Chapter 83

Question 0

Low voltage systems may have an acceptable voltage variation of plus or minus:
A) 10%
B) 5%
C) 1.5%
D) 7.5%
E) 12.5%

Answer 0

B) 5%

Question 1

A typical extra low voltage device would be a:
A) toaster
B) set of tree lights
C) doorbell
D) dry cell battery charger
E) night light

Answer 1

C) doorbell

Question 2

When working with high voltage systems, the minimum distance of approach should be:
A) 1 meter
B) 4 meters
C) 2 meters
D) 3 meters
E) 60 centimetres

Answer 2

C) 2 meters

Question 3

The best type of diagram for showing supply and distribution systems is the:
A) riser
B) one line
C) elementary
D) connection
E) terminal and connection

Answer 3

B) one line

Question 4

An electrical distribution system is composed of service, feeders and:
A) secondary circuits
B) primary circuits
C) branch circuits
D) trunk circuits
E) tertiary circuits

Answer 4

C) branch circuits

Question 5

According to the Canadian Electrical Code, AC electrical supplies and systems may be divided into three voltage classes. List the three classes and state the voltage range for each.

Answer 5

High voltage - > 750 V
Low voltage - 30 - 750 V
Extra low voltage - < 30 V

Question 6

In a single phase 240 volt circuit, there are three wires to connect motors and other devices. State the colors of these wires and what each connect is called.

Answer 6

Red, black - hots, live circuit conductors or leads

White - identified, grounded or neutral

Question 7

Describe the steps that must be taken to ensure that high voltage circuits are safe to work on.

Answer 7

The disconnect switches must be locked in the open position

Ground connections must be attached to ensure the circuits are fully de-energized