Txfm

Question 1

Which 3 phase transformer configuration would match all X2 line connections with H2 line connections to ensure a 30deg displacement

Answer 1

Delta/Wye

Question 2

When using a bank of 3 single phase transformers in a 3 phase distribution system, which condition would provide the Largest step-up ration between primary and secondary

Answer 2

Delta-wye

Question 3

When connecting a 3 phase open delta autotransformer, one of the primary lines is connected to a second line.

These two common lines are also connect to?

Answer 3

The 0% taps

Question 4

If a 3 phase transformer bank is to be constructed using three single phase transformers (two additive and one subtractive)

Answer 4

The three transformers can be used for any three phase connection

Question 5

When comparing a 3 phase isolation transformer to a 3 phase autotransformer one advantage of the autotransformer is that for a given KVA rating an autotransformer is much smaller in size than the isolation ( T or F)

Answer 5

True

Question 6

Why is it unsafe to open the secondary circuit of a CT whenever there is primary current flowing in one of the lines

Answer 6

The secondary voltage may rise to a high value