EICR code - type C breakers with undersized CPC

[westward10]

Thank you everyone for your very detailed answers, it makes it much clearer

I did actually ask the NAPIT technical guy about this today and it was all news to him, he had never seen the table B7 before and told me if it complies on the final circuits page it should be fine

I wonder how many general electricians are even aware of this?

Last question, Does anyone have any data for MEM memshield 2, C type 6a &10a mcb's and whether they too would be compliant on a 1mm CPC?

So im assuming if its not compliant, on an EICR a C3 code would be due maybe even a C2 which could have significant ramifications if its not possible to swap it over to a B type MCB

Can you reference this "non compliance" in BS7671.

 

[pc1966]

Thank you everyone for your very detailed answers, it makes it much clearer

I did actually ask the NAPIT technical guy about this today and it was all news to him, he had never seen the table B7 before and told me if it complies on the final circuits page it should be fine

I wonder how many general electricians are even aware of this?

I suspect very few...

Last question, Does anyone have any data for MEM memshield 2, C type 6a &10a mcb's and whether they too would be compliant on a 1mm CPC?

So im assuming if its not compliant, on an EICR a C3 code would be due maybe even a C2 which could have significant ramifications if its not possible to swap it over to a B type MCB

The data for the Eaton Memshield MCBs lacks detailed info on the I2t let-through, which is disappointing.

However, given the OSG lists 1.5/1.0 circuits as compliant in Table 7.1 for 6/10A MCBs of both B & C curve I doubt it is a significant risk in practice. Has the DB in question got a PFC near or above 3kA?

I suspect if it is down in the 1-2kA region then really nothing to worry about.

 

[Welchyboy1]

Can you reference this "non compliance" in BS7671.

Not as such really, without delving into technical data for individual brands of mcb devices it seems

 

[Welchyboy1]

I suspect very few...

The data for the Eaton Memshield MCBs lacks detailed info on the I2t let-through, which is disappointing.

However, given the OSG lists 1.5/1.0 circuits as compliant in Table 7.1 for 6/10A MCBs of both B & C curve I doubt it is a significant risk in practice. Has the DB in question got a PFC near or above 3kA?

I suspect if it is down in the 1-2kA region then really nothing to worry about.

Ok bit of a storm in a teacup then

 

[pc1966]

Just to add that this BEMA guide has the maximum let-through specifications on pages 16 & 17:

BEAMA Guide to Low Voltage Circuit Breaker Standards june 2015 Corrigendum 2020

www.beama.org.uk

And yes, I should be finding more interesting things to do on a Saturday morning!