Apex 300 - UPS on 30 and 50 amp plugs

Product Discussion BLUETTI Apex & AC Series
1

I’m trying to understand the UPS features of my new Apex 300. North American 120/240VAC split phase.

For the four NEMA 5-20R on the front, the manual states “When the output voltage switches to the 240V, the 20A sockets [on the left] has a difference of 0ms and [on the right two sockets] 20ms. When the output voltage switches to 120V, both are 20ms”

My question: what about the other two output sockets - the Apex has a NEMA 14-50R (120/240V) and a NEMA TT-30R (120V @ 30A). Do these operate in 0ms or 20ms UPS mode?

My goal is to have an “always online” UPS where the inverter is always running and use the NEMA 14-50R socket to power a transfer switch.

2

I think when connected to grid power in 120 you are in pass through mode and when the grid is lost you switch over to the battery, that’s why its 20ms. When in 240 mode the 2 outlets on the left are fed exclusively from the battery through the inverter, that’s why its 0ms, because its already on battery. That tells me that if you are in 240 mode and the inverter is on, the 2 outlets on the side are on as well. I would love to hear from others because I’m a little fuzzy on this myself.