Over time modifications to your home such as new kitchens, bathrooms, electrical sockets etc may mean that your electrical system is no longer up to date. As a result it might not be capable of carrying all the load and amount of circuits it was designed for when it was originally installed.
Often on findings from a Periodic Inspection, we find that two or more circuits have been wired into the same fuse / MCB (Miniature Circuit Breaker) or do not have the correct rating of overload protection, leaving your home at risk to fire.
The latest BS7671 regulations stipulate that all circuits must be protected by an RCD (Residual Circuit Device). Many homes don’t have an RCD, and this is crucial as it protects your home from and fires and potentially electric shocks.
The latest consumer units have MCBs to protect the circuits from overload i.e. if a cable is rated at 10amps then an MCB must be rated below that, so it will trip instead of the cable getting hot. Also the new consumers units have two RCDs for fault protection. The reason for having two is so the circuits (sockets and lights etc) can be split, and then if a fault occurs you don’t lose all the electricity in the house so you can see in the dark and the fridge can be plugged in.