The Complete Guide to Electrical Supplies for Domestic & Commercial Projects

First fix electrical work covers all the wiring and containment that goes in before plastering, so the materials list centres on cables, back boxes, and cable management. You will typically need twin and earth cable in 1.0mm² for lighting circuits and 2.5mm² for ring main and socket circuits, along with 6.0mm² or 10.0mm² for cooker or shower supplies. Metal or dry-lining back boxes need to be fitted at this stage so they are set flush once the board goes on. Armoured cable is required for any buried external runs, and conduit or trunking is used where cables need protection in high-traffic areas. Consumer unit position and meter tails routing should also be confirmed at first fix to avoid costly remedials later. All first fix wiring in domestic properties must comply with BS 7671 and Part P of the Building Regulations, so ensure your electrician is registered with an approved scheme.

Standard domestic lighting circuits use 1.0mm² twin and earth flat cable, which is rated to carry the load of a typical lighting circuit protected by a 6A MCB. For longer runs or circuits feeding higher loads such as outdoor fittings or heated bathroom mirrors, 1.5mm² twin and earth provides a useful safety margin and reduces voltage drop. Bathroom zones require cables with the appropriate IP rating or correct mechanical protection, and any cable buried in a wall must be run in conduit or protected at the correct depth to meet Part P requirements. Switch drops are also typically run in 1.0mm² twin and earth, with the switch wire conventionally sleeved brown to indicate it is a switched live. For commercial or multi-circuit installations, singles in conduit or SWA cable may be specified. Always check the current edition of BS 7671 or consult a qualified electrician if in doubt about the correct cable size for your circuit.

An MCB (miniature circuit breaker) protects against overloads and short circuits by tripping when current exceeds the rated value — it performs the same basic function as a fuse but can be reset rather than replaced. An RCBO (residual current circuit breaker with overcurrent protection) combines the overcurrent protection of an MCB with the earth fault protection of an RCD in a single device. This means each circuit gets individual residual current protection, so if a fault occurs on one circuit, only that circuit trips rather than the entire board going down. Modern 18th Edition consumer units increasingly specify RCBOs on all circuits for this reason, improving both safety and convenience. RCBOs are required on certain circuits as standard, including bathroom, kitchen, and outdoor supplies. They cost more per unit than MCBs but offer significantly better fault discrimination and are now the preferred solution on new or rewired installations.

In the vast majority of full rewire projects, yes — a new consumer unit will be required to bring the installation into compliance with the current 18th Edition of BS 7671. Older fuse boards with rewirable fuses or older MCB-only boards do not meet current requirements for RCD protection on all circuits. A new consumer unit fitted with dual RCD protection or individual RCBOs per circuit is now the standard for domestic installations. Metal-clad consumer units are also required under current regulations rather than the older plastic versions, which offer less fire resistance. Beyond regulatory compliance, a new consumer unit allows the circuits to be correctly divided, labelled, and rated for the property's actual load. The installation of a new consumer unit is notifiable work under Part P of the Building Regulations and must be carried out by a competent, registered electrician or submitted to building control for inspection.

For site and trade applications, robustness and IP rating are the primary considerations. LED festoon strings and portable site LED floodlights are the workhorses of most construction sites, offering good light output, low energy consumption, and resistance to the kind of handling that would damage domestic fittings. Where fixed temporary or permanent lighting is needed in dusty or damp conditions, IP65-rated LED bulkheads or LED batten fittings are the practical choice as they can be wiped down and are sealed against ingress. For welfare units and site offices, standard surface-mounted LED panels or battens provide reliable, energy-efficient illumination. All site electrical equipment should be run through 110V centre-tap-to-earth (CTE) transformers rather than 230V mains supply wherever possible, significantly reducing the severity of any electric shock. Site leads and transformers are available in the site electricals range at MP Moran, alongside a full selection of LED site lighting options.

