BACK

#electrical

Tech Tips:

How does a typical single phase motor know how fast to run? Typical induction motors are dependent of the electrical cycle rate of the entering power (measured in hertz) for their speed. Our power in the US makes one complete rotation from positive electrical peak to positive peak 60 times per second or 60hz (50hz […]

What Makes an Autotransformer Different?

The definition of a transformer is a device that changes the voltages in an alternating current circuit. You may have heard of an autotransformer or a buck-boost transformer, and these terms are usually used for the same type of device; they just highlight different aspects. A transformer does not need to be a buck-boost to […]

Crankcase Heaters and Single-Pole Contactors

We keep two-pole, 40-amp 24v coil contactors on all of our vans. They are versatile and reliable, and you can replace most residential A/C contactors with them. There are a few things to watch for, though, especially when you have a crankcase heater. Many brands power the crankcase heater constantly and shut it on and […]

An Electric Heat Mistake

I started working as a tech when I was 17 years old, fresh out of trade school. My first winter out on my own, I went to a service call in an older part of Orlando, a part of town I had never worked in before. It was an especially cold winter that year, and […]

Strip Control Wires Properly

Erich Vinson is a tech from Colorado and one of the most entertaining people I interact with online. He wrote this quick tech tip on stripping back the outer jacket properly on control wires, and it happens to also be something I preach. Thanks, Erich. In the first picture (above), you can see what happens […]

Grounding and Bonding Myths

Grounding is an area of many myths and legends in both the electrical and HVAC fields. This is a short article, and we will briefly cover only a few common myths. For a more detailed explanation, I advise subscribing to Mike Holt's YouTube Channel HERE. Myth – Current Goes to Ground Actually, current (electrons) will […]

Start Capacitor & Inrush, Facts & Myths – Part #4

Now is the part where we get specific about start capacitors and inrush. If you haven't read the first three parts, please do so before reading this one, or it may not make sense. (You can find Part #1, Part #2, and Part #3 at these links.) I'm going to come out and say it […]

Commercial Contactor Considerations

This tip was created by Jason Pinzak and originally posted on the HVAC Technician's Facebook group. It is reposted here with permission from Jason. Thanks! Contactors are useful in commercial and industrial applications, particularly for controlling large lighting loads and motors. One of their hallmarks is reliability. However, like any other device, they are not […]

Multimeter Categories

Testo 760 Category IV Multimeter I was standing at a booth at the HVAC Excellence Educators conference, and an instructor walks up, grabs a meter, and asks me, “What's the difference between a category 3 and a category 4 meter?” Well, I really wasn't sure, but I knew that the category 4 meter is rated […]

Newer Posts 1 2 3 4 5 Older Posts

Users with Tag #electrical

Check out our most recent video

How to Evacuate an AC system, Full Vacuum Procedure

Our latest Podcast

HVAC School – For Techs, By Techs

Real training for HVAC ( Heating, Ventilation, Air Conditioning and Refrigeration) Technicians. Including recorded tech training, interviews, diagnostics and general conversations about the trade.

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

Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.

Purchase your tickets or learn more about the 8th Annual HVACR Training Symposium at https://hvacrschool.com/symposium.

Subscribe to our podcast on your iPhone or Android.

Subscribe to our YouTube channel.

Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android.

Search Episodes

Compressor Failures, What and Why w/ Ty

07/09/2026

Bryan Orr

Multi Position Valves and More – Short #293

07/07/2026

Bryan Orr