Other peoples work

[SUNRAY]

And they've even used those bloody awful (not) square nuts

Of course they have as they are as cheap as sh... excrement.

Oo thinking about it they are sh...for the job.

I was some way into the thread, before I twigged to what a 'gutter bolt' was. They are what I would call a galvanised roofing bolt - yuk!

I believe you may be correct but the term I always seem to hear is gutter bolt.

 

[333rocky333]

Rocky ??

To clarify a few things.
I took the pic not really because things were actually wrong, but it just all looked wrong, if that makes sense, a bit of planning it could have been done a lot neater.
Reminiscent a bit of RF'S pic of the week

Not used banjos for some time, I like Earthing nuts.

Banjos when used, most of the time fitted on the outside and bolted through the box, if not exposed to water.
Banjo Inside with the tab bent down sometimes , earth bolted on to tab, relying on the locknut and gland for continuity to the box, when exposed to water or maybe outside.

To be fair in most of my cases the boxes are adequately earthed via the gland body, so the banjo likely surplus, but as said i like them more as washers.
Like Sunray I would try to avoid any steel in the earth path where possible, but never considered the slight bit between the bolt, though it makes sense, in cases where the earth fault current levels may be high, but in most of my work the boxes are really used as Junction boxes for Low current equipment like a light.

Bolts always Brass with Full flat washers, lug direct against the steel, if more than one lug, then the Brass bolt would be nutted on to the box first and a second nut and washers to clamp the lugs.
#
Never more than about 4 lugs per bolt if possible, if need be i would fit a second Bolt and strap an Earth across the Two.

Multiple lugs especially yellow ones, wont fit good on a bolt as the bulky bits tend to clash and seem to stress the lugs, like in the pic
I never use Gutter bolts or Square nuts.

As for the Op, probably would have used a longer box and used Din rail terminations, failing that some sort of earth bar or even a Domestic type 8way bolted on the side inside the box.

 

[333rocky333]

...

 

[JohnW2]

To clarify a few things. .... I took the pic not really because things were actually wrong, but it just all looked wrong, if that makes sense, a bit of planning it could have been done a lot neater. ...

Thanks for clarifying and, yes, that was what I presumed was your view. I think that view probably corresponds to most of our first reactions but, as we've seen, it's actually difficult to produce any convincing argument as to why is is 'wrong'. As you know, I think that all of SUNRAY's concerns about brass/steel interfaces in the electrical path are essentially 'barrel scraping'!

I imagine that most of us agree that it "could have been done a lot neater" but, as I've said, I think the first step on that path would be to use larger boxes - since most of the 'lack of neatness' has nothing to do with the termination of the CPCs we have been discussing. Indeed, at least in aesthetic terms, I would personally have said that the termination of the CPCs is one of the 'neater' aspects of what is going on in those boxes!

Not used banjos for some time, I like Earthing nuts. .... Banjos when used, most of the time fitted on the outside and bolted through the box, if not exposed to water.

Indeed, and you're far from alone in that. However, one (at least I) see it mainly with plastic, not metal, boxes - and most of the discussion here started when, back on page 1, Simon, and then I, suggested that banjos were probably not necessary with a metal box.

Banjo Inside with the tab bent down sometimes , earth bolted on to tab, relying on the locknut and gland for continuity to the box, when exposed to water or maybe outside.

Fair enough. Even if you use a banjo, you would be "relying" on the locknut creating adequate continuity between gland, banjo and box, so I'm not convinced that there is much difference.

To be fair in most of my cases the boxes are adequately earthed via the gland body, so the banjo likely surplus, but as said i like them more as washers.

Fair enough - but, as above, if the locknut is not tight enough to create adequate electrical continuity between gland body and box, then nor would it be tight enough to create adequate electrical continuity between the gland body and banjo, would it? (after all, there is only one locknut doing both of those things).

Like Sunray I would try to avoid any steel in the earth path where possible, but never considered the slight bit between the bolt, though it makes sense, in cases where the earth fault current levels may be high, but in most of my work the boxes are really used as Junction boxes for Low current equipment like a light.

I have never disagreed with SUNRAY's theoretical argument. I don't think it's so much the CCC of steel that concerns him as much as the potential electrochemical issues when the path includes dissimilar metals in contact, but I don't really think that is a significant issue in 'dry' situations.

