18th Edition of the Wiring Regulations is coming into force in January 2019. This rule book is viewed as best practice for electrical installations. Since the 1st edition in 1882 the wiring regs primary focus has been safety. This 136 year legacy has protected against fire and electric shocks in domestic or commercial environments.
Although it’s still in the draft for public comment (DPC) stage, the 18th Edition has new stipulations for protecting against electric shock, thermal effect, voltage disturbances, electromagnetic disturbances, selection and erection of wiring systems and earthing arrangements.
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Chapter 54 of the 18th Edition covers earthing arrangements and protective conductors. New modified regulations requires an additional earth electrode, supplementing any earthing facility provided by the electricity supplier to prevent the risk of dangerous touch voltage in the event of the loss of the main connection to earth.
So how does this effect you?
First, let’s talk about earthing systems…there are in the main 2 types of earthing systems.
1: PME (Protective Multiple Earthing) also known as TN-C-S.
This earthing facility is supplied by the electricity supplier. The cables coming into your property have a protective (earth) and a neutral conductor that are combined. So the electric cables supply the earth. The utilities sector introduced PME in the 1970’s and the system has become universally used since then.
2: Earthing Rod also known as TT system.
This is a metal rod (electrode) that is buried in the ground in an earth pit outside the premises. The earth rod supplies the earthing. Concerns about the aging electrical supply network and the increasing possibility of power cuts causing the loss of the PME earthing have arisen. Loss of PME could result in dangerous touch voltage hazards. RCDs do NOT provide protection against PME faults so dangerous touch voltage hazards could occur without tripping the RCD. The potential risk to life if this occurs has been reassessed and earthing rods will now be used in conjunction with a PME system.
We think that this is a good measure, and would encourage everyone to Install an earth rod and earth pit. Though it may be belt and braces. We think that it is better safe than sorry. Sorry, dead would be a better word than sorry. Yes, it’s that serious…
Please see our price list of Installation of earthing rods and earthing pits.