While bays have other names in Europe, see
http://www.electropedia.org/iev/iev.nsf/display?openform&iev...
I have researched this before and I have it in my electricity glossary. I'm quite sure "paño" is what a "bay" is called in LatAm, I just wasn't sure what the "conexión" part meant.

I found a document containing references to "paño de conexión de línea", "paño de conexión a la barra de alta tensión" and also "paño de conexión del transformador". Link for that document is here:
https://www.cne.cl/wp-content/uploads/2016/09/Res-Exenta-N-2...

This is consistent with the three main possibilities for these bays in a substation:

"According to the function, a distinction is made between:

Line switchgear bay – this connects the high voltage power line with the busbars.

Transformer switchgear bay – this switchgear bay connects the transformer with the busbars. Noteworthy is that the transformer is connected directly and not by means of a disconnector.

Coupler bay – this switchgear bay forms a flexible connection with the busbars."
https://electrical-engineering-portal.com/what-is-what-in-ou...

All the above include switchgears, so I deduce think that is what is meant by "conexión" here.

Here's a glossary entry from Chile regarding "paño":

"Paño
Conjunto de equipos que permite conectar una instalación eléctrica al sistema de transmisión, compuesto en general, por interruptores, desconectadores, transformadores de medida, pararrayos, trampas de onda, condensadores de acoplamiento, etc."
https://www.transelec.cl/glosario/#tab_content-p