Separation of busbars from the functional units:

Protection against contact with live parts upstream from outgoing devices.

Limitation of risk of propagation of short-circuit currents between functional units and busbars (electric arcs or solid bodies).

TWO TYPES OF FORM 2 SEPARATIONS AS SPECIFIED BY I.S. EN 60439-1

FORM 2A:

Terminals for external conductors not separated from the busbars. Functional units are separated from the busbars, but not the terminals for external conductors.

FORM 2B:

Terminals for external conductors separated from the busbars. Functional units and terminals for external are separated from the busbars.