RMO FINAL Flashcards
Under certain circumstances is it ok to chain an exit door?
Yes, to keep your building safe from intruders
Yes, to keep students from leaving school
Mel
No, it is never of (FDNY)
Both A and B are correcT
No, it is never of (FDNY)
How would you calibrate a thermometer?
Place the thermometer in a cup of ice water
Place the thermometer in a cup of hot water
Place the thermometer in superheated steam
Compare temperature to another thermometer
Place the thermometer in a cup of ice water
What device automatically controls the speed of a steam turbine?
Governor valve
Gimpel valve
Sentinel valve
Main steam valve
Governor Valve
What happens when a steam turbine reaches critical speed?
Turbine will shut down
Turbine will vibrate violently
Turbine will slow down
Turbine will speed up
Turbine will vibrate violently
Superheat on the suction line has been increasing gradually for over a week. What could
be the cause?
Leak in the system
System is overcharged
Scale is clogged in the orifice
Leak in the system
A cold front is coming into the area. What would it cause liquid line solenoid to do?
Close and go off on low pressure
Close and go off on high pressure
Close and go off on low pressure
What is the sight glass on a compressor used for?
Check refrigerant level
Check oil level
Check oil level
Shader valve stem caps protect against all except?
Air getting into the system
Refrigerant leaking of the system
Oil leaking out of the system
Damage to the valve
Air getting into the system
A motor winding is touching the inside of the motor housing. This could result in:
Motor would overheat and shut down
Shock may occur to personnel
Motor would speed up
Motor would slow down
Shock may occur to personnel
An engineer suspects a short of the motor windings have caused the motor to trip on
overload. The engineer should use what instrument to check the motor:
Capacitor
Voltmeter
Ohmmeter
Ammeter
Ohmmeter
How many BTU’s are removed in a 30 ton system:
12,000 BTU’s per hour
360,000 BTU’s per minute
12,000 BTU’s per minute
360,000 BTU’s per hour
360,000 BTU’s per minute
An engineer is requested to replace a gauge on the high side of the system. The pressure
graduation rate should be:
At least 1.2 times the design pressure
Design pressure
A compound gauge
Same as low side pressure
At least 1.2 times the design pressure
An automatic expansion valve maintains a constant:
Evaporator pressure drop
Evaporator superheat
Refrigerant flow
Evaporator pressure
Evaporator pressure
If the air louvres below the fans in an induced draft cooling tower become clogged the
rest would be:
A decrease in make up water supply
Higher return water temperature
Lower return water temperature
A lower condenser approach
Higher return water temperature
You have a cold front and there is a sudden drop in temperature. The thermostat will cause solenoid valve to:
Close and pump the compressor down and shut down on low pressure
Close and the compressor will stop on high pressure
Open and compressor pumps down and goes off on high pressure
Open and compressor will continue to run at a reduced speed
Close and pump the compressor down and shut down on low pressure
Cross connections and standpipe risers must be painted:
Green
Red
Yellow
Green with yellow stripe
Red
Ir a sprinkler system is offine for two days how often do you need to inspect it until it is returned back to service?
Only in the morning not at night until restored
Only in the evening not the morning until restored
Continuously 24 hours a day until system is restored
12 hours a day until system is restored
Continuously 24 hours a day until system is restored
The only refrigerant/temperature chart avallable to a refrigerant engineer lists thg
temperature in degrees Celsius. If the chart indicates a celsius temperature of 5 degrees the
equivalent in Fahrenheit is?
18.4 degrees
39.2 degrees
41 degrees
27 degrees
41 degrees
In the picture below what does the equipment detect?
Carbon Dioxide
Oxygen
Halogen
Refrigerant leaks
Halogen
In a building with a multizone standpipe system, how does each zone get supplied with
water?
Each zone will be connected to the main water supply
It will supply only the highest standpipe zone
Each zone will have its own automatic water supply
It will supply only the lowest standpipe zone
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?
Two way valve
Three way valve
Plug valve
Stop valve
Three Way Valve
When will the BTU’s exchanged be the greatest?
High evaporator temperature, low condenser temperature
High evaporator temperature, high condenser temperature
Low evaporator temperature, low condenser temperature
Low evaporator temperature, high condenser temperature
Low evaporator temperature, high condenser temperature
You find that the check valve on a centrifugal pump is leaking. When would the most
damage be caused to the pump?
On shutdown of the pump
On startup of the pump
When another pump is turned on
When servicing the pump
On startup of the pump
When you are finished leak testing with R22 and nitrogen the next step would be?
Vent refrigerant and nitrogen to open air
Remove refrigerant and nitrogen with recovery tank
Add refrigerant back into system
Add refrigerant if needed and put system back online
Vent refrigerant and nitrogen to open air
What is the device used to measure the speed of a turbine?
Governor
Gimpel valve
Look
Tachometer
First stage nozzle gauge
Tachometer
The condenser pump is on the first floor and not running. The pressure gauge shows 55
psi. There is 15 feet for each floor. What floor is the cooling tower on?
10
12
6
8
8
There is 7.48 gallons per cubic foot. How many gallons of water are in a pipe 8 feet in
diameter and 10 feet long?
26
80
3758
748
3758
A technician has been asked to estimate the cost of operating a 5 horse power motor.
Because the plant is billed by energy consumed as kilowatt-hours, the technician will have to
calculate the conversion. The equivalent in energy of a 5 horse power motor operating for 9 hours in kilowatt-hours is closet to:
33.6
4.79
3.73
11.9
33.6
A circuit breaker has a similar function as what?
