BUFF BOOK IEEE Std 242-2001 vs 1986 (Transformer Impedance Table)

[majesus]

I can't seem to find the Impedance Data for three Phase Transformers in the IEEE 242-2001 Buff book.

It use to be on page 52 of the IEEE 242-1986 edition.

Did they remove it?

 

[rbulsara]

Not having recently referred to the 2001 edition, I am not sure of this particular table, but I do know that the latest version is not as insightful and helpful to new engineers. I was not impressed. It has removed many hand calculation procedures too. Anyone who has 1986 version, hang on to it. It will become another highly sought after edition.

As for tranformer impedance data, go to Square D website, look up power transformers and will get many tables. I am sure other leading mfr websites will have too.

 

[wareagle]

majesus
I have the book. Did you need the impedance for a particular size?

 

[majesus]

Thanks a lot guys for the info and help.

I do have both books, I am just interest and really curious on why did the IEEE remove a lot of the hand calculations and typical transformer impedances tables from the buff book? It seems that the 1986 is a lot more useful then the 2001 edition. That doesn't make sense to me, wouldn't a new edition just refine and improve the older edition? In this case, it looks worse.

 

[dpc]

It may have been because they expected the Violet Book on Short Circuit Calculations to be published some day. But this still hasn't happened yet.

This data is in Conrad St Pierre's book on Short Circuit Calculations.

 

[stevenal]

I believe the impedance tables are badly outdated, and warranted removal. Energy Star rated and other low loss transformers don't follow the table, and the newer versions of the referenced transformer standards no longer dictate impedances for most distribution transformers. Using these values for sizing equipment would not be wise.