Any ideas how to solve this?

[dave0984]

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?

 

[James]

Sorry, it’s a case of cut back the outer sheaf until you come across a good and in corroded section
Then joint it and replace cable

 

[Pete999]

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?

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?

 

[Strima]

Is water being sucked up from the gland end we can see in the picture? Is this indoor or outdoor? Do you have a picture showing more of the cable run? Is water running down the cable through the shroud causing the corrosion? If the latter this could be fixed quite easily.

 

[Pete999]

Sorry, it’s a case of cut back the outer sheaf until you come across a good and in corroded section
Then joint it and replace cable

Remake the two cables off into another enclosure and, join the conductors and lengthen them using single core cable.

 

[dave0984]

Sorry, it’s a case of cut back the outer sheaf until you come across a good and in corroded section
Then joint it and replace cable

Thought so thanks

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?

It's just to make the cables of into the inner cores then go about 1m in trunking and feed the panel board

The water seems to be dripping out of the armoured cables not just a spill as it's constantly wet

 

[James]

Just noticed my typo, in corroded should read uncorroded
Oops.

 

[dave0984]

Is water being sucked up from the gland end we can see in the picture? Is this indoor or outdoor? Do you have a picture showing more of the cable run? Is water running down the cable through the shroud causing the corrosion? If the latter this could be fixed quite easily.

No water seems to coming down the inside of the cable
The cables are visible for 2m above the glands then go under ground to a sub station

 

[Strima]

No water seems to coming down the inside of the cable
The cables are visible for 2m above the glands then go under ground to a sub station

Get digging then.

 

[dave0984]

Get digging then.

Ha ha lol you don't want to help do you

 

[Strima]

Ha ha lol you don't want to help do you

I do have a few days off as I have no work planned in for November, but I'd rather sit at home watching TV than digging in the dirt thank you very much...

 

[multimick]

is it condensation ,damp, etc.? to bre honest the quality of galvanising is very poor these days

 

[ipf]

Forgive me for being thick, but I can't get my head around why the cables go upwards to underground. Is this below ground level?
The bloke who gave it a code 2 was carrying out an EICR. Was he given the task of trace and repair?
[automerge]1572563049[/automerge]

is it condensation ,damp, etc.? to bre honest the quality of galvanising is very poor these days

It's rusting because of the drilling that's taken place....the first point being the earth bolt.

 

[multimick]

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.

 

[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.

But the steel isn't galved internally and the bolt isn't galved...although, I do agree, it's not done as well these days as it used to be. My schoolboy physics (common sense) tells me that a weak point occurs where something is broken.

 

[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
[automerge]1572708915[/automerge]

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.
[automerge]1572709123[/automerge]

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.