Exam 14: Three-Phase Transformers

Checking a delta connection for proper connection is called ____.

Which of the following is a three-phase transformer connection requiring only two transformers?

When all three lines of a delta-wye connection are carrying the same amount of amperage, what is the neutral current value?

A voltmeter is a low-impedance device.

Which of the following would most likely be used to show the power distribution system of a large industrial plant?

Three-phase transformer connections are often used to supply single-phase loads, which tend to unbalance the system.

Which term is used for the voltage measured from the center tap of one transformer in a delta connection to the junction of the transformer(s) that are not center tapped?

A three-phase load that has unequal current flow through the phases is said to be ____.

Which of the following is a three-phase connection formed by connecting the start end of a phase winding to the finish end of another?

The amount of magnetic flux produced by one object that influences another is called magnetic ____.

What is the output power of an open delta connection?

If power is applied to the transformer bank before the delta connection is closed, the voltmeter should indicate ____ volts.

Delta connections should be checked for proper polarity after applying power.

Which of the following is a three-phase connection formed by connecting one end of each phase together to form a center point?

A tap in the center of a transformer winding that will provide one half of the rated voltage of the winding is called a ____ tap.

If the output voltage of a delta secondary is 240 volts, and one winding of the delta connection has been reversed, the voltmeter will indicate a voltage of ____.

A true three-phase transformer contains six separate transformers wound on a single core.

Single-phase transformers connected in three-phase configurations are called three-phase transformer ____.

As a general rule, three-phase transformers will have one side connected as a ____.

The disadvantage for three-phase transformers is that if a single transformer should fail, the entire transformer must be repaired or replaced.