Limitations Of Turns Ratio Testing - Raytech TR-MARK III Instruction Manual

3.4.4 Limitations of Turns Ratio Testing:

In general, there are few limitations on ratio testing of Transformers. However, there are
limitations to be aware of when attempting to test the following transformer:
Phase relationships other than 30° .
•
Non symmetrical Zig Zag windings
•
Uncentered neutral points.
•
Suspected broken, damaged, or missing core laminations.
•
In the cases listed above, Raytech recommends the use of the optional unit, model T-Rex, in
conjunction with the TR-MARK III. To get further Information on the T-Rex please check
chapter 'A.A, T-Rex', or contact Raytech to get additional details and information.
Also current transformers are in effect nothing else than opposite wound voltage
transformers. Most current transformers can be tested by TR-MARK III. Please see chapter
'A.B Current Transformer Testing' for details about CT testing.
You may find some small low power current transformer difficult to test by TR-MARK III. In
this case, please contact Raytech for information about TR-1.
90100.1.02 Instruction Manual TR-MARK III Page 11 of 70