Part P of the Building Regulations requires that certain electrical installation work in dwellings is either carried out by a registered competent person or notified to the local authority building control before work begins. Notifiable work includes the installation of a new circuit, replacement of a consumer unit, and any work in a bathroom, kitchen, or outdoors — regardless of scope. Straightforward like-for-like repairs such as replacing a damaged socket, switch, or light fitting on an existing circuit do not require notification, provided the work is done safely and to BS 7671. Adding sockets to an existing ring main circuit in a main living area is also considered non-notifiable in most cases, though the work must still comply with the wiring regulations. If you are unsure whether your planned work is notifiable, the safest course is to use an electrician registered with a Part P competent person scheme such as NICEIC or ELECSA, who will self-certify their own work. Failure to obtain proper certification for notifiable work can cause problems when selling a property.

A single gang socket contains one set of outlet pins, accepting a single plug, while a double gang socket contains two sets and accepts two plugs simultaneously from the same faceplate. Both are typically fed from the same ring main or spur circuit, but a double gang socket draws from one wiring connection point, meaning the total load of both outlets is still limited by the circuit rating rather than doubled. Double gang sockets are the most practical choice for most domestic installations as they reduce the number of socket positions needed and minimise reliance on extension leads. You can also specify double gang sockets with built-in USB-A or USB-C charging ports, which are increasingly popular in kitchens and bedrooms. Back box depth is an important consideration — a double gang socket in a retrofit situation may need a deeper or slimmer back box depending on the wall build-up. MP Moran stocks a wide range of switches and sockets in standard white, brushed steel, and polished chrome finishes to suit all project specifications.

Where cables cannot be chased into walls or run within the fabric of a building, surface-mounted cable management provides a clean, compliant solution. Mini trunking — the white plastic channel with a clip-on lid — is the most common option in domestic settings and comes in a range of widths to accommodate single or multiple cables. Larger flat or square conduit trunking is used in commercial and industrial settings or where a higher cable count or more robust protection is needed. Round conduit in white, grey, or black PVC is widely used for exposed runs in garages, loft spaces, and outbuildings, and can be bent or jointed using standard fittings. Cable clips and saddles are the simplest option for securing individual cables along joists, rafters, or wall surfaces where aesthetics are less critical. Self-adhesive cable ties and cable tie mounts are used where temporary or flexible routing is needed. The correct choice depends on the number of cables, the environment, and whether the installation is domestic, commercial, or industrial.

Any electrical fitting installed outdoors must carry a minimum IP44 rating, which provides protection against splashing water and solid particles — and for fittings exposed to direct rain or jets of water, IP65 or higher is strongly recommended. Outdoor sockets must be weatherproof and ideally positioned in an IP65-rated enclosure with a sprung cover that closes when not in use. External circuits should be protected by an RCD with a 30mA trip threshold as a minimum, and the supply cable should be SWA (steel wire armoured) or run in conduit if buried underground to a depth of at least 450mm in low-traffic areas and 600mm where vehicle crossing is possible. Outdoor lighting fittings should be specified as IP65 or above and rated for the intended lamp type. PIR sensors, dusk-to-dawn photocells, and smart controllers can all be integrated into external lighting circuits. All outdoor electrical work is notifiable under Part P, so use a registered electrician or ensure the installation is inspected and certified by building control.

Yes — MP Moran offers Click and Collect across all six branches in London and Hertfordshire, including Watford, Kilburn, Willesden, West Hampstead, Tottenham, and Kennington. You can browse the full electrical supplies and lighting range online, place your order, and collect from whichever branch is most convenient for your job. This is particularly useful for trade customers who need to consolidate electrical materials with other building supplies in a single branch pick-up. If you are buying in volume across multiple jobs, a trade account with MP Moran gives you access to competitive pricing, consolidated invoicing, and priority service in branch. You can find out more about trade accounts and apply online at mpmoran.co.uk/accounts-landing. The team in branch can also advise on stock availability for specific cable lengths, consumer units, or other items you need quickly.