be easily inspected. Within a confined space, any odors created due to overheating will not leak out and serve as a warning that the device is being stressed beyond its limits.
I am even more concerned outside of sockets: there is no safe cable blocking (sorry I don’t know the correct terms in English) so anyone in the house could easily pull the cable and the Live would be exposed: these accidents are NOT rare events.
If an officer gave a certification to such a product he should be fined and fired
I believe the English expression is “strain relief”. It reduces/eliminates the physical forces applied to an electrical connection. If the AC supply wire can be pulled, a strain relief device minimizes the risk of the wire pulling out of its connection.
In the old days, it was simply a matter of creating an Electrician’s Knot. It’s also called the Underwriter’s Knot. Nowadays, there are devices that either attach to the wire or are molded directly onto the wire. Nevertheless, the principle remains the same.
I agree with your comment about housing them but we’re talking about Home Automation here and a lot of things that should be completely common sense often are lost.
How many times have we heard BAD advice like “If you don’t have a neutral just use ground…” and such. It is too prevalent.
The problem is that lack of common sense plus products like the Sonoff that are well priced; lots of flexibility; and attractive to the tinker community end up being used by people who struggle to not kill themselves plugging something into a wall outlet; let alone wiring up something to plug into said outlet…
While we could say “Darwin Wins” and go forth we need to be aware of this.
So it’s perhaps a shame that Sonoff doesn’t have this somewhere “These units needs to be installed a suitable approved wall box or project box with correct strain relief and wiring practices…” or similar. Still won’t stop all the “morons” but at least cuts down a bit.
But like all such products from China they don’t give a flying fu<k and therefore omit this to sell more and ignore the reality of the situation.
To those who suggest that you should not use the Sonoff… This is NOT a Sonoff problem, it is a USER problem. If you don’t know enough to use a FUSE then don’t mess with mains power!!!
DrZZs (or whatever his nom-de-plume is) suggests an inline fuse in his video.
A few of things to note:
This thread started off being about a modded sonoff, so no amount of certification of the unmodded sonoff is going to make that mod safe, or save you from fire/death/insurance denial/manslaughter charges.
Everyone needs to look at their OWN country’s certification processes and legalities. A CE sticker means nothing in most countries, and I imagine are pretty easy to come by in some markets.
Allied to this is different voltages in different countries. My country (NZ) uses 240V and most power points are rated at 10A, as are the circuit breakers in the switchboard. Therefore I can run a 2.4kW heating element safely from a plug in my lounge and not exceed 10A. In the US, to generate the same power at 120V I need 20A, which exceeds the rating of the sonoff, and I have seen mentioned that most US power points are rated at 15A anyway, so I am limited to 1.8kW.
Nothing is at your own risk, there are also the lives and property of family, visitors, your neighbours, firemen etc to consider.
I would bet that 99% of people using a Sonoff do NOT use to add an in line fuse.
That should be the producer obligation, instead he flashes a CE certificate on its website and lots of people think those Sonoff are (electric) “certified”, hence safe. I red that here (this and other thread) and on reddit multiple times.
The fault is 100% on the producer not on the user.
Common!!! Those product (especially Sonoff Basic) should be banned.
Correct, strain relief. That could be so easily added with no additional industrial production cost. Of course they do need to redesign the item entirely (and put a fuse, and isolate better, and put more lead and and and)
I get your point, just prefer to add for clarity to other readers:, what about minors, or somebody visiting a “moron’s” house right in the moment of a Sonoff failure.
Electric code is there for a reason: to protect lives from moron’s actions, or better say from greedy and unscrupulous manufacturers
Which as I said is easily fixed as is the other main issue (not rated for household fault current). If you don’t know how to rectify these problems you have no business messing with mains voltages in the first place.
Also as I said, I have 15 years of mains powered PCB design design experience to base my judgement on and I’m quite happy to use the Sonoff Basic with a couple of modifications.
Hardly moronic and I don’t appreciate being called such.
@tom_l, @Klagio, @jwelter, @nickrout, @123 and others, you look like to have more experience in electricity/electronic than most of readers / future readers of this post.
To keep this thread constructive and helpfull for future readers, I understand that Sonoff basic can be a good tool if used wisely, but for standard users it can be dangerous if they don’t really know what they are doing with.
So what would be your choice in hardware to achieve this kind of automation and keep our home safe ? (I mean sending orders to heaters through pilot wire. FR, like NZ use 240V ).
Let’s take a step back here.
There are many Home Automation products that have neither a fuse or strain relief.
For example the Z-Wave 10A relay module at the bottom of this post.
At the end of the day it’s down to the person installing a product to understand how it should be installed and any local requirements for doing so.
Please remember that also ‘local’ requirements / rules vary across the globe.
I don’t understand why there is a requirement for a fuse ? It’s no different to an digital time plug that we all used before the days of WiFi enabled sockets (which by the way don’t have a fuse either)
Lets get back to @wouf and the original install. @wouf can you provide a diagram it’s still unclear to me what’s connected to the sonoff and what goes directly to the heater from the ‘line in’
