Quy trình bảo dưỡng hệ thống điều hoà trung tâm Water chiller

CHILLER

Monthly (M)  

General
 Check for water leaks.
 Rectify and report to engineer
 Check for excessive noise and vibration and report to engineer.
 Check for excessive temperatures and pressures as below. Report adverse conditions.
 Check for full refrigerant charge.

Gauge Readings
With compressors running record:
 Compressor discharge pressure.
 Compressor suction pressure.
 Compressor oil pressure.
 Chilled water flow temperature.
 Chilled water return temperature.
 Condenser water flow temperature.
 Condenser water return temperature.
 Condenser air on temperature.
 Condenser air off temperature.

Crank Case Heaters
 Check operation of heaters.

Compressor Oil Levels
 For compressors off line check and record crankcase oil levels.
 Record oil level of operating (after compressors have been in operation for at least 30 minutes).
 Record quantity of oil added.

Three Monthly (3M) 

Liquid Line, Sight Glass & Moisture Indicators
 Check temperature drop across line filter/drier (where fitted).
 Wash condenser coil and comb and coil damage.
 Non-running compressors may be started to complete checks required.
 Non-completed monthly checks should be done concurrently.

Compressor Unloaders
 Check sequence and operation of compressor unloaders and unloader controls.
 Record adjustments made to unloaders and maintained mean suction pressure.

Liquid Line, Sight Glass & Moisture Indicators
 Leak test all refrigerant circuits. Rectify minor leaks, immediately advise engineer of any major
leakages found.

Leak Test of Refrigerant
 Leak test all refrigerant circuits. Rectify minor leaks, immediately advise engineer of any major
leakages found.

Six Monthly (6M) 

Chiller Set General
 Check TX valve superheats.
 Check and report condition of mountings.
 Clean chiller equipment surfaces and immediate plant area.
 Check condition of chiller set paintwork.

Compressor Motor
 Check all terminals for tightness.
 Record amperage draw on each phase and load level.

Safety Controls
 Check operation of all safety controls external to machine by simulation of fault.

Chilled Water Low Temp. Thermostat
 Check operation and calibration.

Chiller Load Controller
 Check operation and calibration.

Safety Controls
 Operational check on all safety & operating controls, (Setpoints shall be strictly in accordance with
chiller set manufacturer’s specifications.)
 Carry out “Controls Quick Test” in accordance with Carrier’s instructions.
 Yearly (Y) 

Chiller Set General
 Inspect and clean condenser coils. (Refer manufacturer’s instructions included in operating and
maintenance manuals.)
 Clean and inspect suction strainers/driers where fitted.
 Ensure filter drier has been changed at least once during the year.

Compressor Motor
 Disconnect mains power terminals and perform insulation resistance test strictly in accordance with
equipment manufacturer’s procedures.
 Record readings taken.

Compressor Oil
 Obtain laboratory test of sample of used compressor oil for acidity and metal content levels (if
acidity is indicated refer to schedule for service procedure.)
 Forward laboratory report to engineer. If oil does not meet specification then after confirmation by
the engineer, drain compressor oil and recharge with new oil to compressor manufacturer’s
requirements.
 Clean oil strainer screen.
 Clean suction strainer screen.

As Required

Acidity Rectification
Service procedure to rectify acidity in compressor oil:

 Drain crankcase.
 Clean all strainers as above.
 Obtain laboratory test of new oil sample prior to use and recharge with new oil to manufacturer’s
specification.
 Install replacement covers in liquid and suction line driers were fitted.
 Obtain new laboratory test of oil sample on next scheduled maintenance visit. If acidity condition is
still indicated, repeat service procedure until negative acidity reading is obtained.
 Leak test refrigerant circuit.