The minimum back box depth required will depend on the cable type, the style of module or fascia and the type of faceplate used. The table below gives the minimum recommended back box depths for various different configurations that will ensure that the required minimum cable bend radius is maintained. The table also shows the recommended back box cable entry point(s) that will help to optimise cable bend radii.
When working with floor boxes it is important to consider both the depth required below the floor box adaptor mounting plate for the incoming cables and the height between the floor box adaptor plate and the bottom of the floor box lid when the lid is closed for plug tops, patch cords and plug top transformers. The table below show the recommended minimum distance above and below the floor box plate that will ensure minimum bend radii for both the incoming cables and the attached equipment cable.