A PTAC unit in a hotel room holds 4.5 pounds of R-410A and is factory-sealed. A technician must replace the compressor. Before opening the sealed system, the technician must:

Question

Accepted Answer

Recover to the small-appliance level — A factory-sealed PTAC with less than five pounds of refrigerant is a small appliance, so recovery must meet the 80%/90% or 4 inches Hg vacuum requirement before opening the system. The deeper 25 mm Hg absolute level applies to low-pressure (Type III) appliances. Recovery is mandatory before any repair that opens the sealed circuit.

Answer

Evacuate the system to 25 mm Hg absolute

Answer

Do nothing special because R-410A is nontoxic

Answer

Recover to the small-appliance level

Answer

Add refrigerant to raise the pressure first

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