CME CME Power Quality & Energy Efficiency

Question 1

What is the acceptable range of Total Harmonic Distortion (THD) for voltage at a point of common coupling per IEEE 519?

Accepted Answer

Less than 5%

Answer

Less than 10%

Answer

Less than 15%

Answer

Less than 20%

Question 2

Which device is most effective for mitigating voltage sags caused by motor starting on a distribution system?

Accepted Answer

Static VAR compensator (SVC)

Answer

Surge arrestor

Answer

Ground fault relay

Answer

Overcurrent relay

Question 3

A facility's power factor is measured at 0.72 lagging. What is the most efficient corrective action for a master electrician to recommend?

Accepted Answer

Install capacitor banks at the load

Answer

Add resistive heating loads

Answer

Install additional transformers

Answer

Replace conductors with larger gauge

Question 4

Which harmonic order is typically the most problematic in three-phase systems powered by six-pulse VFDs?

Accepted Answer

5th and 7th

Answer

2nd and 4th

Answer

3rd and 9th

Answer

11th and 13th

Question 5

What is the purpose of a K-factor rating on a transformer serving nonlinear loads?

Accepted Answer

Indicates the transformer's ability to handle harmonic heating without derating

Answer

Defines the transformer's short-circuit withstand rating

Answer

Specifies the maximum inrush current tolerance

Answer

Sets the insulation voltage class

Question 6

Under ASHRAE 90.1, which lighting control strategy is REQUIRED for commercial spaces greater than 5,000 sq ft?

Accepted Answer

Automatic shutoff controls

Answer

Dimmable ballasts only

Answer

Occupancy sensors only

Answer

Daylight harvesting only