Bolts always Brass with Full flat washers, lug direct against the steel, if more than one lug, then the Brass bolt would be nutted on to the box first and a second nut and washers to clamp the lugs. Never more than about 4 lugs per bolt if possible, if need be i would fit a second Bolt and strap an Earth across the Two. Multiple lugs especially yellow ones, wont fit good on a bolt as the bulky bits tend to clash and seem to stress the lugs, like in the pic.

I take your point about the 'bulky bits' of the lugs, but that's a potential issue with just two, and I don't see that (if they are arranged sensibly), it would be any more of a problem with, say, 8 lugs than with 4. In situations in which there was space for a long bolt, I've seen people put nuts (or just thick washers/'spacers') in between each lug but that then introduces a number of further potential 'issues' and uncertainties (particularly if one uses multiple nuts)!

I never use Gutter bolts or Square nuts.

I wouldn't have expected that anyone would (for this purpose) - I'm not sure where that one came from

As for the Op, probably would have used a longer box and used Din rail terminations, failing that some sort of earth bar or even a Domestic type 8way bolted on the side inside the box.

As I've implied, so would I - but, as I keep saying, I think I would have to facilitate that by starting with larger boxes. As I've said above, although most of this discussion here has been about the termination of the CPCs, most on the 'non-neatness' is down to the live conductors.

Kind Regards, John

 

[333rocky333]

Throughout my career i have heard talk about dissimilar metals, yet always baffled by various combos,
Was it ever an issue to be concerned about, only issues i have encountered is parting them, if needbe after many years.

Brass bushes with Galv or Black enamel locknuts/rings
4mm or 2BA Brass screws in Galv or Black enamel boxes
Brass Pyro glands with steel lockrings
Steel conduit couplers with Brass bushes
Are just a few.

 

[333rocky333]

' Simon, and then I, suggested that banjos were probably not necessary with a metal box.


Kind Regards, John

Sorry to disagree with that

Maybe i have been wrong all these years, I thought the point of a Banjo was to attach an Earth wire to, to get a direct connection to the gland body and hence the Armour, so how does the box material affect that.

Banjos become more popular in the late 80's when the fad increased to Feed METAL Dist boards with SWA and run a Fly lead in the board from the Banjo bolt to the Earth bar.
I quess to limit steel being in the earth path.

I was taught banjos were not to be used in the suggested way with plastic boxes, due to the density of plastic, and to fit a locknut inside first then double lock the banjos with a second locknut also inside.
One reason why Earthing nuts feature an allen key screw to nip into the thread when used with plastic boxes.

 

[JohnW2]

Throughout my career i have heard talk about dissimilar metals, yet always baffled by various combos, .... Was it ever an issue to be concerned about, only issues i have encountered is parting them, if needbe after many years.

As I implied, I think it's only something to be potentially concerned about in wet/damp environments (the worst probably being 'salt water' or 'corrosive environments) but, even then, I think it's likely to be many years before any significant problems are likely to arise, particularly if the dissimilar metals are tighly clamped together so that the moisture does not usually get to their interface..

Brass bushes with Galv or Black enamel locknuts/rings ... 4mm or 2BA Brass screws in Galv or Black enamel boxes ... Brass Pyro glands with steel lockrings ... Steel conduit couplers with Brass bushes ... Are just a few.

Quite so - and, as you imply, countless others. What, for example about the brass 'earth terminals' riveted into steel back boxes? .... and how about the one below? All of that earth bar, including the outer part of the terminals, and the terminal screws, are steel - but there are actually copper or brass 'inserts' within the terminal holes.

Kind Regards, John

 

[JohnW2]

Sorry to disagree with that

Yes, I understand and accept that you, and others disagree with what Simon and myself suggested.

Maybe i have been wrong all these years, I thought the point of a Banjo was to attach an Earth wire to, to get a direct connection to the gland body and hence the Armour, so how does the box material affect that.

