RMO REVIEW 1 Flashcards
1. What refrigerant systems are most likely to leak refrigerant in building spaces that are being cooled? A. Indirect Systems B. Direct Systems C. Indirect Closed Systems D. Indirect Open Systems
B. DIRECT SYSTEM
- An operator has been assigned to a large reciprocating machine without unloaders, of the following safety proper procedures for starting this machine is
A. Filter suction and discharge valves
B. Suction valve and discharge bypass both open
C. Suction bypass and discharge valve both open
D. Discharge bypass and suction valve both closed
B. Suction valve and discharge bypass both open
- Upon being assigned to a facility during inspection of the facility, you find there has been failure to maintain water treatment. Inspecting the condenser water, the first evidence would most likely be:
A. Decrease in super heat temp entering compressor
B. An increase in compressor head pressure
C. An increase in the flow rate of non-condensables
D. Condenser to metering device line frozen
B. An increase in compressor head pressure
4. During a particular round an operator notices that the suction line and part of the compressor are frosted. The most likely cause of the condition is: A. Not enough refrigerant in the system B. Expansion valve open to wide C. The compressor is running continually D. Compressor valves are leaking
A. Not enough refrigerant in the system
5. When charging an R-22 reciprocating refrigeration system, an operator would want to use warm water to increase the release rate of refrigerant from the drum. To perform this operation the water temp should not exceed the degree F of: A. 80 F B. 90 F C. 110 F D. 130 F
B. 90 F
6. With respect to fire safety ANSI/ASHRAE refrigerant safety classification that is most dangerous is: A. A1 B. B2 C. A3 D. B1
C. A3
- At the condenser, refrigerant enters as:
A. High pressure gas and leaves as low pressure liquid
B. High pressure gas and leaves as high pressure liquid
C. Superheated gas and leaves as high temperature liquid
D. High temperature gas and leave as superheated gas
C. Superheated gas and leaves as high temperature liquid
8. According to NYC fire code classification of refrigeration, Ammonia would fall under which group? A. Group 1 B. Group 2 C. Group 3 D. Group 4
B. Group 2
- In an electric motor is rewound to cut resistance by ½ , all other factors being equal, the motor power would
A. Reduced by ½
B. increase by a factor of 2
C. Stay the same
D. Increase by a factor of 4
B. increase by a factor of 2
- Assuming an operator is able to observe R-11, water and lubricating oil together at 70F. Under these conditions, the water, moisture and fluids would settle in the container from top to bottom in what order?
A. Water, oil and refrigerant
B. Oil, refrigerant and water
C. Refrigerant oil and water
D. Oil, water and refrigerant
D. Oil, water and refrigerant
- A reciprocating refrigerant compressor cylinder has a 12” bore and a 16” stroke. The volume of refrigerant in cubic inches would be closer to:
A. 1204
B. 1002
C. 1808
D. 1406
C. 1808
- You have been informed that the outside temperature has been dropped by 10 C the temperature in degrees F is:
A. 32
B. 28
C. 40
D. 18
D. 18
- An automatic purge unit is required for those refrigerating systems that have:
A. Double indirect open space systems
B. System operating below atmospheric pressure
C. Absorption compressors
D. Outside air dampers
B. System operating below atmospheric pressure
- Orifice plates may be used as a metering device component in a centrifugal system. The vessel which they are contained in, can also serve as:
A. A vapor recycling unit
B. An economizer
C. A refrigerant cleaner
D. A condenser
B. An economizer
- A rupture disc in a centrifugal refrigerating machine is normally located on the:
A. Condenser
B. Economizer
C. Compressor discharge
D. Evaporator
D. Evaporator
- A pump affects the pressure of a fluid or gas by:
A. Reducing pressure
B. Raising pressure
C. Regulating pressure
D. Stabilizing pressure
B. Raising pressure
- An operator is running two centrifugal condenser water pumps in parallel, one of the pumps is at maximum pumping rate, if the operator throttles back on the discharge valve of the other pump, the most likely effect would be:
A. A reduction on both the water flow rate and pressure into the condenser
B. A reduction in total flow rate to condenser
C. A reduction in water pressure at the condenser inlet
D. For the pumps to compensate to maintain both the flow rate and the discharge pressure
B. A reduction in total flow rate to condenser
- As an RMO in charge, you are required to replace the gauge on the high side of the refrigeration system. The pressure graduation rate should be:
A. 1.2 of the designed pressure (at least)
B. The rupture guard has to be a replaced also
C. The gauge has to be a compound gauge
D. The gauge should be graduated to pressure
A. 1.2 of the designed pressure (at least)
- When operating a refrigeration unit, the operator notices that the motor compressor is short cycling, the unit is using a low side float valve. The following service requirements would indicate:
A. Inspections should be made for dirty TEV strainer
B. Partially clogged discharge line
C. Checking compressor wires for overloaded equipment
D. Additional refrigerant be charged
D. Additional refrigerant be charged
- Of the following the most correct way to describe a brazed joint is
A. Pressure fitting
B. Gas tight fitting
C. Start to melt at 400 F
D. Start to melt at 500 F
B. Gas tight fitting
- You are the RMO assigned to the 3rd floor in an assembly room. Attendance and temp have increased during the afternoon, therefore a colder water supply is to be produced in order to accomplish this you should:
A. Re-adjust the TEV superheat setting
B. Deactivate the freeze stat
C. Raise the compressor discharge operating pressure
D. Lower the compressor suction operating pressure
D. Lower the compressor suction operating pressure
- Of the following the most undesirable property in refrigerant is:
