Heat which is added to a vapor after the change of state occurs is called
superheat
A refrigerant gives up heat when;
it vaporizes.
It is desirable for refrigerant in the suction line to be slightly superheated in order to;
insure liquid refrigerant does not enter the compressor.
The state of the refrigerant in the suction line should be;
low pressure/ low temperature vapor
The state of the refrigerant entering the condenser is
The state of the refrigerant entering the condenser is
the evaporator;
transfers heat from the refrigerated space to the refrigerant.
Zero psig (pounds per square inch gauge) is
the same as atmospheric pressure.
approximately 14.7 psig at sea-level.
A compound pressure gauge measures;
pressure and vacuum.
A mechanical shaft seal is necessary on a
open drive compressor
The clearance space in a reciprocating compressor;
has an effect on compressor capacity.
A thermostatic expansion valve is designed to maintain
constant evaporator superheat
When mounting a thermostatic expansion valve sensor bulb
the contact surfaces must be clean.
it must be tightly clamped to the suction line.
it must be insulated from ambient temperature.
A temperature change across a filter-drier indicates
a restricted filter-drier.
A liquid receiver is used;
.
to store liquid refrigerant
An accumulator is used;
.
to prevent liquid refrigerant from reaching the compressor
A clear sight glass could indicate;
all liquid refrigerant.
no refrigerant.
an be used for leak detection and is safe with all refrigerants
Soap/ bubble solution
Before using an electronic leak detector
the system should have sufficient pressure.
the detector must be properly calibrated.
the detector must be compatible with the type of refrigerant used.
all of the above.
What type of gauge is used to measure a vacuum of 500 microns?
An electronic vacuum gauge.
Before a vapor/ compression system is opened for service;
CorrectC.
the refrigerant must be recovered using approved equipment.
Technician "A" says that a low refrigerant charge can cause the compressor to overheat.
Technician "B" says that a low refrigerant charge can cause a starved evaporator. Who is correct?
Both technicians "A" and "B
Technician "A" says that a system that does not hold vacuum during a standing vacuum test probably has a leak. Technician "B" says that a soap bubble solution is the best way to locate leaks when a system is under vacuum.
Neither technician "A" nor "B
At a residential service call "no cooling" complaint, the service technician finds the unit to be completely out of refrigerant. Rather than wasting R-22 refrigerant for leak testing, the technician decides to use ______________ in order to pressurize the
an inert gas