Defintion of "Transformer-Rated Current"

[richwaskowitz]

In the 2005 Code, article 450, table 3b refers to "Currents of 9 Amperes or More", "Less Than 9 Amperes", and "Less Than 2 Amperes".

It seems clear to me that the 9 and 2 amps referred to in the first three columns under "Primary Protection" are talking about primary current. The last two columns, I am not too sure about. Does the 9 amperes referred to in the two "Secondary Protection" columns to the right refer to 9 amps of SECONDARY current or PRIMARY current?

I could really use an authoratative opinion on this to resolve an issue we are having here.

 

[charlie b]

I can't give you anything "authoratative." But I can give an opinion. It refers to secondary current. The basis of that statement, weak as it may be, is that the overcurrent setting limit, as shown in the row directly below the 9 and the 2, is given in terms of a pecentage of secondary current.