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WorksheetsEPA Type 2 (REVISED)
Total questions: 78
Worksheet time: 39mins
Heat pumps that use R-410A should be leak checked with
HFCs
HCFCs to lower the cost of discarding the refrigerant.
pressurized nitrogen.
compressed oxygen.
Heat pumps that have been retrofitted from R-22 to R-407C should be leak checked with
HFCs
HCFCs
pressurized nitrogen.
compressed air.
To change the compressor on a system containing R-410A, you must isolate the compressor and then
simply remove the compressor.
evacuate the isolated section of the system to atmospheric pressure and hold. If the system pressure does not rise, remove the compressor.
evacuate the isolated section of the system to 10 inches of vacuum and hold. If the system pressure does not rise, remove the compressor.
evacuate the isolated section of the system to 15 inches of vacuum and hold. If the system pressure does not rise, remove the compressor.
Which of the following is the correct way to charge a refrigeration system?
vapor through the suction line service valve.
liquid through the discharge service valve.
liquid through the suction service valve.
liquid through the liquid line service valve.
After installation of a field-piped R-410A split heat pump, the unit should first be
evacuated.
pressurized with R-22, then leak checked.
pressurized with R-410A, then leak checked.
pressurized with nitrogen, then leak checked.
Pressure relief valves must not be
installed in series.
installed in parallel.
installed vertically.
installed in horizontally.
What is the required recovery vacuum for a system?
10 psig
20 psig
35 psig
100 psig
Your recovery/recycling machine has R-22 refrigerant in it. You now have to recover refrigerant from a unit with R-410A. What must be done before your recovery unit can be used to recover R-410A?
The recovery unit must be EPA-certified for use with R-410A.
The recovery tank must be designed for the pressure of R-410A.
The filter and lubricant in the recovery unit must be changed and the recovery unit evacuated.
All of the above.
After reaching the required recovery vacuum on a system you must
immediately disconnect the recovery or recycling equipment and open the system for service.
immediately break the vacuum with nitrogen and open the system for service.
immediately pressurize the system with nitrogen and perform a leak check.
wait to see if the system pressure rises indicating that there is still refrigerant in liquid form or refrigerant trapped in the oil.
In a refrigeration system, the component directly following the evaporator is the
receiver.
metering device.
accumulator.
condenser.
A reciprocating compressor should not be energized while
the discharge service valve is closed.
the suction service valve is open.
the discharge service valve is open.
there is a demand for cooling.
R-410A requires a high-pressure manifold gauge and hose set. They must have a
2000 psig burst pressure and a 400 psig working pressure.
2000 psig burst pressure and a 800 psig working pressure.
4000 psig burst pressure and a 400 psig working pressure.
4000 psig burst pressure and a 800 psig working pressure.
The refrigerant pressure inside an R-410A unit which is at room temperature (72F) and not operating is
approximately 74 psig.
approximately 110 psig.
approximately 210 psig.
approximately 310 psig.
Every air conditioning or refrigeration system should be protected by a
pressure relief device.
properly located stop valve.
low-pressure control.
refrigerant receiver.
To change the compressor on a system containing 40 pounds of R-500 using a recycling machine that was manufactured AFTER November 15 1993, you must isolate the compressor then
simply remove the compressor.
evacuate the isolated section of the system to atmospheric pressure, then remove the compressor.
evacuate the isolated section of the system to 10 inches of vacuum and hold. If system pressure does not rise, remove the compressor.
evacuate the isolated section of the system to 15 inches of vacuum and hold. If system pressure does not rise, remove the compressor.
When inspecting a system for leaks, you should look for
frost on the pipes.
puddles of liquid refrigerant.
particles from the drier core.
traces of oil.
When a new system has been assembled, the first thing to do is
evacuate the system.
pressurize the system with an inert gas and leak check.
pressurize the sytem with refrigerant to be used in the system.
introduce an initial charge of refrigerant and start the compressor.
R-410A is different from other ASHRAE 400 series non-azeotropic blends because
R-410A behaves as a near azeotropic refrigerant and can be topped off.
R-410A is an HCFC.
R-410A uses mineral oil.
All of the above.
Manifold gauge set hoses should have self-sealing connectors or hand valves to
minimize the chance of an explosion during use.
prevent venting during recycling.
prevent a vapor lock during rapid liquid transfer.
minimize the release of refrigerant when the hoses are connected and disconnected.
When using recovery or recycling equipment that was manufactured AFTER November 15 1993, you must evacuate a system containing MORE than 200 pounds of CFC-12 to ______ before making a major repair.
0 psig
4 inches of Hg vacuum
10 inches of Hg vacuum
15 inches of Hg vacuum
With an air-cooled condenser on the roof of a building and the evaporator on the first floor, recovery should first occur
from the vapor line entering the condenser,
from the discharge side of the compressor.
from the liquid line entering the evaporator.
on the suction side of the compressor.
