House alarm fuse spur

Security alarm protocol dictates that an unswitched spur should be used to connect the main panel to the supply. However, it could have been omitted. If its not located next to the main panel can you visually trace the cable to where it is running? Look inside the airing cupboard or hw cylinder/boiler cupboard if you have one.

Alarm panels should defiantly have a fused spur to isolate the system. Most of the time they are located locally to the panel itself. If this is not the case I would advise you to look in a near by cupboard e.g. airing cupboard. If you still cant locate it, check your fuse board to see if the alarm panel has its own dedicated supply and isolate from that

I'd start by switching off breakers at consumer unit untill you find the correct circuit but it looks like the alarm supply had been taken from lighting supply in roof space. Contractor installed possibly took short cut and didn't fit a fused spur unit for alarm.