Surface & Flush Switch Boxes and GI Back Boxes
The boxes that terminate the conduit run at an accessory. Surface and flush patterns in PVC-U, plus galvanised steel back boxes to BS 4662 where the specification calls for metal.
Also searched as: switch box, socket box, back box, pattress, 1 gang box, 2 gang box, GI box, flush box
Surface mounted
1 gang and 2 gang, square corners, 32mm depth — codes AEMSSB17K and AEMSSB23K. All standard surface boxes have a combination of 16 × 16mm, 25 × 16mm and 20mm round conduit knockouts, so they accept both mini trunking and round conduit entries.
Flush mounted
1 gang and 2 gang at 35mm depth — codes AEMSSB1 and AEMSSB3. The 1 gang has entries of 1 × ø20mm and 1 × ø25mm on the horizontal sides and 2 × ø20mm on the vertical sides; the 2 gang has 3 × ø20mm and 1 × ø25mm horizontally and 2 × ø20mm vertically.
GI back boxes
Galvanised steel switch and socket boxes in 35mm and 47mm depths, 1.1mm thick, complying with BS 4662. The 1 gang is available with two adjustable lugs at 90°, which is what saves the accessory sitting crooked when the box has been set slightly out of plumb.
Cover plates
Flat cover plates in 1 gang (86 × 86mm) and 2 gang (86 × 146mm), codes AEMSCP2 and AEMSCP3, for blanking a box or closing a junction position.