BACK

#electrical

Tech Tips:

There are many great diagnostic tools available to the service technician today, but I haven't found a tool as versatile as the simple isolation diagnosis. There are many ways this concept can be applied, but let's start with some examples so that you get what I mean. Low Voltage Short Circuit Isolation Diagnosis You arrive […]

Michael Faraday: Patron Saint of HVAC Technicians

Who was Michael Faraday—besides the guy we named the capacitor after? Well, actually, we named the measure of capacitance after him (the farad), but let’s not get all caught up in semantics. Faraday was a scientist who lived from 1791 to 1867. He was an experimental scientist who had little to no formal education but […]

Blower Fan Watt Draw Considerations for ECMs

I'd like to give special thanks to Steve Rogers from TEC for helping write this tech tip about ECM blower fan watt draw and sharing some helpful visuals. Thanks, Steve! ACCA Standard 310 introduced a grading protocol for HVAC systems. While HVAC practitioners won’t be the ones carrying out the tasks laid out in Standard […]

Tool Selection: Electrical Meters

I'd like to give a special thanks to Tony Gonzalez from Fieldpiece for providing technical guidance about the SC680's power measurement capabilities, as well as VAC and AAC measurements on ECMs. You can learn more about the SC680 and other electrical meters on Fieldpiece's website. We’ve talked through specifications, applications, and features for a few […]

Understanding 240-Volt Circuits

It can be useful to think of a multimeter as a “voltage drop” tool. Bryan covers the concept here in an excellent class that I highly recommend. This concept was a big help to me as I began to truly learn how to use a multimeter. A meter reads the voltage differential between two points. […]

The Unexpected Result of Series Circuits

When I teach electrical basics, we do this exercise where we sit down and connect a 10-watt bulb to a power supply and through a switch. It's a SUPER SIMPLE circuit—the kind you might have learned about in a high school science class. But then I grab another 10-watt bulb and tell them to connect […]

Understanding Relays With the 90-340

Relays can be used for many different control applications, including controlling fans, blowers, other relays, or contactors, valves, dampers, pumps, and much more. A 90-340 is a very common, versatile relay that many techs have on their truck. So, we will use it as an example. A relay is just a remotely controlled switch that […]

What is a GFI?

First off, the correct acronym for a GFI (ground fault interrupter) is “GFCI” (ground fault circuit interrupter). The purpose is to act as a safety device to protect from electrical shock. GFCIs are important components of electrical safety. GFCIs can be built into outlets, circuit breakers, and even extension cords. We generally use them for […]

What are Dry and Wet Contacts?

I was talking about dry contacts with one of my techs, and he looked at me like I had three heads—and one of them was on fire. So, I figured it would be good to cover the difference between wet and dry contacts in a tech tip. Basically, “dry” contacts are switches with no shared […]

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