I purchased extra sensors to monitor a dedicated circuit. I placed the sensors on the circuit and plugged it into the middle port, the solar port. I then went to the settings on the Sense app and enabled the solar sensor thinking this is what I needed to do to activate the sensors.
I then read up on monitoring a dedicated circuit and noticed that I needed to enable it and not the Solar. I tried going back to the app and disabling the solar so I can activate the Dedicated Circuit Monitoring but it doesn’t give me that option.
Any suggestions on what I must do the disable Solar and enable Dedicated Circuit Monitoring?
If I may ask you a question as I guess you have been successful in monitoring a dedicated circuit(s).
I have read that you can monitor two circuits, two 120V or just one 240V circuit if its on a natural bus. You can also monitor two 240V circuits if they are not on a neutral bus.
I wish to monitor my hot water tank. It’s not on a natural bus as far as I can tell. There are three leads on the cable coming into the panel from the hot water tank. One a ground and the other two into their own 30Amp breaker.
If I can monitor the hot water tank on a single sensor then I could also monitor my cook top which also has the same configuration as the hot water tank.
Not sure if you can offer any advice but any thoughts would be very helpful.
My thoughts - I think you can monitor a single hot wire (red of black) on a 240V circuit so you can squeeze 2 x 240V monitoring even if there is a neutral, as long as you are willing to put up with a little inaccuracy. The range top and the water heater both probably have some 120V electronics inside, usually for any digital controls. The electronics usually don’t use much power relative to the heating element, though they are always on. Also, if your water heater includes an integrated recirculation pump that can be a bigger 120V load. When you put the Flex sensor on only one of the two hot wires, you either get the one that feeds the extra 120V loads, or you get the one without. When you use the Flex sensors in single wire mode (measuring 2 devices using DCM), Sense does this by multiplying the current by 2, so your error with a single wire approach will be 2x the power usage of the 120V section of the device.
ps: I use one of my Flex sensors on a 240V “device” (a floor heater subpanel) with a neutral wire and one load on 120V only and it seems to work just fine.
I think I am experiencing this with my two 240 mini-splits. I had incorrectly wired them where I fed both wires through the CT clamp, one backwards, I swear because I read that on one of the sense install guides. Obviously I’m wrong, so I adjusted it and removed one of the wires from each CT. However, I now get times when the mini splits are on, but Sense shows 0w usage. My guess is that the circulator fan is 120v and is using electricity from the leg I’m not monitoring, and when I see electricity usage, it’s when the 240 is being used by the compressor or whatnot. Not sure if I’m correct anymore, hence why that’s my theory.
Sounds like a good theory. That’s the challenge with using DCM in single CT 240V mode, when there is some 120V load living in the mix. You either tap the leg without the120V load and miss some, or hit the leg with the 120V load and get and get double the 120V load. Many 240V devices have some 120V - ovens, dryers, most HVAC (power supply for the control boards and perhaps a fan).
