Do tails HAVE to be upgraded?

[imago]

It could be reasonably argued though that for a CU change only no load is being added....and if it's been running for the last 20 years on the existing tails without melting whats going to change?....that would be a reasonable assumption without any calculation.

Yes it could, but that wouldn't be good practice. Anyone who carries out a CU change assumes responsibility for the work involved in doing so, and must be able to demonstrate why they have done something or why they have not done something.

"it's been OK for the last 20 years." is the sort of statement that a customer might make to query work required. It's not the sort of statement that a trade professional should make to justify cable selection/re-use.

If you can't back up a technical descision with facts and figures it's just a guess. If guessing is OK why would anyone need an electrician?

 

[whazza22]

Sorry for the delay.

The main fuse is 100a.

They DNO will be fitting an isolator which I assume will also be 100a.

 

[imago]

That's the question answered then.

 

[londonlec]

Sorry for the delay.

The main fuse is 100a.

They DNO will be fitting an isolator which I assume will also be 100a.

Then fit your own Wylex 60A BS1361 sw/fuse at the cut out/meter and refeed the existing cable from there.

 

[whazza22]

Then fit your own Wylex 60A BS1361 sw/fuse at the cut out/meter and refeed the existing cable from there.

Will the DNO replace the main fuse with an isolator or have both installed? They are installing next week.

Do the isolators they fit have its own fuse? If so I could replace it with a 60a like you said.

 

[londonlec]

No, the DNO will be fitting an isolator (switch) in an enclosure presumably after the meter.

The isolator they fit will be just that, an isolator. You would need to feed your switch fuse from the isolator.

I hope you don't mind me saying but some of this stuff is fairly basic.

 

[Steve_P]

I hope you don't mind me saying but some of this stuff is fairly basic.

You'd have thought so wouldn't you?

 

[CP Electrics]

I can't believe what I'm reading, I take it your registered and are competent to upgrade a consumer unit?

 

[Guest55]

I take it your registered and are competent to upgrade a consumer unit?

which takes all of 5 weeks training as far as the schemes are concerned ;-)

 

[Geoffsd]

The main fuse is 100a.

Is that what it says on the label?

 

[guest119]

How did you kill the supply to replace the cu?
What size is the main earthing conductor with the tails?
You say ..tails.. but is it just that or an armour etc?
What is the ZE at the cu (tails length unnknown) and is it within that specified for your proposed fuse (bs88?) at incomer location. ( ZE measurement taken on the supply only, ie before connection to the cu and its associated paralell paths.)

Boydy

 

[whazza22]

Is that what it says on the label?

Yeah, I cannot remove fuse without breaking seal to check if the main fuse is different than stated.

I can ask the person installing the isolator to check.

 

[whazza22]

Also the tails are approx 5 meters from the meter to the consumer unit and run through some plastic pipe.

Is the maximum 3 meters?

 

[Robson689]

Also the tails are approx 5 meters from the meter to the consumer unit and run through some plastic pipe.

Is the maximum 3 meters?

I think it's a maximum of 3 metres without mechanical protection.

 

[Octopus]

I think it's a maximum of 3 metres without mechanical protection.

The blind leading the blind