A technician is removing a compressor that suffered a motor burnout, and the oil coming out of it is dark and smells sour. What precautions belong on that job?
- Gloves and eye protection together with good ventilation, because the oil and residue carry acid and irritating breakdown products
- BA grounding strap, because a burned motor leaves a static charge in the oil that can discharge when the shell is opened
Oil does not hold a static charge from a burned motor, and grounding addresses an electrical hazard that is gone once the unit is disconnected. It does nothing about the corrosive residue actually in the oil.
- CNothing beyond the usual gloves and glasses, because the acid in the oil neutralizes as soon as the system is opened to the atmosphere
Acid in burnout oil does not neutralize on contact with air. That belief is what leads technicians to handle the oil bare-handed and to skip the filter driers the cleanup procedure depends on.
- DA respirator only, because the breakdown residue is hazardous to breathe but does no harm to the skin it touches
The residue is corrosive to skin as well as irritating to breathe. Protecting only the lungs leaves hands and eyes exposed to the material that is easiest to get on them while pulling the compressor.
Why A is correct
Burnout residue is acidic and irritating, and it is present in the oil, on internal surfaces and in the vapor coming out of the opened system. Skin contact, eye contact and inhalation are all real routes of exposure, so hand and eye protection plus ventilation cover the actual hazards of the job.
What this question is testing
The item checks whether the candidate knows what a burnout produces chemically and can select protection matched to a corrosive contact and inhalation hazard.
On the job
Cleanup goes well beyond personal protection: the contaminated refrigerant goes to its own cylinder and then to a reclaimer, the liquid line drier gets replaced, a suction line drier with access ports goes in so the pressure drop can be checked, the system gets evacuated with nitrogen sweeps, and the oil is disposed of properly rather than poured into a shop drum. An acid test kit tells the technician what they are dealing with before the new compressor goes in.
Memory technique
Black oil, sour smell, acid. Gloves and glasses before anything else comes apart.
Exam tip
Burnout equals acid. Any answer that treats the residue as inert or self-neutralizing is wrong.
Where to look it up
Motor burnout produces acidic decomposition products in the oil and refrigerant; skin, eye and respiratory protection plus ventilation are required.