How Dry Type transformers can be ground?

There are new requirements for grounding dry-type transformer enclosures.  Connections for equipment grounding conductors and supply-side bonding jumpers must now be made at a terminal bar that is mounted inside the transformer enclosure.

The terminal bar must be bonded to the enclosure and cannot be installed on or over any vented portion of the enclosure. 

There is an exception that permits the grounding and bonding connections for dry-type transformers with wire-type leads to be made with pressure connectors, fasteners,.

When a terminal bar is mounted to the transformer enclosure, it is important that the terminal bar or the conductors connected to it do not block the vents that provide air flow around the transformer coils.

A terminal bar will ensure that all of the grounding and bonding connections made at the transformer have a common point and do not depend on the metal transformer enclosure to tie the connections together.