26408-17 HVAC Controls
The thermostat terminal that connects to the reversing valve control in a heat pump is -
Answer O (orange), heat pump (red) power (Green) Fan Control (yellow) Cooling
contorl y1-y2 stage (white) heating contorl
Increase Furnace efficiency, the start of the furance blower is delayed using - Answer
Time delay relay
A conventional thermostat should not be thrown into the regular trash because it -
Answer may contain mercury
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? - Answer 50%
Automatic changeover thermostats have a minimum interlock setting, also known as the
- Answer deadband
If a lockout relay becomes defective, it should be replaced with an exact duplicate,
sometimes called a (an) - Answer Impedance relay
The principle that heat is created in one place and carried to another by means of air or
water? - Answer Heat-transfer principle
Thermostats with bimetal sensing elements typically use a combination of copper or
brass and - Answer Invar
A freezestat is a - Answer normally closed bimetal switch
When the bimetal coil in a cooling-only thermostat heats up and unwinds, the mercury
switch - Answer closes its contacts and starts the cooling system compressor
Connecting a 120V heating cable to a 240V circuit will - Answer melt the cable
Which of the following is an example of an external analog device? - Answer
Thermistors
If a mercury thermostat seems out of adjustment, the first thing to do is_ - Answer check
for accurate leveling
The tubing that carries heat-laden refrigerant gas from the evaporator to the compressor
is known as the - Answer suction line
The thermostat terminal that connects to the reversing valve control in a heat pump is -
Answer O (orange), heat pump (red) power (Green) Fan Control (yellow) Cooling
contorl y1-y2 stage (white) heating contorl
Increase Furnace efficiency, the start of the furance blower is delayed using - Answer
Time delay relay
A conventional thermostat should not be thrown into the regular trash because it -
Answer may contain mercury
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? - Answer 50%
Automatic changeover thermostats have a minimum interlock setting, also known as the
- Answer deadband
If a lockout relay becomes defective, it should be replaced with an exact duplicate,
sometimes called a (an) - Answer Impedance relay
The principle that heat is created in one place and carried to another by means of air or
water? - Answer Heat-transfer principle
Thermostats with bimetal sensing elements typically use a combination of copper or
brass and - Answer Invar
A freezestat is a - Answer normally closed bimetal switch
When the bimetal coil in a cooling-only thermostat heats up and unwinds, the mercury
switch - Answer closes its contacts and starts the cooling system compressor
Connecting a 120V heating cable to a 240V circuit will - Answer melt the cable
Which of the following is an example of an external analog device? - Answer
Thermistors
If a mercury thermostat seems out of adjustment, the first thing to do is_ - Answer check
for accurate leveling
The tubing that carries heat-laden refrigerant gas from the evaporator to the compressor
is known as the - Answer suction line
