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Electrical Power Supply and Distribution


Quiz Questions

1. System reliability describes and quantifies the ability of a system to consistently provide power to a facility. The designer will evaluate the supply source reliability data (outage record) and determine the system configuration required to meet the required availability.
True
False
2. Electrical system and electrical equipments will be designed for the design life of the facility:
35 years permanent construction, 10-30 years for semi-permanent and 8 years for temporary construction.
25 years permanent construction, 6-24 years for semi-permanent and 5 years for temporary construction.
20 years permanent construction, 6-10 years for semi-permanent and 3 years for temporary construction.
3. The most feasible method of supplying and distributing electrical power will be determined by first quantifying the electrical power requirements ( or maximum demand load) for the installation. In the early design staged, this demand should be based on area or population; in later design stages, summation of individual building connected loads modified by suitable demand and diversity factors will be used.
True
False
4. The design of electric supply and distribution systems can proceed only after a distribution voltage level has been determined.
True
False
5. A primary distribution system delivers energy from a main electric supply station to utilization transformers. A secondary distribution system delivers energy from a utilization transformer to point of utilization.
True
False
6. At existing installations, new stations will be provided either when it is not possible or when it is impractical to modify an existing station to serve both the existing facilities and the new projects.
True
False
7. Criteria for electric distribution lines will be based on the requirement of agency criteria. Distribution lines will be sized to meet which one of the following:
Current demand load
Future demand load
Line-loss factor
All of the above
8. Aerial transformer installations may utilize a three-phase unit or banked single-phase units. Transformers either singly or in banks, having an individual unit or combined capacity greater than 300 KVA will not be mounted on single wood poles.
True
False
9. Even the best design electrical system is subject to voltages resulting from physical conditions not subject to the owners control. Dangerous potential gradients can result also from improper design.
True
False
10. The most elaborate grounding system that can be designed may prove ineffective unless the connection of the system to earth is adequate and has a sufficiently low resistance. Since the desired resistance varies inversely with the fault current to ground, the larger the fault current the lower the resistance must be.
True
False
11. The maximum outage period for a security lighting of an area is:
2 minutes
5 minutes
10 minutes
12. Whenever performance of the security lighting is to be measured after installation and compared to design criteria or predicted performance, design documents will need to identify test conditions, instrumentation, and expected or acceptable performance under specific conditions and at specific times.
True
False
13. Illumination measurements should be performed after a
100-hour burn-in period
50-hour burn-in period
20-hour burn-in period
14. Figure 8-2 shows:
A crossarm-mounted transformer bank installation.
A cluster mounted transformer bank installtion
A pad mounted compartmental transformer installation
15. Figure 9-2 shows:
Grounding of a main electric supply substation.
Grounding of secondary unit substation installation
Surge arresters at a medium-voltage riser pole.