ACS-64 technical description - Trains Magazine

From a copy of the ACS64 Familiarization and Orientation manual:

No weight given for the main transformer (which is between the trucks) but it is p/n A2V00002028490, and using that information might get you physical parameters.

It includes two 480VAC dedicated HEP transformers.

The two stepdown voltages for different catenary voltages are given as 1957 VAC and 1878 VAC, "depending on the catenary input".  

"Voltage switching Is Done Electronically By The Primary Side Tap Changer"

There is a modular "HEP Rack" (A2V00002106069) which produces 480 VAC "to locomotive as a secondary source of electricity ... it can be used during full catenary line operation".  (This to me indicates that the inverter modules do not perform any HEP duty...)

The traction converters are A2V00002028491.  The nominal DC link voltage is 3600 V nominal.  Nothing is said about having HEP-compatible outputs in these converters.