Book 2: 1-11 - "Electric Controls for Heating Systems"

Question 1

Electrical control systems usually employ a normal line voltage of:
Select one:

A. 12 or 24 volts DC

B. 120 or 240 volts AC

C. 240 or 600 volts AC

D. 12 or 24 volts AC

E. 120 or 240 volts DC

Answer 1

B. 120 or 240 volts AC

Question 2

When dealing with electrical controls line voltage refers to:
Select one:

A. The electric switch configuration of a relay

B. A term that refers to the normal electric supply voltage

C. A device consisting of a solenoid coil, which operates load carrying contacts when the coil is energized

D. A device used to change AC voltage from one value to another

E. A term that refers to wiring or other electrical devices using 30 volts or less

Answer 2

B. A term that refers to the normal electric supply voltage

Question 3

In a typical electric control system in a warm air heating system the thermostat is referred to as the:
Select one:

A. Controlled variable

B. Set point

C. Controller

D. Manipulated variable

E. Final control element

Answer 3

C. Controller

Question 4

When dealing with electrical controls relay refers to:
Select one:

A. A device consisting of a solenoid coil, which operates load carrying contacts when the coil is energized

B. A term that refers to wiring or other electrical devices using 30 volts or less

C. A term that refers to the normal electric supply voltage

D. The electric switch configuration of a relay

E. A device used to change AC voltage from one value to another

Answer 4

A. A device consisting of a solenoid coil, which operates load carrying contacts when the coil is energized

Question 5

The thermostat equipped with a coil-shaped bimetal element operating a mercury bulb switch has an operating range of between:
Select one:

A. 10°C and 32°C (50°F and 90°F)

B. 0°C and 20°C (32°F and 68°F)

C. 12°C and 30°C (54°F and 86°F)

D. 5°C and 28°C (41°F and 82°F)

E. 20°C and 42°C (68°F and 108°F)

Answer 5

A. 10°C and 32°C (50°F and 90°F)

Question 6

In a typical electric control system the electric current is transmitted through a wire called the _____ to the burner.
Select one:

A. Connecting link

B. Control link

C. Neutral line

D. Negative loop

E. Positive loop

Answer 6

A. Connecting link

Question 7

When dealing with electrical controls transformer refers to:
Select one:

A. A device used to change AC voltage from one value to another

B. A term that refers to the normal electric supply voltage

C. A device consisting of a solenoid coil, which operates load carrying contacts when the coil is energized

D. The electric switch configuration of a relay

E. A term that refers to wiring or other electrical devices using 30 volts or less

Answer 7

A. A device used to change AC voltage from one value to another

Question 8

The electrically operated radiator valve is a _____ valve, (and) is used for two position (on-off) control of steam or hot water to radiators, convectors, etc.
Select one:

A. Single seated

B. Gate

C. Ball

D. Butterfly

E. Double seated

Answer 8

A. Single seated

Question 9

Electrical contacts that complete circuits when a relay is energized are referred to as _____ contacts.
Select one:

A. Normally open (NO)

B. Naturally Closed (NC)

C. Naturally open (NO)

D. Normally closed (NC)

E. Not open (NO)

Answer 9

A. Normally open (NO)

Question 10

A three-way valve is a:
Select one:

A. Ball-seated valve

B. Single-seated valve

C. Double-seated valve

D. Triple-seated valve

E. Gate-seated valve

Answer 10

C. Double-seated valve

Question 11

The duct thermostat is used to sense the air temperatures in:
Select one:

A. Freezers

B. Ducts and plenums

C. Rooms

D. Coolers

E. Boilers

Answer 11

B. Ducts and plenums

Question 12

The sensing element of the _____ is liquid filled and the switch is actuated by the expansion and contraction of the liquid when there is a temperature change of the controlled medium.
Select one:

A. Humidistat

B. Pressurestat

C. Immersion thermostat or Aquastat

D. Remote bulb thermostat

E. Bimetal thermostat

Answer 12

C. Immersion thermostat or Aquastat

Question 13

When dealing with controls a control valve is a device:
Select one:

A. Used to change AC voltage from one value to another

B. Used to position dampers and control valves

C. That connects an actuator to a damper or control valve

D. Used to control the flow of air in a duct or through a wall louvre

E. Used to control the flow of fluid or gas such as water, air, or steam

Answer 13

E. Used to control the flow of fluid or gas such as water, air, or steam

Question 14

Electrical contacts that complete electric circuits when a relay is de-energized are referred to as _____ contacts.
Select one:

A. Naturally open (NO)

B. Normally open (NO)

C. Naturally Closed (NC)

D. Normally closed (NC)

E. Not open (NO)

Answer 14

D. Normally closed (NC)

Question 15

When dealing with controls a controller is a device:
Select one:

A. That connects an actuator to a damper or control valve

B. Used to position dampers and control valves

C. Which reacts to pressure, temperature, or humidity to provide two position, floating, or proportioning control of an actuator or relay

D. Used to change AC voltage from one value to another

E. Used to control the flow of fluid or gas such as water, air, or steam

Answer 15

C. Which reacts to pressure, temperature, or humidity to provide two position, floating, or proportioning control of an actuator or relay

Question 16

When dealing with controls an actuator is a device:
Select one:

A. Used to change AC voltage from one value to another

B. Used to position dampers and control valves

C. Used to control the flow of air in a duct or through a wall louvre

D. That connects an actuator to a damper or control valve

E. Used to control the flow of fluid or gas such as water, air, or steam

Answer 16

B. Used to position dampers and control valves

Question 17

The motor operator used with a motor-operated valve consists of a:
Select one:

A. Reversible driving motor and reduction gears mounted in a sealed casing and completely submerged in water

B. Reversible driving motor and reduction gears mounted in an open casing and completely submerged in oil

C. Direct driving motor and reduction gears mounted in a sealed casing and completely submerged in oil

D. Direct driving motor and reduction gears mounted in a sealed casing and completely submerged in water

E. Reversible driving motor and reduction gears mounted in a sealed casing and completely submerged in oil

Answer 17

E. Reversible driving motor and reduction gears mounted in a sealed casing and completely submerged in oil

Question 18

Electrical control systems may use a low voltage of:
Select one:

A. 12 or 24 volts DC

B. 12 or 24 volts AC

C. 122 or 240 volts AC

D. 120 or 240 volts DC

E. 240 or 600 volts DC

Answer 18

B. 12 or 24 volts AC

Question 19

A room thermostat should be mounted on an inside about _____ above the floor and in the wall about path of natural air circulation when the heating system is off.
Select one:

A. 4.0 m (157 in)

B. 1.5 m (60 in)

C. 4.5 m (180 in)

D. 2.5 m (100 in)

E. 3.5 m (140 in)

Answer 19

B. 1.5 m (60 in)

Question 20

A capacitor type control motor has the rotor and gear train sealed in a housing partially filled with:
Select one:

A. Nitrogen

B. Glycol

C. Grease

D. Water

E. Oil

Answer 20

E. Oil