Type I — Small AppliancesQuestion 112 of 240

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:

a.Do nothing special because R-410A is nontoxic
b.Evacuate the system to 25 mm Hg absolute
c.Add refrigerant to raise the pressure first
d.Recover the refrigerant to the small-appliance level (80%/90% or 4 inches Hg vacuum)

Explanation

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.

Law Reference: 40 CFR §82.156

Practice all 240 questions free — no signup required.

Related questions on this topic

Last reviewed: · editorial process

PrepPass Editorial Team · Verified against EPA Section 608 Technician Certification Exam · How we review
Report