TT earth rod to shed or non connected garage..advice please

[davesparks]

Lightning protection systems will be bonded to all exposed metalwork outside and the structural metalwork of the building, this will extend into the equipotential zone of the installation.

You will rarely see the main bond to a lightning protection system, the correct place to connect the bond is below ground level, often connected to the earth rod nearest the MET.

 

[Engineer54]

Lightning protection systems will be bonded to all exposed metalwork outside and the structural metalwork of the building, this will extend into the equipotential zone of the installation.

You will rarely see the main bond to a lightning protection system, the correct place to connect the bond is below ground level, often connected to the earth rod nearest the MET.

Lightning Protection systems should ''Always'' be bonded to the buildings MET, and as stated the connection is generally to the nearest down conductor earth rod, or in the case of a buried copper tape ring, to the nearest point on the copper tape!!

 

[Deleted member 9648]

Lightning protection systems will be bonded to all exposed metalwork outside and the structural metalwork of the building, this will extend into the equipotential zone of the installation.

You will rarely see the main bond to a lightning protection system, the correct place to connect the bond is below ground level, often connected to the earth rod nearest the MET.

Lightning Protection systems should ''Always'' be bonded to the buildings MET, and as stated the connection is generally to the nearest down conductor earth rod, or in the case of a buried copper tape ring, to the nearest point on the copper tape!!

Neither of which explains the point of bonding a lightning conductor.....yes possibly if the LC is in contact with sructural steel,but more often than not the LC's I come across could not possibly introduce an earth potential into the equipotential zone.

 

[Engineer54]

Neither of which explains the point of bonding a lightning conductor.....yes possibly if the LC is in contact with sructural steel,but more often than not the LC's I come across could not possibly introduce an earth potential into the equipotential zone.

What sort of buildings with LP systems do you work on?? You'd be surprised what a few million volts can penetrate to get to earthed metalwork inside the building or structure or even metalwork that forms part of the buildings fabric (eg.. concrete rebar/reinforcement etc)

 

[ferg]

I went to quote for a domestic after a lightning strike.

I was astounded by the damage.

The pole mounted TX was in bits all over the place.

The metal clad CU was blown to bits.

The internal fabric of the building had been destroyed by cables flapping about and bits of the roof were missing.

It was a bit unusual though.

The DNO guy attending afterwards said he'd been to loads of lightning strikes but never seen anything like it.

I got a couple of calls after the event from folks wanting lightning protection

 

[Engineer54]

I went to quote for a domestic after a lightning strike.

I was astounded by the damage.

The pole mounted TX was in bits all over the place.

The metal clad CU was blown to bits.

The internal fabric of the building had been destroyed by cables flapping about and bits of the roof were missing.

It was a bit unusual though.

The DNO guy attending afterwards said he'd been to loads of lightning strikes but never seen anything like it.

I got a couple of calls after the event from folks wanting lightning protection

Probably caused by multiple streamers from a single lightning strike, unusual but decidedly devastating to an unprotected building, even in some cases where an LP system had been installed but not very well designed or installed....

 

[Deleted member 26818]

I think the vehicle charging installer has misunderstood.
There are requirements which differ between DNOs for the provision of TN-C-S earthing for street furniture.
As far as I am aware, those requirements do not apply where the charging point is to be added to an existing installation.
Where a charging point is to be street furniture, invariable an earth electrode will be required.

 

[Deleted member 9648]

What sort of buildings with LP systems do you work on?? You'd be surprised what a few million volts can penetrate to get to earthed metalwork inside the building or structure or even metalwork that forms part of the buildings fabric (eg.. concrete rebar/reinforcement etc)

Last EICR was a medieval stone build church with no other services requiring bonding....but also schools with LC provision. I have not seen any evidence of main bonding to the LC in any of the schools I work,but that does not mean it is not present. I remain unsure of this, there is a requirement to bond CH pipes,but I would only do so if those pipes were introducing an external earth potential to the equipotential zone,which is a rare scenario. Same for an LC entirely on the outside of the building. If that LC is attached to structural steel then it would be the steel i was looking to be bonded,not the LC.

 

[telectrix]

Compared to the **** that's going on in places like Syria I don't think any of us has got much to get arsey about. Especially stuff wrote on forums. Lol

how long have they had part p in syria then?

 

[Engineer54]

Last EICR was a medieval stone build church with no other services requiring bonding....but also schools with LC provision. I have not seen any evidence of main bonding to the LC in any of the schools I work,but that does not mean it is not present. I remain unsure of this, there is a requirement to bond CH pipes,but I would only do so if those pipes were introducing an external earth potential to the equipotential zone,which is a rare scenario. Same for an LC entirely on the outside of the building. If that LC is attached to structural steel then it would be the steel i was looking to be bonded,not the LC.

If you are still not convinced, i suggest you check out all or any of the many LP articles covering the protection of buildings on the internet. You will find that ''ALL'' will stipulate the need for the connection of a LP system to the equipotential bonding to the buildings MET (the better ones giving the reasons why), be they based on BS, NFPA (NEC), VDE/DIN, IEC etc, or come to that, any countries LP standards.... It can't get any clearer than that!!

 

[Knobhead]

Last EICR was a medieval stone build church with no other services requiring bonding....but also schools with LC provision. I have not seen any evidence of main bonding to the LC in any of the schools I work,but that does not mean it is not present. I remain unsure of this, there is a requirement to bond CH pipes,but I would only do so if those pipes were introducing an external earth potential to the equipotential zone,which is a rare scenario. Same for an LC entirely on the outside of the building. If that LC is attached to structural steel then it would be the steel i was looking to be bonded,not the LC.

Time you did some reading up about lightning conductors. Especially at what point you can connect the MET to.