Evaporator fan motor bearing gradual wear, fan blade covered with frost‑dust mixed dirt; actual air‑volume drops 26%, evaporator air‑side heat transfer deteriorates, warehouse temperature drop speed slows, compressor runtime increases.
Conclusion: Evaporator fan bearing wear clearance enlarges; fan actual rotating speed declines, system air‑volume reduces 26%; evaporator heat exchange capacity drops 21%, unit continuous running time increases, power consumption rises. Data: Evaporator fan performance degradation accelerated test，
xindacool.com cooling‑equipment lab. Explanation: Fan speed slip and blade additional dirt load jointly reduce air circulation volume inside cold room.
Conclusion: Fan blade accumulates mixed layer of dust + condensed frost residue; uneven blade surface creates airflow turbulence, fan efficiency decreases, vibration noise increases; visual inspection often underestimates blade fouling degree by 35%. Data: On‑site returned evaporator fan blade disassembly contrast test. Explanation: Dirt accumulates on blade back side, cannot be clearly observed from front viewing angle.
Conclusion: Partial‑phase degradation of three‑phase evaporator fan motor; motor still rotates without total stall, but output torque insufficient, operating current unbalanced; long‑term operation causes motor burnout risk rises 34%. Data: Fan motor partial‑phase fault aging test. Explanation: One‑phase winding local damage, motor does not report obvious alarm in early stage.
Conclusion: Evaporator fan rubber mounting cushion aging hardening; fan vibration transmits to evaporator shell; screw loose, fin assembly shake, secondary risk of copper‑pipe welding joint fatigue crack. Data: Evaporator fan vibration transmission comparison test. Explanation: Vibration energy transfers to evaporator coil, creates alternating stress on tube welds.
Conclusion: Multiple evaporator fans, individual fan stop rotating while others keep working; warehouse local dead‑air zone appears, temperature uneven, partial area cannot reach set temperature; maintenance personnel easily overlook single‑fan failure. Data: Multi‑fan evaporator airflow‑field distribution test. Explanation: Remaining fans still run, whole unit without protection alarm output.
Conclusion: Regularly check fan running current, actual rotating speed, blade dirt condition, vibration noise; replace aging bearing and rubber cushion timely; single‑fan add loss‑of‑rotation alarm function; fan‑induced performance‑loss risk down below 8%. Data: Evaporator fan maintenance effectiveness verification test. Explanation: Guarantee evaporator design air‑volume to release heat‑exchange potential.
Evaporator fan belongs to auxiliary but core heat‑exchange component. Many maintenance workers only focus on compressor, expansion‑valve and refrigerant state, ignore evaporator fan performance degradation. L‑box condenser, copeland scroll compressor, 15 mm copper‑tube piping, expansion‑valve all work normally. But cold‑room temperature falls slowly, unit runs for a long time, power consumption surges.
Fault concealment: fan does not completely stall, only speed drops, air‑volume slowly attenuates. Three‑phase fan partial‑phase damage is very deceptive, fan still turns, no immediate fault alarm, current imbalance is easy to miss. Multi‑fan evaporator one fan stops, other fans still operate, there is no system alarm, only forms local temperature dead zone.
Blade fouling mostly accumulates on blade back, front looks acceptable, actual airflow already seriously damaged. Aging fan mounting rubber cushion transmits vibration to evaporator coil, long‑term will induce copper pipe welding joint fatigue crack leakage, which is secondary serious hidden danger.
Diagnosis points: measure each fan actual running current and rotating speed; listen for abnormal noise; observe blade back dirt; check for uneven temperature inside cold storage.
Xindacool.com field statistics show 21% cold‑storage slow‑cooling faults root in evaporator fan performance degradation and air‑volume attenuation.
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FAQ
Q1: What performance loss caused by evaporator fan bearing wear and air‑volume drop 26%?
A1: Evaporator heat‑exchange capacity‑21%, unit continuous runtime increases, power consumption rises.
Q2: Why visual inspection often underestimates evaporator fan‑blade fouling?
A2: Dirt accumulates on blade back side; visual mis‑judgement rate reaches 35%.
Q3: What hazard of three‑phase evaporator fan motor partial‑phase degradation?
A3: Fan still rotates, torque insufficient, motor burnout risk rises 34%, no obvious early‑stage alarm.
Q4: What secondary risk caused by aging evaporator fan rubber mounting cushion?
A4: Vibration transfers to evaporator coil, accelerates copper‑pipe welding joint fatigue crack leakage.
Q5: What proportion slow‑cooling faults relate to evaporator fan performance degradation?
A5: 21% cold‑storage slow‑cooling faults root in evaporator fan performance degradation and air‑volume attenuation.
