Mitsubishi EAHV – Weekly Water-Cooled Chiller Maintenance Procedure

Use this weekly checklist to maintain Mitsubishi EAHV water-cooled chillers, improve reliability, and ensure long-term system efficiency.

General System Overview

  • Inspect for leaks, corrosion, or damage to pipes, insulation, and supports
  • Record compressor runtime hours and start count for the week
  • Review alarm status and analyze historical logs from past week
  • Verify all safety signage and equipment labels are visible and intact
  • Check equipment room ventilation and ambient conditions

Compressor & Refrigerant System

  • Check for abnormal noise, vibration, or heat from compressor
  • Verify refrigerant suction and discharge pressures within specs
  • Calculate and record superheat and subcooling values
  • Oil Level:Check oil sight glass for proper level(Oil-lubricated models only)
  • Oil Quality:Inspect oil color and clarity(Oil-lubricated models only)
  • Oil Heater:Confirm operation and standby temperature(Oil-lubricated models only)

Electrical System

  • Check terminal tightness, corrosion, and discoloration
  • Log motor amperage and verify against specifications
  • Confirm proper operation of control panel and all indicators
  • Check voltage balance across all three phases
  • Inspect motor starter contacts for wear or pitting
  • Verify proper grounding connections throughout system

Water Circulation System

  • Measure chilled water flow, pressure, and delta-T
  • Measure condenser water flow, pressure, and delta-T
  • Inspect pump operation for abnormal noise or vibration
  • Inspect cooling tower basin and clean if necessary
  • Check cooling tower float valve and make-up water system
  • Verify cooling tower fan operation and drive belt tension

Heat Exchange Components

  • Inspect condenser and evaporator for fouling or scale buildup
  • Log approach temperature and compare to specifications
  • Clean coils if heat transfer performance is degraded
  • Check refrigerant sight glass for proper charge and moisture
  • Verify proper refrigerant flow through expansion device

Water Treatment

  • Verify dosing pumps operating and chemical levels correct
  • Test and record pH levels for chilled and condenser water
  • Test water hardness and total dissolved solids (TDS)
  • Clean strainers and replace filters as needed
  • Check biocide levels and adjust if necessary
  • Review chemical feed rates and inventory levels

Safety & Protection Systems

  • Check pressure relief valves and safety interlocks
  • Verify shutdowns trigger properly for temperature/pressure faults
  • Ensure emergency stop buttons are accessible and functional
  • Verify lockout/tagout tools and procedures are available
  • Test refrigerant leak detection system if installed
  • Check ventilation system in equipment room

Performance Monitoring

  • Record kW/ton ratio and compare with efficiency goals
  • Review temperature and pressure trend logs for the week
  • Flag and escalate any significant performance anomalies
  • Calculate weekly energy consumption and cost analysis
  • Compare actual vs design capacity at current conditions
  • Document load profile patterns and cycling frequency

Documentation & Compliance

  • Complete weekly checklist log with date and technician name
  • Attach trend reports or alarm summaries as needed
  • Document all maintenance activities performed
  • Update equipment logbook with findings and actions
  • Ensure compliance with OSHA safety standards
  • Verify compliance with ISO 9001, 14001, and 50001
Use Checklist Online