I was searching and found the internals appear to be the same for 120/240 on some of the models.

"Higher ratings of 100-277v, 50/60Hz, and 20 amps require appropriate country specific cord set and receptacle, and is NOT UL listed.  Internal electronics are the same. "

That was from this website, and they also have the manuals for download.

https://www.powermeterstore.ca/p5674/eed_watts_up_net.php