EPA 608 Type 2 Chapter 12 (Take full course for free)
In this module, we will discuss some problems related to oil foaming in a system. We will also learn about EPA’s classification of major repairs. Skip to quiz!
1. Oil Foaming
Foam is the object formed by trapping pockets of gas in a liquid or solid. A bath sponge and
the head on a glass of beer are examples of foams. Similar to this, the refrigerant oil also foams.
Most refrigerant oil is in the compressor of an appliance, so oil foaming is also seen in the compressor. The reason is that the oil is in continuous motion and subject to high pressures in the compressor.
Foaming can have a lot of negative effects like:
The lubricating ability of the oil is lost.
The foam can ooze out of the joints due to high pressures.
Overheating is a problem as the foam is a pretty good insulator.
These are common problems in many systems.
2. Major Repairs
EPA defines major repairs as “Maintenance, service, or repair that involves removal of the appliances"
Condenser
Evaporator
Auxiliary heat exchanger coil or
Compressor”
Apart from these, any other repairs are considered as “minor repairs.”
An evaporator or condenser coils are removed/replaced if there is an irreparable flaw in it. Examples of an irreparable flaw would be if the coils have rusted or a hole in the coil piping is so big that it cannot be closed by repairing it.
Evaporator and condenser coils are types of heat exchangers. An auxiliary heat exchanger means a secondary or an extra heat exchanger in the system. It is generally seen in heat pumps and large systems cooling vast spaces.
Examples of major compressor repairs are
A compressor burnout, causing its replacement.
A non-working compressor due to mechanical problems.
A broken or leaking compressor.
We will talk about compressor burnout in more detail.
A compressor burnout is a major repair, and an oil sample is taken to detect it. A sample of the oil is taken to check its properties whenever there is a compressor burnout. A compressor burnout means that the compressor's motor windings have burnt due to a short circuit.
A short circuit in the electrical component produces very high voltage and temperatures. This burns the refrigerant oil during a burnout. Burnt refrigerant oil has acidic properties that harm the system.
While repairing any system, a technician should follow these steps,
Isolating the component.
Evacuate the isolated section.
Wait for a few minutes to see if the pressure rises in the system.
Recall that all this has been discussed in the evacuation topic.
Consider an example of changing the compressor of a system having 150 pounds of R-410A. The steps are:
Isolating the compressor.
Evacuate to 0 psi (500 microns).
Wait for a few minutes.
Recall the evacuation levels for a system with less than 200 pounds of R-410A, a high
pressure refrigerant.
3. Conclusion
In this module, we discussed some problems related to oil foaming in a system. We also understood EPAs classification of major repairs. These classification of major repairs is an important part of the EPA Type II Course.
Question #1: Oil foaming in a system can usually be detected in;
Condenser
Evaporator
Compressor
Expansion device
Scroll down for the answer...
Compressor
Most refrigerant oil is in the compressor of an appliance, so oil foaming is also seen in the compressor.
Question #2: A "major repair" under EPA's regulations would be;
Replacing a condenser coil.
Replacing a filter-drier.
Replacing a condenser fan motor.
Replacing a blower fan motor.
Scroll down for the answer...
Replacing a condenser coil.
EPA defines major repairs as “Maintenance, service, or repair that involves removal of the appliance
Condenser
Evaporator
Auxiliary heat exchanger coil or
Compressor”
By this definition, replacing a condenser coil is a “major repair.”
Question #3: We would take an ____ if a unit has a compressor burnout, and it is considered a ____.
refrigerant sample; major repair
air sample; minor repair
oil sample; major repair
oil sample; normal repair
Scroll down for the answer...
oil sample; major repair
A compressor burnout is a major repair, and an oil sample is taken to detect it. A sample of the oil is taken to check its properties.