Power Quality

Many tools designed to improve a   ?   quality are not only among the first to suffer from a lack of quality, but sometimes contribute to the problems they are intended to resolve.

• load supply

• load resistance

• power supply

• supply resistance

Companies invest in additional back-up equipment for sensitive equipment, which adds to the demand on the power supply and are sensitive to   ?   in the system.

• equipment manufacturers

• fluctuations

• load demands

• personnel interactions

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Voltage phasors, or vectors, are separated by   ?   degrees in a normal three-phase power distribution system.

• 45

• 90

• 120

• 180

A   ?   is a decrease from the nominal voltage supply level.

• cutout

• sag

• swell

• spike

The three electrical theory laws: Ohm’s Law, Kirchoff’s voltage law and Kirchoff’s current law, are used to trace the   ?   of most PQ-related problems.

• equipment

• imagined

• remediation

• source

Which of the five scenarios identified by NIOSH that describe the incidents resulting in 244 fatalities had the highest percentage for workers in the electrical industry   ?  .

• Boomed vehicle contact with an energized power line.

• Conductive equipment contact with an energized power line.

• Direct worker contact with energized equipment.

• Direct worker contact with an energized power line.

The use of proper personal protective equipment is intended to reduce or prevent   ?  .

• competition

• injury

• PQ phenomena

• profit

What single activity was identified as being performed when an accident occurred?

• equipment installation

• device installation

• software configuration

• troubleshooting

A 3% voltage imbalance between phases may result in the need to de-rate electric motors by   ?  .

• 3%

• 10%

• 12%

• 25%

Both voltage unbalance and harmonics are generally considered as   ?   power quality problems.

• estimated

• intermittent

• steady state

• temporary

Answer explanation

Steady state. • A system (e.g. circuit) is in the steady state. when the current at each point in the circuit is constant (does not change with time). – In many practical circuits, the steady state is achieved in a short time.

turbines, pumps, compressors, fans, and blowers