A Look at Old Consumer Units (Fuse Boxes)

Remember the Fuse Box? A Look at Old Consumer Units

Before the sleek, modern consumer units with their neat rows of miniature circuit breakers (MCBs), there was the humble fuse box. Often lurking under the stairs or in a cupboard, this now-vintage piece of electrical equipment was the unsung hero protecting our homes from electrical faults. Today, finding an old fuse box is increasingly rare, often replaced for safety and compliance, but photographs remain, capturing a snapshot of electrical history.

Old fuse boxes, more accurately called consumer units, typically featured rewireable fuses or cartridge fuses. Rewireable fuses, the more common type in older installations, used a thin piece of fuse wire held between terminals. When an overcurrent occurred, the fuse wire would melt, breaking the circuit and preventing damage to wiring or appliances. The user then had to replace the wire – a fiddly process often done in the dark with a dodgy torch!

Cartridge fuses, found in some older installations and often in appliance plugs, contained a pre-rated fuse element within a glass or ceramic tube. These were generally considered safer and easier to replace than rewireable fuses, but still required a replacement fuse of the correct amperage.

Looking at photos of these old units, you'll often notice several key characteristics. The enclosures were typically made of Bakelite, a hard, brittle plastic, or sometimes metal. They were often quite small and cramped, making modifications or additions a challenge. Labelling could be rudimentary, sometimes just handwritten on masking tape – hardly the clear and durable markings seen on modern consumer units.

One of the biggest limitations of these older units was the level of protection they offered. While they could protect against overcurrents, they didn't provide residual current protection (RCD). RCDs are now mandatory in most modern installations and are crucial for preventing electric shock. An RCD constantly monitors the current flowing through a circuit and quickly disconnects the power if it detects a difference, indicating a leakage to earth, such as when someone touches a live wire.

Furthermore, the capacity of older fuse boxes was often limited by the size of the incoming service cable and the number of circuits available. As our reliance on electricity has increased, with more appliances and higher power demands, these older units often struggled to cope, leading to frequent fuse blowing and the temptation to "upgrade" to a higher amperage fuse wire – a dangerous practice that could easily lead to overheating and fire.

While old fuse boxes may seem quaint or even charming in photographs, it's crucial to remember that they represent a bygone era in electrical safety. Replacing these with modern consumer units offering MCBs and RCD protection is a vital upgrade for any older property, ensuring the safety of occupants and protecting the building from electrical hazards. Photos of old fuse boxes serve as a reminder of how far electrical safety has progressed and the importance of keeping our electrical installations up-to-date.