Z-51 REFRIGERATION TEST 2024-2026 ACTUAL EXAM
QUESTIONS AND CORRECT DETAILED ANSWERS
|ALREADY GRADED A+
Efficiency of the refrigerant cycle is affected by the operations of the
condenser. Of the following, a more efficient centrifugal compressor
operation results from: - CORRECT ANSWER Lowering the condensing
pressure
The heat removed from the refrigerant in a condenser is: - CORRECT
ANSWER Sensible and latent heat
The refrigerant unit that you have been assigned to is being taken out of
service for a major repair. You have been assigned to withdraw
refrigerant for storage in suitable containers. According to the NYC Fire
Code, you must ensure that the containers: - CORRECT ANSWER Are
approved by the US Dept. of Transportation
A standpipe system will be out of service for two days. How long should
there be a fire watch? - CORRECT ANSWER The entire time the
standpipe is out of service
A circuit breaker has a similar function as what: - CORRECT ANSWER A
fuse
1
,How do you start a centrifugal chiller? - CORRECT ANSWER Start the
chilled water pump, start the condenser water pump, check oil, start
cooling tower, start compressor
If a sprinkler system is offline for two days, how often do you need to
inspect it until it is returned back to service? - CORRECT ANSWER
Continuously, 24 hours a day until system is restored
The only refrigerant/temperature chart available to a refrigerant
engineer lists the temprature in degrees Celsius. If the chart indicates a
Celcius temperature of 5 degrees, the equivalent in Fahrenheit is -
CORRECT ANSWER 41 degrees
In the picture below, what does the equipment detect? - CORRECT
ANSWER Refrigerant leaks
In a building with multi-zone standpipe system, how does each zone get
supplied with water? - CORRECT ANSWER Each zone will have its own
automatic water supply
Which service valve should be installed to isolate a dual pressure relief
valve while keeping system in service? - CORRECT ANSWER Three way
valve
When will the BTU's exchanged be the greatest? - CORRECT ANSWER
Low evaporator temperature, high condenser temperature
2
,You find that the check valve on a centrifugal pump is leaking. When
would the most damage be caused to the pump? - CORRECT ANSWER
On startup of the pump
A motor winding is touching the inside of the motor housing. This could
result in: - CORRECT ANSWER Shock may occur to personnel
An engineer suspects a short of the motor winding have caused the
motor to trip on overload. The engineer should use what instrument to
check the motor: - CORRECT ANSWER Ohmmeter
An engineer would expect a relief valve to start function at a pressure: -
CORRECT ANSWER Design pressure
How many BTU's are removed in a 30 ton system? - CORRECT ANSWER
360,000 BTU's per hour
An engineer is requested to replace a gauge on the high side of the
system. The pressure graduation rate should be: - CORRECT ANSWER
At least 1.2 times the design pressure
An automatic expansion valve maintains a constant: - CORRECT
ANSWER Evaporator pressure
3
, During inspection of a facility, you notice that there has been failure to
maintain water treatment of the condenser water. The first evidence of
a problem would be: - CORRECT ANSWER An increase in compressor
head pressure
The efficiency of the refrigerant cycle is affected by the operation of the
condenser. Of the following, a more efficient centrifugal compressor operation
results from
Lowering the condenser pressure
What happens when a steam turbine reaches critical speed
Turbine will vibrate violently
What Device automatically controls the speed of a steam turbine
Governor valve
Under what circumstances is it OK to chain and exit
Never OK
The heat remove from the refrigerator in the condenser is
4
QUESTIONS AND CORRECT DETAILED ANSWERS
|ALREADY GRADED A+
Efficiency of the refrigerant cycle is affected by the operations of the
condenser. Of the following, a more efficient centrifugal compressor
operation results from: - CORRECT ANSWER Lowering the condensing
pressure
The heat removed from the refrigerant in a condenser is: - CORRECT
ANSWER Sensible and latent heat
The refrigerant unit that you have been assigned to is being taken out of
service for a major repair. You have been assigned to withdraw
refrigerant for storage in suitable containers. According to the NYC Fire
Code, you must ensure that the containers: - CORRECT ANSWER Are
approved by the US Dept. of Transportation
A standpipe system will be out of service for two days. How long should
there be a fire watch? - CORRECT ANSWER The entire time the
standpipe is out of service
A circuit breaker has a similar function as what: - CORRECT ANSWER A
fuse
1
,How do you start a centrifugal chiller? - CORRECT ANSWER Start the
chilled water pump, start the condenser water pump, check oil, start
cooling tower, start compressor
If a sprinkler system is offline for two days, how often do you need to
inspect it until it is returned back to service? - CORRECT ANSWER
Continuously, 24 hours a day until system is restored
The only refrigerant/temperature chart available to a refrigerant
engineer lists the temprature in degrees Celsius. If the chart indicates a
Celcius temperature of 5 degrees, the equivalent in Fahrenheit is -
CORRECT ANSWER 41 degrees
In the picture below, what does the equipment detect? - CORRECT
ANSWER Refrigerant leaks
In a building with multi-zone standpipe system, how does each zone get
supplied with water? - CORRECT ANSWER Each zone will have its own
automatic water supply
Which service valve should be installed to isolate a dual pressure relief
valve while keeping system in service? - CORRECT ANSWER Three way
valve
When will the BTU's exchanged be the greatest? - CORRECT ANSWER
Low evaporator temperature, high condenser temperature
2
,You find that the check valve on a centrifugal pump is leaking. When
would the most damage be caused to the pump? - CORRECT ANSWER
On startup of the pump
A motor winding is touching the inside of the motor housing. This could
result in: - CORRECT ANSWER Shock may occur to personnel
An engineer suspects a short of the motor winding have caused the
motor to trip on overload. The engineer should use what instrument to
check the motor: - CORRECT ANSWER Ohmmeter
An engineer would expect a relief valve to start function at a pressure: -
CORRECT ANSWER Design pressure
How many BTU's are removed in a 30 ton system? - CORRECT ANSWER
360,000 BTU's per hour
An engineer is requested to replace a gauge on the high side of the
system. The pressure graduation rate should be: - CORRECT ANSWER
At least 1.2 times the design pressure
An automatic expansion valve maintains a constant: - CORRECT
ANSWER Evaporator pressure
3
, During inspection of a facility, you notice that there has been failure to
maintain water treatment of the condenser water. The first evidence of
a problem would be: - CORRECT ANSWER An increase in compressor
head pressure
The efficiency of the refrigerant cycle is affected by the operation of the
condenser. Of the following, a more efficient centrifugal compressor operation
results from
Lowering the condenser pressure
What happens when a steam turbine reaches critical speed
Turbine will vibrate violently
What Device automatically controls the speed of a steam turbine
Governor valve
Under what circumstances is it OK to chain and exit
Never OK
The heat remove from the refrigerator in the condenser is
4
