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1. If a lockout relay becomes defective, it should be replaced with an exact duplicate, sometimes called a(n) ________.

time-delay relay

impedance relay

control relay

induced-draft relay

Question 1 of 20

2. NEC Article 440, Part V covers ________.

the control and protection of fixed electric space heating equipment

requirements for motor compressor controllers

digital control systems

resistors and reactors

Question 2 of 20

3. Thermostats with bimetal sensing elements typically use a combination of copper or brass and ________.

Elinvar®

Invar®

nickel

aluminum

Question 3 of 20

4. A device that uses dissimilar metals to control electron flow is known as a(n) ________.

firestat

freezestat

thermocouple

thermistor

Question 4 of 20

5. The purpose of the defrost cycle in a heat pump is to ________.

warm the unit circuits for optimum electrical operation

remove frost buildup throughout the system ductwork

prevent ice buildup on the indoor coil

prevent ice buildup on the outdoor coil

Question 5 of 20

6. Which of the following principles states that heat is created in one place and carried to another by means of air or water?

Heat-transplant principle

Heat-movement principle

Heat-transfer principle

Heat-creation principle

Question 6 of 20

7. A conventional thermostat should not be thrown into the regular trash because it ________.

contains sulfuric acid

is easy to repair

has a 10-year warranty

may contain mercury

Question 7 of 20

8. In a cooling system, the heat absorbed by the refrigerant is transferred to the cooler outdoor air in a heat exchanger known as a(n) ________.

compressor

expansion device

condenser

evaporator

Question 8 of 20

9. Which of the following is an example of an external analog device?

Lights

Relays

Switches

Thermistors

Question 9 of 20

10. If a mercury thermostat seems out of adjustment, the first thing to do is ________.

reset the system switch to Off

recalibrate the thermostat

adjust the setting lever

check for accurate leveling

Question 10 of 20

11. When the bimetal coil in a cooling-only thermostat heats up and unwinds, the mercury switch ________.

closes its contacts and shuts down the system

opens its contacts and initiates defrost

opens its contacts and stops the cooling system compressor

closes its contacts and starts the cooling system compressor

Question 11 of 20

12. A freezestat is a ________.

thermostat that has seized

normally open bimetal switch

digital control

normally closed bimetal switch

Question 12 of 20

13. Connecting a 120V heating cable to a 240V circuit will ________.

cause the system to operate within acceptable standards, but at less than full efficiency

produce only 25% of the rated cable wattage

enable the system to operate most efficiently

melt the cable

Question 13 of 20

14. The thermostat terminal that connects to the reversing valve control in a heat pump is ________.

Question 14 of 20

15. Multi-stage thermostats provide energy savings by cycling on stages of heating or cooling based on ________.

preset timers

time delay relays

pump size

demand

Question 15 of 20

16. To increase furnace efficiency, the startup of the furnace blower is delayed using a ________.

time delay relay

thermocouple

short-cycle time

limit control

Question 16 of 20

17. Conventional line-voltage thermostats do not provide precise temperature control because ________.

the sensor must be routed through a delay switch

the bimetal elements are heavier and do not respond as quickly

occupants often use the override controls

they have staggered startup

Question 17 of 20

18. If lighting units and other appliances are also supplied, the rating of cord- and plug-connected room air conditioners must not exceed what percentage of the branch circuit rating?

70%

80%

90%

50%

Question 18 of 20

19. The tubing that carries heat-laden refrigerant gas from the evaporator to the compressor is known as the ________.

hot gas line

discharge line

suction line

liquid line

Question 19 of 20

20. Automatic changeover thermostats have a minimum interlock setting, also known as the ________.

deadband

differential

compensator

evaporator

Question 20 of 20

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