Change of electrics required for new oven?

[EFLImpudence]

So what mcb would you put a single 2.5 on?

It's CCC in Method C is 27A, therefore ... any one less than that will be compliant.

 

[Michaelsf90]

And the closest modern mcb is 20A

 

[AndyPRK]

25A ones are made

 

[Michaelsf90]

So they are but I'd say most standard practice is to use a 20A. I've never come across a 25A radial circuit before

 

[Taylortwocities]

So they are but I'd say most standard practice is to use a 20A. I've never come across a 25A radial circuit before

You should get out more:
Here's mine

 

[ban-all-sheds]

So what mcb would you put a single 2.5 on?

It's CCC in Method C is 27A, therefore ... any one less than that will be compliant.

There are (probably) millions of single lengths of 2.5mm² installed on 32A breakers.

 

[Michaelsf90]

Maybe it's just where I work they always use 20A haha I can honestly say I've never known anyone use a 25A

 

[ban-all-sheds]

Maybe the installation method has dropped Iz to below 25.

Maybe the make of board doesn't have a 25.

 

[Taylortwocities]

I can honestly say I've never known anyone use a 25A

You really should get out more!

 

[Dave123456789]

I had the work done yday and put in a 16 mcb breaker

I took comfort from his original explanation:

“ sure 20mcb that could work. Happy to be corrected on parts available. However, having just checked the cable ratings for twin and earth cable, 2.5mm, installed in a cavity wall (assuming some sort of insulation also within) and the cable touching the inner surface of the cavity wall, ref method 102, the maximum current allowed for the cable would actually be 21A.

Without knowing the exact construction method of the walls containing the cable, it’s generally best to assume the worst case scenario and therefore avoid any potential issues in the future.

I appreciate trying to find the easiest and quickest possible way to solve the issue at hand but there are many variables at play.

I still stand by my suggestions as being the safest most reliable method given your current situation and the information available without opening up walls for further investigation etc...

The rating of 27A that you were given earlier is correct, but only when the cable is run clipped directly to the surface of a wall. Not the most attractive way of running a cable, and not the way that the cabling in question is run in your house to your utility/kitchen areas.”

No issues to report yet!

 

[ban-all-sheds]

I took comfort from his original explanation:

“ ..
The rating of 27A that you were given earlier is correct, but only when the cable is run clipped directly to the surface of a wall. Not the most attractive way of running a cable, and not the way that the cabling in question is run in your house to your utility/kitchen areas.”

He didn't tell you that it also applies to cables buried in chases in walls and/or plastered over?

OK - in your case your cables aren't but millions are, and they do have a rating of 27A and they are not surface mounted.

 

[Dave123456789]

Fair point.
At the end of the day he’s seen the job in person

Clearly people think 16/20/25 could work - as long as it’s 16 isn’t dangerous tho it’s surely a matter of opinion!