Super Combo
When using recovery or recycling equipment that was made after 11-15-93 you must evacute a system containing MORE than 200 pounds of CFC-12 to ________ before making a major repair.
15 inches of HG vacuum
When using any solvent, chemical, cleaner, chemical or refrigerant you should review
MSDS (data sheets)
Atmospheric pressure
Our atmosphere extends abut 50 miles above the earth and consists of 78% nitrogen. 21& oxygen, the remaining one percent is composed of other gases.
For what refrigerant is an equipment room refrigerant monitor required under ASHRAE standard 15?
R-123
HCFC
R-22 R-123 R-124
Disposable refrigerant containers are used for ______ refrigerent
Virgin
Recycling and recovery equipment maufactured after 11-15-93 does not need an oil separator
...
A ternary refrigerant blend is a ____ part mixture
3
high pressure refrigerant
410a
To change the compressor on a system cantaining 40 pounds R-500 using a recycling machine that was manufactured AFTER 11-15-93 you must isolate the compressor then:
evacuate the isolated section of the system to 10 inches of vacuum and hold. If the system pressure does not rise, remove the compressor.
Long hoses between the unit & the recovery machine should not be used because they cause:
excessive pressure drop increased recovery time increased emissions
With an air-cooled condenser on the roof of a building and the evaporator on the first floor, recovery should first occur:
from the liquid line entering the evaporator
refrigerant that enters the compressor, under normal operating conditiona is a:
low pressure vapor
Systems charged with R410A should be leaked checked with?
pressurized nitrogen
Recovery Cylinder
yellow at the top gray at the bottom.
According to ASHRAE's 1992 refrigerant safety classification, which designations is the most safe
A-1
Non-Azeotropic refrigerants leak from a system
in uneven amounts due to different vapor pressures
defined as the force per unit area
pressure/vacuum.
When a new system has been assembled, the first thing to do is:
pressurize the system with inert gas and leak check
Heat pumps that have been retrofitted from R22 to R407C should be leak checked with:
pressurized nitrogen
Ozone layer
protects all life from the sun's harmful radiation
410a is a refrigerant for
pure on
A cyclinder with a grey body and yellow top is designed to hold:
recovered refrigerant
A compressor heater is used to:
reduce the amount of refrigerant in the lubricating oil
A system is dehydrated to:
remove water & water vapor
A system is dehydrated to:
remove water and water vapor
When operating refrigerant recovery or recycling equipment the following precautions should be taken
safety glasses & gloves along with following equipment safety precautions
System- dependent recovery equipment CANNOT be used when:
the appliance contains over 15 pounds of refrigerant
When evacuating a system the hoses should be:
equal to or larger than the vacuum pump inlet connection
When evacuating a system, the hoses should be:
equal to or larger than the vacuum pump inlet connection
When moisrture exists in an operating system which is likely to occur?
Acid will form
Which refrigerant has the highest ozone depletion potential
CFC's
To change the compressor on a system containing R-410A, you must isolate the compressor then:
Evacuate the isolated section of the system to atmospheric pressure and hold. If system pressure does not rise, remove the compressor.
Which refrigerant will not damage the stratospheric ozone
HFC
R-134a is a
HFC refrigerant
When dehydrating a system, the system can be heated to:
decrease the dehydrating time
clean air act
(EPA) regulates section 608 of the federal clean air act. Failure to comply could cost you and your company as much as $27,500. per day, per violation and there is a bounty of up to $10,000 to lure your competitors
Refrigerant leaves the condenser of an operating system as a:
high pressure liquid
The high pressure guage on service manifold sets has a contiuous scale, usall calibrated to read from:
0-500 psi.
ozone molecule
3 oxygen bonding together. Exist in a layer in the stratosphere in 10 to 30 miles above sea level.
When charging an R-12 refrigeration system that uses a water cooled condensor, you must first charge with vapor to a pressure of at least _____ , before switching to a liquid charging.
35 psig
EPA regulations require that leaking commercial or industrial process refrigeration equipment must be repaired when the leak rate exceeds______ of the charge per year.
35%
When using recovery or recycling equipment that was made BEFORE 11-15-93 technicians must evacuate a unit that has a normal charge of 10 pounds of CFC-500 to _____ before disposing of the system.
