Bonding question

[tomlonsborough]

Alright folks,

Looking for a bit of advice with supplementary bonding - pictures attached for context. 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. I should also add, the frosted PVC surround will be replaced during the repairs.

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.

 

[Strima]

Are those 951 clamps on the SWA armour?

 

[Midwest]

I'm thinking the bollards are an exposed conductive part, as opposed to an extraneous conductive part. Is the new led luminaire, Class 1 or 2?

Edit, would also be looking in Section 709, to see what it says in there, generally.

 

[casperLennon]

Is that wood that the earth is screwed to on picture 2?

 

[Ian1981]

If they are anything then They maybe exposed conductive parts requiring to be earthed.
It would be hard to maintain an equipotential bonding zone with the bollard light as you will be stood directly on the ground while outside, so bonding would be pointless and is not is necessary.
Main Bonding is required when a conductive part enters a building/installation which introduces an earth potential and does not form part of the installation.

 

[tomlonsborough]

Are those 951 clamps on the SWA armour?

Yes mate - not my work I might add! There's a single core attached to the armour used as a CPC into the fuse block.

 

[Wilko]

Hi - my thought is - if the LED lamp is Class 2 then you may have a chance if all your good works are properly contained etc, otherwise it looks like a Class 1 with exposed conductive parts and should be earthed.

 

[Strima]

Yes mate - not my work I might add! There's a single core attached to the armour used as a CPC into the fuse block.

I would be replacing those as they can cause damage to the cable insulation and the correct glands will also reduce the risk of corrosion in the future.

A Lucy two way plate would maintain continuity and also provide a good bonding point:

Two way cable entry plates - Lucy Zodion

The Lucy Zodion range of two way brass or insulated gland plates are able to receive 20 or 25mm tubes for the termination of cables. Alternatively grommets and cable glands can be used to accommodate different sized tubes, indicated in the Selection charts below. Internal earth leads are...

www.lucyzodion.com