Introduction
Overheat‑triggered shutdown is one of the most frequent protective failures of screw‑type air compressors. The machine halts automatically for protection once the temperature protection is activated. Primary triggers cover cooling‑system breakdown, abnormal lubricant, excessive load from the air‑intake assembly and electrical‑environment defects. Inspections shall proceed from simple exterior checks to internal components. All causes, symptoms and solutions are explained below.
Detailed Analysis
1. Malfunction of the heat‑dissipation system (top‑rank cause)
Clogged heat radiator
Dust, lint and grease stick to the cooling fins of air‑cooled compressors. Water‑cooled radiators suffer limescale buildup. Blockage weakens heat exchange.
Check‑up: Inspect radiator fins. Blow debris off with compressed air or dedicated detergent. For water‑cooled units, test water flow and remove limescale.
Defective cooling fan
Burnt‑out fan motor, faulty temperature sensor, broken fan blades result in zero‑rotation or low fan speed.
Check‑up: Observe fan behaviour when temperature rises. Test power supply and temperature probes.
Blocked air duct
Missing cabinet panels, cramped compressor room, surrounding obstructions or hot‑air circulation cause accumulated waste heat.
Check‑up: Clear obstacles and guarantee smooth ventilation to avoid recycled hot wind.
2. Troubles related to compressor lubricating oil
Insufficient oil level
Oil leakage and long‑term consumption reduce lubricant below the marked scale, limiting lubrication and heat transfer.
Check‑up: Check the oil sight glass after machine standby. Top‑up matched‑specification compressor oil when necessary.
Deteriorated, emulsified oil or blocked oil separator
Aged or water‑contaminated emulsified oil changes viscosity. A clogged oil separator raises back‑pressure of the air‑end, increases operating resistance and generates surplus heat.
Check‑up: Inspect oil colour and milky emulsion. Replace the oil separator, lubricant and oil filter on schedule.
Blocked oil pipeline
Sludge hinders oil circulation so heat cannot be delivered to the radiator.
Check‑up and clean oil pipelines and oil filters.
3. Air‑intake trouble and excessive air‑end load
Stuck inlet valve
A jammed inlet valve keeps the compressor under continuous full‑load loading status and generates excessive heat.
Check‑up: Service the inlet valve and loading solenoid valve and clear oil sludge.
High‑temperature intake air
The air inlet draws in hot ambient air and lifts the initial compression temperature.
Check‑up: Relocate the air inlet to access cool outdoor air.
Worn‑out air‑end
Worn bearings and rotors increase mechanical friction and heat generation.
Check‑up: Listen for abnormal vibration and noise, and overhaul the air‑end if needed.
4. Defects on electric and pressure‑control components
Low supply voltage
Undervoltage makes the motor labour hard and produce extra heat.
Check‑up: Measure operating voltage and repair loose terminals and ageing wiring.
Damaged temperature sensor
Faulty probes deliver wrong temperature readings and trigger false high‑temperature protection.
Check‑up: Calibrate or replace the temperature sensor.
Excessively high working‑pressure setting
Over‑high preset air pressure keeps the air‑end working under heavy‑duty compression.
Check‑up: Reset the pressure to a reasonable working range.
Conclusion
In summary, follow this inspection sequence for overheat shutdown: examine ventilation condition, cooling fan and radiator, then lubricant status and oil separator, afterwards the inlet valve and pressure parameter, electrical supply and temperature sensor, and finally air‑end wear‑and‑tear.
Routine filter replacement, radiator cleaning and oil maintenance together with good ventilation will prevent most overheat‑protection halts.
Post time: Aug-14-2026
