Compressor Failures, What and Why w/ Ty

Key takeaways

Proper maintenance and system cleanliness are crucial for compressor longevity.
Making internal compressor failures visible helps prevent misdiagnosis and repeated failures.
Copper plating inside compressors is a common indicator of moisture and acid contamination, underscoring the need for proper system evacuation.
Avoid contamination by thoroughly cleaning and deburring lines, and ensure systems are properly vacuumed and dried.
Non-condensable gases like oxygen and nitrogen can cause false readings and risk of fire, so managing gases in the system is vital.
Flooded starts are a significant but often overlooked hazard; using crankcase heaters, pump-down solenoids, and correct refrigerant charges can mitigate this risk.
Electrical issues often stem from bad wiring or connections; regular inspection and testing voltage at startup can identify problems early.
Staying diligent with service practices, including correct handling of nitrogen and proper system evacuation, will greatly reduce compressor failures.
Field diagnosis by cutting open compressors can be an effective way to understand failure causes on-site and improve troubleshooting skills.

Summary

The Importance of Making the Invisible Visible in Compressor Failure Analysis

The podcast emphasizes the significance of physically inspecting failed compressors by cutting them open. Ty Branaman shares insights from years of dismantling compressors to identify causes of failure, which helps technicians understand what really happens inside. Key points include the fact that a compressor should last virtually forever if maintained correctly, but external factors like installation or service mistakes—especially contamination—are common failure causes. Making the internal workings visible dispels myths and helps prevent future damages.

Common Causes of Compressor Failures and Internal Damage

The discussion covers the predominant failures found inside compressors, chiefly copper plating caused by moisture reacting with POE oil to form acid. These acids etch copper, which then plates onto moving parts, increasing thickness and resistance, leading to hard starts or seized compressors. Ty stresses that many failures are related to external contamination or improper handling during service, not just wear and tear. Other causes for failures include solid debris from unswept lines or improper deburring, moisture, and non-condensable gases like oxygen and nitrogen, which can cause false pressure readings and pose fire risks in certain refrigerants.

Contamination and its Prevention

Ty and Bryan discuss types of contamination—solid particles, moisture, and non-condensables—and how to prevent them. Proper line cleaning, deburring techniques, vacuuming, and heat-assisted dehydration are essential. Wet nitrogen and poor recovery tank maintenance are highlighted as issues leading to internal moisture. Ty shares stories on the dangers of poorly prepared nitrogen tanks, including wet nitrogen and nitrogen pressurized incorrectly, which can cause compressor shell ruptures. The importance of using clean, dry nitrogen, quick pressure testing, and avoiding contamination when opening systems is stressed.

Gases in the System: Oxygen, Nitrogen, and Flammability Risks

The role of non-condensable gases such as oxygen and nitrogen in causing system issues is analyzed. Oxygen, being reactive, can cause corrosion and pose fire hazards with flammable refrigerants like A2Ls. Ty shares experiences with nitrogen, including its presence as a contaminant from improper handling or critical timing during service. The story of a compressor rupturing after being left pressurized with nitrogen illustrates the risks. The use of inert gases like argon for specific applications is briefly discussed, focusing on their properties and cost.

Flooded Starts and Prevention Strategies

Flooded starts occur when excess refrigerant migrates into the compressor, often causing violent vaporization at startup and damaging scroll plates. Ty underscores the importance of crankcase heaters, pump-down solenoids, and appropriate refrigerant charge reduction to prevent this. Practical tips include field-diagnosing compressor failure by cutting open the top of the compressor quickly, allowing on-the-spot analysis of issues like overheating, copper plating, or oil washout, instead of relying solely on back-shop teardown.

Electrical and Mechanical Failures in Compressors

Electrical causes of failure, especially bad connections or phase loss, are examined. Ty emphasizes testing voltage at startup to detect issues like low voltage drops, which can cause long-term damage. The importance of quality components, proper wiring, and replacing aging parts like contactors and capacitors during compressor replacement is advised. The significance of phase monitoring for three-phase systems and preventing electrical surges from lightning or overvoltage is discussed, along with strategies such as surge protection and voltage regulation.

Show notes

In this episode, Bryan sits down with compressor teardown specialist Ty Branaman for a deep dive into what really kills refrigeration and AC compressors. After some lighthearted banter, the conversation quickly turns technical: Ty has spent years cutting apart failed compressors on video, and he explains why that practice matters so much. As he puts it, he is "all about making the invisible visible" — once a technician actually sees what happened inside a dead compressor, vague explanations like "it just got old" stop holding up.

Bryan and Ty establish that a properly maintained compressor should essentially last forever, since it is a sealed system with no external contaminants — unlike an engine. The catch is that installation and service mistakes introduce the very contaminants that shorten its life. Copper plating tops Ty's list of the most common findings: moisture combines with POE oil to form acid, which etches copper that then plates onto moving parts, thickening them and eventually causing hard starts that get mistaken for a "tired" compressor. They also trace how a shorted or seized compressor is usually the end result of an earlier root cause, not the cause itself.

The two work through the major categories of contamination one by one: solid debris from unswept lines and copper shavings left behind during deburring; moisture, which requires a proper pressure test, deep vacuum, and decay test to remove, plus heat to actually drive water molecules out; and non-condensable gases like oxygen and nitrogen, which throw off pressure readings and, with flammable A2L refrigerants, introduce real fire risk. Ty shares a memorable story about a compressor shell that ripped open after being left pressurized with nitrogen, and both discuss the surprisingly common problem of "wet" nitrogen and poorly maintained recovery tanks.

The conversation closes on flooded starts — a hazard Ty considers hugely overlooked — where migrated liquid refrigerant mixes with crankcase oil and violently flashes to vapor on startup, often shattering scroll plates. They cover practical prevention methods, including crankcase heaters, pump-down solenoids placed ahead of the metering device, and reduced refrigerant charges, before wrapping up with Ty's quick field technique for cutting the top off a failed compressor to get an on-the-spot diagnosis rather than waiting on a full teardown back at the shop.

Topics Covered

Why compressors fail from external contamination rather than simply "wearing out"
Copper plating as the most frequently found problem inside failed compressors
Solid contaminants: dirt, copper shavings, and proper deburring technique
Moisture control: pressure testing, deep vacuum, decay testing, and heat-assisted evacuation
Wet nitrogen and poorly maintained recovery tanks
Oxygen and nitrogen contamination, including flammability risks with A2L refrigerants
Flooded starts, crankcase heaters, and pump-down solenoids
Superheat measured at the compressor versus at the evaporator outlet
Ty's quick-cut technique for on-the-spot compressor diagnosis in the field

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