It really shouldn't matter - the wires will essentially go straight to a
transformer in the rectifier box, perhaps through a fuse and/or a switch.
The secondary side of the transformer will have some diodes to "rectify" the
AC into DC. Part of their function ensures that the output polarity is
correct. There will usually be some capacitors there to smooth out the
output voltage, and maybe a regulator, if your fridge needs a narrow voltage
range (like a computer does...).

But, if you want to be correct, the long blade goes to the "neutral" side of
the mains, and the short blade goes to the "hot" side, per NEMA guidelines.

It would be very advisable to install anything directly connected to the AC
panel on a protected circuit, meaning on the downside of an existing or new
breaker. Don't just wire to the main distribution busses - if you were to
get a short in the rectifier unit, or in the cable, you would likely have no
overcurrent protection and you'd probably get a fire.

Good luck.
Dennis

"GBM" wrote in message
...
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