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Hot Weather Tips

Jul 12, 2019

Download the pdf on PLM's Hot Weather Tips here

Keep the heat out of your refrigerated trailers and wallets by taking some preventative measures.  Pre-cooling and proper temperature settings when loading can lower the number of service calls on your units.  PLM recommends the following tips for pre-cooling your trailer during the hot weather :

Pre-Cool the trailer:

  • All trailers should be pre-cooled to set point or below, prior to loading product.
  • Run unit pre-trip to ensure that the unit will perform as expected and no alarms are present prior to loading.
  •     If alarms are present or unit fails the pre-trip call for service immediately and do not load the trailer. 
  • For multi-temp trailers- Only Zone 1 should be used when pre-cooling the trailers. All other zones should be off during the pre-cool process and any bulkheads need to be placed to the side of the trailer. 
  • To pre-cool the trailer, set the TRU set point to within 10 degrees below the desired set point of the product being loaded into the trailer. 
  •     Trailer should be empty of all pallets and cleaned out of all trash, wash out if needed.
  •     Close all doors and check fuel level.

    Run unit until it reaches set point. Caution- Pre-cooling trailer too far below or above actual  product temperature could cause product damage.

 

Prior to Loading

 

  • Pre-cool trailer to within 10 degrees below the desired set point of the product being loaded in to the trailer. 
  • Reefer units are designed to maintain temperature in the compartment and are not designed to pull product temperature down to a specific temperature over time
  • Verify product being loaded into trailer is pre-cooled to desired temperature prior to loading.
  • All product is picked and staged ready for loading before moving it from the temperature controlled area.

Any staging of product should be done in a controlled temperature area that is the same temperature as the product being staged.

 

Loading the Trailer

 

  • DO NOT load trailer before unit has reached set point.  This is to ensure unit can perform as needed and interior of trailer is colder than the product being loaded.
  • Loading warm product into a trailer will cause the unit to cycle into defrost more frequently and product loss could result.
  • All product loaded into any refrigerated trailer needs to have proper air flow around it to keep it cool/cold.  
  • Keep all product at least 2 inches from trailer walls, bulkheads and between other palletized product.

 

  • If loading palletized product onto a flat floor (non-ducted) trailer it is important to note that the pallet is the path for return air to flow back to the reefer unit and this path needs to be unrestricted by the pallet orientation. 

 

Load Zone 1/Single temp trailer

 

  • Place the pre-cooled trailer in door for loading of zone 1 or the entire trailer.
  • Turn off reefer unit and all multi-temp zones prior to loading trailer or zone 1 or opening the rear door for loading.
  • Load all product for Zone 1 or the entire trailer immediately after opening doors.
  • Install bulkhead( if multi-temp trailer) and/or close trailer doors for single temp trailer.
  • Turn reefer unit zone 1 on and change set point for zone 1 to the desired set point of the product being loaded in to the trailer.
  • If multi-temp trailer Zones 2 and 3 (if equipped) are to remain off
Load Zone 2 of multi-temp trailer

 

  • Load Zone 2 product from staging area onto trailer
  • Install bulkhead behind zone 2 product
  • Turn reefer unit zone 2 on, change set point for zone 2 to the desired set point of the product being loaded in to the trailer.
  • Zone 3(if equipped) is to remain off.

 

Load Zone 3

 

  • Load Zone 3 product from staging area onto trailer
  • Install bulkhead behind zone 3 product or close trailer doors
  • Turn reefer unit zone 3 on, change set point for zone 3 to the desired set point of the product being loaded in to the trailer.

 

Once trailer is loaded check and verify all zone set points and defrost intervals are properly set.

  • Final step- defrost the unit manually to remove any ice accumulation from the evaporator coils in all compartments.

 

Download the pdf on PLM's Hot Weather Tips here