AP9566 - Can it be plugged into a NEMA L6-20R Plug on Mains Power?

[Anonymous user]

Let me start by saying I am not an Electrician and the following was verified by an Electrician.

We have an AP9566 that we want to plug into an NEMA L6-20R 208 Volt wall plug that is on Mains Power, Single Phase.

We have confirmed on the NEMA L6-20R wall plug that we are seeing 208 volts when monitoring X and Y sockets, and 120 when monitoring X to Ground or Y to Ground.

We plug the https://showbox.bio/ https://tutuapp.uno/ https://vidmate.cool/ AP9566 into the L6-20R wall plug, and we do not see 208 volts on the X and Y connectors of the C13 plug on the AP9566.

If we take one side of the C13 connector sockets and check the voltage to Ground, we see 120, and on the other C13 plug connector we see 50 Volts.

So, here are my questions.

1- can the AP9566 be connected directly to Mains Power or does must it be plugged into a UPS.

2- if the AP9566 can be connected to Mains Power, what voltages should show on the C13 Plug.