4 inches of HG vacuum
R-410A requires recovery tanks rated for at least:
400 psig
Reusable refrigerant containers that are normally under pressure above 15 psig, must be hydrostatically tested and date stamped every:
5 years
three types of refrigerants
CFC, HCFC, HFC.
the highest ozone depletion potential
CFC, and HCFC
Chloro floro carbon contains
Carbon, Chlorine , Florine , Hydrogen- green
4 things ultra violet light
Causes skin cancer, eye diseases, Reduction in crop fields, Affects small organism in the water
When using nitrogen to pressurize a system, you should always:
Charge through a pressure regulator
Compound gauge
Compound gauges that are used to measure low side pressure in air conditioning system can measure pressure both above below 0 psig.
Which refrigerant will not damage the stratospheric zone
HFC's
what type of refrigerant is clorine free
HFC's
CFC
Is released from the AC in the car from the refrigeration cycle and takes many years to travel to the stratosphere.
______ is the process of removing refrigerant in any condition from storing it in an external container without necessary testing or processing it in any way
Recovering
_______ refers to the process of cleaning refrigerant by oil seperation 7 single or multiple passes through filter driers which reduce moisture and acidity?
Recycling
it is necessary to place a refrigerant label on:
a frigerant cylinder that is being returned for reclaiming
Use _______ to remove ice from a sight glass
alcohol spray
In genreal blended refrigerants should be charged:
as a liquid
To obtain accurate vacuum readings during system evacuation, the system vacuum guage should be located:
as far from the vacuum pump as possible
Mercury barometer
atmospheric pressure will support a column of mercury 29.2 inches in the sealed tube
DOT requires youdo this when transporting cylinders
attach DOT classification tags
Prior to replacing the condenser coil in a high pressure system, the refrigerant was recovered and stored in a refillable container. The refrigerant:
can probably be charged back into the system
After refrigerant liquid has been recovered from a system, any remaining vapor is:
condensed by the recovery system
The evacuation of a system is a method of:
dehydration
A reciprocating compressor should not be energized if the
discharge service valve has closed
HCFC's
do not contain chlorine and have no ozone depletion potential.
The over-evacuation of a system:
does not occur
Which gas causes the least damage to the enviroment during a leak check?
dry nitrogen
The type of oil that is most commonly used in stationary refrigertion applications with HFC-134a refrigerant is:
ester oil
When a unit is opened for servicing the ______ should always be replaced
filter drier
The backseating of a suction shutoff valvee will close the:
guage port
Ozone depletion potential (ODP)
is a measurement of CFC's and HCFC's ability to destroy ozone
Reclaim
is the process that returns refrigerant to the new-product specifications and that requires chemical analysis.
It is illegal to
knowingly release refrigerant during the service, maintenance, repair or disposal of appliances with the exception of de minimis releases
A system can be evacuated to only atmospheric pressure when:
leaks in the appliance make the evacuation to the prescribed level unattainable
to recover liquid refrigerant you must connect one hose to the
liquid line
After refrigerant liquid transfer between recovery unit & the system being emptied ou need to avoid trapping:
liquid refrigerant between service valves
The primary water source for cooling the condenser of a water-cooled recovery unit is:
local municipal water supply
You can determine a safe pressure for leak testing a system from the:
low side test-pressure data-plate valve
When using recovery unit the fill level of the recovery tank can be controlled by
mechanical float switch electronic shutt-off device weight
the recovery of refrigerant from a system as a vapor only will minimize the loss of:
oil
When dealing with small systems, how many refrigerants may be recovered into the same cylinder?
one
When using nitrogen to pressurize a system you should:
only charge with nitrogen vapor
When evacuating a system the hoses should be:
short in length & as large in diameter as possible
Refrigerant that has been recovered can be returned to:
the same system or other systems owned by the same person without restriction
What factor affects the speed of evacuation?
the size of the equipment the ambient temperature the amount of moisture in the system
Measuring the system's final vacuum is always done with
the system isolated & the vacuum pump off
When a system will not hold a vacuum after it has been evacuated then:
the system may be leaking
When a systemwill not hold a vacuum after it has been evauated, then:
the system may be leaking
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 125 degrees F. This is the same guidance given for R-22 and other common refrigerants.
A system is considered dehydrated when:
the vacuum indicator shows you have reached & held the required finished vacuum
Whenever dry nitrogen from a portable cyclinder is connected to a system, what item is of most importance to consider for safety?
there is a relief valve in the downstream line from the pressure regulator
Refrigerant vapors or mist should not be inhaled because
they may cause heart irregularities & or unconsciousness
ozone
three oxygen atoms bonded together.
R134
used In our newer refrigerant and cars
R22
used in residential and commercial applications
Moisture is removed a system by:
using a filter drier
Never use oxygen or compressed air to pressurize a sytem because:
when mixed with compresser oil or some refrigerants it could explode
The color code for refrigerant recovery cylinders is
yellow tops with grey bodies