A fuse
A solenoid
A resistor
A relay
A Fuse
How do you start a centrifugal chiller?
Start the chilled water pump, start condenser water pump, start compressor, check oil,
start cooling tower
Start the chilled water pump, start condenser water pump, check oil, start compressor,
start cooling tower
Start cooling tower, check oil, start compressor, start the chilled water pump, start
condenser water pump
Start the chilled water pump, start condenser water pump, check oil, start cooling tower,
start compressor
Start the chilled water pump, start condenser water pump, check oil, start cooling tower,
start compressor
What does a wiring diagram display?
Wiring of components
Wiring of switches only
Switch functions
All of the above
Wiring of components
Filter driers remove?
Air and acids
Moisture and particles
Oil and acids
Moisture and air
Moisture and particles
Show a picture of an insulated pump and ask what is this pump?
Centrifugal pump
Reciprocating pump
Centrifugal chill water pump
Condenser pump
Centrifugal chill water pump
If 29.92” HG is equal to 14.7 PSIA then 26” HG converts to what in PSIA?
13
12.77
30.3
7.5
d. 7.5
12.77
When charging refrigerant on the low side of a reciprocating machine with manifold
gauge what is the position of the manifold?
High and low side backseated
High and low side frontseated
High side backseated low side frontseated
High side frontseated low side backseated
High side frontseated low side backseated
You are the engineer running a 2,000 ton steam driven turbine centrifugal refrigeration
system supplying chilled water to a college campus with multiple buildings. You are supplying 45
degree chilled water. All the buildings are satisfied except one building. What action should the
engine do?
Put an additional chilled water pump online
Lower the set point from 46 degrees to 40 degrees
Add additional make up water to the cooling tower
Put an additional chilled water pump online
The cooling medium for a cooling tower is?
Air
Water
Air and water
Tower fan
Air
The charge in a TEV sensing bulb is?
Non flammable non toxic
similar to refrigerant in system
Highly toxic highly flammable
Different type of refrigerant than in system
similar to refrigerant in system (FDNY)
What tvpe of sprinkler system needs inspecting?
Automatic
Non-automatic
Residential
Commercial, hotel & office buildings
AUTOMATIC
You are performing hot works near a sprinkler head. What can You do to prevent the fire alarm from going off?
Take the building offline
Drain the sprinkler system in that area
Put a non-combustible barrier to protect the sprinkler head
Perform hot works in service area
Put a non-combustible barrier to protect the sprinkler head
How long does it take to warm up a steam turbine?
10-15 minutes
30-40 minutes
No less than 60 minutes
Doesn’t need warm-up
10-15 minutes
Why is a pressure relief valve better than a fusible plug?
Less costly
Minimizes refrigerant loss
Can be tested
Adjustable
Minimizes refrigerant loss
What is the state of refrigerant entering the compressor on a reciprocating machine?
Vapor
Superheated vapor
Saturated vapor
Liquid
Superheated vapor
In the absence of water chemical treatment of a cooling tower?
Drain the tower every one to two weeks & replace with fresh water
Punch tubes every week
Clean condenser pump strainers
None of the above
Drain the tower every one to two weeks & replace with fresh water
What is ammonia’s refrigerant ASHRAE classification?
A1
B3
B2
A3
B2
What is the function of a safety head on a compressor?
Capacity control
Prevents liquid slugging from damaging the valve plate
Purge air from cylinders
Prevent friction
Prevents liquid slugging from damaging the valve plate
When is a chemical fire extinguisher system needed?
Where water is not sufficient
Pre action system
Deluge system
Where water is not sufficient
What is most accurate about fire alarm books?
Must be kept on premises within 1 year from log of last entry
Must be kept in the fire alarm panel
Must be kept in the building managers office
Must be kept on the premises no less than five years
Must be kept in the fire alarm panel
What is the volume of a box 12”x12”x12” measure?
1728 inches
1728 square inches
1 cubic foot
144 cubic feet
1 cubic foot
A condenser pump is supplied with 85 degree water from a cooling tower and returns to
tower at 88 degrees. Engineer is sure the condenser tubes are clean and free of obstructions,
condenser has high condenser pressure. The reason for this could be?
Overcharge of refrigerant
Undercharge of refrigerant
Thermostat is damaged
Wide open water regulating valve
Overcharge of refrigerant
Fireproof decorations in buildings are useful for?
Seasonal purposes
Don’t catch fire in an emergency
Usually energy efficient
Help reduce heat load
Don’t catch fire in an emergency
What is the lowest temperature a cooling tower can be?
Ambient temperature
Dry bulb temperature
Wet bulb temperature
Between dry bulb and wet bulb
Wet bulb temperature
Manifold hoses should be equipped with?
Quick disconnects
Low loss fittings
Schrader valves
Service apertures
Low loss fittings
Water regulating valves are used to?
Vary flow based on water temperature
Maintain refrigerant temperature
Maintain condenser pressure to a pre-determined level
Maintain condenser pressure to a pre-determined level
Which of the following does not require flame resistant treatment?
Decorations in a hotel lobby
Decorations in a building lobby
Art work in a museum
A heavy curtain in a theater
Art work in a museum
Regardless of the ASHRAE refrigerant classification in use, in the event of a refrigerant
escaping the engineer should be aware of?
