冷风机八大常见故障排查与全生命周期保养清单

(English version)

A well-built unit cooler should last 8–12 years, yet the spread we see on site is enormous: some units run a decade on one set of bearings, others corrode into a refrigerant leak within three years. Maintenance makes almost all the difference.

Below is the four-step approach — symptom, cause, action, prevention — we use to train our own service crews.

Fault 1: Room will not reach temperature

Causes: dirty or heavily frosted fins; insufficient liquid feed (underfed TXV, blockage, dirty filter-drier); oil logging in the coil; low refrigerant charge or air/moisture ingress; actual load far above design (over-loading, doors left open).

Sequence: inspect frost → measure superheat to judge feed → check sight glass and filter-drier ΔT → check pressures → verify intake volumes. Do not top up refrigerant first; most "low charge" cases are actually heat-transfer or feed problems.

Fault 2: Uneven frosting

One side thick, one side thin — usually uneven liquid distribution (blocked distributor or unit not level), a fan running in reverse or single-phasing, partially blocked fins from product stacking, or defrost water re-freezing because the unit is not level.

Action: clean/replace distributor, correct rotation and phase sequence, adjust stacking, re-level.

Fault 3: Incomplete defrost

Short defrost time, burnt-out heater elements, poor termination settings, blocked drain causing refreeze, or liquid still feeding during defrost. Check heater currents circuit by circuit, extend duration or shorten interval, clear the drain pan and pipework.

In fresh-keeping and CA rooms keep the defrost temperature rise below ~1 °C, or produce will sweat and spoil.

Fault 4: Fan stopped or airflow reduced

Burnt motor, seized bearings, failed capacitor, thermal protection trips, ice rubbing the blade, or moisture in the junction box. Rotate the fan by hand after isolation, test windings and capacitor, and fit a sealed moisture-proof junction box. Specify suitable insulation class and IP rating; fit moisture-resistant heaters in coastal or humid sites.

Fault 5: Dripping water and ice on the floor

Blocked or deformed drain pan, insufficient pipe slope, missing trap, unheated drain line in low-temperature rooms, or water blown off by the fan. This is the most complained-about yet most overlooked issue — carry out a drainage test at commissioning.

Fault 6: Vibration and noise

Failed isolators, unit out of level, poor blade balance or ice strike, worn bearings, panel resonance. Use damping hangers and re-tighten fasteners regularly.

Fault 7: Corrosion, fin degradation, tube leaks

Salt spray and acid/alkali in coastal, seafood, pickling or chemical environments, plus galvanic corrosion between aluminium fins and copper tubes. After a leak appears, specify stainless casing, coated fins and waterproof junction boxes; rinse salt deposits with low-pressure water — never blast the fins.

Fault 8: Compressor short-cycling / mismatched capacity

Air cooler larger than the rack causes low suction pressure and protection trips; too small and the compressor never unloads; wrong fin spacing drives excessive defrost cycles. Compare actual capacity at the operating condition against rack output and adjust.

Maintenance schedule

Shandong BRT Refrigeration Equipment Co., Ltd. (山东博瑞特制冷设备有限公司) provides scheduled inspections, emergency repairs, spare parts and operator training with 24-hour response — including remote diagnosis for existing stores built by others.

Website: https://www.sdbrt.com　|　Service hotline: +86 15898896999

General technical guidance only. Live electrical work, work at height and confined-space entry must be performed by certified personnel following safety procedures.