Industrial Unit Earthing Arrangement - Lack of

[cprfenom]

Back in the 80's having an earth in any size was a bonus given what I see from time to time. Spin is right though in terms of Western Power, they will not generally add a PME to a steel from. Normally they advise a TT.

 

[davesparks]

Well took a little longer to get here but seems we’re running a 35mm earth cable through the wall and expanding an earth block that was hidden away in the distribution room, seems weird even back in the 80s that they just put a 6mm earth cable from the consumer unit to the isolator but guess it must have been ok back in the day!

Have you calculated the size of earth required?

 

[sleepyfolk]

I haven’t, the man in the know has, I thought he said 25mm before but he’s told me to get enough 35mm in to go through the wall into the meter cupboard where he’s connecting it in somewhere

 

[davesparks]

I haven’t, the man in the know has, I thought he said 25mm before but he’s told me to get enough 35mm in to go through the wall into the meter cupboard where he’s connecting it in somewhere

What size is the incoming supply? You’ve shown a 100A cutout, but based on that you wouldn’t need anything bigger than a 16mm earth and actual calculation would probably prove the 6mm to be ok.

 

[sleepyfolk]

ill check tomorrow and make sure I remembered the size right!