Mitsubishi EAHV-P – Daily Chiller Maintenance Procedure
Use this checklist to perform daily inspections of Mitsubishi EAHV-P screw vapor chillers, ensuring safety, operational performance, and maintenance compliance.
General System Overview
- Visual inspection of chiller unit and surrounding areas for leaks, damage, or abnormal conditions
- Record total operating hours and compressor starts for maintenance schedules
- Verify all alarms (temperature, pressure, water flow) are functional and audible
- Check proper labeling and warning signs for hazard identification
- Inspect for corrosion, cracks, or loose components
Control System & Display
- Mitsubishi Electric controller display functional and clear
- No active alarms or fault codes displayed
- Control panel buttons and navigation responsive
- Operating parameters within normal ranges
- Historical data logging functioning properly
- BMS communication (if applicable) active and error-free
Screw Compressor System
- Screw compressor operation smooth with no unusual vibrations or noises
- Vapor injection system pressures and temperatures within specifications
- Oil levels clean and at correct level in sight glass
- Oil separator functioning correctly with proper differential pressure
- Oil heater operation preventing refrigerant migration during off cycles
- Slide valve or capacity control operating smoothly
Electrical Components
- Chiller receiving correct voltage and current per specifications
- Proper grounding and secure electrical connections
- All electrical connections free from corrosion and wear
- Motor amperage within specified limits for current load
- VSD (if equipped) operating properly with adequate cooling
- Starter contacts and control circuits in good condition
Refrigerant System
- Refrigerant levels checked and no leaks detected
- Superheat and subcooling values within manufacturer specifications
- Electronic expansion valve operation stable and responsive
- Filter driers showing acceptable pressure drop
- Sight glass clear indicating proper refrigerant charge
- Refrigerant recovery equipment available and functional
Water Systems
- Proper chilled water flow and pump operation within parameters
- Adequate condenser water flow with no obstructions or debris
- Chilled and condenser water temperatures within specified ranges
- Water pressure gauges accurate and within acceptable limits
- Flow switches and sensors calibrated and functional
- Water treatment system operating with proper chemical levels
Heat Exchangers
- Evaporator and condenser approach temperatures within limits
- Shell and tube heat exchangers inspected for fouling indicators
- Proper water treatment preventing scale buildup
- No visible leaks in heat exchanger connections or gaskets
- Pressure drop across heat exchangers within acceptable range
Safety & Protection Systems
- High/low pressure switches tested and functioning properly
- Oil pressure and temperature safety controls operational
- Emergency shutdown systems tested for functionality
- All emergency switches clearly labeled and accessible
- Pressure relief valves properly seated and functional
- Lockout/tagout procedures clearly posted and accessible
Performance Monitoring
- System efficiency (kW/ton) monitored and within targets
- Energy consumption tracking for optimization opportunities
- Performance data reviewed for trends or anomalies
- Actual values compared with design specifications
- Load balancing and staging operating efficiently
- Maintenance schedules updated based on runtime hours
Documentation & Reporting
- Daily inspection log maintained with all activities recorded
- Maintenance records properly documented and filed
- Refrigerant usage logged per EPA requirements
- Safety inspections documented per OSHA guidelines
- Water treatment logs updated and compliant
- Energy performance data recorded for analysis