#What smart plug with power monitoring do you recommend?

1 messages · Page 1 of 1 (latest)

forest hare
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What smart plug with power monitoring do you recommend? zigbee or wifi? I want know when my washing machine is done

carmine sand
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I’ve not had a lot of luck using smart plugs on my washing machine. They burn out after a little while.

I expect this has something to do with the current draw when the motor spins up exceeding the capacity of the plugs hardware.

I’m about to install a CT clamp on the line to my outlet to avoid this burnout.

somber marsh
# forest hare What smart plug with power monitoring do you recommend? zigbee or wifi? I want k...

as @carmine sand mentioned you don't want to use a smart plug that has a relay in it on a washing machine.

its because washing machines have an inductive load which causes the relay to arc.

you should also include the country you are in when asking for things like this as recommendation may change between them.

a CT clamp solution is a great option. or you can get something like this - https://www.shelly.com/products/shelly-pm-mini-gen3 and wire it inline. it doesnt have a relay so doesn't suffer from the arcing problem that switchable stuff has.

carmine sand
somber marsh
carmine sand
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Smaller load though, I suppose. Given the higher MTBF I’m seeing on those plugs.

Good to know!

somber marsh
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athom make a no relay smart plug for monitoring only UK VERSION HERE but they do them in a bunch of plug types for various countries. but they are limited to 10A which may be an issue for some appliances peak draw

carmine sand
somber marsh
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think there might be a tosmota version as well as an esphome version. i would go for the esphome but some people like tasmota

carmine sand
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You can flash esphome over top, I believe. If you’re into that sort of thing.

somber marsh
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ct clamp tracking is going to be more reliable long term though most likely

somber marsh
carmine sand
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That was a subtle pro-tasmota jab.

somber marsh
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the shelly device i linked above is great though and can be wired behind a socket easily for example

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i have some bulbs running tasmota but mostly a esphome enjoyer 🙂

inner topaz
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I am using a Shelly Plug (no S - the discontinued one with a 16A rating) for my washing machine. The washing machine's max is at 2200 W and the plug can take up to 3500 W - so there is a bit of wiggle room for inductive loads.

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Would recommend a CT clamp solution nevertheless.

grave prairie
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Unless you trigger the relay it shouldn't really matter, no?

somber marsh
grave prairie
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Have you had this happen? How does that look like?

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But to answer the question I'm using the cheapest tuya plugs I could find and after a firmware upgrade they just works fine for my fridge, dishwasher, washing machine, oven, etc.

somber marsh
# grave prairie Have you had this happen? How does that look like?

there's a lot of variable in the mix. some setups I am sure will be fine but a lot wont be. the inductive load messes with the magnetic field that controls the relay causes it to "flicker" and as the motor turns and pushes power during the flicker it causes arcing which generates a shitload of heat. sometimes its just burn marks inside from it sometimes it will fuse the relay open/closed. the heat can fuck with the other components too.

if the plastic of the device is not made from self extinguishing plastic then it can definetly set on fire from the heat/spark too.

somber marsh
# grave prairie But to answer the question I'm using the cheapest tuya plugs I could find and af...

oven is gunna be resistive load, the bigger issue with electric ovens is usually earth leakage but that's an RCD's job.

in general other appliances might have high loads but the load is split between resistive/inductive.
the heating elements are resistive which is largely fine but motors are inductive. depending on the size depends how much power they are push/pulling. and the fields they generate and how that reactions to the field from the relay. these fields can change a bit over time with oxidation of components and whatnot. so one day its fine and the next day it arcs like mad.
will some people do it and never have a problem? sure absolutely. but i am never gunna recommend someone do it. if you know and accept thats fine but the issue is when one sets on fire due to it and then you get mad reddit posts "PSA: XYZ company make unsafe products they set my kitchen on fire then told me I wasn't using it right" etc...

am i over simplying stuff a bit? probably
am i 100% correct on the specifics? probably not

forest hare
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@somber marshI live in Sweden if that changes anything

somber marsh
forest hare
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What about those p1-port for power meter. Can those tell me when the washing machine is done?

somber marsh
paper osprey
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The trick I've heard for washing machines is to use a vibration sensor. Alternately, yes, a clamp style load meter that can handle that load range would be safest.

river gazelle
patent wraith
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I have a circuit breaker monitoring setup, tells me the power usage of each circuit. I find that I was able to write an automation to use that to monitor washer/dryer quite effectively

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it uses clamp style in the panel

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it even works when my dryer goes into wrinkle-free mode

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another option.. someone makes a zwave device that can monitor an led, basically a light sensor. So you can tape it over the front of the dryer where the indicator light is

inner topaz
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Wrinkle-free electricity is called DC