SWA in drain permissable?

[dksanders]

Hi All,

I've been asked to get a supply for a car park PIR light across the car park entrance from the existing light. The only way across would be by running the SWA cable in a drain that runs across the driveway (see picture).

Is there any reason that I shouldn't do that? I can't think of any regulation of the top of my head that prohibits it.

TIA

 

[PEG]

I suppose the issue is,that either there is no warning or expectation of such a cable being in there,and the labourer hacks away at it,with his graft,whilst cleaning it out...or... you put clear and visible warning notices,nearby,and inform the world,you bypassed good practice.

 

[Deleted member 26818]

Alongside rail tracks and also in other places, cables are often run in concrete trenches with concrete slabs as covers.
Then of course there’s those run in ducts and those just buried in soil.
Not sure that any of the above methods are water proof?

 

[Astolat]

As a member of a local Bowls club for thirty years I can tell you that they are as tight as a duck’s rear end and we all know that this is water tight otherwise the poor old duck would sink.
They only like spending money at the bar and then always complain at the prices which are normally half what the pub down the road charges.

Offer them a floodlight on a timer fixed to the wall of their pavilion and if that is not suitable/ possible walk away.

Remember that these people have memories like elephants and will discuss your work with all and sundry. If anything goes wrong you will never hear the end of it and their grapevine network is more efficient that the local press and TV put together.

 

[Octopus]

The BYB/BBB aren't step by step guides. If they had to cover every detail and scenario they would be a lot bigger and cost a lot more..

Hum ......... this has come up on here so many times - a simple table of recommendations would resolve about 95% of questions

 

[telectrix]

if you do run the SWA in the soakaway, make sure you bond the ironwork with at least 10mm. .

 

[The Ghost]

There are no stated depths for SWA in bs7671

708.521.1.1 0.6m
522.8.10 sufficient depth to avoid reasonably foreseeable..
Of course that is not for SWA specifically but it does say the cable should be armoured and that armour capable of acting as protective earth. And yes it is a special location.
I wonder where I got the 450mm from. Used to be 18 inches when I started up? It has stuck in my head.

 

[Octopus]

Those regs allow numpties to believe 150mm is acceptable...

 

[PEG]

I su

708.521.1.1 0.6m
522.8.10 sufficient depth to avoid reasonably foreseeable..
Of course that is not for SWA specifically but it does say the cable should be armoured and that armour capable of acting as protective earth. And yes it is a special location.
I wonder where I got the 450mm from. Used to be 18 inches when I started up? It has stuck in my head.

All of this conjecture,does not detract from what is basically,going to be the OP's decision.

There will not be regs to approve such an idea,because it is not good practice. Will the world end? Is it worse than a thousand other scenarios we encounter? No.

The OP needs to decide,and stand by that,with concise arguments at the ready,for if the shape of a pear appears...

As a prominent contributor to the IET,Mr Y Oda once remarked..."do,or do not...there is no try..."

 

[The Ghost]

Certainly according to regs quoted, it is reasonably foreseeable that at some point traffic, maybe a tractor/digger will cause sufficient damage to break the cover over the soak away and damage the cable so it would be unacceptable to use this method.

 

[dksanders]

I suppose the issue is,that either there is no warning or expectation of such a cable being in there,and the labourer hacks away at it,with his graft,whilst cleaning it out...or... you put clear and visible warning notices,nearby,and inform the world,you bypassed good practice.

As the covers are cast metal, any labourer would have to remove the cover to be able to do any work to the soak away which is only 2" deep so the cable would be blindingly obvious, laying in the bottom of the channel.

To get from the end of the soak away to where the light is wanted it would need to run along the bottom of a hedge separating the car park from the road. It wouldn't be possible to dig the cable down so I was considering running it inside 20mm galvanised conduit along the bottom of the hedge. I assume if I also used conduit in the soak away that would negate the concerns mentioned about damage to the cable?

 

[telectrix]

think it's just common sense here. if the cable is protected from foreseeable damage, i'd say you are good to go. the regs. can't cover all possible scenarios.

 

[dksanders]

I su


All of this conjecture,does not detract from what is basically,going to be the OP's decision.

There will not be regs to approve such an idea,because it is not good practice. Will the world end? Is it worse than a thousand other scenarios we encounter? No.

The OP needs to decide,and stand by that,with concise arguments at the ready,for if the shape of a pear appears...

As a prominent contributor to the IET,Mr Y Oda once remarked..."do,or do not...there is no try..."

I won't do anything that's not right or that I'm not happy is totally safe.

Whilst I am an experienced electrician, I've not encountered this situation/possible solution before hence asking the wider forum members who may have.

If a single reply could show me a valid reason on safety grounds why it shouldn't be done then I won't do it. If however initial objections are countered by sensible suggestions to overcome that objection, to make the solution acceptable to others, then I would be happy.

That it's not best practice I understand and it's not something I've considered doing in the past, but in this instance there really is no other option to getting a cable across the drive.

 

[dksanders]

Alongside rail tracks and also in other places, cables are often run in concrete trenches with concrete slabs as covers.
Then of course there’s those run in ducts and those just buried in soil.
Not sure that any of the above methods are water proof?

The cable itself is waterproof.

 

[dksanders]

As a member of a local Bowls club for thirty years I can tell you that they are as tight as a duck’s rear end and we all know that this is water tight otherwise the poor old duck would sink.
They only like spending money at the bar and then always complain at the prices which are normally half what the pub down the road charges.

Offer them a floodlight on a timer fixed to the wall of their pavilion and if that is not suitable/ possible walk away.

Remember that these people have memories like elephants and will discuss your work with all and sundry. If anything goes wrong you will never hear the end of it and their grapevine network is more efficient that the local press and TV put together.

The clubhouse is too far away from the car park unfortunately.

I am also a new member to this club so walking away isn't an option (especially as they're giving me quite a bit of other work in bringing the place up to date). I had warned them that I wasn't sure if this would be an acceptable solution and would be consulting you guys.

 

[telectrix]

digging a narrow trench in the tarmac, about 1ft. inside from the drain, 12" to 15" deep, would not be too difficult, and a better solution all round. IMO.