Best option for outdoor fused isolator?

[JohnW2]

Why do we earth anything at all then?

As a general question, you know answer as well as I do. However, when there are two layers of insulation between live conductors and touchable matter (as in metal encased Class II items), we do not necessarily earth that metal (indeed, as we know, many a Class I item comes with instructions that one "MUST NOT" earth it).

I think a general principle of most safety standards is that it is simply not considered possible/reasonable to protect "idiots with tools".

Maybe that's realistic, but I was responding to your comment about what was "reasonably foreseeable", and I'm quite sure that it is very much "reasonably foreseeable" that some silly people will fiddle in CUs in ways which they shouldn't. As you go on to agree ...

I do see your point though that the temptation to "mess around" in a partially-live CU is much greater than in most other domestic electrical situations and the risk to people doing that is increased by the use of metal enclosures. ...

Exactly my point

Whether that outweighs the benefits in terms of better containing thermal events I could not say....

One of the many (in my opinion) stupidities of the regulation, that it does not require any "containment of thermal events". Provided only that what little material is left is deemed to be 'non-combustible', you can have as many ~12mm diameter holes as you like in the front, bottom and sides of a metal domestic CU!

Kind Regards, John

 

[crappy]

thanks all. @ericmark that is a nice option. I could try that.
I've retraced the cable and I think I might know where it's being spliced in - the storage space under the stairs is a possibility.
Seeing as it's SWAMBO's storage space I need caving gear to get in there and search. Pretty sure the ast sparky has not emerged either....

If I do find it I will put an isolator in at that point. easier.

C

 

[crappy]

I dug around and found the fused isolator under the stairs!

 

[sparkwright]

I dug around and found the fused isolator under the stairs!

There was already one there?!

 

[crappy]

Yup. Hidden under the stairs, around 20m from the point it comes outside the house. Quite random.

 

[sparkwright]

.

 

[SUNRAY]

Yup. Hidden under the stairs, around 20m from the point it comes outside the house. Quite random.

Stick a lable on it while you remember what it's for.