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EPA 608 Type III Quiz English
A typical setting for the high pressure cut-out control on a recovery unit used for evacuating the refrigerant from a low pressure chiller is:
a) 2 psig.
b) 5 psig.
c) 10 psig.
d) 15 psig.
A charged low pressure refrigeration system can be efficiently leak checked by:
a) adding compressed air, since it will be removed from the system by the Purging unit.
b) operating the purge system.
c) adding HCFC-22.
d) raising system pressure by heating with circulated hot water or heating blankets.
The existence of air in a low pressure system, causes __________.
a) low head pressure.
b) low suction pressure.
c) high head pressure.
d) high liquid level.
Which safety precaution should be adhered to for low pressure systems?
a) Do not siphon refrigerant by mouth.
b) Avoid spilling liquid refrigerant on the skin.
c) Use gloves and safety goggles when working with liquid refrigerant.
d) all of the above
Refrigerant-11 at 14.7 PSIA will boil at about:
When there is excessive moisture collecting in the purge unit of a low pressure refrigeration system, this indicates that the __________.
a) the system was charged with contaminated refrigerant.
b) the condenser or chiller barrel tubes are leaking.
c) the purge unit is not operating properly.
d) the purge unit needs adjustment.
ASHRAE Standard 15 - 1994 requires equipment room refrigerant sensors for what safety group classification?
d) All refrigerant safety groups
When recharging a refrigeration system with R-11, what vapor pressure is necessary in the shells before charging with liquid?
a) 21.1" Hg vacuum
b) 19.7" Hg vacuum
c) 18.1" Hg vacuum
d) 16.9" Hg vacuum
After reaching the required recovery vacuum on a chiller, you should:
a) Immediately disconnect the recycling or recovery equipment and open the system for service.
b) Wait for at least a few minutes to see if the system pressure rises, indicating that there is still refrigerant in liquid form or in the oil.
c) Immediately break the vacuum with nitrogen and open the system for service.
d) Immediately pressurize the system with nitrogen and perform a leak check.
A hydrostatic tube test kit is used to
a) blow all water from the tubes.
b) remove any water from the machine.
c) vent refrigerant.
d) determine if a tube leaks.
When charging a chiller, refrigerant vapor is introduced into the system before charging with liquid. This is because:
a) Vapor charging increases pressure slowly, preventing failure of the rupture disk.
b) Vapor charging is faster than liquid charging.
c) Liquid charging is more difficult to control than vapor charging.
d) Liquid charged into a deep vacuum will cause the refrigerant to boil and may lower temperatures enough to freeze the water in the tubes.
When evacuating a system, the use of too large a vacuum pump can cause:
a) trapped water to freeze.
b) trapped oil to freeze.
c) trapped refrigerant to freeze.
d) valves to freeze.
On a low-pressure chiller with an open-type compressor, the ________________ is very susceptible to leaks.
a) chiller tubes
b) shaft seal
c) charging connections
d) shaft bearings
What steps may be taken to prevent air accumulation into an idle low pressure refrigeration system?
a) Leave the purge unit on-line at all times.
b) System pressure should be maintained slightly above atmospheric.
c) Open the air vents on the condenser.
d) Intermittently operate the system with no load.
Commercial and industrial process refrigeration systems must be repaired when the leak rate exceeds ______ percent of the charge per year:
When recovering vapor from a low pressure refrigeration system the:
a) water pumps should be on, and the recovery compressor should be off.
b) system water pumps should be on, the recovery compressor should be on, and the recovery condenser water should be off.
c) system water pumps, the recovery compressor, and the recovery condenser water should all be on.
d) system water pumps should be off, and the recovery compressor should be on.
Where does refrigerant go after it leaves the purge unit of a low pressure centrifugal system?
a) the evaporator
b) the condenser
c) the compressor intercooler
d) the recovery service vessel
The purge unit takes its suction from the:
a) top of the condenser.
b) compressor oil sump.
c) top of the evaporator.
d) suction elbow.
Which of the following repairs would ALWAYS be considered "major" under EPA's regulations?
a) replacement of an evaporator coil
b) replacement of a filter-drier
c) replacement of a switch
d) replacement of a purge unit
Charging refrigerant liquid into a refrigeration system when it is under a 29 inch Hg vacuum can cause the:
a) liquid to absorb excess moisture.
b) purge unit to operate.
c) system water to freeze.
d) refrigerant liquid to freeze.