Refrigerant fire
Refrigerant toxicity
Asphyxiation
Asphyxiation
What type of refrigerant is found inside the machines gauges?
R-134A
Same type of refrigerant inside the machine
R-22
Glycol
Same type of refrigerant inside the machine
If resistance is cut in half, what happens to the power factor?
Gets cut by half
Increases by a factor of two
Decreases by a factor of two
Increased by half
Increases by a factor of two
What are pre hot works procedures performed prior to hot works?
Check area once a day leading up to hot works
Check area one week prior to hot works
Check area day of hot works
Check area day after hot works
Check area once a day leading up to hot works
A chilled water system has an air cooled condensing unit on a roof during cold weather
has what type of protection?
Glycol running through it
Heater coil
Air limiting device
Resistor
Air limiting device
What is a compressor safety head?
A pressure relief on the low side
Cylinder head with a pressure relief on the high side
A spring on the valve plate
Rupture disc
A spring on the valve plate
Standpipe certificate should be available for?
FDNY & OSHA
FDNY and building inspector
FDNY and EPA
FDNY and NFPA
FDNY and building inspector
Which of the following does not require flame resistant treatment?
Decorations in a hotel lobby
Decorations in a building lobby
Art work in a museum
A heavy curtain in a theater
Art work in a museum
A FDNY permit is required to conduct hot works for?
Brazing
Welding
Use of oxygen and flammable gas
All of the above
Use of oxygen and flammable gas
FDNY is most concerned with which ASHRAE refrigerant classification?
A1
B2
A3
B1
A3
How long must a Fire alarm log book be kept?
5 years
1 year from last entry
6 months
3 years
3 YEARS
What is the minimum requirement an engineer needs to log readings?
Every 2 hours
Once per shift
Every hour
Every 4 hours
Once per shift
You are the only engineer on duty with a machine running. A vice president tells you to shovel snow. What should you do?
Call your union rep
Shovel snow
Do not leave building
Shovel but check the machine regularly
Do not leave building
How often must you do emergency power testing?
Weeklv
Bi-weekly
Annually
Monthly
Monthly
What is the responsibility of a B29 COF holder?
Maintain the battery system
Test the battery system
Inspect the battery system
Repair minor problems
Inspect the battery system
Why is a refrigerant gauge called a compound gauge?
You can read the pressure on the high side and the low side
You can read the temperature and pressure
It has scales for different types of refrigerant
At reads positive pressure and vacuum
At reads positive pressure and vacuum
What is not required to be serviced annually?
Fire extinguishers
Fire pump motors
Compressors
Diesel engine systems
Compressors
What is the advantage of a shell and tube condenser, as opposed to a shell and coil
condenser?
Easier to clean
Prevents less leaks
Better heat transfer
Less efficient
Better heat transfer
Fusible plugs on a condenser?
Release refrigerant by pressure
The melting point is marked on it
Can be back seated
Are not allowed by code
The melting point is marked on it
How much extra refrigerant can be stored in a machine room?
20% above the normal charge
220 Ibs
The amount equal to the design pressure
330 lb
330 lbs
What is used on an outside pipe to prevent it from freezing?
Capacitor
Resistor
Heater coil
Transformer
Resistor
Of the following centrifugal chillers are best characterized as?
High tonnage, low pressure machines
Low tonnage, high pressure machine
High tonnage, high pressure machine
Low tonnage, low pressure machine
High tonnage, low pressure machines
As an engineer you notice pressure drops across the evaporator. You check and notice the external equalizer line is disconnected. What will occur in the evaporator?
Evaporator will flood
Evaporator will starve
Evaporator will stabilize
Evaporator will be unaffected
Evaporator will flood
When entering Phase Il fireman’s service, what statement is correct?
Does not need a special key
Can only be used by a firefighter
The elevator operator is the only person that could control the elevator
Must be tested semi-annually
The elevator operator is the only person that could control the elevator
What is the most widely used regulation book by operating engineers is?
OSHA
EPA
BOMA
NFPA
EPA
What type of refrigerant do you need FDNY approval for?
Ammonia
R-22
Propane
R-134A
PROPANE
Centrifugal pressure is determined by?
Speed of motor
Variable guide vanes
Design speed
Electrical voltage
Speed of motor
A single phase 208 VAC circuit has 2 hot wires the third is the?
Spare wire
Ground
Control wire
Common
Ground
Liquid refrigerant that has passed through a metering device is a?
High pressure liquid
Sub cooled liquid
Low pressure saturated liquid
Low pressure vapor
Low pressure saturated liquid
With a 75 degree dry bulb and a 73 degree wet bulb the relative humidity is?
Normal
Very low
100% relative humidity
Very high
Very high
After recovering liquid refrigerant from a centrifugal chiller the next step is to?
Blow the system out with nitrogen
Pull a deep vacuum
Recover vapor
Leak Test system
Recover vapor
Where is the muffler located?
Between the compressor and condenser
Between the evaporator and condenser
After the condenser
Before the compressor
Between the compressor and condenser
In the picture the valve is in what position:
The valve is closed
The valve position cannot be determined
The valve is cracked open
The valve is fully opened
The valve is cracked open
A high-side float valve is used to maintain:
Constant level of refrigerant in the evaporator
Constant rate of refrigerant flow
Constant flow of condenser water
Constant level of refrigerant in condenser
Constant level of refrigerant in the evaporator
A facility has failed to maintain water treatment to a refrigerant system?
