Well if you spelled that correctly, it's throwing Google for a loss.
In general, I have YET to come across any kind of magic box whole house "energy saver" that was not a scam of one sort or another. So to my mind, regardless of the details there is a 99.9999999999999% chance it's a scam. I'm leaving a very tiny region of possibility there though, stranger things have happened...
But if by chance this is the 0.0000000000001% chance device that actually is a whole house energy saver, then it's remotely possible that the part that connects ahead of the main will be compliant with exception 4:
(4) Instrument transformers (current and voltage), impedance
shunts, load management devices, surge arresters,
and Type 1 surge-protective devices.
But be VERY careful here, just because they SAY it is does not mean they aren't stretching the truth. In other words if it IS a scam device, then why believe ANYTHING they say? However if you are a licensed electrician and YOU install it, YOU are taking responsibility for it and if it burns down the house because it failed and could not be disconnected by opening the main service disconnect, the insurance adjuster will be calling YOU.
Plus, in spite of having zero details on what it is, I fail to see why it would need to be AHEAD of the main service disconnect. If it does <cough> work, it would <cough> work in either position.
That kind of requirement almost smacks of one of the ever elusive "makes your meter spin backward" or "retards your meter" devices. Contrary to popular belief they do exist and can be bought over the internet from Asia, but they are HIGHLY illegal and you could be spending time in jail just for connecting it.
