Compressors

Scroll vs. reciprocating, single-phase wiring, grounded/open/shorted failures, protection and burnout cleanup.

5 guides

• Compressor Burnout: Acid Test and System Cleanup
  How to tell a clean mechanical compressor failure from an acid-producing motor burnout, and the cleanup procedure — acid testing, suction-line driers, and protecting the new compressor from contamination.
• Compressor Terminals C, S, R and How to Ohm Them Out
  How to identify the Common, Start, and Run terminals on a single-phase compressor and ohm the windings to confirm they're healthy, including the resistance relationship that tells you which terminal is which.
• Diagnosing a Grounded, Open, or Shorted Compressor
  How to confirm the three electrical death modes of a compressor — grounded, open, and shorted — with an ohmmeter and a megohmmeter, and how to be sure before you condemn an expensive part.
• Locked Rotor and Compressor Overload Protection
  What locked rotor means, how to read locked-rotor amps versus running amps, how the internal overload protects the compressor, and how to tell a seized compressor from one that just can't start.
• Scroll vs Reciprocating Compressors in the Field
  How scroll and reciprocating compressors differ in how they pump, what that means for sound, efficiency, and liquid tolerance, and the field gotchas unique to each — including scroll rotation direction and recip valve failures.

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