If you use a banjo then, as you say, the box material does not affect the connection between the banjo and whatever conductor is bolted to it. However, as I keep saying, how well the banjo is (electrically) connected to the gland body is dependent upon how well ('tightly') it is clamped to the gland's body (and the box) by the gland's locknut. So, as I've said, if that connection is good (tight) enough to achieve the required continuity between banjo and gland body, then so will it be good (tight) enough to achieve the required continuity between the box and the gland body. In other words, no matter whether one connects one's CPCs to the banjo or box, the continuity (with gland body) will be equally good (or bad) depending upon how well the locknut is keeping the gland/banjo/box sandwich tightly clamped together. The fact that some of the 'path' would be through steel if one didn't use a banjo is, to my mind, essentially irrelevant.

Banjos become more popular in the late 80's when the fad increased to Feed METAL Dist boards with SWA and run a Fly lead in the board from the Banjo bolt to the Earth bar. ... I quess to limit steel being in the earth path.

I would be inclined to suggest that it's a little silly to worry about 'steel in the earth path' (within the board) when the armour to which it was connecting would be entirely steel!

I was taught banjos were not to be used in the suggested way with plastic boxes, due to the density of plastic, and to fit a locknut inside first then double lock the banjos with a second locknut also inside.

Same here. That's sensible and is what I would usually do.

One reason why Earthing nuts feature an allen key screw to nip into the thread when used with plastic boxes.

Indeed, and again sensible. In both cases it means that even if the mechanical connection between plastic box and gland becomes 'loose', the electrical connection between the gland body and the earth nut (hence anything connected to it) will remain 'tight'.

Kind Regards, John

 

[SUNRAY]

To clarify a few things.
I took the pic not really because things were actually wrong, but it just all looked wrong, if that makes sense, a bit of planning it could have been done a lot neater.
Reminiscent a bit of RF'S pic of the week

Not used banjos for some time, I like Earthing nuts.

Banjos when used, most of the time fitted on the outside and bolted through the box, if not exposed to water.
Banjo Inside with the tab bent down sometimes , earth bolted on to tab, relying on the locknut and gland for continuity to the box, when exposed to water or maybe outside.

To be fair in most of my cases the boxes are adequately earthed via the gland body, so the banjo likely surplus, but as said i like them more as washers.
Like Sunray I would try to avoid any steel in the earth path where possible, but never considered the slight bit between the bolt, though it makes sense, in cases where the earth fault current levels may be high, but in most of my work the boxes are really used as Junction boxes for Low current equipment like a light.

Bolts always Brass with Full flat washers, lug direct against the steel, if more than one lug, then the Brass bolt would be nutted on to the box first and a second nut and washers to clamp the lugs.
#
Never more than about 4 lugs per bolt if possible, if need be i would fit a second Bolt and strap an Earth across the Two.

Multiple lugs especially yellow ones, wont fit good on a bolt as the bulky bits tend to clash and seem to stress the lugs, like in the pic
I never use Gutter bolts or Square nuts.

As for the Op, probably would have used a longer box and used Din rail terminations, failing that some sort of earth bar or even a Domestic type 8way bolted on the side inside the box.

Thanks for clarifying and, yes, that was what I presumed was your view. I think that view probably corresponds to most of our first reactions but, as we've seen, it's actually difficult to produce any convincing argument as to why is is 'wrong'. As you know, I think that all of SUNRAY's concerns about brass/steel interfaces in the electrical path are essentially 'barrel scraping'!

I imagine that most of us agree that it "could have been done a lot neater" but, as I've said, I think the first step on that path would be to use larger boxes - since most of the 'lack of neatness' has nothing to do with the termination of the CPCs we have been discussing. Indeed, at least in aesthetic terms, I would personally have said that the termination of the CPCs is one of the 'neater' aspects of what is going on in those boxes!
Indeed, and you're far from alone in that. However, one (at least I) see it mainly with plastic, not metal, boxes - and most of the discussion here started when, back on page 1, Simon, and then I, suggested that banjos were probably not necessary with a metal box.
Fair enough. Even if you use a banjo, you would be "relying" on the locknut creating adequate continuity between gland, banjo and box, so I'm not convinced that there is much difference.
Fair enough - but, as above, if the locknut is not tight enough to create adequate electrical continuity between gland body and box, then nor would it be tight enough to create adequate electrical continuity between the gland body and banjo, would it? (after all, there is only one locknut doing both of those things).
I have never disagreed with SUNRAY's theoretical argument. I don't think it's so much the CCC of steel that concerns him as much as the potential electrochemical issues when the path includes dissimilar metals in contact, but I don't really think that is a significant issue in 'dry' situations.
I take your point about the 'bulky bits' of the lugs, but that's a potential issue with just two, and I don't see that (if they are arranged sensibly), it would be any more of a problem with, say, 8 lugs than with 4. In situations in which there was space for a long bolt, I've seen people put nuts (or just thick washers/'spacers') in between each lug but that then introduces a number of further potential 'issues' and uncertainties (particularly if one uses multiple nuts)!
I wouldn't have expected that anyone would (for this purpose) - I'm not sure where that one came from
As I've implied, so would I - but, as I keep saying, I think I would have to facilitate that by starting with larger boxes. As I've said above, although most of this discussion here has been about the termination of the CPCs, most on the 'non-neatness' is down to the live conductors.

