The DC in is on the right side..
The AC out is on the left side.
I've heard those little transformers are the same ones used in the 400w GTIs.
They just add more when they want more power.?.
There are two automobile type fuses on the +PV DC input.
And, inside the shipping box were two glass type fuses with solder tails.?.
It seems that Power Jack makes these units without any regard to RFI.
This unit transmits very loud RFI noise on the AM band. Jamming all
most all the local stations. I understand this is a problem common
to much of the PJ inverter product line.
The Power Jack 3500 Watt inverter - buyers beware!