... Blocks whenever I can avoid them. They are designed for mains single strand wiring of either 1mm or 2.5mm and as such aren't suitable for small multistranded wiring. If they are unavoidable then it is much better to use ferrules to spread the load. I use 5mm Terminal blocks soldered back to back on stripboard and these can be used in a variety of configurations ie one in one out or ganged together as needed. (See attached) I also use ferrules wherever I can in TBs (unless it's single strand wire.) 2083_230510_300000000.jpg It's difficult to see clearly in your photos but I have a suspicion that some of the wires in the TB have been tinned. If so that is a bad idea since the solder is so soft that through time it will get more compressed and eventually result in a bad connection. HTH Regards Ian Trotter posted: 23 Apr 2020 11:40 from: FraserSmith Hi again Andrew Further reading of the DCO instructions says "Therefore it is inadvisable to use cabling with cores of cross-section area lighter than 1.5sqmm or 16AWG ...