2-way switching: wiring the strapper cable

2-way switching lets two switches each control the same light — ideal for top and bottom of stairs, or either end of a corridor. Already wired for you (shown in grey): • The mains supply (feed) connects to the ceiling rose. • The pendant connects the rose to the lamp. • Switch drop 1 is terminated at the rose end (L → rose L, CPC → rose E). You will wire the switch end onto sw1. • Switch return 2 is terminated at the rose end (switched live → rose Sw, CPC → rose E). You will wire the switch end onto sw2. Your job: terminate both switch drops at the switch back-boxes and wire the 3-core strapper between the two 2-way switches. Key terminal — COM: the 'common' terminal on each switch. Permanent live arrives at sw1's COM; switched live leaves sw2's COM. The strapper (L1↔L1 and L2↔L2) is what lets either switch make or break the path between the two COMs. Note 1: a 2-way switch has four terminals — COM, L1, L2, and E. This is different from a 2-gang switch (two 1-way switches on one faceplate). Note 2: in real wiring, the blue core of each switch drop carries live to/from COM and must be brown-sleeved at both ends to mark it as live, not neutral.