Almost every fabric cable says “2x0.75 / 3x0.75” – and choosing between them is one of the most common support questions. The rule is simple.
The rule
Touchable metal parts that could become live in the event of a fault need an earth conductor. Specifically: metal lamp holder, metal ceiling rose with a conductive connection to the lamp holder, metal shade on a metal lamp holder → 3x0.75, connect the earth conductor (green-yellow) at the lamp holder and in the ceiling rose. Lamp holders made of thermoplastic, Bakelite, porcelain or wood with a plastic core → 2x0.75 is enough, because the lamp holder is protectively insulated (protection class II).
A metal ceiling rose with a plastic lamp holder is a borderline case: if the ceiling rose has an earth connection, it is earthed at the ceiling via the building wiring's protective earth – the cable to the lamp holder can then be two-core. If in doubt, go three-core; it costs 20 to 40 cents more per metre and never hurts.
What if the earth wire isn't needed?
With three-core cable on a plastic lamp holder, the green-yellow conductor stays insulated at the lamp holder (in a spare terminal, or with a ferrule and insulating cap) and is still connected to the ceiling's PE in the ceiling rose. Never cut it short and leave it exposed. And never use it as N or L – the colour green-yellow is reserved exclusively for the earth conductor.
0.75 mm² is enough
H03VV-F 0.75 mm² is rated for 6 A, which is 1,380 W. An LED pendant light with five bulbs of 8 W each draws 40 W. Even with old 60 W incandescent bulbs on five drops (300 W) there's headroom. Larger cross-sections (1.0 or 1.5 mm²) are available as fabric cable for power strips and extension leads, where appliances of over 1,000 W may be plugged in – for lights they're unnecessary and don't fit through lamp holder shafts.
Two-core in practice
A 2x0.75 cable is thinner (6 instead of 7 mm), more flexible, cheaper and hangs straight more easily on very long pendants. That's why it's the standard choice for plug-in lights with a plastic lamp holder and Euro plug. With metal lamp holders and Schuko plugs it's automatically three-core.
How the configurator handles it
In the configurator you first choose the ceiling rose and lamp holder, then the cable. For metal lamp holders we point out the need for three-core cable; the cable list shows the cross-section for every cable. Pre-assembled lights from our workshop always get the right number of cores – and every metal lamp holder gets a continuity test of the earth conductor before shipping.