So why would anyone...

[surreal]

...do this? Yes, the cable tray has been totally enclosed in lead along with the exposed SWA's, but only in the switch room. Who ever did it must thought to hell with the rating factors.

Untitled

• surreal
• 28 Feb 2011
• 1

Untitled

• surreal
• 28 Feb 2011
• 1

Untitled

• surreal
• 28 Feb 2011
• 1

It would be a nice little rip out job

 

[Buzx1313]

wow..never seen that

is it a mod building?

 

[RF Lighting]

What does it feed? I guess it'll have been done for RFI suppression.

You didn't break into a Vodafone property last night to take those pics did you?

 

[Chri5]

What type of premises was that ?

Radio, signal, communications, Tv, transmission ?


As for derating, I'm not sure if there would be any major issues, at worse no more than steel trunking. Old days cable was sheathed in lead- I'm surprised that if screening for RFi was so important that they didn't consider bespoke lead cased order from a cable firm like AEI

 

[Chri5]

An another thing, wouldn't the SWA being earthed no be a suitable screen

 

[surreal]

The building is a bog standard eight floor office block in London. The comms room is at the other end of the building and as far as I could establish there didn't seem to be anything near the switch room that would be affected by electrical radiation.

I know they are pretty poor pics but if you look closely you will see that firstly the lead has not been earthed and secondly, the bits around the SWA's are not even continuous.

And although I'm no expert in this field, I would agree that under normal circumstances the core layering and the steel armouring should provide plenty of RFI screening.

With regards to down rating, the next time a regs book is open try a quick cable calc for a 300amp submain fed via a PVC SWA enclosed in steel trunking with an ambient temp of something like 30deg. And then compare it with clipped direct.

 

[SgtTrojan]

is it a mod building?

If it was he would be shot for taking pictures

Very unusual practice

 

[1john]

That all needs removing ASAP, and weighing in!

 

[aptsys]

An another thing, wouldn't the SWA being earthed no be a suitable screen

Depends what you're screening against.

 

[holmslaw]

..

 

[radioredcat]

That all needs removing ASAP, and weighing in!

I hope it's well guarded otherwise the metal thieves will pinch it and weigh it in.

http://www.wigantoday.net/news/thieves_cause_power_outage_1_2622775

Andy

 

[surreal]

In the early days of IT in the 80's - 90's, the IT people would always blame all their own cock ups on power supply problems. They were not necessarily believed, but generally nobody could argue against them and their new fangled technology.

I would bet thats why its there, it was instructed by some IT bloke, because it gave him time to sort out his programming problems.

That could very well have been the case. It has all the hall marks of a techno geeks **** up.

 

[Stoday]

It happened a few years ago now, thieves got into a sub in Leicester. One of them took the lid off a transformer and got a flash off it.

Local residents reported seeing a bloke running away with a wheelbarrow with a bloke in it. That learned him a lesson!

(For pedants: I am aware of the double solecism in the last sentence. It is deliberate)

 

[radioredcat]

Maybe he fancied a good smoke but they deserve what they get.

This is what they do cause when they don't know what they are doing.

http://www.dailymail.co.uk/news/art...ters-called-71-homes-massive-power-surge.html

I bet they would kick up a stink if this happened in their homes.

Andy

 

[RF Lighting]

That digital meter in the top two pics didn't handle 400V very well