A legacy low-temperature rack still charged with R-502 normally holds four hundred pounds, and the recovery machine in use was built in 2008. Which evacuation level applies before the suction header is cut open?
Correct Answer
D) Fifteen inches of mercury vacuum
R-502 is one of the refrigerants the table groups as other high-pressure, separate from the R-22 line. For that group, an appliance normally holding two hundred pounds or more that is being worked with equipment built on or after November 15, 1993 must be evacuated to fifteen inches of mercury vacuum. That is the deepest requirement anywhere in the high-pressure part of the table, and it applies to this rack because both the refrigerant family and the charge size push it into that row.
Why This Is the Correct Answer
Fifteen inches of mercury vacuum is the requirement for an appliance in the other high-pressure group, normally holding two hundred pounds or more, worked with equipment built on or after November 15, 1993. R-502 sits in that group rather than on the R-22 line, and four hundred pounds is well past the two hundred pound split, so the rack takes the deepest high-pressure figure in the table.
Why the Other Options Are Wrong
Option A: Zero inches of mercury vacuum
Zero inches applies only to R-22 appliances below two hundred pounds and to very high-pressure appliances. Neither description fits a four hundred pound R-502 rack.
Option B: Four inches of mercury vacuum
Four inches would be right if the recovery machine predated November 15, 1993. A 2008 machine sits in the later column, which asks for considerably more.
Option C: Ten inches of mercury vacuum
Ten inches is the figure for smaller charges in this group and for large R-22 appliances. Treating R-502 as though it were R-22 costs five inches here.
Memory Technique
Deepest row, deepest number. Not R-22, big charge, new machine, fifteen.
Reference Hint
Other high-pressure appliance, two hundred pounds or more, equipment built on or after November 15, 1993: fifteen inches of mercury vacuum.
More epa-608-type-2 Questions
A walk-in cooler condensing unit holds a full charge of twenty-five pounds of R-404A, which is below the fifty pound threshold that brings an appliance under the leak repair provisions. What still applies to this unit?
An office building has thirty water source heat pumps on a common water loop, and each one left the factory assembled, hermetically sealed and charged with four pounds of R-410A. How is one of those units classified?
A data sheet for an unfamiliar refrigerant lists a boiling point of about fifty-five degrees Fahrenheit at atmospheric pressure. What does that tell a technician holding Core and Type II certification?
A technician holds Core, Type I and Type III certification and is sent to recover the charge from a twenty ton rooftop unit charged with R-410A. What does that combination of sections allow on this job?
A fleet garage technician holds only the vehicle air conditioning certification issued under Section 609 and is asked to recover the charge from the shop's own rooftop air conditioner. What does that credential allow?
A split system's outdoor unit, indoor coil and the line set the installer ran and brazed between them are being considered. For the purposes of the refrigerant rules, what makes up the appliance here?
On a new installation the line set is brazed to a factory charged outdoor unit and an indoor coil shipped under a nitrogen holding charge, with the outdoor unit's service valves still closed. What does the recovery requirement call for before that brazing?
A rooftop unit's data plate has weathered until the charge figure cannot be read, and the technician needs the full charge to place the appliance under the evacuation and leak provisions. Where should that figure come from?
A computer room air conditioning unit holds forty pounds of R-407C and connects to a remote air cooled condenser through refrigerant piping run and brazed by the installer. How is that unit classified?
A shop's office manager, who holds no technician certification, is sent to a supply house to pick up a new recovery machine for the commercial crew. What does the sales restriction require at that counter?
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 system is charged with a zeotropic blend whose components boil at different temperatures. Why is refrigerant taken out of the liquid line rather than drawn off as vapor whenever the job allows it?
Next Question
A brazed joint made without flowing nitrogen through the tubing develops a pinhole leak after a season of operation, and the system also shows a restricted metering device. What did the missing nitrogen contribute to?