Steel Container

[ChrisElectrical88]

A client has recently had a 10ft x 6ft Steel Cabin delivered. It will be a permanent addition for a block of flats outside for storing things in for contractors. They want a light inside and a floodlight outside.
Currently next to it about 5 yards away is a bin store which has a light in it from the main building which is on a 6A supply. The earthing System is PME. I can’t run a dedicated supply from the main building due to the amount of paths and obstacles now in the way.
Not keen to continue the PME into the steel container as it’s permanent, I’d rather TT. I have thought about coming from the Bin store supply into a 3A FCU, TTing the outgoing supply here and going into the cabin with this. Any thoughts?

 

[Strima]

I'd use an RCD FCU.

 

[ChrisElectrical88]

I'd use an RCD FCU.

Yes it would be a RCD FCU. Sorry should have put that.

 

[ChrisElectrical88]

Completing the job tomorrow. Nice and easy.
just a quick one, the steel container isn’t extraneous, I’ve only used class 2 light fittings inside. Does the steel container need a fly lead from the fused spur or would you just leave it?

 

[pc1966]

I think a steel box in contact with the Earth very much is extraneous as far as earthing is concerned!

So yes, if it were me the steel box should be bonded to the earth system inside the container.

 

[ChrisElectrical88]

Of course it is extraneous ?. I’ll take a bond from the earths at the spur to the steel itself then .

 

[Ian1981]

I’m not sure that RCD spurs are compliant as they are not included in bs7671 and bs 7288 state that they only provide supplementary protection and that additional protection is assumed upstream.

 

[suffolkspark]

Of course it is extraneous ?. I’ll take a bond from the earths at the spur to the steel itself then ☺.

You'll need a correctly sized bond back to the MET if it is

 

[Ian1981]

How can a steel box forming the enclosure of the spur be an extraneous conductive part by definition,when it forms part of the electrical installation? Is it not an exposed conductive part rather than an extraneous conductive part ?

 

[ChrisElectrical88]

You'll need a correctly sized bond back to the MET if it is

There will be. The MET will be a 6mm Earth in the fused spur from the Rod. I’ll tap a 6mm earth from there onto the container.

 

[telectrix]

Of course it is extraneous ?. I’ll take a bond from the earths at the spur to the steel itself then ☺.

How can a steel box forming the enclosure of the spur be an extraneous conductive part by definition,when it forms part of the electrical installation? Is it not an exposed conductive part rather than an extraneous conductive part ?

wrong... by that you would have to say that any room with electrical equipment fixed to the walls, is a part of the installation.

 

[Ian1981]

wrong... by that you would have to say that any room with electrical equipment fixed to the walls, is a part of the installation.

So you are saying that a metal enclosure on a metal clad socket is not an exposed conductive part??
Why would a wall be part of the electrical installation?

 

[telectrix]

yes. it's extraneous because it is not a part of the electrical installation.

 

[Ian1981]

yes. it's extraneous because it is not a part of the electrical installation.

Of course it’s part of the electrical installation, it forms the enclosure of the spur and is exposed ie class 1 an exposed conductive part.

 

[telectrix]

Of course it’s part of the electrical installation, it forms the enclosure of the spur and is exposed ie class 1 an exposed conductive part.

afraid we have to disagree on this one. anyway Zebedee says "time for bed",