A household refrigerator's sealed circuit has been opened to change out a failed compressor, and the technician is laying out parts for the rebuild. What should happen to the filter drier that is already in the system?
Correct Answer
B) It is cut out and a new drier of the correct size is brazed in before the system is closed
A filter drier is a one use part. Its desiccant is loaded with whatever moisture and acid the system has produced since it was installed, and the moment the circuit is opened to room air the desiccant begins taking on water from the shop atmosphere. Reinstalling it puts that moisture straight back into a system that is about to be sealed for years. Every time a sealed small appliance circuit is opened, the drier comes out and a new one of the correct size and connection type goes in before the system is evacuated and recharged.
Why This Is the Correct Answer
Desiccant in a filter drier is saturable and cannot be regenerated in the field. Once the sealed circuit is opened, the old drier has both a service history and a lungful of shop air in it. Fitting a new drier sized for the system is a standard part of closing a small appliance back up, and it is done before evacuation so the new desiccant is dried down with the rest of the system.
Why the Other Options Are Wrong
Option A: It is heated and back flushed, then brazed into the same position it came out of
Field heating drives off some moisture but does not restore desiccant, and it cannot remove the acid and debris a failed compressor sent downstream.
Option C: It is left alone, because a drier only matters on systems that use an expansion valve
Capillary tube systems need a drier more than most, because the tube is a tiny orifice that a trace of moisture can freeze shut and that a fleck of debris can plug.
Option D: It is moved to the suction line, where it can catch debris the compressor sends out
A suction line drier is a separate part used after a burnout. Relocating a liquid line drier to the suction side leaves the capillary tube unprotected and does not filter where the debris will do harm.
Memory Technique
Open the system, open a new drier. They come in pairs.
Reference Hint
New filter drier every time the sealed system is opened, installed before evacuation.
More epa-608-type-1 Questions
An under-counter ice maker is one factory-sealed cabinet, while a modular ice machine head is joined to a remote condenser by field-run tubing. What certification does servicing the modular machine's circuit require?
A technician recovers refrigerant from a small appliance using a recovery machine that was manufactured in 1991. What recovery level must that older equipment achieve?
Two technicians recover from identical refrigerators with working compressors, one using a 1991 recovery machine and the other a 2015 machine. Why do their required recovery levels differ?
System-dependent recovery equipment may be used only on appliances that normally hold up to what amount of refrigerant?
What feature defines a self-contained recovery unit and sets it apart from the system-dependent kind?
When system-dependent recovery equipment is used on a small appliance whose compressor still runs, how can that working compressor be put to use?
Recovery from a small appliance has slowed down and the pressure is barely moving. What accepted technique helps drive the remaining refrigerant out?
After the recovery unit stops pulling on a small appliance, how does a technician confirm that the recovery is actually complete?
A sealed small appliance offers no service port at all. What has to happen before recovery equipment can be connected to it?
As refrigerant from a string of small appliances collects in a recovery cylinder, what fill limit applies to that cylinder?
People Also Study
Business & Financial Management
120 questions · 70% to pass
Contract Administration
60 questions · 70% to pass
Project Management
60 questions · 70% to pass
Related Study Resources
Previous Question
A hotel's through-the-wall PTAC unit left the factory fully assembled, hermetically sealed, and charged with 3 pounds of R-410A. Which certification covers opening its refrigerant circuit?
Next Question
What requirement applies to recovery equipment manufactured on or after November 15, 1993 that will be used on small appliances?