Mitsubishi EAHV – Monthly Water-Cooled Chiller Maintenance Procedure
Use this checklist to perform monthly maintenance on Mitsubishi EAHV water-cooled chillers, ensuring safe, efficient, and compliant operation.
General System Overview
- Comprehensive inspection of entire chiller system for leaks, visible wear, or corrosion.
- Detailed examination of pipes, joints, insulation, and support structures.
- Record total monthly operating hours and compressor starts.
- Compare operating data with manufacturer's service schedule requirements.
- Test all alarm systems for proper function and audibility.
- Verify alarm setpoints match current operational requirements.
Compressor & Refrigerant System
- Detailed compressor performance inspection for smooth operation.
- Listen and document any unusual vibrations or noises.
- Verify motor amperage matches manufacturer specifications.
- Comprehensive refrigerant pressure measurements and analysis.
- Perform detailed leak detection using electronic leak detector.
- Oil analysis for contamination, acidity, and moisture content.
- Replace oil if analysis indicates degradation or contamination.
Heat Exchanger & Cooling Tower
- Thorough inspection of condenser coils for cleanliness and efficiency.
- Remove all debris and dirt buildup affecting heat exchange.
- Clean condenser tubes if fouling is detected.
- Measure and verify water flow rates through condenser.
- Document entering and leaving water temperatures.
- Deep clean cooling tower basin and remove accumulated sediment.
- Inspect and service cooling tower fans and drive systems.
- Check cooling tower fill media for fouling or damage.
Water System & Treatment
- Comprehensive verification of water circulation and pressure.
- Detailed inspection of water pumps for leaks or unusual sounds.
- Verify water treatment system chemical dosing accuracy.
- Adjust chemical feed rates based on water analysis results.
- Complete water quality testing including pH levels.
- Test alkalinity, hardness, and total dissolved solids.
- Document water chemistry trends and treatment effectiveness.
Electrical System
- Comprehensive inspection of all electrical connections.
- Tighten loose terminals and clean corroded connections.
- Test all fuses, circuit breakers, and protective relays.
- Detailed motor inspection including bearings and windings.
- Verify motor amperage and voltage balance across phases.
- Control panel diagnostic check for error codes or faults.
- Calibrate control sensors and verify accuracy.
Safety & Protection Systems
- Comprehensive testing of all pressure relief valves.
- Verify relief valves are not obstructed and seat properly.
- Full emergency shutdown system test and verification.
- Test high and low-pressure cutoff switches under load.
- Verify all safety interlocks function correctly.
- Test refrigerant monitoring system and leak detection.
- Update safety inspection tags and documentation.
Performance Monitoring
- Comprehensive system efficiency analysis and trending.
- Review monthly cooling output versus energy consumption.
- Analyze temperature and pressure trending data.
- Compare current performance with historical baselines.
- Calculate and document kW/ton efficiency metrics.
- Identify efficiency improvement opportunities.
- Review energy usage patterns for anomalies.
Documentation & Reporting
- Complete monthly maintenance log with all findings.
- Document all corrective actions taken during inspection.
- Create summary report of system performance metrics.
- Update water treatment logs and chemical inventory.
- Verify compliance with ISO 14001 environmental standards.
- Ensure OSHA safety compliance documentation is current.
- Schedule follow-up maintenance based on findings.