this post was submitted on 16 Mar 2024
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I've got a couple of Zigbee plugs, all work well, except one I use for the washing machine. It randomly turns off. When I check the history in HA, it just says that it turns off, no source. My guess is that it trips, ie temporarily exceeds 10A. The plugs are rated 10A from Aliexpress.

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[–] Magister@lemmy.world 8 points 7 months ago (1 children)

I buy hundreds of stuff on AE, but I'll never buy something that plugs on AC, it's all weak and not tested. You play with fire.

[–] avidamoeba@lemmy.ca 3 points 7 months ago

I'm with this. There's a huge variety in the quality of electronics components that change with cost. And relays are one of those things that can get really shitty with cost and the good ones aren't cheap. Running wall power through shit relays can start fires. So if it plugs in the wall, it's gotta have a western brand and UL/ETL/MET logo on it.

[–] solidgrue@lemmy.world 3 points 7 months ago* (last edited 7 months ago) (1 children)

Edit: derp, I didn't read all the words. Yes, you're overdrawing your smart plug with inrush current fron a large inductive load. Look for a smart plug rated for at least 20A. It'll be safe enough to use on a 15A circuit because the breaker will be the limiting factor instead if the plug.

~~Check the amperage and wattage rating on that plug. Heavily inductive and some resistive loads can draw a large "inrush" current during startup that can briefly exceed the capacity of some smart receptacles. Chances are it's rated for 10A resistive load, and a washer (which is an inductive loadl can briefly exceed that.~~

For example: halogen lights. A halogen light tube like you'd use in floodlights or those old floor-standing torchiere are tyoically rated fo 150 to 300W. That rating is derived from the bulb's filament when it is up to ita operating temperature, which is something like 1000°C or more. A hot filament has a higher resistance than that same filament when it's cold, so that 300W element might briefly draw over 600W instantaneous load while it's coming up to temperature, briefly drawing potentially more than 15A at 120V. It doesn't pop your breaker because they have a sort of time delay that can accommodate these brief, large inrush currents. Electric motors in pumps and drives have a similar effect, but that's more from their inductance/capacitance as they spin up, rather than a change in their resistance. Their "apparent resistance" is actually AC inductance, which can draw significantly more amperage when the motor is not spinning at its designed operating speed. Same thing for compressors like in air conditioners, fridges and ice makers.

Most ZigBee smart switches and receptacles are rated for 10A at 120V, or total 600W continuous load. They're designed to handle smaller inrush currents from loads like incandescent bulbs, LEDs, and small electrics. They're generally not rated for things like halogen bulbs or large motors.

Washing machines are an interesting case because they employ several motors to drive the agitator (or drum), the spin cycle and the drain pump. They have a highly dynamic cureeebt draw that depends on both startup inrush, but also on the torque demanded for varying cycles. A heavy load if jeans or towels can draw significantly more power to agitate and spin dry than a lught load of bed linens or delicates.

~~I bet~~ your smart plug is rated for 600W, and probably says not to use on halogen bulbs. (Most do.) If so, its also not going to be suitable for your washer for substantially the same reason: peak draw exceeds its capacity.

For higher draw applications, you'll need to look for a 20A or 30A rated smart switch. They're available on AliExpress at least, and possibly Amazon as well. I can't recommend any for you because I don't use them, myself. Look for ones that are designed for window or wall Air Conditioning units.

Anyway, you're not likely to be able to solve your problem with your current kit. It'll have to be an upgrade or a rethink.

Good luck!

[–] ArbiterXero@lemmy.world 1 points 7 months ago (1 children)

10A at 120v is 1200w, 15a is 1800w.

Right idea, you just forgot to “carry the one”

[–] solidgrue@lemmy.world 2 points 7 months ago

By the math you are correct. I blew out some switches that were 10A, 120VAC peak, but somehow only rated for 600W continuous, resistive. Amazon doesn't sell them anymore, but it would be printed on the housing if that's the case. That's why I was saying to look.

My switches might have been the "no neutral" variety, though those are a special kind of janky.

[–] ThePantser@lemmy.world 3 points 7 months ago

If it is a power tracking one you should be able to see if it's being overloaded. Unplug the washer and see if it still turns off if it does then something is turning it off. I really trust the sonoff ones that I flash with tasmota, they are WiFi but they are rock solid and offline. They make zigbee ones too. The sonoff one on my all in one washer never has had a problem.

[–] AA5B@lemmy.world 1 points 7 months ago* (last edited 7 months ago)

I don’t know if it’s true for cheap ones off Ali Express, but I always look for “appliance” plugs, as that will be easily searchable. Usually it means a 20a (in US) rated relay.

Actually, in reference to the other poster’s discussion about halogen lights, I did the same there. I have a set of halogen lights that’s pretty much at the threshold for common smart switches/receptacles/plugs, so used an “appliance switch” with a 20a rated relay, so I never head to worry about it. It’s really not worth going cheap for things that plug in

[–] ScottE@lemm.ee 1 points 7 months ago

I have not encountered this with my Sonoff Zigbee plugs, for whatever that is worth (US split phase). I also haven't put large appliance loads on them.

[–] MangoPenguin@lemmy.blahaj.zone 1 points 7 months ago

Unless they have current sensing with a build in interrupt for overcurrent, they're not going to shut off when exceeding 10A.

[–] teawrecks@sopuli.xyz -1 points 7 months ago (2 children)

Assuming this is in the US, aren't washing machines normally on a 20A circuit? Or even 240V?

[–] IrateAnteater@sh.itjust.works 7 points 7 months ago

Assuming my setup is typical, the dryer is on a 240V circuit. The washing machine is on a 15A 120V circuit.

[–] sylverstream@lemmy.nz 2 points 7 months ago

I'm in NZ, 220V.