My central a/c unit is not draining enough water, therefore condensation is building up on the bottom of the handler. What needs to be done to correct this.
A/C man said a larger duct is necessary from the return to the handler??

Are you meaning condensation on the outside of the air handler case or in the overflow catch pan below the unit? Or do you mean inside the unit down near or below the filter? Is the condensate drain restricted or clogged? Is the filter dirty or wet? Is the system cooling the house like it should? No ice visible on the air handler? Is this unit in the attic or where?

Need some more details.

EPM