Refrigeration License Written Test Study Material
#1: Questions & Step-by-Step Answers
How do Automatic Expansion Valves work? Right Ans - By
evaporator pressure which opens the valve and spring pressure
which closes the valve.
When does a faulty check valve cause the most damage ? Right
Ans - On Start-Up
When does High Condenser or Head pressure occur ? Right Ans -
During a loss of pressure due to a clogged pump strainer.
What can happen to a unit if the TEV's sensing bulb falls off the
suction line ? Right Ans - Flood the evaporator and raise the
suction pressure.
What three components are part of the Pump Down Cycle. Right
Ans - Thermostat, Solenoid Valve and Low Pressure Control Switch.
What is the proper Start Up Sequence of chiller system ? Right
Ans - Check oil, start chill water pump, start condenser water pump,
Cooling Tower fans, and start Chiller
, How does a reciprocating machine cycles multistage compressors
On and Off ? Right Ans - With the Low Pressure Control Switch.
Which refrigerant has the best refrigerant effect ? Right Ans -
AMMONIA
At what temp is the leaving water temp in an Induced Draft Cooling
Tower that is operating efficiently ? Right Ans - Between the Dry
and the Wet bulb temperatures.
What is another way that a system can create an increase in Head
Pressure ? Right Ans - A sudden decrease in the supply of Cooling
Tower water.
How does a reciprocating compressor un-loader work ? Right
Ans - By keeping the compressor suction valves open.
At what point of the compressor is R-22 vapor charged from?
Right Ans - From the Suction side of the compressor.
What is the percentage amount of lubricant that should flow in a
system ? Right Ans - It should not exceed 10 %
#1: Questions & Step-by-Step Answers
How do Automatic Expansion Valves work? Right Ans - By
evaporator pressure which opens the valve and spring pressure
which closes the valve.
When does a faulty check valve cause the most damage ? Right
Ans - On Start-Up
When does High Condenser or Head pressure occur ? Right Ans -
During a loss of pressure due to a clogged pump strainer.
What can happen to a unit if the TEV's sensing bulb falls off the
suction line ? Right Ans - Flood the evaporator and raise the
suction pressure.
What three components are part of the Pump Down Cycle. Right
Ans - Thermostat, Solenoid Valve and Low Pressure Control Switch.
What is the proper Start Up Sequence of chiller system ? Right
Ans - Check oil, start chill water pump, start condenser water pump,
Cooling Tower fans, and start Chiller
, How does a reciprocating machine cycles multistage compressors
On and Off ? Right Ans - With the Low Pressure Control Switch.
Which refrigerant has the best refrigerant effect ? Right Ans -
AMMONIA
At what temp is the leaving water temp in an Induced Draft Cooling
Tower that is operating efficiently ? Right Ans - Between the Dry
and the Wet bulb temperatures.
What is another way that a system can create an increase in Head
Pressure ? Right Ans - A sudden decrease in the supply of Cooling
Tower water.
How does a reciprocating compressor un-loader work ? Right
Ans - By keeping the compressor suction valves open.
At what point of the compressor is R-22 vapor charged from?
Right Ans - From the Suction side of the compressor.
What is the percentage amount of lubricant that should flow in a
system ? Right Ans - It should not exceed 10 %
