Adding an Amp Meter for Transformer

To measure the total current from each of two transformers, just follow for each transformer the instructions above for measuring the total current from one transformer.

When you are done, the only thing connected to each transformer's common terminals will be one terminal of the ammeter that measures that transformer's current.  The wire that formerly connected the transformers' commons together will have moved to connect the other terminals of the ammeters.  This node in the wiring will serve as the new layout common.  The transformers' outputs will still be in phase with each other.

Why do you have the transformers in phase?  For some purposes, it is better to have them out of phase.  What do you power with each transformer?