HVAC Final Exam Electrical For Air Conditioning(quizzes with complete solutions)2022

HVAC Final Exam Electrical For Air
Conditioning
When using a low voltage T-stat for heating and cooling, when would there be a jumper
between Rh and Rc?
Select one:
a. When using a single transformer system
b. When heating with an oil boiler
c. When heating with a gas boiler
d. When using a two transformer system - Answer A) When Using a single transformer
system

Digital thermostats usually display temperature, time of day, programming and
operating status.
Select one:
True
False - Answer True

With the fan switch in the on position, the indoor fan will,,,
Select one:
a. Run in cooling mode
b. run continuously
c. run only when the outdoor unit runs
d. none of the above - Answer b. run continuously

What is the most common type of T-sat in the HVAC industry?
Select one:
a. Line voltage
b. Remote bulb
c. Low voltage
d. None of the above - Answer c. Low voltage

What device is added to a oil or gas forced hot air system when it is not AC ready?
Select one:
a. Fan limit switch
b. Fan Center
c. Multi Stage Thermostat
d. Mars Relay - Answer b. Fan Center

When a technician is taking an ohm reading across an open switch what should the
reading be?
Select one:
a. 0
b. OL

,c. Source Voltage
d. Some Number - Answer b. OL

What does the "Y" terminal connect to on a wall mounted low voltage T-stat?
Select one:
a. Outdoor fan relay
b. Cooling Contactor
c. Primary side of transformer
d. Indoor fan relay - Answer b. Cooling Contactor

In a transformer the ______________________ winding is the windings to which
voltage is supplied and is considered the load side of the transformer.
Select one:
a. primary
b. secondary
c. start
d. run - Answer a. primary

What would be the cause of a transformer failure?
Select one:
a. Compressor amps too high for circuit
b. Overloading the control circuit
c. Underloading the control circuit
d. None of the above - Answer b. Overloading the control circuit

What does the "G" terminal control on a low voltage wall mounted T-sat?
Select one:
a. Outdoor fan Relay
b. Cooling Relay
c. Indoor fan Relay
d. Heat Relay - Answer c. Indoor fan Relay

Contactors are rated according to the maximum amperage through the;

Select one:
a. coil
b. contacts
c. thermostat
d. fuse - Answer b. contacts

A cooling thermostat ___________________________.
Select one:
a. opens on temp. rise
b. closes on temp. rise - Answer b. closes on temp. rise

When ohming out a load what reading should the technician get?

, Select one:
a. 0
b. OL
c. Some Number
d. Source Voltage - Answer c. Some Number

When a technician is taking a volt reading across a closed switch in an energized circuit
what should the reading be?
Select one:
a. 0
b. OL
c. Source Voltage
d. Infinity - Answer a. 0

When a technician is taking a volt reading across an open switch in an energized circuit
what should the reading be?
Select one:
a. 0
b. OL
c. Source Voltage
d. Infinity - Answer c. Source Voltage

Most thermostats in the HVAC industry are 120 volts.
Select one:
True
False - Answer False

Where does the "R" terminal of a thermostat connect to?
Select one:
a. transformer secondary
b. transformer primary
c. relay
d. fan motor - Answer a. transformer secondary

What is the term used to descibe the output side of a transformer?
Select one:
a. Low inductive side
b. High inductive side
c. Primary side
d. Secondary side - Answer d. Secondary side

Snap action contact points are often used in controlling instruments to ____.
Select one:
a. decrease noise
b. prevent electrical arcing
c. maintain desired condition