According to the EPA, there is approximately _______ refrigerant vapor left in an average 350 ton R- 11 chiller at 0 psig pressure once all the R-11 liquid has been removed?
b) 10 lbs
c) 20 lbs
d) 100 lbs
An oil sample should be taken when __________________.
a) a new filter drier has been installed.
b) there has been a compressor burnout.
c) the unit is not cooling properly.
d) recycled refrigerant has been added to the unit.
Both CFC-11 and HCFC-123 chillers require purge units because:
a) the purge units remove moisture
b) the system operates below atmospheric pressure
c) purge units remove refrigerant from the oil sump
d) purge units remove CFCs from the chiller
Refrigerant recovery typically starts with_______ it is faster.
a) vapor recovery
b) liquid recovery
c) combined vapor and liquid recovery.
d) oil separation.
Under EPA's regulations, __________________ is used to pressurize a low-pressure chiller for the purpose of opening the system for a non-major repair?
a) adding nitrogen
b) warming the refrigerant
c) adding compressed air
d) adding carbon dioxide
The primary water source for a recovery unit condensing coil is ______.
a) chilled water
b) condenser water
c) local municipal water supply
d) de-ionized water
Which statement is NOT true of recycling and recovery equipment manufactured after November 15, 1993?
a) It must be tested by an EPA-approved third party.
b) It must meet vacuum standards more stringent than those met by equipment manufactured before November 15, 1993.
c) It must be equipped with low-loss fittings.
d) It must be able to handle more than one refrigerant.
A system does not have to be evacuated all the way to the required level when:
a) the repair is major.
b) the repair is followed by an evacuation of the appliance to the environment.
c) the appliance is being disposed.
d) leaks in the appliance make evacuation to the prescribed level unattainable.
Which action listed below is the proper method to reduce refrigerant loss from a purge unit on a CFC-11 chiller?
a) leak test and repair the chiller
b) seal the purge-unit discharge
c) pipe purge-unit back into the low side
d) pipe purge-unit into recovery unit
Identify the pressure corresponding to 32F for R-123:
a) 23 PSI
b) 20 PSI
c) 17 PSI
d) 11 PSI
What precaution should be taken prior to recovering refrigerant from a chiller suspected of having tube leaks:
a) Drain the water sides of the evaporator and condenser.
b) Run the circulating pumps.
c) Be certain the purge unit is operating.
d) Open the condenser vents.
Pressure relief valves must never be:
a) installed in series.
b) installed in parallel.
c) installed vertically.
d) installed horizontally.
If you are going to removing oil from a low pressure system, you should heat the oil because:
a) you can warm your hands on the container.
b) less refrigerant will be contained in the oil at the higher temperature.
c) warmer oil has a lower viscosity and flows more easily.
d) it shows that the heater is working.
After recovering the liquid refrigerant you must:
a) recover the vapor refrigerant
b) pressurize system with nitrogen
c) remove the oil from the system
d) solvent-flush the entire system
EPA regulations require that any appliances containing more than 50 pounds of refrigerant (except for commercial and industrial process refrigeration) must be be repaired when the leak rate exceeds ______ of the charge per year.
If you are using a recovery machine manufactured BEFORE November 15, 1993, you must evacuate any low- pressure appliance to ________ before making a major repair:
a) 0 psig.
b) 15 inches of Hg vacuum.
c) 25 inches of Hg vacuum.
d) 25 mm of Hg absolute.
On low pressure chillers, moisture typically enters the refrigerant system through:
a) air leaks in the rupture disc assembly.
b) tube leaks.
c) air leaks from areas with gaskets or fittings.
d) air leaks from the charging valve.
Refrigerant-11 at a pressure of 17 inches Hg vacuum has a saturation temperature of:
The lowest access point on a low pressure centrifugal air-conditioning unit is the:
a) the evaporator charging valve
b) the condenser service valve
c) the compressor cooler jacket
d) the purge unit exhaust port
A rupture disc on a recovery vessel for low pressure refrigerants relieves at:
a) 5 psig.
b) 10 psig.
c) 15 psig.
d) 20 psig.
