Tony M Nov 23, 2012:

2 ft tubes Note that these are the kind of square box fittings you find in suspended ceilings etc., using the short 2 foot (60 cm) tubes. This type of fitting is commonly found with 1, 2, 3, or 4 tubes, and the 'corss section ' simply refers to the shape / layout of the fitting when seen in profile / cross-section view.

Here is a web page that illustrates a few (rather basic!) types — don't take any notice, though, of the English!!

http://kanjin.en.alibaba.com/product/223221251-200669822/Hig...

Note that they are not invariably square of course; the 4-tube types do tend to be, but the 1- and 2-tube types are often rectangular.

Note, too, that these needn't specifically be the 'square tray' type I've described, as they can be used for longer tube sizes too; however, for these short tubes, the 'inset tray' type is very common.

Tony M Nov 23, 2012:

@ Johannes No, it's nothing to do with the cable rating, it is referring to the profile of the light fittings.

Johannes Gleim Nov 23, 2012:

Cross-section? '1-lamp cross-section, 3-lamp cross-section, and 4-lamp cross-section'
sounds like an arrangement of several fluorescent lamps cut horizontally or vertically, but may also refer to the cross-section of the cables required for the corresponding nos. of lamps.