Clogging of the cooling tower
Increase in the condenser pressure
Corrosion of the cooling tower metals
Cavitation of condense water pumps
Increase in the condenser pressure
Which of these compressors is not a positive displacement type compressor?
Rotary
Screw
Reciprocating
Centrifugal
Centrifugal
Where is emergency power not required according to code?
Egress illumination
Data centers
Fire pumps
High rise elevators
Data centers
There is a decrease in the efficiency of a reciprocating compressor. The most likely
caused by:
High suction pressure
Leaking suction valve
Low suction pressure
Leaking discharge line
Leaking suction valve
The suction and discharge valve of the reciprocating compressor are mounted as follows?
Suction and discharge valve on the upper side of the plate
Suction and discharge valve below the valve plate
Discharge valves below the valve plate and suction valve above it
Discharge valve on top of the valve plate and suction valve below
Discharge valve on top of the valve plate and suction valve below
You are the engineer running a 2000 ton (steam-driven turbine) centrifugal refrigeration system, a refrigeration system supplies chilled water to a college campus with multiple buildings. While making your rounds you notice that the discharge pressure of your condenser water pumps is significantly lower than the normal. Which following action would you avoid taking?
Put on a additional condenser water pump
Flush out the bucket strainer of the condenser water pump
Send your assistant to check for cooling tower level
Put on an additional surface condenser pump and lower the chilled water set point
Put on an additional surface condenser pump and lower the chilled water set point
A water pump is discharge against head 92 feet of water, this approximately to a pressure of:
95 psi
20 psi
40 psi
180 psi
40psi
Which one of the following will connect to the middle port on a gauge manifold?
Solenoid valve
King valve
Vacuum pump
Suction or discharge service
valves
Vacuum pump
The most important reason for installing a muffler in reciprocating refrigerant machine is ?
Prevent compressor damage
Prevent condenser damage
To contain the compressor pulsation noise
To reduce velocity of the refrigerant
To reduce velocity of the refrigerant
Of the following, the statement that most accurately characterize a hermetic compressor is that it?
Typically has a pressure lubrication system
Will have only the motor enclosed in a gas tight housing
Will have both the compressor and motor enclosed is gas tight housing
Is erected in the field
Will have both the compressor and motor enclosed is gas tight housing
The use of oil in the refrigeration machine is to:
Mix the oil with liquid refrigerant
Add non condensables to refrigerant
Reduce wear and friction in the compressor parts
None of the above
Reduce wear and friction in the compressor parts
The following is a desirable property in a refrigeration?
High corresponding operation pressure
High viscosity
High latent heat
High corresponding compressor discharge temperature
High latent heat
The cooling medium for an evaporative condenser is:
Air and water
Air
Water
Condenser fan
Air and water
The ratio of the actual pressure of water vapor in the atmosphere to the saturated
pressure give temperature is?
Partial pressure
Humidly affect
Absolute humidity
Relative humidity
Partial pressure
The only refrigerant/temperature chart available to a refrigerant engineer list the temperature is degrees Celsius if the chart indicates a Celsius temperature of 4 degrees to
equivalent to F?
35.2 degrees
39.2 degrees
27.0 degrees
18.4 degrees
39.2 degrees
A refrigerant engineers was instructed to charge of 60 ton plant with R134A Refrigerant.
The refrigerant engineer will most likely find the charging valve on the
Discharge side of the compressor
Receiver
High side pressure side of the system
Low pressure side of the system
Low pressure side of the system
A refrigerant engineer verifies that a chilled water pump is cavitating. Of the following
the most likely cause for this condition is:
A faulty cooling tower water level controller
Operating at sustaining high loads
Too long a period between pump servicing
Water leaks through the mechanical seals
Water leaks through the mechanical seals
Hoy would you put an additional pump online?
Open suction valve, open discharge valve gradually
Open suction valve, close discharge valve
Close suction valve, open discharge valve
Open suction valve and slowly close discharge valve
Open suction valve, open discharge valve gradually
Of the following, the major advantage of a shell and coil condenser is:
It is easier to clean without disturbing the refrigerant connection
There is less dangers of developing leaks
Has higher heat transfer coefficient
Better level liquid control all the condenser may be activated
There is less dangers of developing leaks
A chill water system uses refrigerant R134 a leak in the evaporator shell may result in?
Set off the refrigerant monitor alarm
Higher than normal high side pressure
The foam of ice around the point of leak
Low pressure shut down
Set off the refrigerant monitor alarm
What are steam ejectors used for on the surface condenser of a system with a turbine?
To regulate turbine speed
To increase the surface area of the condenser
To create a proper operating exhaust vacuum
To remove steam condensate from the condenser
To create a proper operating exhaust vacuum
Water and moisture is a serious problem in a refrigerant system how to avoid?
Use of fins in refrigerant line
Proper evacuation at the charging of the system
Proper handling of refrigerant and oil to avoid exposure to mixture
Use of high viscosity oil in the connection
Proper evacuation at the charging of the system
The most important requirements for a good evaporator is that?
Air or liquid refrigerant can be used as required by the medium being cooled
It must have enough cooling surface to absorb the required heat
Operates only when the heat load exceeds a minimum
The refrigerant is contained in tubes
It must have enough cooling surface to absorb the required heat
While on duty a refrigeration engineer notice that the suction line to the compressor
and part of the compressor itself is frosted of the following, the most likely reason for this
condition would be?
