What can a technician do to minimize oil loss when recovering refrigerant from a high pressure?

What should a technician do if the refrigerant in a recovery cylinder is suspected to be contaminated? Turn refrigerant in for reclamation. Before beginning a refrigerant recovery procedure, it is ALWAYS necessary to; Know the type of refrigerant that is in the system.

When recovering refrigerant into a non pressurized container from a refrigerator with an inoperative compressor it is?

Which of the following refrigerants is most commonly used as a replacement for R-12 in new household refrigerators? When recovering refrigerant into a non-pressurized container from a refrigerator with an inoperative compressor: it is necessary to heat and strike the compressor with a rubber mallet.

Which condition requires assessing both the high and low side of the system for refrigerant recovery when using the system dependent passive recovery process?

using the system dependent (passive) recovery process, which condition requires accessing both the high and low side of the system for refrigerant recovery? it is necessary to heat the compressor and strike it with a rubber mallet.

Which of the following is a reason to obtain an accurate pressure reading of refrigerant inside a recovery cylinder?

Obtaining accurate pressure readings of refrigerant inside a recovery cylinder is necessary to detect excessive non- condensables. The only way to read refrigerant pressure accurately is at a stable, known temperature. Air in a refrigeration system will cause higher discharge pressures.

When using recovery cylinders and equipment with Schrader valves you should do all the following except?

When using recovery cylinders and equipment with Schrader valves, you should do all of the following, except: Use a valve tool to loosen a Schrader valve core before every use. When using nitrogen in repairing a sealed refrigeration system, what should the nitrogen tank always be equipped with?

How is the pressure of a refrigerant cylinder containing saturated refrigerant determined?

The pressure of a refrigerant cylinder containing saturated refrigerant: Is determined entirely by the temperature of the refrigerant. The pressure of a saturated refrigerant can accurately be predicted: By comparing its temperature to the corresponding pressure on a pressure-temperature chart.

Why should low and high side access valves be installed when recovering refrigerant from a household refrigerator?

When recovering refrigerant from a household refrigerator who’s compressor does not run, it is recommended that low and high side access valves be installed, why? Both A and B. It can enhance the speed of recovery, it may be necessary to achieve required recovery efficiency.

When first inspecting a hermetic system known to be leaking you should look for?

TYPE II

Which of the following is an example of a non condensable?

Any gas that does not condense (change from vapor to liquid) under the normal compression refrigeration conditions is called a non-condensable gas or NCG. These would commonly be air, nitrogen, carbon dioxide, argon, and oxygen.

Which refrigerants is very high pressure and generally does not need to be recovered?

Co2 refrigerant R-744 (Carbon dioxide) is a very high-pressure refrigerant and generally does not need to be recovered.

What are non condensables in a refrigeration system?

Air and nitrogen are the most likely non-condensables you will see. Air can enter a refrigeration or A/C system when improper service and evacuation procedures are not followed or when you have had a leak on the low side. Nitrogen can enter the system in other ways.

How can I tell if my air conditioner has non condensables?

Check the pressure on the high side gauge and convert it to temperature using a PT chart. This saturated temperature should be within a couple degrees of outdoor air temperature. If this saturation temperature is any higher, you have nitrogen or non-condensables in the system.

What to do if you have nitrogen in your a / C system?

This saturated temperature should be within a couple degrees of outdoor air temperature. If this saturation temperature is any higher, you have nitrogen or non-condensables in the system. The entire charge should be removed into a clean and dry recovery cylinder. The system should be evacuated to 500 microns and recharged using new refrigerant.

Can a technician recover refrigerant from an air conditioner?

