“Wago connector lamp” is one of the most common searches when it comes to wiring inside the ceiling rose – and rightly so, because the choice of connector helps decide whether the connection will still hold in five years. Here are the differences between the classic terminal block and the modern push-in connector (lever connector, colloquially called “Wago” after the best-known manufacturer).
What a terminal block does
A terminal block is a plastic body with metal screw terminals inside, usually in a strip of 2, 3 or more poles. Two wires are inserted from opposite sides and clamped with a screw. Advantages: very cheap (a few cents per terminal), available everywhere, and you can fine-tune the clamping force with a screwdriver. Disadvantage: with fine-stranded wire – and fabric cable is practically always fine-stranded – the screw squashes the many thin strands together, and individual strands can stick out to the side or loosen over time, because copper yields slightly under constant pressure ("cold flow"). That's why the rule for terminal blocks with fabric cable is: only use them with ferrules.
What a push-in connector (lever connector) does
With a push-in terminal, often called a "Wago terminal" (after the manufacturer Wago, who made this clamping principle popular), the stripped wire is pushed into an opening and a lever closes the clamping spring. The spring compensates for small movements and the cold flow mentioned above by itself – that makes the connection more reliable over the years than a screw terminal, without any need to retighten. Push-in terminals come in ranges for fine-stranded and for solid conductors; for fabric cable, the types for fine-stranded wire with or without ferrules are the relevant ones (it's marked on the terminal, usually "0.75–2.5 mm² flexible"). Disadvantage: push-in terminals are a little bigger than small terminal blocks and so need more space in the ceiling rose.
Fine-stranded wire and ferrules
Fabric cables like those used in pendant lights have a stranded conductor made of many thin copper wires, usually 0.75 mm² in cross-section. That makes them flexible but sensitive in terminals: without a ferrule, individual strands can work their way out of the terminal and, in the worst case, cause a short circuit to the neighbouring terminal or the housing. A ferrule (a few euros for a pack of 100, the matching crimper about 15 to 25 euros) bundles the strands in a metal sleeve that then goes into the terminal as a whole – clean contact, no frayed ends. For terminal blocks, a ferrule is practically mandatory; with modern spring-clamp push-in terminals for fine-stranded conductors it's optional depending on the manufacturer, but always the safer choice.
Tensile strength in everyday use
In the ceiling rose, the weight of the light hangs on the strain relief, not the terminal – even so, small pulling forces also act on the connection when you hang, clean or lightly knock the light. Push-in terminals with a spring mechanism hold these forces constantly because the spring gives rather than staying rigid. With screw terminal blocks, it's worth retightening them once a few weeks after fitting, especially if the light hangs somewhere with vibration (near doors, on wooden beams that flex). With a properly fitted strain relief, though, this is more a precaution than a necessity for both types of terminal.
Space in the ceiling rose
Small ceiling roses (60–80 mm diameter, flat design) often have only a few millimetres of space inside – every cubic centimetre counts. Mini terminal blocks have the edge here because they're narrower than most push-in terminals. In larger or deeper ceiling roses (from about 90 mm diameter or cone-shaped) there's enough room for push-in terminals, which are also easier to release if something needs changing later – a screw terminal needs a screwdriver for that, a lever terminal just the lever. You'll find ceiling roses in various sizes under Ceiling roses.
Clear recommendation
For most DIY pendant lights: push-in terminals with ferrules, if the ceiling rose is big enough. They're quicker to fit, more forgiving with fine-stranded wire and can be opened again without tools if needed. Only in very flat ceiling roses with little space inside are mini terminal blocks with ferrules the more practical choice. In both cases: the actual ceiling connection with the 230-volt wires from the wall is a job for a qualified electrician – if you don't feel up to it, go for a plug-in light instead, which runs from a normal socket. How the full connection in the ceiling rose works, including the order of strain relief and terminals, is covered in the article Fitting a ceiling rose.
You'll find matching accessories such as ferrules, terminals and tools under Accessories. If you want to put together the complete light including ceiling rose and lamp holder, the fastest way is the configurator – there, cable cross-section, ceiling rose size and lamp holder match from the start.