Tx Review 1 Flashcards
What are the basic parts of a transformer?
2 coils and a soft iron core
How efficient are transformers?
95% to 98%
What 2 types of losses are located in the core of the transformer?
Eddy Currents
Hysteresis
Three common Tx applications are?
Step-up
Step-down
Isolation
Two cooling methods for removing the heat from the Tx include?
Liquid dielectric
Air
What are transformers rated for?
Apparent Power
What is the maximum voltage a transformer can withstand above the name plate value?
10%
If the kVA output of a 600V 60Hz transformer is 50kVA, what will the input be?
50kVA
What does the term RCBN stand for?
Reduced capacity below normal
Where would the H1 and X1 winding of a transformer be located, if the polarity is subtractive?
Directly opposite each other
How many individual windings does a 120/240:240/480V 5kVA Tx have?
4 individual windings
What are the three types of transformer construction
Shell
Core
H-type
If a transformer with no load is connected to a source, what current will flow?
Exciting current on pri
No I or V on sec
When measured, the no load secondary voltage is above nameplate values. Why is this an expected condition?
No internal line drop
No current
Under what conditions can core losses be measured?
During an open cct test
