Consumer Unit & Fuse BoxUpgrades in Winchester& Across Hampshire

An MCB protects the cable against overload and short circuit. An RCD detects current leaking to earth and protects people. An RCBO combines both in one device on one circuit: which is why an all-RCBO board behaves so differently from an older split-load board where one RCD covers a whole bank of circuits.

RCD type matters as much as its presence. Circuits with electronic loads that can produce smooth DC residual current - EV chargers, solar inverters, some heat pumps and inverter-driven appliances - require Type A or specific higher types rather than a general Type AC device, or protection can be blinded exactly when it is needed. We select device types against the loads on each circuit, and this is one of the most common shortcomings we find on recent installations.

Surge protection devices divert transient overvoltage from lightning and switching events away from your equipment. They are worth specifying where there is solar equipment, a home office, a heat pump or expensive electronics, and we will tell you plainly when we think one is not worth the money.

A new board cannot be certified in isolation. Main protective bonding to incoming gas and water services must be present and correctly sized, the main earthing conductor must be adequate for the earthing arrangement, and the meter tails must be the correct size and length. Where any of those fall short, correcting them is part of the job, and we identify it at survey so it appears on the quote rather than as an extra.

Where the property has a TT earthing arrangement, an earth electrode and its resistance become part of the design and testing. Where the supply is TN-C-S, PEN fault considerations matter particularly if an EV charger or solar inverter is being added. On some properties the network operator is involved in upgrading the supply or moving the meter position; we will tell you if that applies before you commit to anything.

The single most common cause of a board change going wrong is discovering, after the new board is in, that an old circuit has poor insulation resistance and the new protective device will not hold. Modern devices detect leakage that an old fuse simply ignored, so faults that were tolerated for years become visible instantly.

We therefore test before we quote. If a circuit shows deteriorated insulation resistance - commonly old rubber or lead-sheathed cable, or damp in outbuilding wiring - we tell you before installation day, and quote the remedial work or a partial rewire as an option. Sometimes a full EICR is the sensible first step, and where a rewire is the honest answer we will say so instead of selling you a board that cannot fix it.

Domestic board changes are a one-day job in most houses, planned around an isolation window that suits the household: we agree the time you will be without power in advance so freezers, home working and childcare can be planned.

Rented property brings inspection requirements, and the certificate plus labelled circuit schedule is exactly what an agent or inspector will ask for. We format the handover so it can be passed straight on.

Commercial premises use distribution boards rather than domestic consumer units, often three-phase, with sub-distribution, emergency lighting circuits and heavier documentation requirements. Changeovers are scheduled outside trading hours where downtime matters, and phased where a site cannot lose power all at once.