Question

A major system repair is being performed on a R-22 appliance. What CANNOT be done to recharge the appliance?

1) Add R-22 after the repair is complete.
2) Retrofit the unit to R-407C.
3) Use recovered or recycled R-22 from the same owner.
4) Top off the unit with R-410a.

Answer 1

Option 4, topping off the R-22 appliance with R-410A, cannot be done due to differing refrigerant properties. Retrofitting to R-407C or using recovered R-22 are allowable practices, provided proper protocols are followed.

Step-by-step explanation:

The question revolves around appropriate practices for recharging a refrigeration appliance that uses R-22, a hydrochlorofluorocarbon (HCFC) refrigerant. According to current environmental regulations, and specifically considering the phase-out schedule of HCFCs, what CANNOT be done to recharge the appliance is option 4: Top off the unit with R-410A. R-22 and R-410A are not interchangeable due to different pressures, and therefore systems using R-22 can't be topped off with R-410A without a complete retrofit, which includes changing the lubricating oil and possibly other components as well.

Here are the correct actions that can be taken:

1. Add R-22 after the repair is complete, as long as it is either new, or recovered and recycled R-22.
2. Retrofit the unit to R-407C if a suitable retrofit protocol is followed, including change of oil and other components as needed.
3. Use recovered or recycled R-22 from the same owner, assuming proper recovery procedures were followed and the refrigerant is clean.

It is important to be trained and certified in proper refrigeration repair and maintenance practices to avoid causing damage to the appliance or the environment.