Thanks for the input guys. It was a Line enclosure (as in our forum sponsors). Didn't mention that the the RFC and lighting were connected in terminal blocks, and the smokes cable literally and pointlessly just passed through the enclosure! It really is bad practice in my view to have more than one circuit in a junction box/enclosure, especially when it is completely unnecessary. As Tel said, there is no comparison between such as a junction box and a CU....the CU would be totally isolated before removing the cover anyway. A JB could easily still have live parts inside even if you thought you had isolated the correct circuits. Just seems like adding an extra danger for no reason. As for labeling the JB and CU....why not just do the job right in the first place! Just my view. :bucktooth: