In response to the electrical incidents involving work inside false ceilings occurred in recent years, the CoP has included precautions for work inside false ceilings to enhance the occupational safety of the relevant work. A task-specific risk assessment should be conducted by a competent person assigned by a REC or the owner of the fixed electrical installation to identify all potential hazards associated with work inside a false ceiling before the commencement of work. A REC or the owner of the fixed electrical installation should formulate appropriate method statements with safety procedures and safety measures for the work in accordance with the relevant risk assessments, and provide necessary safety information, instructions, training and supervision to the persons performing such work to avoid danger.

The method statements should include but not limited to identifying the scope of work and circuits of energised electrical installation at the place of work and in the vicinity of the work area, and eliminating the risk of inadvertent contact with live conductors/live part of energised electrical installation at the place of work and in the vicinity (within 1.5 metres) of the work area as well as its access path. In addition, suitable personal protective equipment and testing equipment should be provided to and properly used by the persons performing the work. Entering into or working on fragile false ceilings or similar unsafe places should be strictly prohibited. If access to and working in such places are required, suitable means of access/means of support/working platforms should be provided and properly used.

About 20% to 30% of fire incidents are related to electrical installations worldwide each year and arc fault is one of the causes of electrical-installation-related fire. Possible causes of arc faults include improper installation of cables, intermittent connection or damaged cable insulators. The high temperature resulting from arc faults may cause fire. Since existing mainstream protection devices (overload circuit breakers and residual current devices) are unable to detect some types of art faults, countries across the globe have one after another recommended or mandatorily required the installation of AFDDs in specific venues. In view of the above, the CoP makes reference to the 18th Edition of the Institution of Engineering and Technology Wiring Regulations and recommends that AFDDs complying with IEC 62606 or equivalent should be installed at the following specific premises to further safeguard electricity safety:

• premises with sleeping accommodation (e.g. dwellings, hotels and guesthouses);
• premises for manufacturing or storing of readily combustibles substances, or substance liable to spontaneous combustion (e.g. dangerous goods stores and filling stations);
• premises where combustible materials are used as the main construction materials (e.g. wooden buildings); and
• premises with endangering or irreplaceable goods (e.g. museums).

In view of the growing popularity of environmentally friendly lighting fittings (e.g. LED lamps) with much lower electricity consumption compared to traditional lighting fittings, the calculation method of the assumed current demand and the current demand of final circuit in relation to lighting outlets as stipulated in the CoP has been revised. Lighting outlets should be assumed to demand the connected load with 60W per lampholder for incandescent lamps or the actual wattage of the lamp to be installed, whichever is the greater, except if the design of the luminaire associated with the lampholder only permits lamps of less than 60W to be inserted in any lampholder, in which case, the connected load of that lampholder is the wattage of the highest rated lamp that may be accommodated. For fluorescent and other discharge lamps, the demand of the connected load of the lighting outlets should be assumed as the actual wattage of the installed lamps multiplied by a factor which has taken into account control gear losses and harmonic currents. In the absence of more precise information from manufacturer, a factor of not less than 1.8 shall be adopted.

If the circuit design of the lampholder only permits lamps of less than 60W to be used, the connected load of that lampholder is the wattage of the highest rated lamp that may be accommodated.

Since electrical products which charge with USB outlets have become increasingly common and there are public demand for USB outlets, the CoP has included the requirements for final circuits using USB outlets to ensure the safety of USB circuits. 13A socket outlets incorporated with USB circuits shall comply with relevant requirements included in Part 2, BS 1363. If the USB circuits are not part of the circuits of the 13A socket outlets, they shall be independent of other circuits, comply with the requirements of IEC 60950-1 and use radial final circuits. Moreover, appropriate overcurrent protection (e.g. a fuse) shall be provided on the primary side of each USB circuit to further enhance the safety of USB circuits.

To tie in with the increasingly extensive application of DC systems on fixed electrical installations (e.g. renewable energy power systems, charging facilities for electric vehicles, etc.), the CoP has included technical guidelines on DC systems, which stipulate that all conductors of a DC circuit shall be capable of being isolated by a device for isolation (e.g. with a double-pole circuit breaker), and in the case of a DC circuit having one conductor connected either to earth or to a protective earthing conductor, that conductor need not be isolated or switched. The CoP has also included the requirements and colour codes for identification of DC conductors or cable cores. In general, positive conductors should be coloured brown and negative conductors should be coloured grey.

With the implementation of the Feed-in Tariff Scheme and the increasing maturity of renewable energy technologies, the use of renewable energy power system has become popular. To ensure the electrical safety of renewable energy power system (REPS), the prevailing Code 26P for renewable energy systems has been revised. Since the solar power system uses direct current as the output, the electrical installations on the direct current side (including cables, inverters, protective and switching devices, etc.) shall be suitable for direct current voltage and direct current. Isolation transformers in compliance with IEC 61558 or equivalent should be installed to provide simple separation between the DC side and the AC side. For some REPS installations running in parallel with the system for distribution of electricity to the public, an automatic synchronizing system which considers frequency, phase and voltage is to be preferred. The REPS shall also be equipped with an anti-islanding function. In the event of loss of power supply or deviation of the voltage or frequency at the supply terminals, means of automatic switching to avoid unsynchronized connection and to protect electrical worker working on power system should then be provided. Details of other related technical guidelines and requirements are set out in Code 26P. In addition, checklists for inspection and testing of solar power system installations and typical drawings of the equipment have been included in the CoP for the trade's easy reference.

In view of the growing maturity of the technology and application of the Modular Integrated Construction (MiC), the new edition of the CoP has incorporated particular requirements for fixed electrical installations with the use of MiC in design and construction. For details, please refer to Code 26T.

For other amendments to the CoP, please refer to the Summary of Major Revisions to the Code of Practice for Electricity (Wiring) Regulations 2020 Edition [PDF format (3.6MB)] at the EMSD website.