Is it a Distribution Circuit?

[1Justin]

TN system.
Customer has 16A breaker from CU which supplies FCU to a boiler, but it also supplies a IP66 external box feeding SWA to garden shed DB.

Since the circuit from the 16A breaker doesn't supply ONLY the SWA to the shed DB, (it supplies also end equipment directly - ie the boiler) - then is it technically a distribution circuit?

(What the real question boils down to, is at the far end of the SWA in the garden shed where it terminates at shed DB, am I looking for 5 seconds or 0.4 disconnect time)?

 

[Ben Butcher]

Had regs to hand so had a quick look.... "A circuit supplying a DB or switchgear, A distribution circuit may also connect the origin of an installation to an outlying building when it is sometimes called a sub main"

That dosen't really answer the question does it! I would err on the side of caution as it has effectively a 0.4s circuit combined with it and go for 0.4.

 

[somersetsparks]

0.4 seconds IMO

 

[Guest55]

its not really a distribution circuit , so 0.4 disc time.

 

[guest119]

I got a dig recently from an NICEIC visitation regarding what Ive been puting on the test certs.
5 sec for anything that doesnt have a socket outlet and 0.4 sec for anything that does, not anymore.
NIC chappie insists that anything under 30amp is 0.4 sec nowadays.

 

[Deleted member 72666]

I got a dig recently from an NICEIC visitation regarding what Ive been puting on the test certs.
5 sec for anything that doesnt have a socket outlet and 0.4 sec for anything that does, not anymore.
NIC chappie insists that anything under 30amp is 0.4 sec nowadays.

Sounds like you've been testing to 16th edition! For TN systems it's 5 seconds for distribution cct's and ccccccccccct's :ciappa: over 32 amp 0.4 seconds for everything else.

 

[1Justin]

I think I'd go with the 0.4 seconds then. (Which is what I told/warned customer anyway when I made quick visit for a quote).

Will make things tight at the end of the cable since it's a long way to the end of his garden.

Thanks for the input.