Low condenser water temperature
The TEV is almost close
There is a blockage in the liquid line
There is not enough refrigerant in the system
There is not enough refrigerant in the system
While doing a routine line inspection, the engineer notices the bulb of the TXV on the
floor refrigerant engineer should attach bulb at the?
Three quarters way towards the end of the coil
The inlet end of the coil
The expansion valve outlet
The outlet end of the coil
The outlet end of the coil
Hoy would you put an additional pump online?
Open suction valve, open discharge valve gradually
Open suction valve, close discharge valve
Close suction valve, open discharge valve
Open suction valve and slowly close discharge valve
Open suction valve, open discharge valve gradually
Of the following, the major advantage of a shell and coil condenser is:
It is easier to clean without disturbing the refrigerant connection
There is less dangers of developing leaks
Has higher heat transfer coefficient
Better level liquid control all the condenser may be activated
There is less dangers of developing leaks
A chill water system uses refrigerant R134 a leak in the evaporator shell may result in:
Set off the refrigerant monitor alarm
Higher than normal high side pressure
The foam of ice around the point of leak
Low pressure shut down
Set off the refrigerant monitor alarm
What are steam ejectors used for on the surface condenser of a system with a turbine:
To regulate turbine speed
To increase the surface area of the condenser
To create a proper operating exhaust vacuum
To remove steam condensate from the condenser
To create a proper operating exhaust vacuum
Water and moisture is a serious problem in a refrigerant system how to avoid:
Use of fins in refrigerant line
Proper evacuation at the charging of the system
Proper handling of refrigerant and oil to avoid exposure to mixture
Use of high viscosity oil in the connection
Proper evacuation at the charging of the system
The most important requirements for a good evaporator is that:
Air or liquid refrigerant can be used as required by the medium being cooled
It must have enough cooling surface to absorb the required heat
Operates only when the heat load exceeds a minimum
The refrigerant is contained in tubes
It must have enough cooling surface to absorb the required heat
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:
Raising the condenser liquid level to the maximum
Lowering the chilled water set point
Raising the condenser head pressure
Lowering the condensing pressure
Lowering the condensing pressure
The heat removed from the refrigerant in a condenser is:
Sensible and latent heat
Latent heat only
Radiant heat only
Sensible heat only
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:
Do not weigh more than 200 pounds when filled
Are approved by the US Department of Transportation
Are approved by the OSHA Association
Do not exceed 55 Gallon in Capacity
Are approved by the US Department of Transportation
Which of the following best describes how the cylinder unloader work?
Keep in the suction valve opened while the compressor is in the return stroke
Controls the clearance volume in the compressor with a solenoid
Controls the opening of the passage into the compressor with variable vanes
Unloads the piston to create less pressure
Keep in the suction valve opened while the compressor is in the return stroke
In most semi Hermetic compressors, the suction vapor is used to:
Removes oil from the motor housing
Cools the motor
Minimizes oil foaming
Removes oil foam from the shaft
Cools the motor
The amount of refrigerant that flows through the orifices of a economizer is determined by the:
Number of economizer stages
Temperature of the high side refrigerant
Number of compressor stages
Difference between the high side and low side pressure
Difference between the high side and low side pressure
The installation of an inline refrigerant cleaning system is advisable:
For high pressure refrigerant systems
To purge non-condensables
For systems using toxic refrigerant
To remove impurities from the system
To remove impurities from the system
The type of refrigerant system that is least likely to leak refrigerant into the building space that
are being cooled:
The direct vented closed system
The direct closed system
Any system using reciprocating compressor
The indirect system
The indirect system
The suction pressure of a reciprocating compressor is 65 PSG. The discharge pressure of this compressor is 120 PSIG. The atmospheric is 14.7 PSI. The compression ratio for the given
condition is closest to:
2.07
4,41
1.69
1.84
1.69
A superheated vapor is a:
Dry vapor at the saturation temperature
Dry saturated vapor
Dry vapor above the saturation temperature
Vapor with minimal amount of included liquid
Dry vapor above the saturation temperature
A refrigerant engineer verifies that a condenser water pump is cavitating. Of the following the
most likely cause for this condition is:
A faulty cooling tower water level controller
Operating at sustaining high loads
Too long a period between pump servicing
Refrigerant leaks through the pumps packing
A faulty cooling tower water level controller
A centrifugal water pump is known as a lift pump when the:
The pump lifts the water into the pump upon startup
The water supply to the pump suction inlet is below the pump level
The discharge head exceed 150 feet
The pump is started with the suction valve open
The water supply to the pump suction inlet is below the pump level
A TXV is used to maintain constant:
Refrigerant flow
Evaporator pressure
Evaporator pressure drop
Evaporator superheat
Evaporator superheat
The chilled water supply to the building is 55F. If the chiller is being used for human comfort, should you be concerned about this, and why?
Yes, this temperature is too low for human comfort purpose
Yes, this temperature is too high for human comfort purpose
No, 55F is within an acceptable range
No, temperature gauges often give false high readings
Yes, this temperature is too high for human comfort purpose
The packing gland of a centrifugal pump serves to:
Keep the bearing cooled
Keeps air out of the pumps when the impeller housing is under negative pressure
The drip part of the packing gland gives evidence that there is water in the pump
All of the answers are correct
The drip part of the packing gland gives evidence that there is water in the pump
Capacity control of a reciprocating hermetic compressor is typically achieved through.
