When you have a consumer unit changed or upgraded by a skilled and registered competent electrician they must carry out a variety of electrical tests to make sure that the existing fixed electrical installation (the wires in your walls/floor along with accessories) are safe for continued use before re-energizing your installation. It’s a little bit like a MOT when your car goes to the garage. These tests will highlight any issues and give you an overall condition of your electrical installation. More in depth inspecting & testing can be carried out and this would produce a Electrical Installation Condition Report.
If you have a rewireable consumer unit then you will know how tricky it can be to find the fuse wire and then the screwdriver to change it, add the darkness or limited light from a touch and it is not much fun to get the power restored. With a modern miniature circuit breaker (MCB) resetting is now a quicker and offers a safer way of re-energizing the circuit which was at fault.
With modern consumer units we have the ability to add additional protection at the beginning of the circuit with a Residential Current Device (RCD). An RCD, is a life-saving device which is designed to prevent you from getting a fatal electric shock if you touch something live, such as a bare wire. It can also provide some protection against electrical fires. RCDs offer a level of personal protection that ordinary fuses and circuit-breakers cannot provide.
As with all things when they get older, they generally dont work as good and finding replacement or additional parts gets very limited. With some older consumer units the modern MCB or RCD are simply not made for them. The manufacturers also generally stop supporting their older products after 10-15 years so when tasked with a simple job of adding additional socket outlets or circuits trying to comply with the current electrical standards (which is now the 18th edition) becomes harder and normally more costly.
Are you insured ? A quick check with your insurance provider and policy should tell you. Some insurance companies will not offer cover until a safety electrical certificate has been issued. Increasingly insurance companies are becoming aware of the electrical regulations and are adjusting their policies to suit. Poorly maintained and deteriorating installations/equipment (like your old fuse board) are considered a higher risk and it is the responsibility of the home/business owner or landlord to make sure the electrical installation is safe for continued use as requested by insurers.
The consumer unit is the heart of your electrical system, and comes in many shapes and sizes.The unit distributes the electricity, via fuses or circuit breakers, to the different circuits such as sockets or lighting..Modern consumer units are designed to help reduce electrical risks by incorporating Residual Current Devices (RCDs). In the event if an electrical fault, these devices disconnect the electrical supply thus reducing the risk of electric shock or fire.Miniature circuit breakers also make resetting the system more convenient than replacing old style fuse-wire.