The Magnetic Insulation node is the default exterior boundary condition for the Rotating Machinery, Magnetic interface. It adds a boundary condition that, on boundaries with magnetic vector potential (Ampère’s Law domains) sets the tangential components of the magnetic potential to zero at the boundary n × A = 0. On exterior boundaries with magnetic scalar potential (Magnetic Flux Conservation domains) it sets the normal component of the magnetic flux density to zero n ⋅ B = 0.

For the magnetic vector potential, Magnetic insulation is a special case of the magnetic potential boundary condition that sets the tangential component of the magnetic potential to zero and can be used for the modeling of a lossless metallic surface, for example, a ground plane or as a symmetry type boundary condition. The Magnetic Insulation node can also be applied on interior boundaries in vector potential domains. For more details on this, see also the corresponding documentation section in the Magnetic Fields interface on Magnetic Insulation.