Transformers next size up OCP

[brother]

Im having a little trouble finding where it is NOT allowed to go to the next size up for a transformer conductors, Its my understanding that its for the secondary conductors only and not the primary. I know about 240.4(B), and Ive looked at 450. Im just over looking something. Any help would be greatly appreciated.

 

[iwire]

Table 450.3(B) Maximum Rating or Setting of Overcurrent Protection for Transformers
600 Volts and Less (as a Percentage of Transformer-Rated Current)

 

[brother]

Table 450.3(B) Maximum Rating or Setting of Overcurrent Protection for Transformers
600 Volts and Less (as a Percentage of Transformer-Rated Current)

I appreciate the effort, and I did look at that table, but Im asking about the 'conductors' not the 'windings' of the transformer. Thanks.

 

[augie47]

Perhpas 240.21(C)
in part:
The provisions of 240.4(B) shall not be permitted for transformer secondary conductors.

 

[Dan coulstring]

Im having a little trouble finding where it is NOT allowed to go to the next size up for a transformer conductors, Its my understanding that its for the secondary conductors only and not the primary. I know about 240.4(B), and Ive looked at 450. Im just over looking something. Any help would be greatly appreciated.

I will throw in my $00.02
240.21(C) states that 240.(B) shall not be permitted for transformer secondary conductors

 

[brother]

I will throw in my $00.02
240.21(C) states that 240.(B) shall not be permitted for transformer secondary conductors

THATS IT!! Thanks, for some reason I kept overlooking that one. I kinda wish they had a referrence to it from 450, since that deals with transformers. It would make the NEC easier to read and search.