🔍 Key Concepts

• Role of an unloader in reciprocating air compressors • What happens to starting load and motor current when a compressor starts against full pressure • Basic operation of a two-stage air compressor during startup

💭 Think About

• Think about what problem occurs if a compressor tries to start while the cylinders and discharge line are already at high pressure. What does that do to the motor? • Which option describes something that directly affects how hard the motor has to work at the moment of startup, rather than during normal running? • Look at each choice and ask: Is this a function that is normally done by a separate device (like a dryer, pressure regulator, starter), or is it something that an unloader specifically would handle?

✅ Before You Answer

• Verify which choice directly reduces mechanical load on the compressor at startup. • Confirm whether an unloader acts on air pressure/air admission to the cylinders, not on electrical voltage or motor speed. • Eliminate any answers that describe functions normally done by drains, electrical starters, or speed controllers, rather than by unloaders.