Exam 21: Harmonics

Ammeters that respond to the average value convert the alternating current into direct current. This value must be increased by a factor of_________ to change the average reading into the rms value for a sine wave current.

One way to deal with harmonic problems is to install_________ a neutral conductor.

It is necessary to use an ammeter that responds to _________current when making a check for harmonics.

The most accurate method for determining whether there is a harmonics problem is to use a(n)_________ .

What steps should you follow when determining whether there are harmonic problems in single-phase systems?

A_________ is used to smooth the pulsations caused by a bridge rectifier.

To minimize interference, communication cables are run as close to the _________conductor as possible.

What are some devices that are responsible for harmonics?

THDF stands for_________ .

How are harmonics classified?

Harmonics are produced by loads that draw current in_________ .

Transformers are typically designed for _________-hertz operation.

A ratio of _________between measurements made with a true rms ammeter and an average value ammeter indicates no harmonic distortion.

Harmonics called _________have a zero sequence.

The instantaneous peak value of current is equal to the rms value multiplied by _________.

The phasor rotation of a negative harmonic causes an induction motor to produce_________ .

Harmonics are voltages or currents that operate at a frequency that is the_________ fundamental power frequency.

What problems are caused by harmonics in circuit breakers?

What problems do triplens pose for neutral bus ducts?

Harmonic currents in the neutral conductor induce_________ currents into the communication cable.