J
JCE
basically the metal back box requires earthing , it relates back to regulation 8 of the electricity at work regulations 1989
which states precautions shall be taken ,either by earthing or by other suitable means as to prevent danger ,
i.e a danger could be present if a line conductor comes a drift we need to make sure the fuse or breaker disconnects ,
again 99 times out of a hundred i will have say 3 earth cables in a ring main socket earth terminal the reason for this years ago i looked at the risk of people getting say an electric shock and decided that the larger risk came from the accessory metal plate or plug or after the plug so common sense dictated the lowest path of resistance would be connecting all three earths together ,plus over time doesnt the damp and plaster turn the metal back box terminal green increasing the resistance of that connnection
please also note i still consider myself the apprentice at 49 years old , cheers
which states precautions shall be taken ,either by earthing or by other suitable means as to prevent danger ,
i.e a danger could be present if a line conductor comes a drift we need to make sure the fuse or breaker disconnects ,
again 99 times out of a hundred i will have say 3 earth cables in a ring main socket earth terminal the reason for this years ago i looked at the risk of people getting say an electric shock and decided that the larger risk came from the accessory metal plate or plug or after the plug so common sense dictated the lowest path of resistance would be connecting all three earths together ,plus over time doesnt the damp and plaster turn the metal back box terminal green increasing the resistance of that connnection
please also note i still consider myself the apprentice at 49 years old , cheers