Earthing a PV system question

[Deltatango]

I am fitting up a small PV system on a porch roof using a small (Plug in Solar) 4 panel rig just would like to know if its lightning earth grounding wire can be threaded under tiles to emerge as required at its brackets (to be neater), or would it need to be topside.

Figure there are rules for most things but its finding a line in pages of them........

Many Thanks from Deltatango

 

[Karl Strange]

I am fitting up a small PV system on a porch roof using a small (Plug in Solar) 4 panel rig just would like to know if its lightning earth grounding wire can be threaded under tiles to emerge as required at its brackets (to be neater), or would it need to be topside.

Figure there are rules for most things but its finding a line in pages of them........

Many Thanks from Deltatango

it is good practice to keep lightning conductors as short as possible, running the cables under the tiles may also require Mechanical protection. in my opinion keeping them on the outside would be the preferred method.

 

[James]

I am fitting up a small PV system on a porch roof using a small (Plug in Solar) 4 panel rig just would like to know if its lightning earth grounding wire can be threaded under tiles to emerge as required at its brackets (to be neater), or would it need to be topside.

Figure there are rules for most things but its finding a line in pages of them........

Many Thanks from Deltatango

there are specific regs outside of BS7671 that are all about lightning protection.

however, one point to note is that lightning will be attracted to any well grounded metal object above ground level.
i.e. if you have 2 brick houses on a hill at the same height and one has a lightning rod, it will be hit far more often than the one without stood next to it.

Also, if lightning strikes, it will not only travel down the cable but will also travel down the outside of the cable as the voltage is far higher than the insulation resistance.
by bringing that cable inside of the roof you are giving lightning a path inside the property. a situation that I think you would want to avoid.