Measuring power draw of high current devices

I’d like to be able to measure whether my washer and dryer are running and when they stop.

I’ve seen people do this with vibration/sound sensors but I think I’d prefer to do it by measuring current draw.

I’m guessing some of the z-wave smart plugs you can get would not be rated for the current draw of high-powered appliances?

What’s the best thing to use? I’m in the UK so needs to be something that works with our plugs.

Are you looking for a commercial product or a DIY solution? Are you willing to build something yourself?

I guess I was hoping to buy something. But if there’s nothing available then I could be convinced into a project if there were decent instructions :slight_smile:

Sonoff POW

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Thanks! How does that hook into HA? I can’t see a Sonoff component.

You flash it with a custom firmware and use a mqtt broker. It’s very simple.

Great will do some searching. I’m sure there must be some threads with the detail :slight_smile:

Search for Espurna on GitHub. There is a small tutorial for Home Assistant I think.

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Awesome thanks mate!

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Electrical safety is a common topic this week. I personally do not trust cheap chinese hardware for anything above 5A ( 1000W at 220V ), that’s my completely arbitrary threshold.

To measure power consumption I’d use an induction coil, so that the cheap device is never stressed by the full load. I’m thinking about connecting one of these https://www.aliexpress.com/item/AC-Digital-Multifunction-Meter-Watt-Volt-Power-Amp-Current-Test-Module-PZEM-004T/32802299444.html to an ESP8266 that reads the serial data and publish the consumption over MQTT.

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Hmmmm you make a good point

https://www.amazon.co.uk/dp/B00XUSDHXQ/ref=psdc_1938287031_t3_B01708RIYU will do 3 devices, but it’s £95

At least I think it can do 3 different devices…

Could you use something like that https://m.aliexpress.com/item/32850730914.html ?
With https://home-assistant.io/components/xiaomi_aqara/
It’s around £10 per plug but you need the Xiaomi gateway

Yes maybe. But @namadori made a good point about perhaps not wanting high current devices running through a plug made in China for $1. If it was for a lamp then ok.

The Xiaomi plug is rated only 10A, the Sonoff at least is 16A.

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Both though as you say are cheap. Would you use the sonoff?

I’m tempted to go for a TP-Link HS110. Lot’s of threads of people using them for washer/dryer monitoring and at least it’s a ‘known’ brand.

https://www.amazon.co.uk/dp/B01IBUF48S?ref=emc_b_5_t

Hmmm I"m not sure about these plugin types or the socket replacement types TBH

Before considering installing LightwaveRF power sockets you need to understand that despite being specified for 13 amps the specification requires the load to be resistive. This means if you are controlling a device with a motor i.e Hoover you may have a problem. The relay in these devices is really designed for controlling lighting as most other loads will have some sort of capacitive or inductive component. When inductance or capacitance is present in the load the 13 amp rating needs to be severely de-rated to the point that the switch is unusable for most non resistive medium power applications.

Hmm given washers/dryer have a motor that isn’t a resistive load the 13A rating should be de-rated significantly. I imagine this is true of the plug-in type energy monitors.

More and more I’m thinking these types of thing are really just for lighting and other low-power devices.

I use a WEMO for my washer.

My washing machine doesnt go above the Wattage supported by the WEMO (which I think is about 1800W).