Shelly Pro 3EM Switch Add-On | Add-On Pro 3EM Dry Contacts DIN Rail Mounting | Home Automation | iOS Android app | No Hub Required | Solar Panels | Wind Turbines

This device is great for keeping track of the quality of your power. We were having brownouts and electrical appliances behaving oddly. Suspected there was too much variation in the voltage but couldn't verify it so we had this device installed and it showed one phase running noticeably lower than the other and more importantly it dropped outside the allowed specification for 115V power in the US on several occasions and could be easily seen from the built in webserver.

I used this to pair with my solar installation. I found some open source software that I modified to emulate a Fronius Smart Meter so it polls this Shelly Pro 3EM to get total consumption and that data is stored alongside my production data. It was very easy to install, and the API/etc was very easy to work with to get the data I needed. I was impressed.

Works great. Shelly is good stuff. Find it on sale if you can!

Installation is easy, login is a little complicated, and so everything is fine

If you have Airbnb this is a must. You can control the guests’ energy consumption and more! I recommend.

Works great and is one of the only that offers local API. A function missed by others taking advance of your data

Don't waste your money on this. I checked the 3EM readings against a clamp meter and they weren't even close to being correct. At first I thought I hooked it up wrong but it was wired exactly per the directions. It was reading the voltage correct but way off on the amperage. I got frustrated and just returned it.

BUYER BEWARE!!!I bought this to measure power usage in my home. The advertisements claim it can measure up to 120 amps per channel but Shelly technical support states the most this can measure is 90 amps per channel.