Supplimentary Bonding in an industrial location

[Chri5]

Hi all.

Can somebody please try and clear something up for me.

I'm doing a Periodic Inspection in a medium sized unit.

There's a lot of exposed metalwork (extraneous-conducting-parts) and I'm wondering how much of it needs to be bonded. There's cable tray, unistrut, metal work benches etc and none of it appears to be done.

Thanks for any advice.

Chris

 

[apprentice87]

Hi,

How do you know it is extraneous and not just metal???? remember, extraneous means "liable to introduce a potential, generally earth potential, blah blah,"

I think the proper test, is to do a resistance test between the metal bits and the MET. If you get more than about 25K ohms, then it is not extraneous, and does not need to be bonded.

Having said that, even if it passed the above test, if it was a piece of pipe, say, coming in from "next doors" unit, then i would bond it anyway, as they might bond it to THEIR system, which may then develop an earth fault, which would then i suppose, be "imported" into yours if their earthing system was not too clever, or someone might decide to "earth" their large fabrication they are busy welding to it, not realising that it may well NOT actually be bonded to earth, and it would then be at about 80V all the time they were welding!

I am just a newbie mind, so wait until you get some replies from some of the more experience members before taking my word on this, but i think i am right!!!

Hope this helps!!

john..

 

[Sidewinder]

Chri5,

I'll be my usual cryptic self, and say that I have bonded an incoming copper water pipe in an industrial unit in compliance with the regs 600mm after entry etc. to a DB about 60m away with about 2m of g/y.

Welcome to the forum by the way, you'll get used to me if you stick around, which I hope you do!

 

[binky]

It's not compulsory to get used to sidey or me for that matter :^O

 

[sparky b]

Chri5,I'll be my usual cryptic self, and say that I have bonded an incoming copper water pipe in an industrial unit in compliance with the regs 60mm after entry etc. to a DB about 60m away with about 2m of g/y.

Mr Sidey, does structural steelwork have something to do with that??

B.

 

[Sidewinder]

Yoda impersonation on:

Warm you may be my Padawan...



Could do with a Yoda smilie!

 

[sparky b]

ROTFWL

 

[sparky b]

No pun intended with the NIC boyz here but i did a job and the NIC AC who had wired the mains to the factory couldnt grasp why Structural Steel needed bonding :slap - I did report him to the NIC but they (as any other SCAM would) didnt really care as he had geven them over a grand. He did the unit 2 doors down a year later for the same council under the same NIC badge and i had to install some machines - guess what I noticed !!!

A good Padawan remembers his training does he!!!

 

[Badger]

Yoda impersonation on:Warm you may be my Padawan...



Could do with a Yoda smilie!

one yoda smilie coming right up :slap

View attachment 1636

 

[steptoe]

No pun intended with the NIC boyz here but i did a job and the NIC AC who had wired the mains to the factory couldnt grasp why Structural Steel needed bonding :slap - I did report him to the NIC but they (as any other SCAM would) didnt really care as he had given them over a grand. He did the unit 2 doors down a year later for the same council under the same NIC badge and i had to install some machines - guess what I noticed !!!

did the structural steelwork need bonding though?

or was it part of the earth electrode?

re-bar earthing on a TT ?

just throwing something into the mix for the people that dont understand,

 

[Chri5]

Thanks for all the help.

I'm only posting this so I can see the images lol.

I'll replay when I get chance.