Does anyone have any ideas on how to stop arc flashes on a transformer without short circuiting it? We've thought of enclosing it in a grounded housing where the air vents are located on the bottom allowing the flash to blow out the top. Currently the air vents are located on the side allowing a possible arc to permiate through the spaces.

Am I missing something? Won't tripping the primary protective device stop the arc?

Depending on your system configuration you could implement a transformer differential scheme. This would clear a fault on the primary or secondary windings much quicker than typical overcurrent devices.

What I'm looking at is ABB's REA 101

WHat type of transformer (ratings)are you talking about? What is the OCPD on the primary?

I just looked up this ABB part. No answer to your question. But I have to read about this part more. It seems interesting. I wonder how much it cost.

that's an issue with some dry type transformer
they are vented between elbow and eye level that is kind of dangerous

some other model are at bottom and top of tranformer door those are more secure in case of a flash if you are near by