On our recent IoT Podcast, we took a question that Andrew left on our IoT Voicemail Hotline. Andrew had been using a device from SmartDry to know when his laundry was dry. Unfortunately, SmartDry announced earlier in June that it would be shutting down. So Andrew wants to know what that means for his device.
Unfortunately, this is another one of those sad situations where purchased hardware will cease to work. SmartDry did provide its customers a heads up, telling them that they have a few months before that happens. After September 30th, the SmartDry connected sensor will be a brick.
However, we do have a solution to suggest and it’s quite inexpensive. The folks at Shelly have a Wi-Fi relay switch that can monitor the power draw of an outlet. And it can provide notifications from the Shelly app based on that power draw.
The product is called the Shelly 1PM-UL and it costs $21.50. It has an embedded web server so you can view real-time and historical power usage, and it can handle either 110V or 240V AC power.
That’s key in this use case as most clothes dryers use 240V. If a dryer, or any other appliance, works on 110V, a connected smart outlet with power monitoring would suffice. I can, for example, use an Eve Energy plug with 110V appliances to measure the power draw and either send notifications or trigger other events based on that data.
The Shelly 1PM-UL isn’t exactly a “plug and play” type of device. You can tell that just by looking at it. It has to be hard-wired to the dryer outlet. But as long as you turn the breaker off when doing the wiring, it’s a safe and simple process. Essentially, the relay fits between the incoming power to the dryer and the dryer outlet.
Once wired up, you can use the Shelly app to send you a notification when the dryer status moves from “on” to “off”, for example. Or, if you want to be very precise, you could gather data from the dryer’s power draw for a cycle or two. Then you could create your notification to be fired off when the circuit drops from a set voltage to a lower voltage, or simply zero. However you set it up, this relay could supplant the old SmartDry sensor. Or you could add it to your dryer even if you never had a SmartDry device in the first place.
To hear Andrew’s question, as well as our discussion in full, tune in to the IoT Podcast below:
Another great use for a Shelly! The Shelly relays are extremely flexible. I use them for all kinds of automations around the house – garage doors, fireplace, light switches, etc. And they support standard IoT protocols like MQTT which make them very interoperable with smart home hubs and other smart home gear.
Just a heads-up (i.e. warning) about trying this:
The Shelly 1PM is only rated for 16 Amps. I just check my 240V dryer, and it needs 25 Amps (and the manual says to use a 30A circuit). So the Shelly is woefully underpowered for most electric dryers.
Always check your specs before installing something on your power lines.
If your only goal is to monitor the power on a dryer (and not switch it off), you’d be better off using Shelly EM and a current transformer.
Yeah this is bad advice. The Shelly is rated for 240v most likely to handle non US voltages but those are typically at far lower amperage that a US dryer operates at. If you want to monitor a dryer, us a Shelly EM and just clamp around one leg of the plug.