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26 Cards in this Set
- Front
- Back
Testing with soap bubbles is used; |
to pinpoint refrigerant leaks. |
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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? |
Recover as much of the R-502 from the recovery unit as possible, change filter, and evacuate. |
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What should be done before transferring refrigerant to an empty cylinder? |
The cylinder should be evacuated. |
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EPA regulations require that all appliances containing more than 50 pounds of refrigerant (except for commercial and industrial process refrigeration) be repaired when the leak rate exceeds ___________ percent of the charge per year. |
15 % |
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Many refrigeration units use an open compressor. Which part of the compressor is most likely to leak if a unit is not used for several months? |
The rotating shaft seal. |
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When using recovery and recycling equipment manufactured BEFORE November 15, 1993, technicians must evacuate an appliance containing 10 pounds of CFC-500 to the following level before disposing of the appliance: |
4 inches of Hg vacuum. |
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Which of the following repairs would ALWAYS be considered "major" under EPA's regulations? |
Replacement of an evaporator coil. |
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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. |
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Removal of the refrigerant charge from a system can be conducted more quickly by; |
packing the recovery vessel in ice. |
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When first inspecting a hermetic system known to be leaking, you should look for; |
traces of oil. |
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After installation of a field-piped split system, the unit should first be; |
pressurized with nitrogen/leak checked. |
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Which of the following statements 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 have an oil separator. |
NOT TRUE D. It must have an oil separator. |
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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 of the following procedures should you follow? |
Evacuate the isolated section of the system to 10 inches of vacuum and hold. If system pressure does not rise, remove the compressor. |
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Recovering refrigerant from a system in vapor phase will minimize loss of; |
oil. |
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Non-condensables in a refrigeration system result in; |
higher discharge pressure. |
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After reaching the required recovery vacuum on an appliance, you should; |
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. |
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In general, what is one routine maintenance task which must be performed on most refrigerant recycling machines? |
Change oil and filter. |
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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. |
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Before using a recovery unit to remove a charge, what steps should be taken? A. Check service valve positions. B. Check recovery unit oil level. C. Evacuate recovery unit/receiver. |
D. All of the above. |
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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 following level before making a major repair: |
15 inches of Hg vacuum. |
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Appliances containing CFC refrigerants can be evacuated to atmospheric pressure when; |
the appliance is being disposed. |
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For what refrigerant(s) is an equipment room refrigerant monitor required under ASHRAE Standard 15? A. R-12. B. R-134a. C. R-11. |
D. All of the above. |
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Refrigerant should be removed from the condenser outlet when; |
the condenser is below the receiver. |
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Moisture is removed from the refrigerant in a system by; |
using a filter drier. |
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Every refrigerating system shall be protected by; |
a pressure relief device. |
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