IEC/CEI - Best practice for transitioning from exposed corridor cable trays to concealed classroom electrical installations?
Hi everyone,
I'm an electrical engineering student learning commercial electrical design according to IEC/CEI standards.
I'm looking for the typical construction details used in schools or office buildings.
Project configuration
\* No suspended ceiling (no false ceiling / no controsoffitto).
\* Main distribution runs in exposed cable trays (passerelle a vista) along the corridor.
\* Classrooms on both sides have fully concealed (flush-mounted) electrical installations.
I'm trying to understand how this transition is normally designed and built.
My questions
How do you normally transition from an exposed cable tray to the concealed conduits inside the classroom wall?
Is it common to install a surface-mounted junction box in the corridor and then drill through the wall?
Is it acceptable to install \*\*two back-to-back junction boxes\*\*, one surface-mounted in the corridor and one flush-mounted inside the classroom, connected through the wall or via conduits under the floor?
When entering the wall, do you normally use:
\* rigid conduit,
\* corrugated conduit,
\* a wall sleeve,
\* or another solution?How is the cable tray usually terminated?
\* Directly into a junction box?
\* Into a conduit adapter?
\* Into a rigid conduit?
\* Is there a standard transition fitting?Are there any construction details, shop drawings, executive drawings, or photos from real projects showing these solutions?
I'm not looking only for code references. I'm specifically looking for real construction details used by designers and contractors in IEC/CEI countries.
Any examples, PDFs, books, or project drawings would be greatly appreciated.
Thank you!