Loading and Enroute Inspections

Important Make sure cargo is pre-cooled to the proper temperature before loading. The Thermo King unit is designed to maintain temperature, not cool an above-temperature load.

1. Inspect unit condenser grille openings to ensure they are free of debris.
2. Inspect unit defrost drain tubes to ensure they are not plugged or kinked.
3. Confirm there is sufficient fuel in tank to operate unit for time required for deliveries.
4. Inspect the cargo box compartment inside and out for:

  • Inspect condition of door seals. They must seal tightly with no air leakage.

  • Damaged walls, missing insulation or blocked floor channels.

  • Inspect bulkheads (if applicable) for a air tight fit at ceiling, walls, and floor.

5. Using the HMI Controller, turn the unit on to pre-cool cargo compartment:

  • Adjust setpoint to desired cargo temperature and allow unit to run a minimum of 30 to 60 minutes (longer if possible) before loading.
Important As product is being loaded, make sure evaporator air inlets and outlets are not blocked. Maximum air circulation is necessary to properly maintain the temperature of the entire load.

Inspecting the Load

Never assume that the product has been loaded properly. Watch for and perform the following tasks. It takes only a few minutes and could save you or your employer considerable time and money later on.

  1. Turn the unit off before opening the cargo box doors to maintain efficient operation. Opening the doors while the unit is running allows warm air to enter the cargo box.

    2. Note The unit can be run with the doors open if the truck is backed into a refrigerated warehouse with tight loading dock door seals.

  2. Perform a final check of the load temperature. If the load is too hot or too cold, make a final notation on the manifest.

  1. While inspecting to see that the cargo is loaded properly, make sure the evaporator air inlets and outlets are not blocked.

  2. Close or supervise the closing of the cargo compartment doors. Make sure they are securely locked.

  3. Check to make sure the unit setpoint is set at the desired temperature as listed on the manifest.

  4. If the unit was stopped, restart using the appropriate starting procedure outlined in this manual.

  5. Repeat the after-start inspection.

  6. Defrost the unit 30 minutes after loading by starting a manual defrost cycle.

Enroute Inspections

Note Enroute inspections are recommended every four hours for the prevention of damage to the cargo.

  1. Note the setpoint to make certain no one has altered the setting since picking up the load.

  2. Note the return air temperature reading. It should be within the desired temperature range. If the return air temperature reading is not within the desired temperature range, it indicates one of the following:

    1. The unit has not had sufficient time to pull down the temperature. Refer to log, if possible, for history of load (for example, above temperature load, properly pre-cooled cargo compartment, length of time on road).

    2. The unit is in defrost or has just completed defrost.

      3. Note You can cancel defrost by turning the unit off, then restarting the unit.

    3. The evaporator is plugged with frost. Initiate a manual defrost cycle. The defrost cycle will be automatically terminated.

    4. Improper air circulation within the cargo compartment. Inspect the cargo compartment (if possible) to determine if the evaporator fans are working and properly circulating the air. Poor air circulation can be due to improper loading of the cargo or shifting of the load, or the fan belt slipping

    5. The unit did not start automatically. If the unit cranked without starting, determine and correct the cause for not starting.

    6. The unit may have a low refrigerant charge. If liquid is not showing in the unit receiver tank sight glass, the refrigerant charge may be low. Adding refrigerant or repairing the refrigeration system requires a competent mechanic. Refer such problems to the nearest Thermo King dealer or authorized Service Center, or call the Thermo King Cold Line telephone number shown on the inside back cover of this manual for referral.

      7. Note If the temperature in the compartment is not within the desired temperature range, repeat the Enroute Inspection every 30 minutes until the compartment temperature comes within the desired temperature range.
      Important Stop the unit if the compartment temperature remains outside the desired temperature range from the setpoint on two consecutive 30 minute inspections. Contact the nearest Thermo King Service Center or your company office immediately. Take all necessary steps to protect and maintain proper load temperature.

  3. Initiate a Manual Defrost cycle after each Enroute Inspection.