Has anyone recently used a Shelly 1 Plus UL switch? I absolutly cannot get it to work, either in HA or the Shelly phone app. What I mean is that I can’t get voltage applied to the Shelly output terminals. I have the power supply hot connected to the terminal ‘L’, the power supply neutral connected to terminal ‘N’, load hot connected to terminal ‘O’ and load neutral connected to terminal ‘I’. I have it setup in both HA and the Shelly phone app and can switch the power button and hear the Shelly relay switch. However, when I measure voltage from terminal ‘O’ to terminal ‘I’, I get zero volts. I also have a Shelly Plus 2 PM that I have tested and it works as I expect with similar wiring. Just for grins I tested a Plus 1 UL with the load disconnected and get the same results.
That’s your problem right there. “I” means Input. You’re essentially shorting out load hot and load neutral.
This is a Shelly Plus 1 UL, which could be different than a Shelly Plus 1. It doesn’t matter at this point whether the load neutral or load hot is connected to terminal ‘I’. I measure zero volts either from ‘O’ to ‘I’ or ‘I’ to ‘O’. The diagram from a Shelly Plus 2 PM shows load hot connected to terminals ‘O1’ and ‘O2’ with the load then connected to source neutral. I have measured 120VAC between both O1 and source neutral and O2 vs. source neutral. The Plus 2 PM doesn’t have any ‘I’ terminals. Assuming consistency of design, labeling and production across the 2 products, terminal ‘O’ should have load hot.
as ShadowFist said, i is input, o is output (to the relay) you will not measure voltage across the relay, there is no neutral.
I just ran a test where I wired AC hot to the ‘I’ terminal and measured 120VAC from the ‘O’ terminal to source neutral when I toggled the switch on. However, that does not agree with the instructions included with the switch. I have also purchased a Plus 1 (not UL) for comparison.
The Shelly 2 is not a dry contact (aka potential free) switch, but the Shelly 1 is. You cannot simply try to copy the wiring of one and try to apply it to the other because they are fundamentally different.
I got this drawing from the instructions which come with the switch and clarified it for you. Are you saying you did not have this wiring diagram shown in your instructions?
In case the above is unclear. there is also this video which explains how to do it. However I would highly recommend you call in an electrician at this point and let him know it’s a dry contact - electricity is dangerous if you’re unsure what you’re doing.