KNX switch actuators are typically installed by connecting one terminal of the otherwise independent relays and supplying these connected terminals with phase from a circuit breaker. Depending on the power requirements, we usually group 4-8 relays for common power supply.
Of course, the manufacturer could solve this problem by producing a phase busbar - as commonly used in circuit breakers - but they generally choose to "elegantly" overlook this. There are exceptions, such as the Spanish company Zennio, which offers such a phase busbar for their actuators under the name Comb Busbar. However, let's return to the situation where we don't have one.
In the absence of a phase busbar for the actuator, we are left with the task of bending U-shaped bridging elements from MCu wires:
Anyone who has manually bent 2.5 mm² MCu wire into a 19 mm wide U-shape knows how challenging it is to make these truly neat and uniform. That's why we created a 3D-printable tool for ourselves:
This small tool helps to cut the wires to size and bend them to a uniform width:
Unfortunately, the connection spacing of the manufacturers' relays is not uniform, so we had to create several versions of the tool. The variants we designed are sized for Interra, ABB, and MDT actuators.
You can download the models from printables.com.
If you're just starting to build your first KNX system, don't start with this. Instead, contact us ;)