Regulating the opening of the discharge valve
Variation of the condenser water temperature
Regulating the opening of the TXV
Operation of the hot gas bypass valve
Operation of the hot gas bypass valve
The most important reason to sub-cool the refrigerant in the condenser is to ensure that:
A pure liquid refrigerant will enter the metering device
Liquid slugs will not enter the compressor
The condenser is working efficiently
The cooling tower has sufficient water
A pure liquid refrigerant will enter the metering device
A refrigeration engineer is logging reading from a reciprocating system, compressor discharge
temperature have dropped significantly and the suction line pressure is high. Which of the following that may be causing this set of conditions
Compressor cycle
An expansion valve that is open to wide
Malfunction of a unloader
An expansion valve that is closed to much
An expansion valve that is open to wide
A low side float valve is used to maintain:
A constant refrigerant flow
The water level in the cooling towers
The level of refrigerant in the condenser
The level of the refrigerant in the evaporator
The level of the refrigerant in the evaporator
Regarding fire safety, which ASHRAE refrigerant safety classification indicates no flammability and lower toxicity?
A3
A1
B1
B2
A1
When an expansion valve is operating properly, at the end of the evaporator will contain:
Saturated liquid refrigerant
Only liquid refrigerant
Only vapor
Only superheated vapor
Only superheated vapor
What information is not contained in a Material Safety Data Sheet?
Health and physical hazards of the material
Safety work practice and required protective equipment of the material
Procedures that should be followed in case of an emergency
Cost of the material
Cost of the material
- In a steam turbine, what is the function of the Kingsbury thrust bearing.
Maintain axial positioning of the rotor shaft
Maintain first stage steam pressure
Compensate for coupling misalignment
Adjust shaft torque at start up
Maintain axial positioning of the rotor shaft
A centrifugal water pump is considered to be fully primed when.
The pump is full of air
Liquid or leaking past the packing gland
The pump runs with no knocking noise
The pump is full of liquid
The pump is full of liquid
Copper tubing refrigerant lines must be installed for a new system. It is a well known service practice that tubing collapses at bends that must be made, the refrigerant engineer should use.
Brazed elbows
Annealed tubing
Never type tubing bender
A very small bend radius
Never type tubing bender
A reciprocating compressor is making a knocking sound during operation. If the refrigerant worn
parts are not causing the knocking, what is probably the cause.
Misalignment of the compressor motor
The slugging of the liquid refrigerant
Parallel misalignment of the compressor and motor
Insufficient lubrication
The slugging of the liquid refrigerant
In order for a refrigerant to become superheated it must be heated in a section of the low side refrigerant line:
Where the medium being cooled is hottest
Where refrigerant pressure is lowest
Where no liquid refrigerant is present
Where no liquid refrigerant is present
All Liquid has been recovered from a system to be overhauled, the system.
Should not be opened until all vapor has been recovered
Should have air pumped through it and vented to atmosphere before being opened
Should be pumped with dry nitrogen before being opened
Can be safety opened and repaired
Should not be opened until all vapor has been recovered
- When a refrigerant engineer uses a portable compressor recovery unit to remove vapor refrigerant form a refrigeration system the removal rate of the refrigerant will gradually slow down because.
The vapor density is decreasing
The refrigerant temperature is dropping
The compressor speed decreasing
The compressor efficiency is decreasing
The vapor density is decreasing
You are the engineer running a 2000-ton (steam-driven turbine) centrifugal refrigeration system,
a refrigeration system supplies chilled water to a college campus with multiple buildings. During the course of making your rounds, you check the 9 cell cooling tower on the roof. You note the water level in all of the cooling tower cells is very low. Which one of the following immediate
action would take?
Gradually lower the chiller water set point on the refrigerant system
Add additional make up water to cooling tower
Create a deeper vacuum pressure in the surface condenser and turn on a second condensate pump
Drastically increase the speed of the cooling tower
Add additional make up water to cooling tower
A rooftop water cooling tower is connected to a water pump in the building basement with a 12
inches diameter pipe with the pump turn off, a pressure gauge at the pumps inlet show a
pressure of 140 PSIG the height of the water column, in feet, would be closest to?
277
375
323
190
323
What device protects the steam turbine from excessive speed?
Governor assembly
Maximum speed set point control
High steam flow cutout
Double seat globe valve
Governor assembly
A refrigeration compressor has failed to turn on. The refrigeration engineer on duty verifies that
the electrical circuit to the motor, including all switches and circuit breakers, is complete according to recommended service practice, the next item to be checked would likely be the:
Temperature and pressure controls
Liquid line solenoid valve
Refrigerant charge
Cooling tower operation
Temperature and pressure controls
Refrigerants are characterized by their physical properties included flashpoint, refrigeration
effect, and others of the refrigerants in commercial and industrial the highest latent heat and
refrigerant effect is:
R-12
Ammonia
R-22
Propane
Ammonia
On what characteristics is ASHRAE refrigerant safety group classification system:
Explosives and toxicity
Explosives and flammability
Flammability and toxicity
Acidity and explosiveness
Flammability and toxicity
Of the following, and example of an in-line refrigerant cleaning system that may be used with a
centrifugal compressor containing R123 refrigerant is:
Refrigerant recycling
Refrigerant recovery
Refrigerant reclaiming
Refrigerant disposal
Refrigerant recycling
Information about the physical and chemical properties of a hazardous material can be found in:
NY Medical code
Manufacturers Safety
Directions Sheet
Material Safety Data Sheet
NYC Fire Code
Material Safety Data Sheet
What is the function of the turbine auxiliary oil pump?
