314.29 Boxes, Conduit Bodies, and Handhole Enclosures to Be Accessible. Boxes, conduit bodies, and handhole enclosures shall be installed so that the wiring contained in them can be rendered accessible without removing any part of the building or structure.

(Note that the covers which are of the boxes are covered as part of the UL Listing for those boxes).

The rationale for the rule is very simple. At some point, someone will need to service or inspect this wiring. The electrician cannot possibly be expected to remove every single screw-down panel in the entire building on the blind hope that a junction box or pull point might be behind it.

(only to find out the mystery box or conduit body is actually behind none of them, and is actually behind finished drywall).

Separately, you are relying on a false premise that the plywood panel can be removed non-destructively. That doesn't work out IME. The screws seize up (excessive torque to remove, camming out screw), or they expand from moisture, or they stick, or one thing or another.

314.29 Boxes, Conduit Bodies, and Handhole Enclosures to Be Accessible. Boxes, conduit bodies, and handhole enclosures shall be installed so that the wiring contained in them can be rendered accessible without removing any part of the building or structure.

100 Definitions. Accessible (as applied to wiring methods). Capable of being removed or exposed without damaging the building structure or finish, or not permanently closed in by the structure or finish of the building.

(box and conduit body covers are approved by UL as part of the UL Listing for that equipment, see NEC 110.2.)

The rationale for the rule is very simple. At some point, someone will need to service or inspect this wiring. The electrician cannot possibly be expected to remove every single screw-down panel in the entire building on the blind hope that a junction box or pull point might be behind it.

(only to find out the mystery box or conduit body is actually behind none of them, and is actually behind finished drywall).

Separately, you are relying on a false premise that the plywood panel can be removed non-destructively. That doesn't work out IME. The screws seize up (excessive torque to remove, camming out screw), or they expand from moisture, or they stick, or one thing or another.

314.29 Boxes, Conduit Bodies, and Handhole Enclosures to Be Accessible. Boxes, conduit bodies, and handhole enclosures shall be installed so that the wiring contained in them can be rendered accessible without removing any part of the building or structure.

The rationale for the rule is very simple. At some point, someone will need to service or inspect this wiring. The electrician cannot possibly be expected to remove every single screw-down panel in the entire building on the blind hope that a junction box or pull point might be behind it.

(only to find out the mystery box or conduit body is actually behind none of them, and is actually behind finished drywall).

Separately, you are relying on a false premise that the plywood panel can be removed non-destructively. That doesn't work out IME. The screws seize up (excessive torque to remove, camming out screw), or they expand from moisture, or they stick, or one thing or another.

314.29 Boxes, Conduit Bodies, and Handhole Enclosures to Be Accessible. Boxes, conduit bodies, and handhole enclosures shall be installed so that the wiring contained in them can be rendered accessible without removing any part of the building or structure.

(Note that the covers which are of the boxes are covered as part of the UL Listing for those boxes).

The rationale for the rule is very simple. At some point, someone will need to service or inspect this wiring. The electrician cannot possibly be expected to remove every single screw-down panel in the entire building on the blind hope that a junction box or pull point might be behind it.

(only to find out the mystery box or conduit body is actually behind none of them, and is actually behind finished drywall).

Separately, you are relying on a false premise that the plywood panel can be removed non-destructively. That doesn't work out IME. The screws seize up (excessive torque to remove, camming out screw), or they expand from moisture, or they stick, or one thing or another.