Eddy currents in a planar shield

["emiliano.menghi@xxxxxxxxx"<emiliano.menghi@xxxxxxxxx>]

Hi everybody. 
I've to calculate the eddy currents induced in an alluminium planar shield.
The excitation is a three-phase current system.
The problem is the condition on the shield: Should i set the total current in the shield equal to zero or not (with the circuit property)?
I attach my femm file.

Thanks

Attachment: planar_shield.FEM
Description: Binary data