Fly leads in DB From SWA

[The Ghost]

I know this has been kicked around quite a bit on the forum but I have not seen any answer in terms of solid regs or otherwise. i.e. no compelling reason to fit, or leave it as is.

29 Units have Merlin Gerin boxes. All supplied from switch room by MCCB. Various sizes of SWA. 3 core L-N-E. Armour is terminated on DB (Merlin Gerin again) without banjo or fly lead onto earth busbar. This then goes to Ring CCT and lighting CCT in each Unit.

Question. Should we supply banjo and fly leads and fit them?
with reasons why (or why not) On an EICR what code would you give absence of fly leads (bonus question)

 

[telectrix]

i fit banjos ( or easrthing nuts) and fly leads as you can't always rely on good continuity from the earth bar to the metal case. had it ona a switch/fuse where a Ze was 100+ ohms on a PME system added a flylead and got ).2 ohms.

 

[The Ghost]

Thats an impressive difference, maybe if I did a wander lead test and went on that to make a decision of whether it is necessary. Bear in mind the DB has its own earth though.

 

[7029 dave]

I remember when fly leads were not used, if you cleaned up the job with a file, are they needed, same goes with micc.

 

[telectrix]

in the case i referred to, it was a poor continuity between the earth bar and the casing, although it was manufacturer bolted on.

 

[7029 dave]

It was also a 90's thing under the 16th ed, fly lead on switch and socket boxes, got stupid IMO glad that went.

 

[Octopus]

Use a piranha and you'll not get a bad connection!

 

[telectrix]

Use a piranha and you'll not get a bad connection!

why mention the mother-in-law?

 

[The Ghost]

Use a piranha

Yeh if we HAVE to fit them that is the way to go defo. But tbh I'm trying to find a justification not to.

 

[Wilko]

Thats an impressive difference, maybe if I did a wander lead test and went on that to make a decision of whether it is necessary. Bear in mind the DB has its own earth though.

With my tin hat on :
I haven't seen a reg but am always happy to learn. If it tests ok then it is ok, in my small mind. However if it relies on metals prone to corrosion then inspection intervals should take proper account. So fly leads mean one less thing to worry about.

 

[bigspark17]

I would always fit them on an install but if all tests out ok on an eicr without id say ok as you have core inside swa as earthing conductor also, if the db's are supplied via 2c with screwed panels then if be inclined to c2 observation it.

 

[westward10]

I would always fit them on an install but if all tests out ok on an eicr without id say ok as you have core inside swa as earthing conductor also, if the db's are supplied via 2c with screwed panels then if be inclined to c2 observation it.

Ensuring the armour is earthed is as important whether the cable incorporates a separate core as a cpc or not.

 

[The Ghost]

Ok well thanks for all the replies. Food for thought!

 

[westward10]

I often quote Reg 543.2.7 but this would apply in some eyes where the armour is actually the cpc.

 

[The Ghost]

Reg 543.2.7

Thanks Westward thats something solid to base a decision/discussion on.