Does R410a refrigerant sweat on outside AC unit?

With any refrigeration unit - doesn't matter whether it's an unit with R410a, R22, R12, R134, etc. - you have a rapid exchange of heat taking place between the refrigerant and the ambient air passing through the fins. Condensation will result as a byproduct of this process. Don't be freaked out if you see a bit of water - that's quite normal.