Short #25 - A Costly Screwup

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Short #25 – A Costly Screwup

October 9, 2018

In this short episode we share some quick tips about keeping panels and insulation in place

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How to Evacuate an AC system, Full Vacuum Procedure

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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 informative HVAC podcast episode, Bryan and Bert dive deep into the complex world of locked and internal overload compressors, focusing specifically on single-phase residential units. The discussion begins with Bert explaining one of the most common challenges technicians face: diagnosing a locked compressor. He describes how compressors that are locked will typically run for only a second before overheating and stopping, creating a cycle that can be difficult to detect if technicians aren’t carefully monitoring at the right moment.

The hosts share personal experiences and practical diagnostic techniques, with Bert recounting how he once simulated a locked compressor by cutting the start winding wire and concealing it beneath other wires and zip ties. This demonstration highlights the importance of thorough inspection, including checking terminal connections. Bryan shares a story from his early career when he mistakenly condemned a compressor with damaged terminals, not knowing about terminal repair kits – a candid moment that illustrates how even experienced technicians continue to learn throughout their careers.

A significant portion of the podcast is dedicated to explaining the electrical fundamentals of compressor operation, including an enlightening discussion about start windings, run windings, and common connections. Bryan passionately clarifies misconceptions about current flow through these different windings, explaining that the start winding actually has consistently lower amperage due to its connection through a capacitor. The hosts also detail the critical differences between a compressor that’s overheating versus one that’s truly locked, emphasizing that the physical temperature of the compressor often provides the key diagnostic clue.

Key Topics Covered:

· How to identify a locked compressor versus one that’s out on internal overload

· The importance of checking terminal connections and wire continuity

· Why compressors that are truly locked don’t have time to physically overheat

· Common causes of compressor overheating: condenser fan failure, refrigerant issues, airflow problems

· The proper diagnostic method for catching a locked compressor “in the act”

· The mechanics of start windings versus run windings and their amperage differences

· When and how to use hard start kits appropriately (and why they shouldn’t be used universally)

· How to communicate with customers when diagnosing compressor issues

· The role of crankcase heaters in preventing flooded starts

· Terminal repair techniques and when they’re appropriate

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