Bonding

[D Skelton]

Ok chaps, so why do we bond lightning conductors???

I've asked quite a few people not one of which has got the foggiest?! Seems idiotic to me

 

[telectrix]

i would imagine that the conductor is extraneous and as such requires bonding.

 

[Bobster]

Lightning conductors are tied to earth.

I can understand the reasoning, so there can't be a potential between two earthed items. However bonding in a house won't be rated to take a lightning strike?

 

[D Skelton]

Extraneous or not, does it not strike you as odd. Imagine during a lightning storm a bolt hits your bonded lightning conductor at the same time you happen to be in the bath! mmmm, toasty!

 

[D Skelton]

Lightning conductors are tied to earth.

I can understand the reasoning, so there can't be a potential between two earthed items. However bonding in a house won't be rated to take a lightning strike?

I know that, I just don't understand the advantage of introducing your entire earthing system to a lightning conductor that is already earthed.

 

[ringer]

A nearby earth fault may instigate a rise in potential within the lightning rod with respect to other conductive systems within the property. The point of bonding is to minimise such differences in potential within the property. Ligtning rods are typically installed externally but will still form part of the property's systems.

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[telectrix]

Extraneous or not, does it not strike you as odd. Imagine during a lightning storm a bolt hits your bonded lightning conductor at the same time you happen to be in the bath! mmmm, toasty!

perhaps that's why we don't supp.bond baths any more.

 

[Bobster]

Being devils advocate, would you class the conducting bars as extraneous? Are they not insulated?

 

[D Skelton]

perhaps that's why we don't supp.bond baths any more.

Nothing to say you can't. And if all pipes throughout are copper, the taps will still give you a rather nice tingle when that lightning bolt hits!

 

[D Skelton]

Being devils advocate, would you class the conducting bars as extraneous? Are they not insulated?

Exactly, they're insulated anyway so who cares about nearby earth faults.

 

[D Skelton]

A nearby earth fault may instigate a rise in potential within the lightning rod with respect to other conductive systems within the property. The point of bonding is to minimise such differences in potential within the property. Ligtning rods are typically installed externally but will still form part of the property's systems.

Sent from my HTC Sensation using Tapatalk

I'm fully aware of the reasons for equipotential bonding. Just not like I said introducing your entire earthing system potentially to millions of volts!

 

[Bobster]

All I know is I've never seen it bonded before.

 

[Silly Sausage]

GN8 doesn't shed any light on the subject, just says you have to, reg 411.3.1.2 (presumably that one) BRB

All I know is I've never seen it bonded before.

GN8 also says that should be noted as a departure from above reg on an EIC.

 

[D Skelton]

Yep, as stated by Archy. It's in the regs. It's gotta be done. But whyyyyy godammit

 

[Knobhead]

This may point you in the right direction Lightning & Transient Over-Voltage Protection System Earthing Surge Arrestors Design Guidance by Furse