As with any card, I think it would probably depend on the result of the inquiry, and what your starting point is. I don't think there's a set number, with NFCU or any other card.
If you get a CLI, any CLI, then turn around a day later and ask again, I think it's likely the 2nd request would be declined. The frequency of the CLI would be a factor. Also, keep in mind that each CLI could result in a HP. And at some point, you'll reach the maximum allowable.
