I bought a Nedis WIFIP110 plug and flashed tasmota on it. Works like a charm on HA.
But I’m curious about the safety.
Because I have connected it to a washing machine
Plug specs:
10A max 2500W
Washing machine 2300W max usage
Power outlet 230v
So for Wattage it should be ok.
On 230v the washing machine can pull 2300W (10A) (at least that’s what the specs tell)
So amperage is on it’s limit. I just ran a washing program and it works fine.
Can I assume it’s fine?
Most plugs have a safety feature that turns of when above the recommended power draw. (which didn’t happen) But I don’t know if this one has it and if it’s still usable when I flashed it with tasmota. (is it software or hardware based?)
That plug specification is for a resistive load. The problem is a that a washing machine is not a resistive load, it has a motor in it. This may draw five times it’s VA rating on start up.
That’s a power monitoring plug. What is the measured power draw?
The power draw is not accurate I think. (still have to callibrate it correctly). It measured on it’s max 12.1amp with a wattage of 2115W. I have a kill-a-watt laying here So I will calibrate it.
But do I need to be afraid of fire or anything like that?
And yes it is a power hungry washing machine (about 12 years old) The P1 meter also gives around 2500w when the washing machine is heating (That’s for the whole house normal around 300W). So around 2000w while heating is normal for this washing machine
As Tom says belowabove it’s pretty close, you haven’t said if the unit has a VA rating but I don’t think your switch needs calibrating 2115 W is probably roundabout the actual load but as Tom says it may be an inductive load
so 12.1 amp * 230 v (you have checked what your line voltage is ??? mine’s supposed to be 240 v but I’m actually fed 254 v (so strictly speaking above regulation and therfore illegal))
but 12.1 * 230 = 2783 VA but W = 2115 so your power factor is 2115/2783 or 0.76 or 49 degrees (WOW that’s a really inductive load !)
If you can’t find a VA rating rather than getting a new switch, consider getting a new washing machine.
Inductive loads really punish switchgear and 12.1 amps inductive is WAAAAY worse than 10 amps resistive.
It’s an expensive option I know but I wouldn’t run that machine through that switch at all.
You’ll be fine running it direct (but you’ll get no info).
Ok. That’s something that goes a bit over my head I read the labels and assumed it was fine I think the AMP are a bit off because of the calibration. So I don’t think 12 is correct. These are the labels from the washing machine and the plug.
(voltage fed is 231 so pretty much correct measured with a kill-a-watt)
I run a 3kW immersion off a Shelly 1PM with no issues. Internal temperature sensor approaches 80°C after 35 minutes running but has never tripped its protection circuit.
So what have you got that you trust to measure current ?
Coonect your plug in series with that and (say) an LED bulb (low current device) and then (say) a kettle (high current device) - compare.
The inductive load is only a problem if you try to switch it off whilst running though, surely? In steady state, it’s just the I²R heating to worry about I’d have thought?
It’s in a backbox, but that box doesn’t get more than warm.
But what if you get a spurious de-activation whilst on full load ?
And how many of those can you stand ? (basically just one has damaged the contacts)
It’s not safe.
But then I’m not the home automation device police. He asked if it’s safe and as an Electrical Engineer, I’m advising him that it’s not.
It ain’t easy. No one will pay up if your house is burnt down (hopefully without injuring anyone) and you say “I’ve asked in an Internet forum and they said Yes, you can.”
Many of these cheaper devices are nowadays built in China, and even if they should have a non-fake CE and/or VDE sign, they’re mostly electrically unsafe. And often not for use in wet rooms (like a cellar, bath room or the like).
I’ve seen a lot of these devices, even with legal CE, with absolute unsafe and crappy soldering inside, unsafe connectors, under-dimensioned electronic parts, PCBs with no or insufficient electrical separation, no safety measures at all (like fuses or thermal overheat sensors), and much more. Believe me, I have 16A/230V rated switch plugs with “good papers” here and I wouldn’t even trust these to just measure energy consumption on my (also) 2.3kW washing machine. At least not unobserved or for a longer time. Sad but true.
If you are an EE, you might open up such a device and decide for yourself if you trust it—because you know enough about it.
Maybe I’m over-cautious, but I want to live a while longer, and am responsible for my children, too.
So in any case, try to find reliable reports on such devices, ask an EE or electrician (if you aren’t one yourself), and in any case grossly over-dimension them. (So better go for a 16A one instead of a 10A one!)
Better to be an ‘over-cautious’ user than an ‘under-cautious’ one any day !
And just to be flippant, I’ve met lots of over cautious engineers that ‘slightly regret’ some stuff and of those less cautious (that are still alive) a couple who have regretted their choices bitterly.
As Moonbase says (I paraphrase) “It’s not just ‘your’ life”.
Electrical loads don’t have identical characteristics.
An electric kettle is a resistive load. It converts electric energy to heat.
An electric motor is an inductive load. It converts electric energy to a magnetic field.
When turned on, the initial inrush of current is not the same for both types of loads. An inductive load’s initial current can be, momentarily, higher than normal. In addition, when turned off, the magnetic field it created now collapses and causes a momentary voltage spike.
The takeaway here is that an inductive load, compared to a resistive load, has a different “personality”. From the perspective of the device supplying it with electricity, I suppose that personality could be described as “unruly”. It initially takes more than you expected to give it and then gives back when you expected nothing in return.
This behavior places a greater “strain” on the controlling device. That’s why it’s important to know if the device is rated for inductive loads. For example, I have been using this X10 Heavy-duty Appliance Module to control my 1.5 HP (220V) pool pump for many years. Its spec sheet clearly indicates it can handle a 2 HP motor at 220V.
Time for a wifi enabled washing machine then So I won’t need a plug to let me know when the washing machine is done with it’s program. Thanks you all for your help and explenation. I removed it and will use it for something not so power hungry.
I read the labels and assumed it was fine 
