I agree that the branch circuit rating is 20amp for the reasons that Jerry P cited.

However, I disagree that a GFCI is required. Wendell is right that a GFCI is not required, but is wrong for his reasoning. Let's read the cited code exception again:

A single receptacle or duplex receptacle for two appliances located within dedicated space for each appliance that in normal use is not easily moved from one place to another, and that is cord- and plug-connected.

Let's break down the code, like this:

a) does the branch circuit have a single recpetacle or duplex receptacle?
Yes...the question says duplex.

b) Are two appliances located within a dedicated space?
no...cuz the question only says sump pump...however, the code exception does not say you have to have two applicances...it says ...duplex receptacle FOR two appliances located within the dedicated space.

c) Is a sump pump easily moved in normal use?
I say no, although, I guess the really small ones are.

d) Is the sump pump cord and plug?

Yes. It is.

So I interpret the code to say that a GFCI is not needed in this example question.

Anyone else agree/disagree?

Rob