The required recovery level has been reached on a household refrigerator and the technician is ready to open the sealed circuit so the compressor can come out. What should the tubing be opened with?
Correct Answer
A) A tubing cutter, which leaves a clean square end and keeps heat out of the system
A wheel type tubing cutter separates copper without heat, without chips and without distorting the end, which is what the next braze joint needs. A saw fills the system with steel and copper filings that head straight for the capillary tube. Side cutters crush the tube, so it cannot be reused and the crushed end may still trap oil. Unbrazing with a torch is the worst of the three: even after a good recovery a trace of refrigerant and a lot of oil remain, and heating them produces irritating and toxic decomposition products in a confined kitchen.
Why This Is the Correct Answer
Cutting copper with a tubing cutter produces a clean, round, square end with no swarf falling into the system and no heat applied to the oil left inside. That end is ready to be deburred and brazed. Every other method of opening the line either introduces debris the capillary tube cannot tolerate, deforms the tube so it cannot be rejoined, or applies heat where oil residue and traces of refrigerant are still present.
Why the Other Options Are Wrong
Option B: A torch at the brazed joint, which frees the fitting without deforming the tubing
Heating a system that still holds oil and traces of refrigerant produces decomposition products, and unbrazing a joint leaves filler metal that has to be cleaned off before the new joint can be made.
Option C: A hacksaw at the closest straight run, which cuts faster than a wheel type cutter
A hacksaw drops metal filings into the open tube. In a capillary tube system those filings have nowhere to go except into the metering restriction.
Option D: A pair of side cutters, which crimps the line closed as it separates the two halves
Side cutters crush the tubing instead of cutting it. The crushed end cannot be brazed, and the tube usually has to be shortened again with a proper cutter.
Memory Technique
Cut it, do not cook it or saw it.
Reference Hint
Open a sealed small appliance circuit with a tubing cutter after recovery. No torches, no saws, no crushing.
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?
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