Worksheets03. ACR-104 UNIT 21 PRACTICE TEST
Total questions: 10
Worksheet time: 5mins
The difference in temperature between the boiling refrigerant temperature and the evaporator outlet temperature is known as ___________.
temperature difference
delta T
suction line superheat
evaporator superheat
Low temperature food storage applications typically have a temperature range of ________.
0 to -32°F
0 to -20° F
-20 to -32°F
0 to 32°F
When the evaporator removes heat from the air and lowers the temperature of the air, _________.
sensible heat is removed from the air
latent heat is added to the air
moisture is added to the air
refrigerant vapor condenses to liquid
When moisture is removed from the air, latent heat is removed.
True
False
Natural-convection evaporators use a blower to force or induce air over the coil to improve the efficiency of the heat exchange.
True
False
When a refrigerated space has been allowed to warm up considerably, the system must ________.
go through a hot pulldown
be defrosted at regular intervals
turned off and the product being cooled moved to another cooler
be overcharged to remove the excess heat
Flooding the compressor crankcase with liquid refrigerant can cause ________.
excessive superheat
oil foaming
a starved evaporator
moisture to accumulate in the compressor oil
Low-temperature evaporator coils __________.
have more fins per inch than medium temperature evaporator coils
operate the same as medium temperature evaporator coils
have fewer fins per inch than medium temperature evaporator coils
require more oil circulation that medium temperature evaporator coils
Two common methods for defrosting a low temperature evaporator are __________.
off-cycle and hot gas
off-cycle and electric heat
reverse cycle and hot gas
hot gas and electric heat
When liquid refrigerant floods the compressor crankcase, the oil level in the crankcase can drop causing _______.
bearing washout
excessive superheat
condenser flooding
valve damage
