Trane Thermafit™ – Monthly Screw Vapor Chiller Maintenance Procedure

Use this checklist to perform monthly maintenance on Trane Thermafit™ screw vapor chillers for optimal performance and system longevity.

General System Overview

  • Comprehensive inspection of entire chiller system for leaks, corrosion, damage.
  • Review operating hours log and verify within monthly service intervals.
  • Analyze alarm history for recurring issues and patterns.
  • Inspect piping insulation integrity and repair as needed.
  • Check structural supports and vibration isolators.
  • Clean equipment room and ensure proper ventilation.

Control System Analysis

  • Download and analyze monthly trend data from Tracer™ system.
  • Calibrate temperature and pressure sensors.
  • Update control software/firmware if available.
  • Test all control sequences and safety interlocks.
  • Verify BAS communication and data accuracy.
  • Backup control parameters and settings.

Screw Compressor Service

  • Perform detailed inspection for wear, abnormal sounds, or vibration.
  • Measure and record vibration levels at multiple points.
  • Check rotor alignment and end play measurements.
  • Test slide valve operation through full range.
  • Verify discharge temperature protection functioning.
  • Document compressor performance metrics.

Oil System Maintenance

  • Pull oil sample for laboratory analysis.
  • Change oil filter elements (document pressure drop).
  • Clean or replace oil strainer.
  • Test oil heater functionality and temperature regulation.
  • Verify oil separator efficiency (carryover test).
  • Check oil cooling system operation and cleanliness.

Refrigerant System Analysis

  • Perform comprehensive leak test using electronic detector.
  • Verify refrigerant charge and adjust if necessary.
  • Test and record superheat/subcooling at various loads.
  • Inspect filter drier and replace if pressure drop excessive.
  • Check economizer operation and intermediate pressure.
  • Verify refrigerant quality (moisture and acid test).

Electrical System Testing

  • Perform insulation resistance test on motor windings.
  • Check and torque all electrical connections.
  • Test control circuit components and replace worn parts.
  • Verify motor current balance across all phases.
  • Inspect and test VFD operation and cooling (if equipped).
  • Clean electrical panels and check for proper ventilation.

Water System Service

  • Perform water quality analysis and adjust treatment.
  • Clean Y-strainers and document debris found.
  • Verify flow rates meet design specifications.
  • Inspect pump seals and packing for leaks.
  • Test water flow switches and adjust setpoints.
  • Check expansion tank pre-charge pressure.

Heat Exchanger Cleaning

  • Inspect tubes for fouling, scaling, or biological growth.
  • Perform tube cleaning if approach temperature elevated.
  • Check tube sheet and gaskets for leaks.
  • Verify proper refrigerant distribution in circuits.
  • Document approach temperatures before/after cleaning.

Safety System Testing

  • Test all pressure safety switches and verify setpoints.
  • Verify oil pressure differential protection.
  • Test emergency shutdown sequence completely.
  • Check relief valve certifications and operation.
  • Verify all safety labels are legible and in place.
  • Update emergency contact information posted.

Performance Analysis

  • Calculate monthly average kW/ton efficiency.
  • Compare energy consumption to previous months.
  • Analyze capacity vs.
  • Review setpoint optimization opportunities.
  • Document performance degradation trends.
  • Calculate monthly runtime and cycling statistics.

Documentation & Compliance

  • Complete detailed maintenance log with all findings.
  • Update equipment history and maintenance records.
  • File refrigerant usage reports per EPA requirements.
  • Document water treatment compliance.
  • Review and update safety data sheets (SDS).
  • Schedule next major maintenance activities.