Introduction to Walk-In Freezers : How to Diagnose Failures

 1. Initial Steps:

• Inventory electrical devices to ensure all fans are running smoothly and quietly.
• Check all electrical and ground connections; tighten any loose screws.
• Refer to the wiring diagram for any wiring questions.

2. Visual Inspection:

• Determine the expected operating temperatures and pressures from the unit's manual.
• Understand the design condenser split for troubleshooting the high-pressure side.
• Know the evaporator temperature difference and superheat setting for the low-pressure side.
• Evaporator temperature difference: Difference between the evaporator coil temperature and refrigerated space temperature.
• Suction pressure indicates evaporator temperature.
• Box temperature is shown on the thermometer or electronic thermostat.

3. Diagnostic Steps:

• Use instrumentation to diagnose failures.
• Check for signs of corrosion on fins, cabinet, and tubing.
• Ensure the drain line is clear of debris.
• Look for excessive vibration in the fan and motor.
• Check door seals and gaskets for proper sealing.

4. Routine Maintenance:

• Check temperature daily for accurate thermostat operation.
• Verify heaters are connected and operational.
• Ensure minimal frost and clean coils.
• Make sure fans are clear and running, with no airflow restrictions.
• Clean evaporator and condenser coils at least twice a year.

5. Safety Precautions:

• Wear appropriate PPE: warm clothing, gloves, hats, jackets, protective eyewear, and a face mask.
• Follow safety procedures for handling chemicals.
• Clean the freezer quarterly, addressing spills and spoiled food immediately.
• Use water and soap for cleaning every other week; avoid harsh chemicals.
• Turn off electricity before performing maintenance or cleaning.
• Move food to another freezer if possible during maintenance.

6. Cleaning Procedures:

• Use self-rinsing cleaner, soap, water, or a stiff-bristled brush for coils.
• Catch water runoff from melted ice using containers or a shop vacuum to prevent falls and mold growth.

7. Lifespan and Maintenance:

• Expected lifespan of a walk-in cooler/freezer is around 15 years with proper maintenance.
• Implement a solid preventive maintenance plan to ensure longevity.