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Unit 46 > Unit 46 Quiz > Flashcards

Unit 46 Quiz Flashcards

1
Q

What is used to provide supplemental heat for a heat-pump window unit?

A

Electric resistive heater strips

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2
Q

Single room air conditioning units generally range in capacity from ______ btu/h.

A

4000 to 24,000

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3
Q

The evaporator typically operates _______ the dew point temperature of the room air.

A

Below

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4
Q

Compressors used in window air conditioners are typically hermetically sealed and either _____ or _______.

A

Reciprocating or rotary

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5
Q

True or false: all 208V/230V power cords have the same plug configuration.

A

False

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6
Q

True or false: In the heat-pump heating cycle, the refrigerant condenses in the indoor coil.

A

True

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7
Q

True or false: The capacity of a heat-pump is less in colder weather so supplemental heat will probably be provided.

A

True

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8
Q

True or false: The heat-pump systems use a three-way reversing valve and check valves to ensure correct flow through the correct metering device at the proper time.

A

False

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9
Q

True or false: The most common refrigerant used in older window air conditioners is R-12

A

False

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10
Q

True or false: New models of window air conditioners use R-410A refrigerant.

A

True

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11
Q

Coil temperature for a window air conditioner should be no lower than _______ F.

A

35 degrees F

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12
Q

How is the condensate from the evaporator disposed of from a window unit?

A

Drained out of the pan or evaporation using a slinger ring

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13
Q

When doing a bench test to check a window unit to see if it has a proper charge, what is the purpose of blocking the condenser air flow?

A

Because the condenser and evaporator will be operating in the same ambient temperature, blocking the airflow over the condenser will increase head pressure and push the refrigerant out of the condenser.

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14
Q

The round piece fastened to the outer tips of the condenser fan blade is called the ______.

A

Slinger ring

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15
Q

The window unit must be installed in such a manner that air can circulate across the _______ and not recirculate or high head pressures will result.

A

Condenser

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16
Q

What happens if a window air conditioner is installed with an inward pitch?

A

Condensate could leak into the room

17
Q

What is the result of a dirty air filter on a window unit?

A

Dirty coils
low suction pressure
potential ice blockage in the evaporator

18
Q

Window installation of room units are either double-hung or ______ windows.

A

Casement

19
Q

What is the purpose of the energy saver switch on some window units?

A

To allow or deny the fan motor from cycling on/off with the compressor

20
Q

When bench checking a window unit for a low charge, where should the sweat line be to indicate a full charge?

A

All the way to the compressor

21
Q

The correct head pressure for a window unit that uses R-410A is ______ psig.

A

420

22
Q

What is performed on a window unit for basic preventive maintenance?

A
  • Cleaning the filters and coils
  • lubricating the motor if needed
  • clean out condensate drain pan
  • clean blower fan blades
  • check for mold on the foam insulation
  • check capacitor
23
Q

How can you identify if a window unit is a through-the-wall type unit?

A

The sides will not have vents/louvers.

24
Q

What type of fan motor is used in a window unit?

A

PSC or Shaded pole

25
Q

Dimming of lights and television picture rolling over when the AC unit starts is a sign of what?

A

There are other loads on the AC circuit

26
Q

Your manifold gauge is attached as last resort to confirm a low charge. What are some indications that the window unit has a low charge?

A
  • Evaporator not sweating from bottom to top,
  • suction line not sweating almost all the way to the compressor,
  • compressor not drawing FLA.
27
Q

Any air gaps between the window unit and window should be filled with _____ to keep hot air from entering and conditioned air from escaping.

A

Foam strip or insulation

28
Q

Voltmeter probes placed on the thermostat terminals will have a meter reading of ______ if the thermostat switch is open.

A

Line voltage

29
Q

A large window air conditioner can be used to cool several rooms. How is that accomplished?

A

Use a floor fan to circulate air to the other rooms.

30
Q

What are two types of window unit chassis?

A

Wrap-around or slide out/sleeve

31
Q

A window unit that operates on 115V uses ______ the current than a window unit that operates on 208V/230V.

A

Twice

32
Q

The rear of a window unit , if not properly supported, could cause what type of problems?

A

Condensate/drain problems, vibration noise

33
Q

Two types of fan blades are used in a window unit, what are they?

A

Squirrel cage and propeller blades

34
Q

How is fresh air introduced into a room and indoor air exhausted through a window unit?

A

A Damper that’s operated from the front unit

35
Q

Can a thermostatic valve or automatic expansion valve be used to replace a restricted capillary tube metering device in a window unit?

A

Yes

Unit 46 (1 decks)

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