@OldSurferDude yes, you are correct. this sensor is capable of 50A continuous, which safely I would make it working at 40A max., but for such an important load as in your case I would go for a beefier one, like the ACS75x, 77x, but at this point I would also change the node's form factor for space and insulation reasons.
On my application on the RV I have a max. curr. of 13A running on a AWG14-16 cable (European rules for RVs), so I did not ask myself too many questions beside, of course, safety.
About the signal, it will be a sinusoidal signal swinging around Vcc/2.
Vcc can be easily measured internally on the ATmega328. On all my DC sensors I measure Vcc at every loop, just before measuring the ADCs.
Honestly, when the space is not an issue like in my RV, I would rather use a ring core current transformer, and I would get rid of noise, response time, power dissipation, but over all no need to cut any cable.
Long story short, it has been a nice experiment and I used it for 6 months, and then I switched back to my RF-NANO based RS485-Modbus - Mysensors bridge connected to an off-the shelf power analyzer.
Just for fun I attach a pic of my 12Vdc sensors installed on my RV. Forgive me for the spaghetti wiring on the right side, but this is an area that needs improvement.