Never use oxygen or compressed air to leak check equipment because R-410A can
explode when mixed with air or oxygen.
fractionate when mixed with oxygen.
condense when exposed to oxygen.
None of the above.
Dry nitrogen should be used to break the first vacuum when dehydrating by the double evacuation method. However, it
often contains moisture.
is expensive.
is toxic.
can be dangerous if not used with a pressure regulator.
A recovery machine that uses a hermetic compressor will overheat when drawing a deep vacuum because
it runs faster than other equipment.
the motor needs the flow of refrigerant through the compressor to provide motor cooling.
the oils used in hermetic compressors burn at lower temperatures.
it has a higher compression ratio limit than other equipment.
The proper charging method for blended (non-azeotropic) refrigerants (400 series) is to remove the charge from the cylinder as a
vapor.
liquid.
superheated vapor.
subcooled liquid.
When a refrigerant trace gas becomes absolutely necessary to use, which of the available refrigerants should be used to identify a leak?
CFC-12
HCFC-22
HFC-407c
HFC-410a
After refrigerant liquid has been recovered from a system, any remaining vapor is
purged to the atmosphere.
isolated in the system.
pumped into the system receiver.
condensed by the recovery system.
An oil sample should be taken when
a) a new filter dryer has been installed.
b) the compressor has burned out.
c) the unit is not cooling properly.
d) recycled refrigerant has been added to the unit.
In a refrigeration system with a TXV or other type of throttling device, the component directly following the condenser would be the
receiver.
metering device.
accumulator.
evaporator.
Recovered refrigerant may contain which of the following?
Acids
Moisture
Oils
All of the above
The backseating of a suction shut-off valve will close the
suction line and compressor port.
compressor and gauge port.
gauge port.
compressor port.
Which repair would always be considered “major” under the EPA’s regulations?
Replacement of an evaporator coil.
Replacement of a filter dryer.
Replacement of a schrader valve core.
Replacement of a condenser fan motor.
R-410a requires certified recovery and recycling equipment rated for at least
240 psig
300 psig
400 psig
500 psig
A compressor heater is used to
prevent refrigerant vaporization.
remove entrained water.
prevent acid pitting.
reduce the amount of refrigerant in the lubricating oil.
Your recovery/recycling machine has R-502 refrigerant in it. You now have to recover refrigerant from a unit with R-22. What must be done before the R-22 refrigerant can be recovered/recycled?
Nothing as long as the recovery machine is not full.
Change the expansion valve on the recovery machine.
Change the filter and expansion valve on the recovery machine.
Recover as much of the R-502 as possible from the recovery machine, change the filter, and evacuate.
The fastest way to recover refrigerant from a system is to remove it in the ______ phase.
final
initial
liquid
vapor
Before using a recovery unit to remove a charge, what steps should be taken?
Check service valve positions.
Check the oil level in the recovery unit.
Evacuate recovery unit and recovery tank.
All of the above.
A deep vacuum is usually measured in
psig
psia
inches of Hg
microns
Before transferring refrigerant to an empty cylinder
the refrigerant should be chilled.
the refrigerant should be mixed.
the cylinder should be heated.
the cylinder should be evacuated to avoid mixing air with the recovered refrigerant.
To recover liquid refrigerant, you must connect one hose to the
compressor suction valve.
compressor discharge valve.
liquid line.
top of the condenser.
A system can be evacuated to only atmospheric pressure when
the repair is major.
the repair is followed by an evacuation of the appliance to the environment.
leaks in the appliance make evacuation to the prescribed level unattainable.
the appliance is being disposed.
The vacuum pump used to evacuate a system should be capable of pulling a vacuum of
10mm Hg
20mm Hg
500 microns
1000 microns
While R-410a is a high-pressure refrigerant, it can be stored in the back of your service van as long as
the temperature inside the vehicle does not exceed 125F. This is the same guidance given for R-22 and other common refrigerants.
the temperature inside the vehicle does not exceed 125F. But R-22 can be stored in vehicles with temperatures exceeding 125F.
the temperature inside the vehicle does not exceed 155F. This is the same guidance given for R-22 and other common refrigerants.
the temperature inside the vehicle does not exceed 155F. But R-22 can be stored in vehicles with temperatures exceeding 155F.
When under a deep vacuum, the motor winding of a hermetic refrigeration compressor
will be damaged if energized.
must be kept warm to operate properly.
will be protected by its insulation.
will overheat only if the crankcase heater is energized.
Which statement is NOT true regarding recycling and recovery equipment manufactured after November 15 1993?
It must be tested by an EPA approved third party.
It must meet vacuum standards more stringent than those met by equipment manufactured before 15 November 1993.
It must be equipped with low-loss fittings.
It must have an oil separator.
When servicing an operating unit that has a receiver/storage tank, the
compressor should be isolated off.
liquid should be recovered last.
refrigerant should be recovered into the receiver.
gauge pressure should be achieved by venting.