A. Low corresponding compressor discharge temp
B. Low viscosity
C. Low latent heat
D. Low corresponding operating pressure
C. Low latent heat
- When conducting a routine tour of plant operation a RMO observes a significant increase in superheat temperature. For the refrigerating fluid entering a reciprocating compressor of the following the most likely cause for this condition is:
A. Scale particles lodged in the TEV valve
B. Unraveling of the insulation protecting the TEV valve thermal bulb
C. Build-up of the non-condensables in the condenser
D. Overcharge of refrigerant
C. Build-up of the non-condensables in the condenser
- While monitoring the operation of a reciprocating refrigerating unit you over see that the cycling times are normal, compressor compression and temp are the only readings that are outside the normal rate. Under these conditions service requirements would indicate inspecting for:
A. Faulty machine controls
B. Proper refrigeration charge
C. Faulty compressor valves
D. Poor compressor operation / Dirty tubes
A. Faulty machine controls
- You are a RMO assigned to facility where a refrigerant has been recently changed to from flammable refrigerant to R-22, at the moment you are planning to braze metal. On such making a repair in the machinery room, under these circumstances you:
A. Must ensure the flame is enclosed and vented to open air
B. May make repairs at least 25 ft from the refrigerant unit
C. May make repairs without any restrictions if the refrigerating unit is shut down
D. May not make repairs under any circumstances
C. May make repairs without any restrictions if the refrigerating unit is shut down
- A RMO needed to vary the flow of refrigerant in a system. A continuous variation in the flow of the system does not included the:
A. Solenoid valve
B. High side float
C. Thermal expansion valve
D. Capillary tube
A. Solenoid valve
- An operator has been assigned to run a reciprocating compressor. Of the following, action capacity control would most likely be achieved through:
A. Opening the suction valves with some form of control
B. Controlling discharge pressure
C. Changing the stroke and adding re-expansion volume
D. Returning the discharge gas suction
A. Opening the suction valves with some form of control
- An operator is using a sling psychrometer to measure dry and wet bulb temperatures on a roof of a building where cooling tower is located. If during the day the temperature remains constant and the wet bulb drops by 5 F and all other conditions remain unchanged. The operator should see:
A. Higher cooling water being returned
B. Rise in condenser head temperature
C. Lower cooling water temperature returned
D. No noticeable effect of the cooling water temperature being returned
C. Lower cooling water temperature returned
- A RMO would expect a relief valve to start functioning (For the section of refrigerating system being protected) at a pressure most closest to:
A. 5% over the design pressure
B. The design pressure
C. Recommended operating pressure for normal cooling conditions
D. 20% below the design pressure
B. The design pressure
- It the eliminator plates located below the fan in an induced draft-cooling tower have become clogged, of the following this would most likely result in:
A. Damage to fan blades
B. Increase in cooling tower water temperature being returned
C. Decrease in make-up water requirements
D. A drop in wet bulb temperature
B. Increase in cooling tower water temperature being returned
- Convert 18” vacuum to PSIA
A. 7.7
B. 0.6
C. 5.9
D. 23.5
C. 5.9
- Superheated vapor protects the compressor against liquid intake. What would the RMO notice if the compressor was receiving liquid?
A. Head PSI dropping to low
B. Decrease the capacity of the compressor and refrigeration system
C. Non-condensables are more prone to collect in the system
D. Frost may develop in the suction line
B. Decrease the capacity of the compressor and refrigeration system
- A RMO was instructed to charge a 60 ton plant with R-134a refrigerant. The operator would most likely find the charging valve on the:
A. High pressure side of the equipment
B. Low pressure side of the equipment
C. Discharge side of the equipment
D. Receiver
B. Low pressure side of the equipment
- When properly purging, you should:
A. Purge at a rapid rate
B. Purge with compressor on
C. Stop when compressor ceases to drop
D. Run the compressor as much as possible
B. Purge with compressor on
- Given a refrigeration system which includes a forced draft cooling tower, an economizer and chilled water as the cooling medium, the heat that is removed from the building is finally rejected:
A. As heated of evaporation of the cooling tower
B. In the economizer
C. In the evaporator
D. In the condenser water outlet
A. As heated of evaporation of the cooling tower
- Which is not used as a cooling medium in an indirect system?
A. R-22
B. Calcium chloride
C. Glycol
D. Sodium chloride
A. R-22
- In a refrigeration plant, a small induction refrigeration motor is running a AC current. In order for the operator to determine the true power consumption , assuming every eligible characteristics have been met. Of the following, the power consumption is determined by the application of the formula:
A. Watts = volts x amps x ohms
B. Watts = volts x amps x hertz
C. Watts = volts x amps
D. Watts = volts x amps x power factor
D. Watts = volts x amps x power factor
- Of the following, which refrigerant requires the approval for use by the NYC Fire Dept.
A. R-22
B. R-12
C. Carbon dioxide
D. Butane
D. Butane
- When installing a service valve to isolate a dual pressure device while keeping the system in service, you would use a:
A. Two way valve
B. Three way valve
C. Plug valve
D. Stop valve
B. Three way valve
- The solenoid unloaders on reciprocating compressors are designed to unload:
A. All the cylinders
B. The clearance spaces in the cylinder
C. Control capacity by shutting down the compressor
D. Cylinders that can be unloaded
B. The clearance spaces in the cylinder