HVACR Journeyman Practice Exam
In a (direct expansion) evaporator, liquid refrigerant must boil away as close to the end of the
coil as possible in order to: - ANSOperate at High Efficiency.
What is one of the main reasons that reciprocating compressors are not 100% efficient? -
ANSClearance Volume
A dirty evaporator and return air filters subsequently causes low evaporator pressures which will
cause - ANSHigh Compression Ratios
The automatic expansion valve (AEV) maintains a constant ______ in the evaporator. -
ANSPressure
Short cycling during pump down can be caused by - ANSa leaking compressor suction valve.
What type metering device is best suited in applications where freeze protection is required? -
ANSAutomatic Expansion Valve (AEV)
The "Fan Cycle Control" is used in conjunction with low ambient temperature conditions to
control __________. - ANSCondenser Pressure
What do water cooling towers require? - ANSPeriodic de-scaling
A refrigeration system used to cool another refrigeration system is called a _______. -
ANSCascade System
High temperature refrigeration applications normally provide box temperatures of: - ANS47ºF to
60ºF
Why must an oil separator be kept warm? - ANSTo prevent refrigerant from condensing in the
separator during the off cycle.
If a pressure control has been adjusted to cut in at 30 psig, in order to have a 10 psig cut out,
the differential setting of the control must be: - ANS20 Psig
Ester based oils are ________. - ANSSynthetic Oil
What is the minimum clearance for access panels on an outdoor condensing unit? - ANS30
inches
In a (direct expansion) evaporator, liquid refrigerant must boil away as close to the end of the
coil as possible in order to: - ANSOperate at High Efficiency.
What is one of the main reasons that reciprocating compressors are not 100% efficient? -
ANSClearance Volume
A dirty evaporator and return air filters subsequently causes low evaporator pressures which will
cause - ANSHigh Compression Ratios
The automatic expansion valve (AEV) maintains a constant ______ in the evaporator. -
ANSPressure
Short cycling during pump down can be caused by - ANSa leaking compressor suction valve.
What type metering device is best suited in applications where freeze protection is required? -
ANSAutomatic Expansion Valve (AEV)
The "Fan Cycle Control" is used in conjunction with low ambient temperature conditions to
control __________. - ANSCondenser Pressure
What do water cooling towers require? - ANSPeriodic de-scaling
A refrigeration system used to cool another refrigeration system is called a _______. -
ANSCascade System
High temperature refrigeration applications normally provide box temperatures of: - ANS47ºF to
60ºF
Why must an oil separator be kept warm? - ANSTo prevent refrigerant from condensing in the
separator during the off cycle.
If a pressure control has been adjusted to cut in at 30 psig, in order to have a 10 psig cut out,
the differential setting of the control must be: - ANS20 Psig
Ester based oils are ________. - ANSSynthetic Oil
What is the minimum clearance for access panels on an outdoor condensing unit? - ANS30
inches
