Which piece of equipment requires a technician to hold Type III certification before it may be serviced?
- A centrifugal chiller charged with R-123
- BA packaged rooftop unit charged with R-410A
R-410A operates at high pressure, well above atmospheric on both sides of the system. Rooftop packaged units are high-pressure appliances and are covered by Type II certification, not Type III.
- CA factory-sealed window air conditioner holding three pounds of refrigerant
A factory-sealed window unit holding a small charge is a small appliance. Small appliances holding five pounds or less and charged at the factory are Type I work, regardless of which refrigerant they contain.
- DAn ultra-low-temperature laboratory freezer charged with R-13
R-13 is a very high-pressure refrigerant used in cascade and ultra-low-temperature systems. Very high-pressure appliances are grouped with high-pressure work under Type II certification, so this is not a Type III machine.
Why A is correct
R-123 is a low-pressure refrigerant used almost exclusively in centrifugal chillers, and any appliance charged with it is a low-pressure appliance. Servicing, recovering from, or disposing of that machine is Type III work. A technician needs either Type III or Universal certification to open the machine or connect recovery equipment to it.
What this question is testing
This item checks whether the candidate can sort real equipment into the four certification buckets by refrigerant and pressure class instead of by size or by how the machine looks. It rewards knowing that low pressure means the refrigerant, not the horsepower.
On the job
Chiller plants in hospitals, universities, and older office towers still run R-123 centrifugals, and those machines are usually maintained by a specialty contractor. If a shop sends a Type II tech to break into one, the shop is out of compliance and the tech is working on equipment they were never trained to handle. Most chiller mechanics carry Universal certification for exactly this reason, because a single plant may hold a low-pressure centrifugal, high-pressure screw chillers, and small package units side by side.
Memory technique
Three ones, three number classics: R-11, R-113, R-123 all start with 11 or 12 and all mean Type III.
Exam tip
Match the refrigerant first: R-11, R-113, and R-123 point to Type III every time. Big physical size alone does not make a machine low pressure.
Where to look it up
Certification categories are set out in 40 CFR 82.161; Type III is the low-pressure appliance category.