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NozSpark

Seaman stains™
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Just been thinking of a disconnection job I went to last week (not the wet one)..

Customer had a leak in a flat roof in a comercial building that he owns and as he doesn't use that part of the building didn't notice it for ages, however now he's spotted it he wants it sorting.. it's been so wet for so long that there is a mushroom type fungus growing in the wall behind the CU:O

So this part of the building has it's own CU fed by 25mm tails (must be 15 - 20 meters long) in the ceiling and behind the plaster board without and fused protection (direct into henly blocks)... I've now disconnected this so that the contractors don't have to worry about any "Live" cables, but it's going to have to be reconected in the future.

Thinking about connecting this back up, In all honestly I think I'll have to replace the tails for SWA/XPLE so that it can have the RCD at the SUB DB and add a switch fuse at the supply.... RCD at DB end just in case he rents this part of the building out in the future. There is another T&E sub main without a switch fuse, but I'll deal with that later;)

 
Just been thinking of a disconnection job I went to last week (not the wet one)..

Customer had a leak in a flat roof in a comercial building that he owns and as he doesn't use that part of the building didn't notice it for ages, however now he's spotted it he wants it sorting.. it's been so wet for so long that there is a mushroom type fungus growing in the wall behind the CU:O

So this part of the building has it's own CU fed by 25mm tails (must be 15 - 20 meters long) in the ceiling and behind the plaster board without and fused protection (direct into henly blocks)... I've now disconnected this so that the contractors don't have to worry about any "Live" cables, but it's going to have to be reconected in the future.

Thinking about connecting this back up, In all honestly I think I'll have to replace the tails for SWA/XPLE so that it can have the RCD at the SUB DB and add a switch fuse at the supply.... RCD at DB end just in case he rents this part of the building out in the future. There is another T&E sub main without a switch fuse, but I'll deal with that later;)

 
Noz,

Can you surface mount the "tails"?

Else SWA or MIMS it seems then?

I think that your idea of "KMF" up front with RCD at consumer end is best.

That is as long as you can get the Zs low enough.

 
Noz,

Can you surface mount the "tails"?

Else SWA or MIMS it seems then?

I think that your idea of "KMF" up front with RCD at consumer end is best.

That is as long as you can get the Zs low enough.

 
This raises an interesting concern I have for a job I have soon.

A new house built this year. Supply head and meter in outside box at front of house. Consumer unit inside in a cupboard half way along the side wall (semi detached house) perhaps 5 metres from the meter.

My job is install power to a shed.

I need to drill through the side wall to get the SWA outside, ideally right at floor level, drilling down at 45 degrees so the cable emerges below ground level into the trench.

I can't drill directly under the CU, that's a safe zone and likely to be full of cables.

I will drill one side of CU, some way away so I shouldn't be in a safe zone and there shouldn't be any cables.

But I can only drill to the left of the CU. that's the direction the feed from the head gets to the CU.

So my big unknown is HOW are the cables from the meter to the CU run and where?

At times like this I wish I had a really big and powerful cordless SDS drill so I could cut the power completely before drilling.

I'm going to try and identify the sparks that wired the house to see if I can ask them.

So to avoid anyone having the same dilemma, I would advise the OP to run whatever feed method he chooses on the surface in trunking.

 
This raises an interesting concern I have for a job I have soon.

A new house built this year. Supply head and meter in outside box at front of house. Consumer unit inside in a cupboard half way along the side wall (semi detached house) perhaps 5 metres from the meter.

My job is install power to a shed.

I need to drill through the side wall to get the SWA outside, ideally right at floor level, drilling down at 45 degrees so the cable emerges below ground level into the trench.

I can't drill directly under the CU, that's a safe zone and likely to be full of cables.

I will drill one side of CU, some way away so I shouldn't be in a safe zone and there shouldn't be any cables.

But I can only drill to the left of the CU. that's the direction the feed from the head gets to the CU.

So my big unknown is HOW are the cables from the meter to the CU run and where?

At times like this I wish I had a really big and powerful cordless SDS drill so I could cut the power completely before drilling.

I'm going to try and identify the sparks that wired the house to see if I can ask them.

So to avoid anyone having the same dilemma, I would advise the OP to run whatever feed method he chooses on the surface in trunking.

 
Been thinking about this a bit more, I might be able to move the DB closer to the supply onto a wall that will allow the cables to be fed through a crawl space under the other part of the building. As for MIMS, I don't have a potting tool and I've never used any before.

 
Been thinking about this a bit more, I might be able to move the DB closer to the supply onto a wall that will allow the cables to be fed through a crawl space under the other part of the building. As for MIMS, I don't have a potting tool and I've never used any before.

 
I quite like MICC find it very therapeutic making the ends off

 
I quite like MICC find it very therapeutic making the ends off

 
Prodave

I would not try to drill at 45o at floor level< swa has a constricted bend radius, a better solution would be to come from the cu in suitable twin and earth and to an external box which can be used to terminate the swa supply to the shed.

Anything at floor level will interfere with the buildings damp proofing.

To the OP

Surface mounted cables do not require RCD protection and can be very usefull for the type of install you are dealing with.

At one time micc cables where commonplace, very often seen incorectly terminated, I have fond memories of the aroma:p

 
Prodave

I would not try to drill at 45o at floor level< swa has a constricted bend radius, a better solution would be to come from the cu in suitable twin and earth and to an external box which can be used to terminate the swa supply to the shed.

Anything at floor level will interfere with the buildings damp proofing.

To the OP

Surface mounted cables do not require RCD protection and can be very usefull for the type of install you are dealing with.

At one time micc cables where commonplace, very often seen incorectly terminated, I have fond memories of the aroma:p

 
ProdaveI would not try to drill at 45o at floor level< swa has a constricted bend radius, a better solution would be to come from the cu in suitable twin and earth and to an external box which can be used to terminate the swa supply to the shed.

Anything at floor level will interfere with the buildings damp proofing.

To the OP

Surface mounted cables do not require RCD protection and can be very usefull for the type of install you are dealing with.At one time micc cables where commonplace, very often seen incorectly terminated, I have fond memories of the aroma:p
That's why I was thinking of putting them in the crawl space and through a wall into this unit (which is lower than the rest of the building)

Cheers anyway.

 
ProdaveI would not try to drill at 45o at floor level< swa has a constricted bend radius, a better solution would be to come from the cu in suitable twin and earth and to an external box which can be used to terminate the swa supply to the shed.

Anything at floor level will interfere with the buildings damp proofing.

To the OP

Surface mounted cables do not require RCD protection and can be very usefull for the type of install you are dealing with.At one time micc cables where commonplace, very often seen incorectly terminated, I have fond memories of the aroma:p
That's why I was thinking of putting them in the crawl space and through a wall into this unit (which is lower than the rest of the building)

Cheers anyway.

 
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