fdny z51 rmo Questions and Verified Answers
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 Correct Answer: lowering the condenser
pressure
In most semi hermetic compressors, the suction vapor is used for Correct Answer: cools the motor
The amount of refrigerant that flows through the orifices of an economizer is determined by the Correct
Answer: difference between the high side and the low side pressure
the instalation of an inline refrigerant cleaning system is advisable Correct Answer: to remove impurities
from the system
a refrigerant engineer verifies that a condenser pump is cavitation of the following the most likely cause
for this condition is: Correct Answer: a faulty cooling tower water level controller
when an expansion valve is operating properly, at the end of the evaporator will contain Correct Answer:
only superheated vapor
a centrifugal water pump is considered to be fully primed when Correct Answer: the pump is full of
liquid
A refrigeration compressor has failed to turn on. the engineer on duty verifies the electrical circuit to the
motor, including all switches and circuit breakers is complete, according to recomended service practice,
the next item to be checked would likely be the: Correct Answer: temperature and pressure controls
Refrigerants are characterized by their physical properties including Flashpoint, refrigeration effect and
others, of the refrigerants in commercial and industrial the highest latent heat and refrigerant effect is:
Correct Answer: ammonia
which of the following ashrae refrigerant safety classification is the most toxic Correct Answer: b3
which of the following ashrae refrigerant safety classification is the most flammable Correct Answer: a3
in q indirect refrigeration system,of the following, the one that would not be used as a cooling medium
for building spaces being cooled is Correct Answer: r 22 (cooling medium= glycol or any brine solution)
the primary way of achieving capacity control of a an centrifugal compressor is by: Correct Answer:
adjustment to the inlet impeller pre rotation vanes
, regarding the functioning of a steam turbine, why is it advisable to keep moisture in the inlet low as
possible Correct Answer: keeps turbine blades wear to minimum
a water chiller is equipped with a reciprocating compressor, a thermostatic expansion valve and a an air
cooled condenser. A restriction in the refrigerant line would result in Correct Answer: high suction super
heat
the process by which refrigerant is extracted and cleaned for reuse without requirements for reclamation
is called Correct Answer: recycle
the purpose of wear rings in a centrifugal pump is to Correct Answer: prevent wearing of the pump
housing and impeller
a centrifugal compressor is in operation with suction pressure is 3 psig and the discharge is 10psi what is
the atmospheric pressure is 14.7 which is the ratio closest to Correct Answer: 1.39
electrical current us measured in Correct Answer: amperage
how would you put an additional pump online Correct Answer: open suction valve, open discharge valve
gradually
of the following, the major advantage of a shell and coil condenser is Correct Answer: there is less danger
of developing leaks
an engineer needs to vary the flow of refrigerant in a refrigeration system, which operation in the flow
of the system does not include Correct Answer: solenoid valve
thermal bull is attached to the suction plate between the evaporator cokl and the compressor by an
insulated line. assume that the machine room is 85deg f . break down of the insulation results in: Correct
Answer: flood the evaporator
water and moisture is serious problem in a refrigerant system how to avoid Correct Answer: proper
evaluation at the charging of the system
while on duty a refrigeration engineer notic That the suction line to the compressor and part of the
compressor itself is frosted over the following the most likely reason for this condition would be Correct
Answer: There is not enough Refrigerant in the system
While doing a routine inspection the engineer notices the bulb of the TXV on the floor. The refrigerant
engineer should have attached a bulb at the Correct Answer: The outlet end of the coil
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 Correct Answer: lowering the condenser
pressure
In most semi hermetic compressors, the suction vapor is used for Correct Answer: cools the motor
The amount of refrigerant that flows through the orifices of an economizer is determined by the Correct
Answer: difference between the high side and the low side pressure
the instalation of an inline refrigerant cleaning system is advisable Correct Answer: to remove impurities
from the system
a refrigerant engineer verifies that a condenser pump is cavitation of the following the most likely cause
for this condition is: Correct Answer: a faulty cooling tower water level controller
when an expansion valve is operating properly, at the end of the evaporator will contain Correct Answer:
only superheated vapor
a centrifugal water pump is considered to be fully primed when Correct Answer: the pump is full of
liquid
A refrigeration compressor has failed to turn on. the engineer on duty verifies the electrical circuit to the
motor, including all switches and circuit breakers is complete, according to recomended service practice,
the next item to be checked would likely be the: Correct Answer: temperature and pressure controls
Refrigerants are characterized by their physical properties including Flashpoint, refrigeration effect and
others, of the refrigerants in commercial and industrial the highest latent heat and refrigerant effect is:
Correct Answer: ammonia
which of the following ashrae refrigerant safety classification is the most toxic Correct Answer: b3
which of the following ashrae refrigerant safety classification is the most flammable Correct Answer: a3
in q indirect refrigeration system,of the following, the one that would not be used as a cooling medium
for building spaces being cooled is Correct Answer: r 22 (cooling medium= glycol or any brine solution)
the primary way of achieving capacity control of a an centrifugal compressor is by: Correct Answer:
adjustment to the inlet impeller pre rotation vanes
, regarding the functioning of a steam turbine, why is it advisable to keep moisture in the inlet low as
possible Correct Answer: keeps turbine blades wear to minimum
a water chiller is equipped with a reciprocating compressor, a thermostatic expansion valve and a an air
cooled condenser. A restriction in the refrigerant line would result in Correct Answer: high suction super
heat
the process by which refrigerant is extracted and cleaned for reuse without requirements for reclamation
is called Correct Answer: recycle
the purpose of wear rings in a centrifugal pump is to Correct Answer: prevent wearing of the pump
housing and impeller
a centrifugal compressor is in operation with suction pressure is 3 psig and the discharge is 10psi what is
the atmospheric pressure is 14.7 which is the ratio closest to Correct Answer: 1.39
electrical current us measured in Correct Answer: amperage
how would you put an additional pump online Correct Answer: open suction valve, open discharge valve
gradually
of the following, the major advantage of a shell and coil condenser is Correct Answer: there is less danger
of developing leaks
an engineer needs to vary the flow of refrigerant in a refrigeration system, which operation in the flow
of the system does not include Correct Answer: solenoid valve
thermal bull is attached to the suction plate between the evaporator cokl and the compressor by an
insulated line. assume that the machine room is 85deg f . break down of the insulation results in: Correct
Answer: flood the evaporator
water and moisture is serious problem in a refrigerant system how to avoid Correct Answer: proper
evaluation at the charging of the system
while on duty a refrigeration engineer notic That the suction line to the compressor and part of the
compressor itself is frosted over the following the most likely reason for this condition would be Correct
Answer: There is not enough Refrigerant in the system
While doing a routine inspection the engineer notices the bulb of the TXV on the floor. The refrigerant
engineer should have attached a bulb at the Correct Answer: The outlet end of the coil
