What makes these moments even more painful is that it’s never been easier to maintain proper cargo temperatures in reefer trucks and trailers. Let’s look at some typical issues with reefers—and do a quick tutorial on how to set temp controls to keep decay on the ropes.
First, here’s a quick checklist of things to do when dealing with perishable loads:
- Pre-cool trucks and trailers for at least one hour before loading perishables.
- Make sure the shipper’s temperature requirements are on the bill of lading.
- Inspect loads for signs of temp fluctuations (like heavy condensation, wilting or mold) before accepting the freight.
- Perform spot checks (pallet and pulp tests) to be sure the load is OK.
Keeping It Cold
The number one reason for cargo spoilage is reefer unit breakdown. The best safeguard against this is scheduled maintenance by qualified technicians. When renting reefers, you want to go with reliable fleets with recent model year trucks that diligently perform Preventive Maintenance. That alone should keep the milk from going sour. Of course, it’s also advisable to keep an updated list of capable reefer techs along your routes so that problems can be dealt with fast.
For their part, drivers have to be able to do a basic visual inspection of a refrigeration unit. The first thing to look for is damage to the chute. Next are door seals. Seals need to be secure enough so that cold air isn’t leaking out, which can be a major source of problems. Temperature monitoring gear must also be checked for signs of damage or excess wear. Reefer units last roughly 40,000 hours—about eight years. Once they’ve hit that mark, chances are they’ve become unreliable.
The good news here is that data systems in newer trucks allow dispatch to remotely monitor the temperature inside a driver’s reefer, allowing dispatch to notify and help drivers in detecting failures on the road long before spoilage occurs. Trucks from manufacturers such as Carrier Transicold and Thermo King allow for this remote, real-time tracking of refrigerated loads, which turns reefer monitoring into a true team effort.
Setting Your Controls
The second most common reason for spoilage is operator error. That typically takes the form of not knowing how to set controls. These days there’s really no reason for this, as reefer manufacturers and rental fleets have instructional videos that explain how to check, test and set temp controls. Here a link to one such video.
Now, let’s run through a basic primer of the temp controller, running modes, and best practices for proper use of a reefer truck:
- The command controller is the computer device mounted inside the cabin.
- Use auto start-stop mode for loads that don’t require rigid temp control (many commodities can tolerate a variation of 5 to 10 degrees from a specific set temperature).
- Use continuous-run mode for delicate perishables needing tight temp control (some cargo requires fixed temperatures—and some shippers insist on it—which requires continuous running of the engine and reefer unit to prevent temp fluctuations).
- Always run a pre-trip test on the command controller before departure. This cycles through all operating modes, and will alert you to any problems.
- The reefer unit will automatically defrost at certain coil temps. Only do a manual defrost when box temp is at or below 40° Fahrenheit. Manual defrost shuts itself off when coil temp reaches 55°.
- If and when alarms sound, note the alarm code, then use buzzer off and function change keys and cursor buttons to reset the alarm. If the unit does not restart after clearing the condition, contact dispatch (or your rental provider) immediately.
- Reefer trucks can be used in electrical standby mode by connecting to 3-phase shore power cables. Place the command controller in the “off” position and press standby. Make sure cable and power input are clean and dry.
- When loading, leave sufficient room around goods to ensure airflow.
This information gives you an overview of typical issues with reefer trucks, how to spot trouble, plus basic settings and best practices. Reefer units are easy to use and incredibly dependable once you’ve familiarized yourself with their operation.