For the optional calculation 220.80 it is asking for the name plate rating of the appliance.
section 250.54 is asking for the name plate rating of the dryer or 5000W whichever is greater.
so my question is, does the 220.54 apply to the optional calculation or we take the name plate even though it may be less than 5000?

Thank you

I think you just take the nameplate if the dryer is present on an optional calc. That is what it says.

5kw is a good guess if it isn't available and also used for a minimum in that multiple dryer table in 220.54.

what if the name plate is 4KW, do take the minimum 5kw required per 220.54 or you take the name plate as called for per 220.82?

I looked at the examples in the annex D of my handbook but all of the dryers were at 5kw or higher.

Since the 220.80 applies to a totally different method personally i think we need to take the name plate and disregard the requirement of 220.54. But I would like to hear other comments.

As I said, I think the 5K minimum is just used when you are using that table. They don't want you to cherry pick a few low ones when you are sizing a multiple dryer service.