Compressor Facts and Troubleshooting (Don Gillis / Trevor Matthews)
802,359
Published 2020-02-01
When troubleshooting compressors, Emerson's mobile apps are some of the best tools you can have in your arsenal. Those apps include the AE Bulletins, Copeland Mobile, HVACR Fault Finder, and White-Rodgers Mobile. These apps contain information about compressors and controls, and they even have troubleshooting maps and tools to assist you with diagnosis in the field.
The Copeland Mobile Lab is a database for all Copeland compressors, and its mobile app can direct you to a wide range of facts, including weight, dimensions, oil, winding resistance, etc., based on the compressor model number and serial number. The app also comes with a calculator that allows you to enter the operating conditions and see how the capacitor, current, and discharge temperature change based on the evaporator and condenser temperatures. You can also view the part numbers for accessories.
The AE Bulletins app contains all of the Application Engineering bulletins and notifies users of updates to the bulletins over time. You can also search for bulletins with keywords and access bulletins based on the equipment type (divided into specific sections for compressors, condensers, accessories, etc.). The app also contains an FAQ page and information about retrofit procedures and appropriate refrigerants and oils for each compressor.
Semi-hermetic Copeland compressors come in two main varieties: Copelametic and Discus. Copelametic (Reed) compressors may be replaced with Discus compressors, but the opposite isn't true. Both types have accessible construction, four-pole motors, cast-iron bodies, and positive displacement oil pumps. However, the oil cup and flinger may vary by individual model. These compressors use reciprocating pistons to compress the vapor refrigerant. Valve plates differ between Copelametic and Discus compressors, with the latter being less prone to overheating. Discus compressors also have minimal reexpansion and come in digital varieties to reduce cycling, making them very efficient.
Many Copelametic (Reed) compressors are air-cooled; air passes over the compressor body to keep the compressor cool. On the other hand, water-cooled compressors use a water jacket to cool the compressor (but these can be replaced with air-cooled compressors). Refrigerant-cooled compressors rely on suction gas to prevent overheating. Compressors may come with a deep sump or a flat bottom. Discus compressors may also come in short-head or tall-head models and can be adapted for the other head size.
Copeland also manufactures scroll compressors for medium and low-temp applications. These Scroll compressors have two main parts: a fixed scroll and an orbital scroll. The orbital scroll oscillates and compresses the gas, and the compliant scroll design allows the scroll to be a bit more tolerant of liquid. These compressors also have a floating seal and motor protection. Copeland has developed a two-stage scroll and a digital scroll, which allow for modulation to match loads more accurately.
You can add VFDs to any fixed scroll or Discus compressor to achieve the capacity of variable-speed systems. Copeland also carries variable-speed scroll compressors.
Compressors generally fail more often due to mechanical reasons than electrical, though many people assume the opposite. Overheating, floodback, contamination, slugging, and flooded starts are the main mechanical causes of failure. These may result in damage to the bearings or pistons, which ultimately leads to mechanical failure. Finding the superheat and following the manufacturer's guidelines can help you prevent floodback, which washes out the oil. Check for oil foaming and other signs of wear, too. You can prevent flooded starts with crankcase heaters. Oil slugging can also happen due to severe migration, floodback, or uncontrolled oil return, and it may lead to broken wrist pins, pistons, and rods. Overheating may happen due to excessive refrigerant temperatures or oil loss, and you can prevent it by maintaining the charge and compression ratio (or using additional cooling when required). To prevent contamination, pull deep vacuums and clean the system out ENTIRELY after a burnout.
Trevor and Don also cover:
Emerson brands, divisions, and technologies
Wholesaler relationships
Oil lubrication
Valve plate configuration
Reed-to-Discus compressor replacements
Miscellaneous compressor valves
Axial vs. radial compliance
Appropriate digital compressor applications
Replacement practices
Setting low-pressure controls
Accumulators
Blow by test
CoreSense and Centronics
Demand cooling
Oil sight glasses and safeties
Copper plating
Troubleshooting questions
Read all the tech tips, take the quizzes, and find our handy calculators at www.hvacrschool.com/
All Comments (21)
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THANKS FOR SHARING BRYAN REALLY GREAT STUFF ππ
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Went to bed watching mechanic videos, woke up 2 hours into this, I love the yt algorithm ππ€£
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I am a test and service technician for a chiller manufacturer Fluid Chillers Inc. The information in this presentation was superb and extremely vital for a very complicated process. This week I will be replacing a 35-ton scroll that was a burnout with a locked rotor. This will be the 3rd compressor on this unit. It is a 410A outdoor air cooled Chiller with fan cycling switches on the condenser fan, So in low ambient conditions my pressures are all over the place. Our new Chillers have variable speed condenser fans. And I'm pushing hardcore for electronic expansion valves and vfds on the compressors.
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went to bed watching ammunition reloadings, woke up 6 hours into this :D
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I'm in a totally different industry. I found this channel accidently. I wanted to say that I appreciate that there is a curriculum for HVAC technicians which uses searchable databases so that you can help your clients more efficiently.
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Man... I just woke up from a deep sleep and I'm here somehow. Running at 3 hours and I just love his energy.
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I let Trevor Matthews know that the class evolved well and I was interested. Thanks guys!
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Super appreciate to have this to reference. It'll be reviewed for long while. Great presentation.
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New drinking game, take a shot every time he says "Uhhh".
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Thanks. Really appreciate these in-depth videos.
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Thanks I have learned a lot these videos were helpful look forward to watching more
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Thank you so much Trevor π
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SeΓ±or Orr, my fine fellow Scotsman, 'pure class' you from bringing Trevor Matthews content to us! Just soaking it all in.
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If you have two or three years on the field and youβre starting to replace compressors. Will you have 20+ years and you have been replacing compressors. Highly recommend you taking Trevor Matthews compressor course. It will get you doing things you forgot you were supposed to do in the first place . Bring you up to the next level . Get you on track if you never knew how to do it right in the first place And for those who are you who are really good and kind of drifted off track and got a little lazy and overconfident . Put you back on track . . π
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Thank you for this excellent opportunity to learn more . Excellent class π π π π π
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Great information thank you
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Thank you very much . I will sign up
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Great information
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Sat in on this class great info !
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Brian, Your a God send thank you for all you do for us and this trade brother
