TOA Electronics EX-16 - Manual (Page 16)

3.5 Piping
* Where wiring is to be passed through a wall or the like, it should be
protected by a hard PVC or metal tube.
* If the number of connecting wires between an indoor terminal board
and a station is small and the station's site is fixed so that it will not be
moved frequently, install a box at that site and pull wiring through a
metal or hard PVC tube as required by job or ordinance.
* Use a floor duct if the number of connecting wires is large and the
stations are likely to be moved frequently.
* Station wiring which must be laid across open areas of floor should be
protected by plastic or metal shields. (See drawing below.)
EXAMPLE:
Wire protector
Floor duct
Floor
Metal or Hard PVC tube
Wall
Plastic or
Aluminum
Desk
Station wiring
Floor
Fig. 10
Wire protector
4-Pin Jack
& Plug
Box
14