Any ideas how to solve this?

[multimick]

no steel is galvanised internally ,and i have no idea if the bolt is galvanised or not (or other coating ) but do agree about weak points . off topic but fitted a couple of chrome lights this week and the chrome plating was dubious to say the least ,very poor and almost pitted

 

[dmxtothemax]

Jobs like this is why we have " trainee's " !

 

[Carl S]

Capillary action will draw water from a nick in the outer serving to the termination glands.

I wish you the best of luck finding the ingress point.

 

[Samspade]

New to this forum so be steady with me.

I would clean this down wire brush etc removing loose debris. Repaint the top of the box and put a light silicone grease around the armouring Go back to it a month later and see if the issue is water ingress from the armoured being damaged, does the armouring have it's own CPC, if not then I'm afraid it's a replacement.

 

[Pete999]

New to this forum so be steady with me.

I would clean this down wire brush etc removing loose debris. Repaint the top of the box and put a light silicone grease around the armouring Go back to it a month later and see if the issue is water ingress from the armoured being damaged, does the armouring have it's own CPC, if not then I'm afraid it's a replacement.

What do you mean by"does the armouring have it's own cpc"?

 

[telectrix]

What do you mean by"does the armouring have it's own cpc"?

think he meant is there a cpc conductor in addition to the steel armour

 

[Samspade]

Does it have a core within the armoured cable that is used for the earth core and not just relying on the armouring for the earth.

 

[ipf]

if the galvanising was better then drilling a hole should not make any difference ( school boy pyhsics ) but it does look like a very damp enviroment.

Could you explain why physics would tell me that galvanised steel shouldn't be compromised by hole drilling?
….a tin of galv paint and a brush, maybe needed...

 

[davesparks]

Could you explain why physics would tell me that galvanised steel shouldn't be compromised by hole drilling?
….a tin of galv paint and a brush, maybe needed...

Sacrificial protection, the same as boat hulls. Good quality galvanising should act as a sacrifucial anode and prevent rusting where it is scratched etc
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New to this forum so be steady with me.

I would clean this down wire brush etc removing loose debris. Repaint the top of the box and put a light silicone grease around the armouring Go back to it a month later and see if the issue is water ingress from the armoured being damaged, does the armouring have it's own CPC, if not then I'm afraid it's a replacement.

It doesn't matter whether there is an additional protective conductor or not, if the armour has rotted then the cable needs to be replaced.
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Seeing as the corrosion is more prevalent where it is glanded into the enclosure, I would imagine that either a spillage on the top of the enclosure coupled with galvanic action brought about by poorly made off glands, and dissimilar metalwork, rather than water being sucked up via a joint in the cable, by and by what is the enclosure being used for?

Why do you say they are poorly made off?

Any damage to the outer sheath can let water in and this will travel along the cable by capillary action, its not all that uncommon.

The first time I saw it I had started to cut an SWA to be jointed and extended only to have water start coming out of the cut, for a moment I thought I'd cut an old black water pipe.

 

[multimick]

when the coating is damaged it forms a galvanic cell around that point,protecting the steel. the opposite happens when it is chrome plated ,the steel sacrifices itself for the chrome ,

 

[marconi]

I am not certain, but that situation looks to me like a problem with three dissimilar metals - galavanized steel wire, brass gland, steel/aluminium enclosure - in contacts with each other in the presence of an electrolyte - which is making a little battery(batteries) powering galvanic current corrosion. In which case the problem is local to the glands and not much further along the cables. The cure is to exclude the electrolyte and 'dismantle' the battery. I think the clues are the white substance on the SWA armouring and the brown rusting around the glands.

Here are two firms which might be able to offer you further advice and suitable products to cure the problem:

Galvanic Corrosion | Cable Cleats | CMP Products Limited - https://www.cmp-products.com/cable-cleats/technical-cable-cleats/galvanic-corrosion-cable-cleats/

https://peppers.co.uk/wp-content/uploads/2018/10/CT0001-Bi-Metallic-Corrosion-Advice-V1.pdf

Products | Cable Glands | CMP Products Limited - https://www.cmp-products.com/cable-glands/products/

IP68 M20 Corrosion Guard Gland - for SWA Cables with 8.0-13.5mm OD - https://www.connexbox.com/ip-68-corrosion-guard-swa-gland-8-13mm.html

 

[bigspark17]

Seeing as the corrosion is more prevalent where it is glanded into the enclosure, I would imagine that either a spillage on the top of the enclosure coupled with galvanic action brought about by poorly made off glands, and dissimilar metalwork, rather than water being sucked up via a joint in the cable, by and by what is the enclosure being used for?

another awfull diagnosis of the problem by @Pete999

itll be a nick in the sheath of the armouring and water being pulled down the cable with gravity not sucked up. You should make client aware of it give them the option to repair it, but if zs/IR readings on that circuit remain ok then no futher action required imo.

 

[Pete999]

another awfull diagnosis of the problem by @Pete999

itll be a nick in the sheath of the armouring and water being pulled down the cable with gravity not sucked up. You should make client aware of it give them the option to repair it, but if zs/IR readings on that circuit remain ok then no futher action required imo.

How did you reach that conclusion Bs? you got exray eyes or any super powers us mere mortals could do with?
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How did you reach that conclusion Bs? you got exray eyes or any super powers us mere mortals could do with?

Forgot to add, can you explain why you consider my diagnosis is so awful?

 

[Megawatt]

Water is being sucked up though the armoured cables and is corroding the armourings , after hours of investigating I'm unable to find the cause as other ends not wet so must be a joint under ground,buried not accessable the last sparky gave this a code 2 but not solved the issue,

Is there anything that can be done to prevent this without digging up looking for a joint no one knows where it is?

Dave how about megging the wire to test it
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Remake the two cables off into another enclosure and, join the conductors and lengthen them using single core cable.

I’ve actually run into a problem with a panel on the in side of the building and the feeder was outside overhead and water was running through the inside of the cable into the panel

 

[davesparks]

another awfull diagnosis of the problem by @Pete999

itll be a nick in the sheath of the armouring and water being pulled down the cable with gravity not sucked up. You should make client aware of it give them the option to repair it, but if zs/IR readings on that circuit remain ok then no futher action required imo.

Regardless of the test results there is clear and obvious degradation of the cable so rectification us required.
Blindly accepting test results when the damage is obvious to the most casual observer is negligent at best.