According to ASHRAE Guideline 3-1996, if the pressure in a system rises from 1 mm Hg to a level above ______ during a standing vacuum test, the system should be checked for leaks.
a) 1.5 mm Hg
b) 2.0 mm Hg
c) 2.5 mm Hg
d) 3.0 mm Hg
During chiller evacuation, water is circulated to:
a) speed up the recovery process.
b) prevent loss of refrigerant to the atmosphere.
c) prevent freezing of the water.
d) maintain constant refrigerant pressure.
When charging an R-410A water chiller, you must first charge with vapor to a pressure of at least _______, before switching to liquid charging.
a) 20 psig.
b) 120 psig.
c) 220 psig.
d) 320 psig.
If you leak test a low pressure chiller with nitrogen in excess of 10 psig you could cause the _____________ to fail.
a) condenser tubes
b) purge unit shells
c) evaporator tubes
d) rupture disc
ASHRAE Standard 15 - 1994 requires that each machinery room must activate an alarm and mechanical ventilation before refrigerant concentrations exceed:
a) the EEL (Emergency Exposure Limit).
b) the TLV-TWA (Threshold Limit Value - Time Weighted Average).
c) the UTL (Upper Threshold Limit).
d) the COP (Coefficient of Performance).
Which repair WOULD NOT fall under the EPA definition for "MAJOR MAINTENANCE, SERVICE, OR REPAIR"?
a) replacing an oil filter
b) replacing the compressor
c) re-tubing a condenser
d) replacing a fin and tube forced air evaporator coil
Refrigerant is added to a centrifugal machine through the:
a) float valve.
b) compressor service valve.
c) condenser charging valve.
d) evaporator charging valve
What is meant by the term "high efficiency purge unit?"
a) Those purge units which discharge a high percentage of refrigerant with the air which they remove.
b) Those purge units which discharge a low percentage of refrigerant with the air which they remove.
c) Those purge units which draw very little electrical power.
d) None of the above.
The PRIMARY purpose of a purge unit on a CFC-11 chiller is to:
a) remove CFCs from the system.
b) condense air out of the system.
c) condense water out of the system.
d) remove noncondensables from the system.
If you are using a recovery machine manufactured AFTER November 15, 1993, you must evacuate any low- pressure appliance to ________ before making a major repair:
a) 0 psig.
b) 15 inches of Hg vacuum.
c) 25 inches of Hg vacuum.
d) 25 mm of Hg absolute.
If you suspect a leak in the water box of a chiller, you should place the leak detector probe ________________________, and sniff for refrigerants:
a) at the rupture disc
b) through the vent valve
c) through a test plug
d) through a drain valve
To determine how much vapor to charge into an evacuated chiller, you should charge with vapor until ____________________.
a) the system pressure corresponds to a refrigerant saturation temperature of 36F.
b) the recovery unit liquid level drops.
c) you have charged with vapor for 15 minutes.
d) the recovery unit pressure drops.
ASHRAE Standard 15 - 1994 requires the use of room sensors and alarms to detect:
a) refrigerant leaks
b) high levels of ozone.
c) refrigerant contamination.
d) excessive oxygen levels.
The discharge from a rupture disc should be piped ____________ for venting?
b) inside the machinery room
c) to the evaporator
d) to the duct system
A centrifugal chiller's rupture disk is connected to the chiller's:
c) liquid line.
To remove ice from sight glasses or viewing glasses, use:
a) R-11 refrigerant.
b) an alcohol spray.
d) a screw driver or flat file.
The maximum test pressure for leak testing a low pressure centrifugal is:
a) 0 psig
b) 10 psig
c) 25 psig
d) 50 psig
According to ASHRAE Standard 34, what is the safety classification of R-123?
Excessive running of a purge system on a low pressure chiller generally indicates that the:
a) air sensors are faulty.
b) ambient temperature is too high.
c) efficiency of the purge unit is too low.
d) system is leaking.
The typical design burst pressure for a rupture disk on a low pressure centrifugal air-conditioning system is set at ________,
a) 7 psi
b) 10 psi
c) 15 psi
d) 28 psi
During the evacuation of a system containing large amounts of moisture, you can prevent freezing of this moisture by increasing the pressure with _______ gas,
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