Why is there no earth conductor (c.p.c.) in a lighting circuit?
Lighting circuits installed before 1966 did not require an earth or more accurately a circuit protective conductor (c.p.c.) to be run to every point and accessory of a lighting circuit as is currently required by the UK Wiring Regulations (BS7671).
Existing installations wired to earlier editions of the Wiring Regulations may not comply with the current edition in every respect. This does not necessarily mean they are unsafe for continued use or require upgrading. There is no legal requirement, and no regulation in BS 7671, that requires an existing lighting circuit to be rewired or upgraded to current standards.
However, it is essential that the safety of the installation is not compromised when any alteration and/or addition is carried out.
This means that no Class I fittings such as metallic lights and switches can be connected to a lighting circuit which has no c.p.c. only Class II fittings which are double insulated and do not require connection to earth.
What to do if you have no earth conductor (c.p.c.) in a lighting circuit?
If you have an Electrical Installation Condition Report carried out on your High Wycombe property and it is found that metal lights and switches are installed in the absence of a c.pc. then the electrician will code this as C2 - Potentially dangerous. The remedy for this situation is to rewire the circuit (often not possible) or remove the metal fittings and replace with Class II fittings, often white plastic switches and pendants, and install a 30mA Residual Current Device (RCD) to the circuit. A sticker (as shown in the picture) indicating the lack of earthing on the lighting circuit should be fixed to the consumer unit.
Please call Tony on 07944 162958 for all your electrical requirements.
