Are there any solutions to use Iotawatt to monitor if there is voltage on the input mains to see if power has returned from an outage? I am planning to connect a generator to backfeed my panel and am looking for solutions to remotely check incoming line voltage before the main breaker while it is off.
I see the only option in the store is to use the 9v AC transformer block connected to an outlet. Has anyone figured if there is a way to do this via direct wire to the main input lugs?
If I understand your intentions, you are bringing in your generator feed either directly or through a large plug like a dryer plug, and switching off your main breaker. You probably know this is more than frowned upon by everyone associated with the other side of your main breaker, so I won’t belabor that point.
Of equal concern is connecting anything to the unprotected side of your service, and anything at line voltage to the IoTaWatt. It’s just not safe.
I sympathize with you on the cost of both buying and having installed a mains transfer switch. What I have done is wire in a per-circuit transfer switch that accepts a generator plug and has eight 15A 120V switches and one 30A 240V switch. They come in various capacities with different number of circuits. It is UL approved and is easily installed. When I am on generator, there are some obvious circuits that are not on generator to indicate when power is restored.
Same for me… When the HVAC starts running, I know external power has been restored. 
It is a little easier for me as I have two panels. The first one is outside, and feeds only 240VAC loads, including the subpanel in the garage. So, it is trivial to turn off that one breaker to isolate the subpanel from the external power. I can then supply generator power to just the subpanel to run all of the 120VAC loads. This has worked great during the hurricanes we get here in North Carolina.
Thanks for the reply. Agreed, I am aware of the issues with backfeeding to the street, I was planning on going with an interlock kit to address that:
https://www.interlockkit.com/
So the remaining issue is just figuring out how to easily detect a return to service, other than looking out the window at the neighbors…
Also, am I correct in assuming that the mains CT’s will not detect anything when the breaker is off since there is no draw?
Yes, that’s correct.
Thanks! Out of curiosity, what does that per circuit transfer switch look like? Anything online you can link?
The sub panel above is fed from the 240V transfer, so I have 16 120V circuits on generator. I could put smaller 240V loads (heatpump) on the branch panel. I have a 6.5kW diesel generator.
[quote=“kernelpanic, post:6, topic:2818, full:true”]Thanks. I also found this alarm which does exactly what I was thinking:
I wonder if it’s possible for Iotawatt to incorporate this kind of sensor that wraps around the input mains? It seems there is a gap in the market where there is no smart version of this, only audible alarm.