Kind Regards, John

When reading through Rockys words theyre not a lot different to my thoughts. Personally I don't like relying on the mechanical joint between gland and enclosure for the earth. The old packs used to supply 2 brass nuts, the plan was to fix the gland in place, add the banjo and second nut so the eletrical connexion was performed by 2 nuts and not pressure against the enclosure,the lazy work done by so many eventually led to dropping one nut unfortunately. Now of course the Earthing nut has recreated that original job very nicely, however I've encountered some poor attempts at using them.
Glad I'm not the only one to suggest the earth bar.
As mentioned already I rarely put a nut in to fix the bolt to the box as when tightening the second nut against the lugs it's quite easy to turn the bolt which can have the effect of unscrewing it and leaving less than secure pressure against the banjo, it is something I've encountered on a number of ocassions and in the older gland packs there would be one bolt, one nut and 3 washers all in brass.
It may be barrel scraping, but it's barrel scraping born out of experience. I too have never said it doesn't comply.
Correct I have no issues with CCC of steel, indeed the steel armour for earth currents has not been mentioned [hope I haven't missed it]. When done properly [the old way] the banjo connexion to the gland doesn't rely on the mechanical lock nut.
I've encountered earth studs with far too many insulated lugs, one stage lighting bar in particular springs to mind, 18 sockets with individual earth wires and the installation done with 18 3 core flexes so 36 lugs on one stud. The pic I put up earlier was a 6 way version but fed with only a single 6mm² earth wire. If there is plenty of room around the stud, one can usually manage about 5 lugs on an M6 without them clashing and then one full washer is often enough for the next layer of lugs but at that point I'd be hoping to be doing something better.
I'm glad to see your doubts about multiple nuts in a pile of lugs, I take it you have the same doubts about a locknut against the enclosure. If there is a specific reason for doing so I'll use studding with a nut each side of the enclosure/banjo so it can be tightened and checked/retightened.
Im not sure where your surprise about using gutter bolts for the earth arrangement comes from, afterall it's right there in OP.

 

[JohnW2]

When reading through Rockys words theyre not a lot different to my thoughts.

Nor mine, other than my doubts about the need for a banjo at all with a metal box.

Personally I don't like relying on the mechanical joint between gland and enclosure for the earth.

... yet you seemingly do 'like' relying on the mechanical joint between gland and banjo?

The old packs used to supply 2 brass nujletrical connexion was performed by 2 nuts and not pressure against the enclosure, ...

As I said, that's what I do with plastic boxes.

It may be barrel scraping, but it's barrel scraping born out of experience. I too have never said it doesn't comply.

And nor have I ever said that I have any problem with how you would do things. Provide they are not 'wrong' (electrically unacceptable), we're all entitled to have our own views about how to do things - indeed, our own ideas about 'the best way' to do things.

When done properly [the old way] the banjo connexion to the gland doesn't rely on the mechanical lock nut.

That's a bit semantic, isn't it, since it does rely on A mechanical lock nut, it's just a different lock nut from the one holding the gland to the enclosure. Indeed, it's arguably slightly 'worse, since if the nut holding the gland to the box was a bit loose, that could compromise the mechanical (hence electrical) connection between the banjo and the nuts on either side of it (like your concerns about having a nut on a bolt, against the box, prior to the lugs).

I've encountered earth studs with far too many insulated lugs

That issue has been agreed - and, as we both have said, it can be mitigated to some extent by the use of washers.

... I take it you have the same doubts about a locknut against the enclosure.

