Upgrades Consumer Unit

The IET defines a Consumer Unit, also known as a consumer control unit or electricity control unit, as “a particular type of distribution board comprising a type-tested co-ordinated assembly for the control and distribution of electrical energy, principally in domestic premises, incorporating manual means of double-pole isolation on the incoming circuit(s) and an assembly of one or more fuses, circuit breakers, residual current operated devices or signalling and other devices proven during the type-test of the assembly as suitable for use.”

Consumer unit

RCD Protection Consumer Dual Split-Load :

With the introduction of the recent (BS 7671 18th Edition IET Wiring Regulations consumer units in the UK must provide RCD protection to all cables embedded in walls excepting high integrity circuits such as those for burglar alarms or smoke alarms.

Consumer units have different methods of protecting circuits. A dual split-load consumer unit can be arranged as follows:


  • Upstairs Lights,
  • Downstairs Ring Final,
  • Garage Sockets,
  • Cooker


  • Downstairs Lights,
  • Upstairs Sockets,
  • Shower,
  • Heating,

By alternating the circuits like this, power will always be present on one floor if either RCD trips out.

Another way to protect circuits under the 17th Edition IET Wiring Regulations is by fitting Residual Current Circuit Breaker With Overload (RCBOs) to every circuit although this can be a very costly method.

Electrical wiring is an electrical installation of cabling and associated devices such as switches, distribution boards, sockets, and light fittings in a structure. Wiring is subject to safety standards for design and installation. Allowable wire and cable types and sizes are specified according to the circuit operating voltage and electric current capability, with further restrictions on the environmental conditions, such as ambient temperature range, moisture levels, and exposure to sunlight and chemicals. Associated circuit protection, control and distribution devices within a building’s wiring system are subject to voltage, current and functional specification. Wiring safety codes vary by locality, country or region. The International Electrotechnical Commission (IEC) is attempting to harmonise wiring standards amongst member countries, but significant variations in design and installation requirements still exist.

Electrical installations and wiring can deteriorate over time or show signs of age, but you would never notice it until it was too late. EICRs will check the overall condition of the electrical installation in the property, and it will help pick up on any faults or electrical damages, and also any wiring that doesn’t meet the current regulations.

It’s important to note that periodic inspection reporting is the process and the document you receive at the end is an Electrical Installation Condition Report (EICR).

Currently, there is no law that requires you to have an EICR carried out on your property, although current BS7671 Wiring Regulations (Regulation 135.1) state that you should keep your electrics in good working order and ensure they are safe.

It is highly recommended you have an EICR periodic inspection carried out every 10 years and for rental properties every 5 years or at the change of tenancy.