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How to tell PSC, constant-torque ECM and variable-speed ECM blower motors apart
Three blower motors side by side: a PSC motor with a run capacitor and colored speed leads, a constant-torque ECM with a line-voltage plug and numbered 24-volt tap terminals, and a variable-speed ECM with a 5-pin power plug and a 16-pin control plug, with how each is told to run and what to test.
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