The refrigerant pressure inside an R-12 unit which is at room temperature (72F) and not operating is
approximately 74 psig
approximately 154 psig
approximately 214 psig
approximately 304 psig
You are going to service a newer residential split-system air-conditioner. You would expect to find the system charged with which refrigerant?
R-11
R-12
R-410a
R-502
Use ____________ to remove ice from the sight glass.
an alcohol spray
water
R-11 rerigerant
a screw driver or flat file
When a unit is opened for servicing, the ___________ should always be replaced.
thermostat
metering device
crankcase heater
filter-drier
A routine maintenance task which must be performed on refrigerant recycling machines is to
check compressor seals.
change electrical fuses.
replace moisture sight glass.
change filter and compressor oil if any.
Refrigerant should be removed from the condenser outlet if the
condenser is on the roof.
compressor is inoperative.
the evaporator has a leak.
condenser is below the receiver.
When evacuating a system, the use of a large vacuum pump could
cause trapped oil to freeze.
cause trapped refrigerant to freeze.
cause trapped water to freeze.
causes the valves to freeze.
The primary water source most often used for cooling the condenser of a water-cooled recovery unit is
de-ionized water.
chilled water.
condenser water.
local municipal water supply.
When using recovery and recycling equipment manufactured BEFORE November 15, 1993, technicians must evacuate a unit that:
meets the required vacuum level as specified by EPA regulations
is completely free of refrigerant
has been pressurized to 0 psig
contains only oil and no refrigerant
A system has a normal charge of 10 pounds of CFC-500 to ______ before disposing of the system.
0 psig
4 inches of Hg vacuum
10 inches of Hg vacuum
15 inches of Hg vacuum
The evaporation temperature of R-410a at 100 psig is about
0 F
30 F
90 F
120 F
Noncondensables in a system cause a
lower suction pressure.
higher suction pressure.
lower discharge pressure.
higher discharge pressure.
When charging an R-410a system that uses a water-cooled condenser, you must first charge with vapor to a pressure of at least ______ before switching to liquid charging.
20 psig
120 psig
220 psig
320 psig
R-410a requires recovery tanks rated for at least
240 psig
300 psig
400 psig
500 psig
The recovery rate can be increased by
submerging a cylinder in a bucket of ice.
turning the recovery tank upside down.
doing it at night.
applying heat to the tank.
Oil foaming usually occurs in the
condenser.
evaporator.
compressor.
expansion device.
During the evacuation of a system that contains large amounts of moisture, it may be necessary to increase pressure in the system with ______ to counteract freezing of the moisture.
hydrogen
oxygen
air
nitrogen
Prior to replacing the condenser coil in a high pressure system, the refrigerant was recovered and stored in a refillable cylinder. The refrigerant
can probably be charged back into the system.
should probably be replaced with R-410a.
must be reclaimed.
must be destroyed.
The evaporation temperature of R-134a at 0 psig is
-21 F
-15 F
-5 F
-1 F
When servicing a 60-ton packaged rooftop unit, the easiest way to check the type of refrigerant it uses is to
use your service gauge set and a refrigerant card.
ask the owner.
EPA regulations require that any appliances containing more than 50 pounds of refrigerant, except for commercial and industrial process refrigeration, must be repaired when the leak-rate exceeds ______ of the charge per year.
5 percent
10 percent
25 percent
35 percent
EPA regulations require that leaking commercial or industrial process refrigeration equipment must be repaired when the leak-rate exceeds ______ of the charge per year.
5%
15%
25%
30%
You are going to service an older residential split-system air conditioner. You would expect to find the system charged with which refrigerant?
R-11
R-12
R-22
R-502
For what refrigerant is an equipment room refrigerant monitor required under ASHRAE Standard 15?
R-12
R-134a
R-11
Heat pumps that use R-134a should be leak-checked with
CFCs
HCFCs
compressed dry air.
pressurized nitrogen.
System-dependent recovery equipment CANNOT be used when
the appliance is leaking.
the compressor of the appliance is operational.
the ambient temperature is over 115 F.
the appliance contains over 15 pounds of refrigerant.
Moisture is removed from a system by
purging the condenser.
draining the oil separator.
reducing water flow to the condenser.
using a filter drier.
Which component is not part of the low side of a system?
Evaporator
Receiver
Suction line
Accumulator
Soap bubble testing is used
to pinpoint refrigerant leaks.
only with CFCs and HCFCs.
to detect water leaks.
to see if the condenser or evaporator is dirty.
Refrigerant leaves the receiver of a system as a
low pressure liquid.
low pressure vapor.
high pressure liquid.
high pressure vapor.
The recovery of refrigerant from a system as a vapor only will minimize the loss of
oil.
water.
refrigerant.
All of the above.
A very-high pressure appliance is one that uses a refrigerant with a liquid phase saturation pressure above 355 psia at 104F. This definition includes but is not limited to appliances using which of the refrigerants listed below?
R-23
R-13
R-503
All of the above
