Discipline: Engineering

Type of Paper: Question-Answer

Academic Level: High school

Paper Format: APA

Pages: 1 Words: 275


Why could a recycling or recovery machine that uses a hermetic compressor overheat when drawing deep vacuums?
The motor relies on the flow of the refrigerant through the compressor for cooling.

Recovering refrigerant from a system in the vapor phase will minimize the loss of which of the following? Oil

For what refrigerant is an equipment room refrigerant detector NOT required under ASHRAE Standard 15 provided the mechanical ventilation system in the machinery is run continuously?  R-717

When recovery is first started, at what phase is the refrigerant removed to save recovery time   Liquid phase

Starting in 2019, what leak rate triggers the EPA requirement that commercial refrigeration systems containing 50 pounds or more of R-22 be repaired?`   20%

Which part of a belt-driven non-hermetic compressor is most likely to leak if the compressor has not been used for several months?  Rotating shaft seal

Before making a major repair, technicians must evacuate an appliance or component containing more than 200 pounds of R-410A to which of the following levels?   25mm HG absolute

Identify the best method to charge a system that has both an air-cooled condenser and evaporator with a nameplate charge of 80 pounds?
Liquid charge through the liquid -line service valve.

It is best practice to use dry nitrogen to break the vacuum when dehydrating by the triple evacuation method. However, it;
requires a pressure regulator.

When first inspecting a hermetic system known to be leaking, you should look for;
traces of oil

When can appliances containing refrigerants be recovered to atmospheric pressure?
For major repairs such as replacing the compressor, condenser, or evaporator.

After a leak repair of a supermarket rack using 3000 lbs of R-22 and a successful initial verification test, when must a foll
Within 10 days.

Which of the following repair would always be considered "major" under EPA's regulations?
Replacement of an evaporator coil.

An initial leak verification test failed after repairing a leak in a rack refrigeration system for a supermarket using an HCF
Conduct additional repairs within the 30 days repair window and mothball and appliance.

How would you remove moisture from the refrigerant in a system?
Use a filter drier.

How can you speed up the removal of the refrigerant charge from a system?
Cooling the recovery cylinder to lower its pressure.

When is it agaist EPA regulation to use system-dependent recovery equipment?
When the appliance contains over 15 pounds of refrigerant.

When could a reciprocating compressor be damaged if energized?`
When the discharge service valve is closed.

Which of the following statement about recycling a recovery equipment used for stationary refrigeration is False?
Purchase of such equipment must be reported to the EPA.

what should be done after reaching the required recovery vacuum on an appliance?
Wait for at least a few minutes to see if the system pressure rises.

You are changing out the compressor of a system containing 40 pounds of R-404A. In addition to isolating the compressor, ...
evacuate the isolated section of the system to 0 psig and if system pressure does not rise after a few minutes, remove the compressor.

What is the state of the refrigerant leaving the reciever in a refrigeration system?
High pressure liquid

Your recovery/recycling machine has R-22 refrigerant in it. you now have to recover refrigerant from an R-410A unit.....
Remove the R-22 from the recovery unit and charge the filter.

After refrigerant liquid has been recovered from the appliance, any remaining vapor is;
Remove by the recovery system

Where must you connect a hose in order to recover liquid refrigerant?
The compressor discharge valve.