PECO Distribution Systems & Infrastructure 2

Question 1

Which type of cable insulation is most commonly used in PECO's underground distribution system for medium-voltage circuits?

Accepted Answer

Cross-linked polyethylene (XLPE)

Answer

Cross-linked polyethylene (XLPE) is the predominant insulation for modern medium-voltage underground distribution cables due to its superior thermal and electrical properties.

Question 2

What does the acronym 'URD' stand for in the context of PECO distribution infrastructure?

Accepted Answer

Underground Residential Distribution

Answer

URD stands for Underground Residential Distribution, referring to the system of underground cables and pad-mounted transformers that serve residential subdivisions.

Question 3

A PECO feeder circuit experiences a permanent three-phase fault. Which protection device at the substation is the first to respond?

Accepted Answer

Substation feeder breaker

Answer

The substation feeder breaker is the first-line protection device and will trip on a permanent three-phase fault at the substation level before downstream devices operate.

Question 4

What is the main advantage of a looped (ring-bus) distribution system over a radial distribution system for PECO's service area?

Accepted Answer

Improved supply reliability through alternate feed capability

Answer

A looped or ring-bus distribution system allows power to be rerouted from an alternate feed point during a fault or maintenance, improving service reliability compared to a radial system.

Question 5

PECO installs capacitor banks on distribution feeders primarily to accomplish which of the following?

Accepted Answer

Provide reactive power compensation and improve power factor

Answer

Capacitor banks supply reactive power (VARs) locally on the feeder, improving power factor, reducing I²R losses, and helping maintain acceptable voltage levels.

PECO - Philadelphia Electric Company Certified Professional Practice Test

PECO - Philadelphia Electric Company Certified Professional Practice Test

PECO Distribution Systems & Infrastructure 2