🔍 Key Concepts

• How a low pressure cutout switch protects a refrigeration compressor • Typical symptoms of a system low on refrigerant vs overcharged • How suction pressure is affected by refrigerant charge and by slightly leaking suction valves

💭 Think About

• Ask yourself: what condition would cause the suction (low-side) pressure to repeatedly drop below the cutout setting, allowing the compressor to start, then quickly stop, then start again? • Which of these choices would tend to keep low-side pressure too high, and which would make it too low during operation? • How would leaking suction valves affect the pressure difference between the high and low sides and the compressor’s ability to maintain suction pressure?

✅ Before You Answer

• Identify which options would lower suction pressure enough to hit the low-pressure safety repeatedly. • Decide whether overcharging a system normally raises or lowers suction pressure when running properly. • Consider whether crankcase oil level directly controls the low-pressure switch, or if it mainly affects lubrication and mechanical wear.