Technicians receiving a passing grade on this small appliance examination are certified to recover refrigerant during the maintenance, service or repair of: A) packaged terminal air conditioners (PTACs) with 5 pounds or less of refrigerant

Related

EPA regulations (40 CFR Part 82, Subpart F) under Section 608 of the Clean Air Act require technicians who service stationary refrigeration and air-conditioning equipment to follow specific practices. These practices are meant to maximize recovery and recycling of refrigerants, which can be ozone-depleting substances (ODSA compound that contributes to stratospheric ozone depletion. ODS include chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), halons, methyl bromide, carbon tetrachloride, hydrobromofluorocarbons, chlorobromomethane, and methyl chloroform. ODS are generally very stable in the troposphere and only degrade under intense ultraviolet light in the stratosphere. When they break down, they release chlorine or bromine atoms, which then deplete ozone. A detailed list (http://www.epa.gov/ozone/science/ods/index.html) of class I and class II substances with their ODPs, GWPs, and CAS numbers are available.) or potent greenhouse gases. Different practices apply to different equipment, depending on their size and manufacture.

Evacuation Requirements

Appliances with More than Five Pounds of Refrigerant

Technicians must evacuate air-conditioning and refrigeration equipment to established vacuum levels when opening the equipment for maintenance, service, repair, or disposal. The required level of evacuation can be found in the following table.

Except for equipment manufactured before November 15, 1993, the recovery or recycling equipment must have been certified by an EPA-approved equipment testing organization. To ensure that they are recovering the correct level of refrigerant, technicians must use the recovery equipment according to the directions of its manufacturer.

Appliances with Five or Fewer Pounds of Refrigerant (Small Appliances)

Technicians repairing small appliances, such as household refrigerators, window air conditioners, and water coolers, must recover:

• 80 percent of the refrigerant when
  • The technician uses recovery or recycling equipment manufactured before November 15, 1993, or
  • The compressor in the appliance is not functional.
• 90 percent of the refrigerant when
  • The technician uses recovery or recycling equipment manufactured after November 15, 1993, and
  • The compressor in the appliance is functional.

To ensure that they are recovering the correct level of refrigerant, technicians must use the recovery equipment according to the directions of its manufacturer.

Technicians may also satisfy recovery requirements by evacuating the small appliance to four inches of mercury vacuum.

Exceptions to the Evacuation Requirements

EPA allows limited exceptions to the evacuation requirements for 1) repairs to leaking refrigeration and air-conditioning equipment, and 2) repairs that are not major and that are not followed by an evacuation of the equipment to the environment.

Repairs to Leaking Equipment

If technicians cannot evacuate to the specified levels because of refrigerant leaks, or because it would substantially contaminate the refrigerant being recovered, they must:

• Isolate leaking components from non-leaking components wherever possible;
• Evacuate non-leaking components to the specified levels; and
• Evacuate leaking components to the lowest level that can be attained without substantially contaminating the refrigerant. This level cannot exceed 0 pounds per square inch (psig).

Repairs that are Not Major and Are Not Followed by Evacuation

If a technician is not evacuating the equipment to the environment after a repair is completed, and if the repair is not major, then the following requirements must be met:

• For high- or very high-pressure appliances, the equipment must be evacuated to 0 psig before it is opened.
• For low-pressure appliances, the equipment must be pressurized to 0 psig before it is opened. Methods that require subsequent purging (e.g., nitrogen) cannot be used except with appliances containing R-113.

Reclamation Requirement

Recovered refrigerant can be returned to the same system or other systems owned by the same person without restriction. However, if recovered refrigerant changes ownership, it must be reclaimedFor purposes of defining a material as a solid waste under RCRA Subtitle C, a material is reclaimed if it is processed to recover a usable product or regenerated by processing it in a way that restores it to usable condition. by an EPA-certified refrigerant reclaimer.

Changing Refrigerant Oil

The requirements described above cover refrigerant contained in oil. The oil in a refrigeration appliance can contain large amounts of dissolved refrigerant. EPA requires a reduction in the pressure prior to an oil change to ensure that the bulk of the refrigerant contained in the oil is recovered. It is a violation to change oil at higher than 5 psig.

There are two acceptable procedures for recovering refrigerant contained in oil:

• Evacuate (or pressurize) the refrigeration appliance, or isolated portion, to a pressure no greater than 5 psig and then remove the oil; or
• Drain the oil into a system receiver to be evacuated (or pressurized) to a pressure no greater than 5 psig.

Information concerning the proper disposal of oil can be found on the Resource Conservation and Recovery Act website.