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What is the maximum allowable factory charge of refrigerant for Type I appliances?
5 pounds
When R-500 is recovered from an appliance, it:
Must be recovered into it's own recovery vessel that is clearly marked to ensure that mixing of refrigerants does not occur.
When servicing a small appliance for leak repair:
It is not mandatory to repair the leak, but do so whenever possible.
If EPA regulations change after a technician becomes certified:
It will be the technician's responsibility to comply with any future changes in the law.
The sale of CFC and HCFC refrigerants is:
Restricted to technicians who are EPA certified in refrigerant recovery.
All appliances must be equipped with a service aperture or other device which is used when adding or removing refrigerant from the appliance. For small appliances, this service port typically is:
A straight piece of tubing that is entered using a piercing access valve.
For what refrigeration system/appliance would it be permissable to use a passive recovery device for refrigerant recovery?
A domestic refrigerator.
To speed the recovery process and ensure that all refrigerant has been removed from a frost-free refrigerator:
Turn on the defrost heater to vaporize any trapped liquid.
Which of the refrigerants can be mixed?
R-11 and R-12
R-12 and R-134a
R-12 and R-22
None
When recovering refrigerant from a system that experienced a compressor burnout, the technician should watch for signs of contamination in the oil because?
The contaminates will eat away at recovery equipment.
What is a method or device presently used for monitoring the 80% fill level in a recovery tank?
Sight glass.
At high temperatures, (i.e., open flames, glowing metal surfaces, etc.) R-12 and R-22 can decompose to form what?
Phosgene gas.
When using recovery cylinders and equipment with schraeder valves, it is "critical" to:
Inspect the schraeder valve core for bends and breakage.
Replace the damaged schraeder valve core to prevent leakage.
Cap the schraeder ports to prevent acidental depression of the valve core.
Refrigerants (i.e., R-12, R-22, R-500, etc.) in large quantities can cause suffocation because?
They are heavier than air and displace oxygen.
The Department of Transportation Regulations, 49 CFR, require what parameter to be recorded on the shipping paper for hazard class 2.2, Nonflammable Compressed Gases?
Number of cylinders of each gas.
In the event of a large release of R-12 or R-22 in a contained area, what she be done?
Self-contained breathing apparatus(SCBA) or leaving the area is required.
When first inspecting a hermetic system known to be leaking, what should you look for?
Traces of oil.
When a new system has been assembled(built up), and is ready for testing, what is the first thing to do?
Pressurize with an inert gas and leak check.
EPA regulations require that leaking commercial and industrial process refrigeration be repaired when the leak rate exceeds what percent of the charge per year?
35 percent.
When using recovery and recycling equipment manufactured AFTER November 15, 1993, technicians must evacuate an appliance component containing MORE than 200 pounds of CFC-12 to the what level before making a major repair?
4 inches of Hg vacuum.
When using recovery and recycling equipment manufactured BEFORE November 15, 1993, technicians must evacuate an appliance containing 10 pounds of CFC-500 to what level before disposing fo the appliance?
4 inches of Hg vacuum.
What is not true of recycling and recovery equipment manufactured AFTER November 15, 1993?
It must be equipped with low-loss fittings.
You are changing out the compressor of a system containing 40 pounds of R-502. Your recycling equipment was manufactured AFTER November 15, 1993. In addition to isolating the compressor as much as possible, which procedure should you follow?
Evacuate the isolated section of the system to 15 inches of vacuum and hold. If system pressure does not rise, remove the compressor.
System-dependent recovery equipment CANNOT be used when?
The appliance contains over 15 pounds of refrigerant.
Which of the following repairs would ALWAYS be considered "major" under EPA's regulations?
Replacement of an evaporator coil.
After reaching the required recovery vacuum on an appliance, you do what next?
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.
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.
Removal of the refrigerant charge from a system can be conducted more quickly by doing what?
Packing the recovery vessel in ice.
Recovering refrigerant from a system in vapor phase will minimize the loss of what?
Oil.
In general, what is one routine maintenance task which must be performed on most refrigerant recycling machines?
Change oil and filter.
What should be done before transferring refrigerant to an empty cylinder?
The cylinder shoud be evacuated.
Refrigerant has been recovered from an air-conditioning system and held in a refillable cylinder, in order to replace the condenser coil. The refrigerant:
Can probably be charged back into the system.
Recovered refrigerant may contain what?
Acids, moisture, and oils.
After refrigerant liquid has been recovered from the appliance, what is done with any remaining vapor?
It is condensed by the recovery system.
The evacuation temperature of R-134 at 0 psig is what?
-5 degrees F.
A deep vacuum is usually measured in what?
microns.
Refrigeration and air-conditioning compressor heaters are used to do what?
Reduce the amount of refrigerant in the lubricating oil.
The state of the refrigerant leaving the receiver of a refrigeration system is what?
High pressure liquid.
A moisture-indicating sight glass is useful for what?
Checking the refrigerant's moisture content.
For what refrigerant(s) is an equipment room refrigerant monitor required under ASHRAE Standard 15?
R-12, R-134a, and R-11.
How must pressure relief valves not be installed?
Must not be installed in series.
What precaution should be take prior to recovering refrigerant from a chiller suspected of having tube leaks?
Drain the water sides of the evaporator and condenser.
What should be done to reduce refrigerant loss from a purge unit on a CFC-11 chiller?
Pipe purge-unit into recovery unit.
Continous excessive moisture collection in the purge unit of a low pressure refrigeration system could indicate what condition?
The condenser or chiller barrel tubes are leaking.
What is not true of recycling and recovery equipment manufactured AFTER November 15, 1993?
It must be able to handle more than one refrigerant.
Appliances need not be evacuated all the way to the prescibed level when?
Leaks in the appliance make evacuation to the prescribed level unattainable.
When using recovery or recycling equipment manufactured AFTER November 15, 1993, technicians must evacuate low-pressure appliances to what level before disposing of the appliance?
25mm of Hg absolute.
What does not fall under the EPA definitions for "MAJOR MAINTENANCE, SERVICE OR REPAIR?
Replacing an oil filter.
During vapor removal from a low pressure refrigeration system what should be done?
The system water pumps, the recovery compressor, and the recovery condenser should all be on.
When using recovery or recycling equipment or recycling equipment manufactured BEFORE November 15, 1993, technicians must evacuate low-pressure appliances to what level before making a major repair?
25 inches of Hg vacuum.
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