According to an Airbus technical representative, unless there is a ban in the FCOM for your specific aircraft (probably through an OEB), there is no restriction to switching on the fuel pumps during refueling. It does not affect the rate at which fuel is uplifted. It must also be remembered that the A320 centre tank fuel pumps will only run when required when in Auto mode, and sitting on the ground with the engines off, these pumps will be de-energized.
Edited to clarify a badly made point.
Last edited by J.O.; 29th Jul 2009 at 11:02.