I purchased a rectifier that will provide 24V DC to our Refrig unit when at
dock ( It has an internal switch that disconnects the battery connection
automatically when on A/C power)

This unit came with a two blade plug on the A/C inlet. In other words, no
ground connection. The two blade plug has, as usual, one blade larger than
the other.

I could install a new outlet and plug the unit in, or I could connect it
directly to the A/C panel.

Question: How do I determine which wire (plug blade) goes where when
connecting into the shore power system? Or does it matter?

GBM