Brass gland plate for SWA

[Lucien Nunes]

Has anyone used a brass gland plate to earth a line of SWA glands e.g. at a DB, and had anyone such as an NICEIC inspection flag it up as non-compliant?

I am proposing to screw a flat plate of brass onto the top of the DB and mount the glands through it with their usual locknuts, A brass bolt through the plate will take the lug of a cable running to the earth bar. I consider this to be a suitable way to earth the glands, but someone else is saying that they did something similar and their NIC man pulled him on it and demanded separate banjos or piranhas with individual flyleads.

Any thoughts?

 

[stevethesparks]

No problem whatsoever as far as I'm concerned.

 

[Rockingit]

Nor me - except - a pedant could argue that if when you open the packet of SWA gland and find a banjo (as you do) then 'that's how the manufacturer intends.....'.

 

[DefyG]

Nor me, can’t see that brass glands on brass plate are really any different than brass banjo’s being bolted together!

 

[timhoward]

In some ways it's better - fewer connections to maintain.

their NIC man pulled him on it and demanded separate banjos or piranhas with individual flyleads.

Might be a distinction between using armour as CPC and simply earthing the armour? A single cable to earthing bar from plate may have not met collective requirements for a group of CPCs.

 

[Lucien Nunes]

Someone like to confirm what that is?

 

[timhoward]

Someone like to confirm what that is?

Don't have BBB with me, Section 543 (can remember that nice number!) covers sharing cpc's somewhere in it - something about the highest current expected from a fault on one of the circuits. Requirements for minimum CPC size in general (as separate) need to be met too. Probably no more than you were going to do anyway.

I was more trying to convey that knowledge of CPC sharing can be sketchy as it isn't common and anything that looks unusual can easily cause an assessor to spit dummy out.

 

[Rockingit]

543.2.9 suggests this is OK to me, although I guess easily confused with 543.2.7

 

[littlespark]

It’s used to be any tight metal to metal contact would suffice for earthing.
Banjos if you were glanding through plastic, but metal, especially brass, don’t need them.

 

[ipf]

Cant see anything wrong with it, myself. Once fitted, it's solid, less complicated, room saving, easier and it's fixed to, and therefore part of, the metal enclosure. With the earth bar link, extremely satisfactory.

 

[loz2754]

Not too dissimilar to using the Wiska gland plate across 2 SWA cables in a Wiska box.

 

[Darkwood]

It's totally fine as others have mentioned and the earth tail sized suitably to meet the needs of the largest cable/highest fault current.
I often link banjos together looping an earth tail between them, it saves a lot of unsightly cable from every banjo.

 

[Lucien Nunes]

Right, good, logic prevails.
Now, supposing the plate were not brass but aluminium?

 

[ipf]

Not too dissimilar to using the Wiska gland plate across 2 SWA cables in a Wiska box.

They should make them for DB's.......Now, there's an idea someone else may have thought of. ? ?

 

[ipf]

Right, good, logic prevails.
Now, supposing the plate were not brass but aluminium?

Or steel, even?
Installed hundreds of pyros into industrial boiler and heating control panels in the past.. without the earth tailed pots, sometimes in groups of 20, 30 or more. Imagine the work involved to banjo or even extend pot tails.
If a problem with the NICEIC, it could be just a case of regulation for today's class of workfolk and materials.

In some extreme situations, maybe one issue could be the adverse affect of different metals but, in general....? Then again, another plus point.......brass or ally wouldn't have the rust factor.

 

[Darkwood]

Given the csa of the gland plate and as long as its thicker than tin foil and conductive you should be fine.. noted we use aluminium plates often when bringing in single core phases to stop circulating eddy currents so it's a well established practice.

 

[pc1966]

Right, good, logic prevails.
Now, supposing the plate were not brass but aluminium?

If brass glands you will have issues of galvanic corrosion in even the slightest of damp environments.

Unless you use jointing compound like Penetrox, etc, between them.

Electrically no issue if plate is of sane thickness so max current density around the earth connection is not any risk of failure!

 

[Lucien Nunes]

I would agree that brass is preferable to aluminium on account of the risk of corrosion and the tendency to make unpredictable contact due to oxide film formation. I raised the original question because the other chap had, like me, intended the plate to provide a neat, reliable connection for his glands, and was peeved to find an NIC inspector quibbling with it, especially in the absence of a clear-cut non-compliance.

Thanks to everyone who has replied.