Supplementary bonding question

[TomLonsborough]

Alright folks,

Looking for a bit of advice with supplementary bonding. Bit of background - I'm in the process of repairing some metal bollards: I decided the best option was to rip out the old guts which comprised of some old fluorescents complete with all the control gear and no IP rating, and replace it with an IP rated LED flood. Supply is via SWA into a fused block; I've terminated the included LED flex into this block.

Question is this: do the bollards require bonding?

Initially I thought no, because they are simply a housing for the self-contained flood and the block. However upon taking a continuity reading between certain parts of some of the bollards and the MET, I was getting around 3 Ohms. R < 50A/100 (C 10A MCB) is therefore not satisfied. I decided to add fly-leads connected to the block via bolts screwed into the bollard housing. Problem is the because of the condition of the bollards, i.e. rusty, painted in parts, continuity readings now vary from 0.2 Ohms to no reading at all. An insulation resistance test between MET and various parts of the bollards are also coming back as not satisfactory, i.e. <22000 Ohms. Am I potentially introducing a potential here under fault conditions with these fly leads which would not be present otherwise? Save for replacing the bollards with shiny new ones altogether, I'm not sure what I could do!

Any advice would be gratefully received!

Tom.

TL;DR Supplementary bonding of rusty metal bollards! Necessary or not?
 

 

[binky]

I would say that depends on whether or not the new equipment is Class II, which would make bonding superfluous. However every lamp post I've seen has an earth bond, including to any opening hatch.

 

[Evans Electric]

All lamposts , in my experience  had an earth connection to the post itself  .   I wouldn't describe it as Bonding  just general earthing .

If Sidey reads this I'm guessing he'd say now you have become a manufacturer  you'd have to have them tested to some BS  and declare them Class 1 or Class 2   .

 

[Sharpend]

What is the original earthing arrangement? 
it can not be TNCS, it has to be TNS. 
The earth is usually connected to both the bollard and the door hatch is present. 
If Class 2 then the earth should go to the bollard only. :C  is my understanding but it has been a while since I’ve been involved in this type of work!!