... yet you seem to have no doubts about a locknut on the gland against the enclosure followed by a second locknut to hold on a banjo ('the proper way')?

Kind Regards, John

 

[SUNRAY]

Yes, I understand and accept that you, and others disagree with what Simon and myself suggested.
If you use a banjo then, as you say, the box material does not affect the connection between the banjo and whatever conductor is bolted to it. However, as I keep saying, how well the banjo is (electrically) connected to the gland body is dependent upon how well ('tightly') it is clamped to the gland's body (and the box) by the gland's locknut. So, as I've said, if that connection is good (tight) enough to achieve the required continuity between banjo and gland body, then so will it be good (tight) enough to achieve the required continuity between the box and the gland body. In other words, no matter whether one connects one's CPCs to the banjo or box, the continuity (with gland body) will be equally good (or bad) depending upon how well the locknut is keeping the gland/banjo/box sandwich tightly clamped together. The fact that some of the 'path' would be through steel if one didn't use a banjo is, to my mind, essentially irrelevant.
I would be inclined to suggest that it's a little silly to worry about 'steel in the earth path' (within the board) when the armour to which it was connecting would be entirely steel!
Same here. That's sensible and is what I would usually do.
Indeed, and again sensible. In both cases it means that even if the mechanical connection between plastic box and gland becomes 'loose', the electrical connection between the gland body and the earth nut (hence anything connected to it) will remain 'tight'.

Kind Regards, John

My belief is the earth lead to the gland body has nothing to do with dissimilar metals. As I remember it the introduction of the current style of SWA glands came in 2 styles; Gland and one lock nut for use when running a separate earthwire or gland, banjo, 2 brass lock nuts, brass bolt set and instrustions on how to fit. in either case there was no reliance on the mechanical jointto the enclosure for the circuits earth fault current.

And of course there is no, and never has been, a requirement to fit a brass gland for a SWA termination.

 

[SUNRAY]

John.
May I assume you would accept this bolt with 2 nuts tightened against a lug forms a sound electrical connexion?

 

[JohnW2]

My belief is the earth lead to the gland body has nothing to do with dissimilar metals.

That's my belief, too - and it certainly was not me who brought 'dissimilar metals' into the discussions.

As I remember it the introduction of the current style of SWA glands came in 2 styles; Gland and one lock nut for use when running a separate earthwire or gland, banjo, 2 brass lock nuts, brass bolt set and instrustions on how to fit. in either case there was no reliance on the mechanical joint to the enclosure for the circuits earth fault current.

True, but in the second case (with a banjo), whilst there was "no reliance on the mechanical joint to the enclosure for the circuits earth fault current", there was "reliance on the mechanical joint between the gland and banjo for the circuits earth fault current" - and, just like "the mechanical joint to the enclosure" that (electrical) 'joint' was reliant on "a" locknut. I somewhat struggle to see any material difference.

And of course there is no, and never has been, a requirement to fit a brass gland for a SWA termination.

Very true, but this discussion appears to be all about the situation when a brass gland is used.

Kind Regards, John

 

[JohnW2]

John. May I assume you would accept this bolt with 2 nuts tightened against a lug forms a sound electrical connexion?

You may assume that ... so long as the nuts don't become loose.

The chances of one of them coming loose would probably be less if one of the nuts were tightened (on the stud/bolt) against something else (like the wall of a 'box').

Kind Regards, John

 

[SUNRAY]

You may assume that ... so long as the nuts don't become loose.

The chances of one of them coming loose would probably be less if one of the nuts were tightened (on the stud/bolt) against something else (like the wall of a 'box').

Kind Regards, John

Well I hope it does form a sound electrical connexion as it is the method used for terminating on to these as there is nothing to tighten against:

I can't find fitting instructions on line to quote from but they say to leave 5mm clear of the resin, fit a nut, washer, lug, washer & nut.

So, as predicted, you have pre-empted my question but I'll ask it anyway. When that bolt is actually the thread on the gland and the thread passes unhindered through the wall of an enclosure, let's say it's plastic as I believe you understand that concept, may I also assume you accept this arrangement is electrically, but not mechanically, sound?

The lug is of course now replaced with the banjo.


Perhaps we should go back to previous arrangements with a tapped hole for a lug to be bolted directly to.