Earthing And Equipotential Bonding

[petercsea]

The house roof super structure is steel. The gutters/spouting steel but not directly connected to the roof super structure.

Have MEN earthing with a distribution box. The earth stake is copper sheathed steel, 2.5 m. The lead from the stake is 10 sq mm attached to the distribution box earth bar and a link from the earth bar to the neutral bar.

Should I connect the roof superstructure and the guttering directly to the earth stake or bring it to the earth bar of the distribution box?

I presume I would use copper cable for the lead and not sure of the physical connection to the guttering. Do I need to accommodate electrolysis and disintegration at the point of connection to the guttering by using a sacrificial electrode.? If so how should I do this?

Thank you for all the good stuff in this forum.

[Crossy]

Metal roofs on domestic buildings is a bit outside my experience, and the UK electrical code (IEE Regs. 16th edition) makes no mention as they are pretty new to the UK. This being the case I'll bow to those with greater experience.

Going by the arrangements used on the metal structures of metro stations (should be relevant):-

The roof and gutter should be bonded.

The roof structure should have a seperate ground rod as far away as possible from the electrical safety ground rod, we don't want to feed anything up the electrical ground if we do have a strike. In our metro installations these two grounds (along with the traction power and communications grounds) are actually linked by a device called a TEC (Transient Earth Clamp) but these are (very) expensive and probably not required in a domestic situation.

No anodes are used.

Our pet Aussie (Elkangorito) should have some relevant info as steel roofs are more common in sunny Oz

[david96]

Metal roofs on domestic buildings is a bit outside my experience, and the UK electrical code (IEE Regs. 16th edition) makes no mention as they are pretty new to the UK. This being the case I'll bow to those with greater experience.

Going by the arrangements used on the metal structures of metro stations (should be relevant):-

The roof and gutter should be bonded.

The roof structure should have a seperate ground rod as far away as possible from the electrical safety ground rod, we don't want to feed anything up the electrical ground if we do have a strike. In our metro installations these two grounds (along with the traction power and communications grounds) are actually linked by a device called a TEC (Transient Earth Clamp) but these are (very) expensive and probably not required in a domestic situation.

No anodes are used.

Our pet Aussie (Elkangorito) should have some relevant info as steel roofs are more common in sunny Oz

Earth bonding, exposed metal work that may be in contact with earth. No we do not earth metal roofing in Australia or guttering. The service L pin may be earthed to supply authority requirements if located within 25mm of metal work if double insulation is not afforded by the service conductors attachments.