Downsizing a cable mid-circuit

[jamie-spark]

It is acceptable to reduce the cable size as long as it is suitable for the ocpd given all the relevent calcs

 

[i=p/u]

id say stick to good practice and stick to same size cable...

what they were discussing is a rule not normally associated with domestic, as it doesnt have to be done that way.. where if industrial you could tap of busbar chamber in 2.5mm as long as you ocp is within 3m.