PECO Distribution Systems & Infrastructure 3

Question 1

What is the purpose of a voltage regulator installed on a PECO distribution feeder?

Accepted Answer

Automatically adjust voltage to keep it within acceptable limits along the feeder length

Answer

A voltage regulator is an autotransformer with a tap changer that automatically adjusts its ratio to maintain feeder voltage within ANSI C84.1 limits despite varying load conditions.

Question 2

According to ANSI C84.1, the preferred service voltage range (Range A) for PECO's 120V secondary system is:

Accepted Answer

114V to 126V

Answer

ANSI C84.1 Range A for 120V nominal service specifies a preferred voltage range of 114V to 126V (±5%) at the utilization point under normal operating conditions.

Question 3

When a PECO lineman installs a new service drop from a secondary distribution line to a residential meter, the maximum allowed service drop conductor span without additional support is typically:

Accepted Answer

100 feet

Answer

PECO construction standards and the National Electrical Safety Code (NESC) generally allow a maximum service drop span of approximately 100 feet without intermediate support for residential services.

Question 4

What does 'loss of neutral' on a 120/240V residential service typically cause?

Accepted Answer

An imbalanced voltage condition where loads on one leg see over-voltage and loads on the other see under-voltage

Answer

Without a neutral, the two 120V legs become a series circuit across 240V; unbalanced loads cause voltage to redistribute so one side rises above 120V while the other drops below, potentially damaging appliances.

Question 5

Which document governs the minimum safety requirements for the construction of overhead and underground electric supply lines in PECO's distribution system?

Accepted Answer

NESC (IEEE C2)

Answer

The National Electrical Safety Code (NESC / IEEE C2) sets minimum safety requirements for electric supply and communication lines and equipment, including PECO's overhead and underground distribution construction.

PECO - Philadelphia Electric Company Certified Professional Practice Test

PECO - Philadelphia Electric Company Certified Professional Practice Test

PECO Distribution Systems & Infrastructure 3