If this helps I ran some comparable trains and noted the current draw. This is with Legacy/TMCC but I suspect the amperage using DCC would be close. The transformer used is a ZW-L, output voltage reading of 17V at the transformer. The amperage is as displayed on the ZW-L ammeters. The track has a max 1% grade so this did not determine the effect of significant grades. The train is nine American Models Budd cars, two with LED lighting. So it is the weight of 9 cars, the current draw of 7 incandescent illuminated cars.
First up was an ES44Ac Legacy engine, smoke on high. Current draw was 3A, a bit less than I expected.
I did not have a TMCC AM Pacific handy so I used an American Models Northern equipped with TMCC. The amperage was 3.2A.
I then decided to go to the high end of a single engine and used the Big Boy. This is basically an oversize S gauge engine with O gauge motors and electronics. Amperage read 3.4A.
I did not run the train with a double headed AM diesel set. I have one with scale wheels. I know that the current draw of one AM diesel at stall is just under 2A and that one AM diesel will not pull these 9 cars up a 2.5% grade. Base on that I estimate that a double headed AM PA/PA set would draw about 3.6A pulling this train. This suggests a 3A DCC system will run one short passenger train but not a longer one nor will it run two trains. In fact any two of these trains running at the same time would draw a minimum of 6A.
Were it my layout I would get a 10A booster to allow for multi train operation.
