Do you need to use fly leads on swa banjos and what size cable shouls you use

[cleatus]

Do you need to use fly leads on swa banjos and what size cable shouls you use, also does it make a difference if you are glanding straight into the db.
If you are not relying on the armouring for you earth and you have a seperate cpc either in the cable or seperate does yhis not create parallel paths.

 

[Deleted member 26818]

Nothing wrong with creating parallel paths.
Yes you should use fly leads, and the cable should be sized appropriately as per a CPC to the size of the other cable conductors.
In some instances, it might be preferable to only earth one end of the armour (usually the supply end).
Such as when supplying a TT'd out building from a TN-C-S installation, or where EMF might cause problems with controls and inverters.

 

[nick611]

using a core as the cpc i wouldnt worry to much about banjo.unless leaving a pvc box.its only a bit of supplementry so a metal enclosure will connect it. if the swa is your cpc then a banjo and earth lead as big as the relevent cpc.

 

[mayfair]

Please be kind and remember i've been out of country for 21 years........ Banjo's????? something ive forgot or new?

 

[Deleted member 26818]

Banjos, sometimes refered to as frying pans.
The brass bit that goes round the gland, and has a bit sticking out with a hole in to connect your fly lead to.

 

[cleatus]

So would you say that the fly lead earth should be half the live conductor or could it be smaller maybe half the size of the cpc conductor?

Is there a table in the regs book for this?

 

[somersetsparks]

I personally use serrated washers instead of banjos, I only use banjos on plastic enclosures to provide earth. I always find it funny that banjos are used with swa when with conduit and pyro they are not!
I always scrape the paint away from where the gland sits as well, on most big jobs I have been on no banjos are used at all, just serrated washers.
Oh forgot to say as well - I would normally put banjo and Flylead at DB end, I always use same size fly lead as live conductor.

 

[MarkieSparkie]

Mayfair, Banjo = solder ring terminal or crimp ring terminal.

 

[grantr37]

Banjo=Frying pan handle=Bonding Tag=Bonding washer... 3 kinds -Solder, crimp and clamp (Bolt) I quite often put one on the Brass Gland with a thin Lockring and a length of earth bond wire, then use yellow or stripey green/yellow heatshrink over the crimp on each end, and either roofing bolts or copper bolts depending on the size of the board and what I have available....and a little "protective earth dont remove" sticker beside it as well... I think its more in case the cable gets pulled out of the panel at any point by accident, as an addition to the earth core...

 

[sparks1234]

Never understood this really, If for example you take a Memshield dis board, the whole casing is classed as earth, as much as the earth bar itself. Also, if the gland is tight and the paint has been scraped then you will have a good earth, if the gland is not tight then you wont have an earth anyway unless you introduce a second lockring to secure the banjo

 

[somersetsparks]

Exactly sparks1234, people go OTT with banjos etc. which is all well and good but then don't tighten the lockring very well anyway! I always scratch off paint and tighten glands with proper spanner, adjustable or box spanner, depending on what I can get on it!
At the end of the day, you dont banjo conduit or pyro and you can use that as earth! If your using a metal earthed enclosure then You can just fly lead to the terminal on that. I.e socket back box, dis board, whatever! If you look in an Pyro dis board there are sometimes no earth fly leads at (i.e. nothing in the bar).

 

[Deleted member 26818]

Perhaps banjos, and fly leads are a bit over the top.
However BS7671 does require us to use good workmanship, proper materials and to follow the instructions of the manufacturers (Reg. No.134.1.1).
We are also required to ensure that the equipment we install meets relevant British Standards (Reg. No. 133.1.1), would ommiting the Banjo and fly lead comply with the standards for SWA cables?
Then there is the consideration on whether it is preferable to rely on a brass banjo and copper fly lead for continuity, or the small amount of steel that the gland is in contact with, which over time will become corroded? This corrosion hastened by the fact that there are two disimilar metals in contact with each other.