- Thread starter Bravheart
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Melvyn Best
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Internal earthing clamps , Screwfix sell them
Bravheart
"Tomorrow will be a good day"captain Tom1920-2021
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Thanks that would have been done by a pro sparky AFAIK a few years ago and was about to copy his install now but see what you mean about using swa glands.
When measuring up for a gland size is it the core cable diameter that's needed or the outer sheath diameter or the armour cable diameter with the outer sheath stripped off?
sparkysy
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Yeah don't copy that, it's not good!
If you know the core size (some cables it's on the outer sheathing) and number of cores then you can select the gland size from a chart that can be found online.
Like this one.
Be careful as not all gland manufacturers recommend the same sizes.
www.meteorelectrical.com
If you know the core size (some cables it's on the outer sheathing) and number of cores then you can select the gland size from a chart that can be found online.
Like this one.
Be careful as not all gland manufacturers recommend the same sizes.
Find the Perfect Gland for Your SWA Cable: A Comprehensive Guide by Meteor Electrical
Find the perfect SWA cable gland with Meteor Electrical's guide and size chart. Ensure safety, efficiency, and durability for your projects today.
www.meteorelectrical.com
All due respect to those that have contributed to this thread but is what being suggested correct?
I read up on this a little while ago and have forgotten much but here goes.
It is indeed correct to say the above photo is/was never the correct method although I have come across many older installations just like this with this type of Earth Strap around the SWA and I suppose it depends on the various DNOs to ignore or get stroppy on such things if they happen upon them.
It's wrong anyway but if it's going to be done an external Tenby type strap should be used not the internal type, they look the same.
The glands being suggested are for the SWA as it enters a metal enclosure of some type.
My understanding is a sweated leaded Earth Gland with a braided Earth strap was the norm, ( where the sheath had been trimed a little further down the SWA ), these can break/weaken/corrode over time hence the Tenby type clamps .
I believe the correct method is the use of a CFS or Constant Force Spring or Constant Pressure Spring with an Earth Braid tail/strap, I think that's what they are called?
I read up on this a little while ago and have forgotten much but here goes.
It is indeed correct to say the above photo is/was never the correct method although I have come across many older installations just like this with this type of Earth Strap around the SWA and I suppose it depends on the various DNOs to ignore or get stroppy on such things if they happen upon them.
It's wrong anyway but if it's going to be done an external Tenby type strap should be used not the internal type, they look the same.
The glands being suggested are for the SWA as it enters a metal enclosure of some type.
My understanding is a sweated leaded Earth Gland with a braided Earth strap was the norm, ( where the sheath had been trimed a little further down the SWA ), these can break/weaken/corrode over time hence the Tenby type clamps .
I believe the correct method is the use of a CFS or Constant Force Spring or Constant Pressure Spring with an Earth Braid tail/strap, I think that's what they are called?
sparkysy
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It's always been a no no as long as I have been in the trade.
Yes constant force springs or sweated earth tail are compliant on a main incoming supply cable.
SWA cables it's always been a gland and earth tag (banjo) or now earth nut or wiska spring tag.
Even if the enclosure was plastic, you would just use two locknuts and sandwich the banjo between them!
Yes constant force springs or sweated earth tail are compliant on a main incoming supply cable.
SWA cables it's always been a gland and earth tag (banjo) or now earth nut or wiska spring tag.
Even if the enclosure was plastic, you would just use two locknuts and sandwich the banjo between them!
Yes, its what I thought'
The glands being suggested for @Bravheart while correct if they entered an enclosure, ( or plastic ), his photo shows that's not the case if I'm viewing correctly.
It's more than likely sometime in the way past someone has trimmed the SWA sheathing and used a Tenby type strap to facilitate an Earth, I've seen it so many times.
The strap as used in the photo was wrong from the start, further its an internal type, these can corrode/rust/get brittle, get lose, ( then there is no Earth ), the same can happen to the external type but if it's going to be wrong, do it right, the external type are better suited.
I'm not even sure if you can buy sweated earth connections as I think they are DNO supplied?
Not sure how you fit a CFS, have read they can be a bitch to fit.
brightspark
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correct no matter when it was fitted or by who its wrong its not a proper mechanical connection .a proper swa gland should be fitted with the earth tag and a brass nut and bolt
Out of interest, what type of gland/brass nut bolt are you considering, thinking of?
brightspark
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But isn't that type of gland for fixing in to a metal or plastic CU for example, if I'm understanding photo, the striped sheath, ( the exposed armour ), is before that, how are you going to attach, fit it?
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You've got to watch your fingers when fitting them!
brightspark
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on the end of the armoured not part of the way down it. just tape up the exposed wire cores
How is it done, do you uncurl it, make sure the braid strap is in position, let go and it curls back up and clamps?
sparkysy
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They are very springy and the edges can be sharp.
If you imagine the inside of a tape measure roll that is wat they are like, you uncurl one end, wrap it round the cable and keep wrapping until the last sharp bit tries to rip your finger to shreds
Dave-sparks
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Disconnect and remove the cable, fit the gland, refit and terminate the cable.
Although it looks like the top of a shroud is visible at the bottom of the picture so it may well have a gland fitted already just missing the earth connection.
Dave-sparks
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It has nothing to do with the DNO, their responsibility ends at the supply cut-out. You may be confusing the above picture of SWA with the lead sheathed type cables used by the DNO in the past which also are quite often seen with an earth clamp on them.
It would be just as wrong to use Tenby as it would any other manufacturers earth clamp, the only thing that would slightly improve it would be to fit metal tube under the armour so that it clamps the armour tightly.
Sweated/plumbed/wiped connections are used on lead sheathed cables, they are made by fitting the cable into a wiping cone and applying molten lead to it to connect and seal the joint, this is formed into shape by a process of wiping with a moleskin cloth (hence being known as a wiped joint). These connections aren't particularly prone to any weakening or corrosion.
Thanks, you are correct, I was getting confused, I had in mind lead sheathed that has an Earth connection sweated on to them. I have seen many where the braid has corroded or the sweated connection has been broken and so a clamp of various kinds has been used.
In fairness I did state " Tenby Type ", I know there are several brands, either way I acknowledged it is the wrong method.
On leaded sheath cable where such a sweated connection is broken, what would a DNO replace it with?