Check proper oil level in pump before start up
Stand by pump if main pump fails
Recovers oil from the condensate tank
Establish oil pressure during turbine start up
Establish oil pressure during turbine start up
The rupture disc for a low-pressure centrifugal refrigeration machine is normally located on the:
Compressor suction
Condenser
Compressor discharge
TXV
Compressor suction
What is the primary reason ribbed metal piping is used for electrical wires connected to the refrigeration system shown below?
It is easier to install than non-ribbed metal piping
It allows the flexibility and accounts for vibrations
It allows for ventilating the heat from wires
It is less costly to use than non-ribbed metal piping
It allows the flexibility and accounts for vibrations
- Modern compressors usually seal the rotating shaft as it exits the compressor housing a spring
loaded seal made of .
Rubber
Low friction plastic
Metal or carbon
Graphite loaded fiber
Metal or carbon
The British Thermal Unit (BTU) is the measurement of heat of energy. If 10 BTU are transferred to 10 pounds of water, the water temperature increase will be closest to:
10F
1C
1F
10C
1F
A reciprocating compressor cylinder has a 10 inches bore and 14 inches stroke. The volume of refrigerant, in cubic inches, will be closer to:
1808
1406
1099
1002
1099
An electrically operated control requires 24 volts to operate to change the available 110 volts to
24 volts.
Rectifier
Step-down capacitor
Low temperature wire
Transformer
Transformer
In an indirect refrigeration system, of the following, the one that would not be used as a cooling medium for the building spaces being cooled is:
A calcium chloride solution
A sodium chloride solution
R22 refrigerant
Glycol
R22 refrigerant
On a steam turbine, what would cause the atmospheric valve to open?
Low vacuum in the surface condenser
Leaking tubes in the surface condenser
All answers are correct
Dirty tubes in the surface condenser
All answers are correct
You are the engineer running a 2000-ton (steam-driven turbine) centrifugal refrigeration system
a refrigeration system supplies chilled water to a college campus with multiple buildings making your rounds, you notice that condenser water pump #1 is making a lot of noise, the discharger gauge reading of the condenser water pump is fluctuating drastically, and motor of the condenser pump #1 is running very hot. Which of the following actions would you take:
Turn on pump #2, shut off pump #1, and trouble shot pump #1
Gradually increase the chilled water set point from 40F to 46F, so the machine can cool down
Leave pump #1 running, but immediately put in a call to the service contractor
Turn on pump #2, shut off pump #1, and trouble shot pump #1
Electric devices may be used to provide built in defrosting of refrigeration machine evaporator units. These devises are classified as.
Induction coils
Thermostats
Capacitors
Resistors
Resistors
The flash point of compressor lubrication oil:
Should be higher than the compression temperature
Is the temperature at which the oil start to foam
Is the temperature at which the viscosity is measured
Should be lower than the compression temperature
Should be higher than the compression temperature
The primary way of achieving capacity control of a centrifugal compressor is by:
Variation in steam pressure
Adjustment of the impeller inlet pre-rotation vanes
Operation of the hot gas bypass valve
Adjustment of the thermal expansion valve
Adjustment of the impeller inlet pre-rotation vanes
Cooling tower water requires the addition of chemical additives in order to:
Lower head pressure
Regulate and maintain the PH level
Reduce the formation of scale and algae
Comply with EPA regulation
Reduce the formation of scale and algae
The viscosity of lubrication oil is described by a number. A low viscosity number describes oil that:
Flows easily
Should not be used with refrigerant
Flows poorly
Does not provide good lubrication
Flows easily
The most likely reason for a refrigeration engineer to use a psychrometer is to measure
Atmosphere pressure
Relative humidity level of the atmosphere
Temperature of the atmosphere
Undesired substance in the atmosphere
Relative humidity level of the atmosphere
The most important reason to use at least two compressors in a cascade system is to:
Accomplish higher temperature
Avoid very high compression ratio for each compressor
Avoid the need for water-cooled condenser
Divide the cooling load between the compressors
Avoid very high compression ratio for each compressor
- The suction service valve of a reciprocating compressor is front seated and the compressor run
until the low pressure cut-out shut the compressor off. When the machine is stopped, the refrigeration engineer notices that the suction pressure increase rapidly. The most probably
cause this pressure rise:
A faulty gauge
A leaking suction service valve
All answers are correct
Malfunction of a compressor valve
Malfunction of a compressor valve
Regarding the functioning of a steam turbine, why is it advisable to keep moisture in the inlet low as possible?
Decrease vacuum leaks
Decrease turbine warm up time
Keeps turbine blades wear to minimum
Keeps steam traps from rusting
Keeps turbine blades wear to minimum
According to the attached Material Safety Data Sheet R134 is a?
Dark blue liquid
Clear, odorless liquid and vapor
Yellow gas that smells like rotten eggs
Light blue liquid
Clear, odorless liquid and vapor
Under normal condition, the refrigerant enters the compressor as a:
Low pressure vapor and leaves as a high pressure saturated vapor
Low pressure superheated vapor and leaves as a high pressure vapor
Low pressure superheated vapor and leaves as a high pressure saturated liquid
High temperature vapor and leaves as a low pressure vapor
Low pressure superheated vapor and leaves as a high pressure vapor
While operating an R-22 single acting compressor system, the refrigeration engineer noticed oil foaming in the crankcase. This condition most likely, would have been caused by a:
Sudden drop in the crankcase pressure
High oil temperature
Moisture in the oil
Addition of liquid Freon
Sudden drop in the crankcase pressure
Assume that an engineer is able to observe refrigerant water and oil together. The fluids would settle in the container from top to bottom:
Water, oil, refrigerant
Oil, refrigerant, water
Refrigerant, oil, water
Oil, water, refrigerant
Oil, water, refrigerant
What is the function of the vacuum breaker in a steam turbine.
To achieve a faster coast down cycle
To keep main bearing oil from foaming
To keep vacuum at proper level
To indicate presence of vacuum leak
To achieve a faster coast down cycle
An equalizer line on a TXV is used to:
Eliminate the pressure across the evaporator
Compensate for the pressure drop across the evaporator coil
Equalize the pressure across the TXV diaphragm or below
Correct for pressure drop in the thermal bulb capillary lines
Compensate for the pressure drop across the evaporator coil
If R134 accidentally touches a refrigerant engineer’s skin, what first aid should be applied from
the MSDS?
R134 is a low acute toxicity, no special medical attention is required
Promptly flush skin with water until all chemical is removed
Rub the frozen parts
The frostbite parts in hot water (above 130F) to warm them up
Promptly flush skin with water until all chemical is removed
In a multi stage centrifugal compressor, each stage:
Has higher tip speed than one before it
Handles more refrigerant than the one before it
Is identical in volume to the other stages
Has smaller volume than the one before it
Is identical in volume to the other stages
A refrigeration engineer notices excessive cycling of the temperature control for a reciprocating compressor refrigeration unit. The crankcase temperature is high, the compressor discharge temperature low, the suction line temperature is high of the following the one that may causing
this set of condition.
An expansion valve that is open too wide
The purge unit operation
The condenser operation, dirty tubes or cooling control
Faulty compressor valves
Faulty compressor valves
On an operating centrifugal compressor refrigerant unit, the refrigeration engineer notices the compressor is short cycling. The unit is using low side float valve as a meeting device of the
following requirements this would indicate that:
Inspection should be made for a dirty and partially plugged discharge line
The system is undercharged with refrigerant
The compressor wiring be inspected
The system is overcharged with refrigerant
The system is undercharged with refrigerant
The vessel depicted below may be used in connection with.
Refrigerant recovery
Refrigerant recycling
Refrigerant reclaiming
Refrigerant disposal
Refrigerant recovery
A refrigeration system used jet ejector to raise settled oil mixed with refrigerant to the oil pump if a restriction in the refrigerant flow to the jet ejector develops:
The flow of oil will be unaffected
The temperature of the refrigerating exiting the jet will decrease
The oil will not lift if it is mixed with less refrigerant
There may be insufficient head to lift the oil
There may be insufficient head to lift the oil
- An indirect low temperature refrigerant system frequently uses glycol, instead of salt brine as the intermediate cooling medium. An advantage of this choice is:
The elimination of corrosion
High flow rate
Better thermal conduction
Low cost
The elimination of corrosion
In relation to the suction pressure of a compressor, the reading on the oil pressure gauge should
read in the range closer to:
15 to 30 PSI higher
15 to 30 PSI lower
30 to 60 PSI lower
60 to 80 PSI higher
15 to 30 PSI higher
Non-condensable gases like air, oil vapor, or nitrogen travel through a refrigerant system with the refrigerant they usually accumulate in the:
Condenser
Compressor crankcase
Filter drier
Evaporator
Condenser
The advantage of forced draft cooling tower over natural draft cooling towers is:
Smaller tower size
That it uses less water
That it improves power efficiency in water tower
Reduced energy cost
Smaller tower size
The sole refrigeration engineer on duty in a building is permitted to leave the building refrigeration system when it is in operation only when:
Lunch or dinner occur
System is an automatic operation
Relieved by another licensed refrigeration engineer
The assistant provides coverage or supervision
Relieved by another licensed refrigeration engineer
A system controlled by a TXV show high discharge pressure and high normal sub-cooling. The cause is most probably a:
Superheat settings that has been set incorrectly
Refrigerant overcharge
Leaking compressor discharge valve
Low system amperage draw
Refrigerant overcharge
Which of the following is a correct statement?
2.5 gallon of water weight 10.7 pounds
2.5 gallon of water weight 1.05 pounds
2.5 gallons of water weighs 20.8 pounds
2.5 gallons of water 2.5 cubic feet
2.5 gallons of water weighs 20.8 pounds
Liquid level gauge glasses (except the bulls eye) are generally equipped with:
Manual and automatic closing shut off valves
Manual shut-off valves only
Automatic shut-off valves only
Either manual or automatic closing shut-off valves
Automatic shut-off valves only
Copper and aluminum are frequently used for condenser tubes in refrigeration system, these
metals are used because of there:
Easy availability
High heat transfer coefficient
Resistance to corrosion
Resistance to failing
High heat transfer coefficient
Assume that a refrigeration engineer has a choice of four valves to select from. Which of the following is the most effective type of valve to control pressure?
Ball valve
Quarter turn valve
Gate valve
Plug valve
Plug valve
Where must the Material Safety Data Sheets be located?
Near the entrance to the machine room
Where flammable liquids are used
Where available to all employees
Where available to all employees
