It doesn’t matter if you are an owner operator running one refrigerated truck or trailer, a large fleet running hundreds or somewhere in between, establishing – and maintaining – adequate transport refrigeration unit (TRU) maintenance schedules is crucial to your success and your bottom line.
Properly maintained TRUs will not only operate more efficiently in cooling performance and fuel consumption, but will also experience fewer breakdown situations, which will save you maintenance costs and downtime. Most importantly, you will avoid a compromised, or worse yet, lost load situation.
Recommended TRU maintenance inspection schedules should be a key component in every business operating plan and documented in food safety plans. While this should be a long-standing best practice for refrigerated fleets, it is now considered to be a requirement of the Food Safety Modernization Act and more specifically, the Sanitary Transportation of Human and Animal Food (STF) ruling that was published last year by the Food and Drug Administration (FDA).
Shippers have the primary responsibility in determining appropriate standards for the safe transportation of food products and carriers – loaders and receivers must abide by the STF ruling and perform as expected.
A documented, thorough TRU maintenance inspection schedule will go a long way in avoiding the unexpected and keeping your refrigeration units running smoothly and compliantly.
Must-Dos
To assist operators, Thermo King provides a recommended maintenance schedule for all of its truck and trailer units and documents the suggested procedures for pre-trip, 1,500 hours, 3,000 hours and 4,500 hours/annual inspection intervals. Important to note is that recommendations do vary, depending on if units are mechanically or electrically driven, and that there are several must-dos when it comes to refrigeration unit maintenance. These include:
- Fans – To cool efficiently, units need to move as much air as possible. Because fans are run off the engines of mechanically-driven units, keeping up with the rpm is crucial.
Belt tension and condition is vital to proper fan operation. If a fan stops spinning, the unit will shut down. The condenser fan is driven by the engine. If the engine overheats, airflow will stop, box temperatures will rise and cargo is at risk.
- Coils – Cleaning condenser and evaporator coils is another essential. Beyond the common build-up of dust and dirt particles that, if not attended to, will eventually slow down air flow, there are risks of shrink wrap or small pallet pieces being pulled into the unit. If air flow is blocked, the unit will try and defrost more often, intuitively thinking it is iced up. This will again put load temperatures at risk.
Condenser and radiator coils should also be checked often as outside elements, such as pollen or pollutants, can quickly build up. This will cause the engine to run hot and create a potential shut-down event due to overheating.
- Batteries – Battery inspections should be done in late summer or early fall. Cold weather will zap weak batteries. Follow the battery manufacturer testing procedures. Some require load testing only; some also require coolant conditioning.
- Fuel Tank/Oil Changes – Clean the tank and fuel filters, perform recommended oil changes and don’t skimp. Just like in an automobile, these simple preventive maintenance steps are the first defense in making sure an engine runs smoothly.
- Electrical Connections – With today’s newer technology, like the Thermo King Precedent trailer units, checking the electrical connections to ensure that they are clean and tight, per the recommended maintenance schedule, should be standard procedure. It should be the first thing checked if something is not right. Simply tightening a loose connection has corrected many error codes.
When In Doubt
While many of the actions on recommended maintenance inspection lists are common sense, not all fleets are equipped to handle them all. When in doubt, look to the professionals, like Thermo King’s nationwide dealer network.
There are definite advantages to choosing factory-certified and trained technicians to perform the preventative service work on refrigeration units. Not only do they utilize genuine parts and perform the maintenance using the right equipment and diagnostic tools, they are documenting the maintenance activities and schedules.
This will eliminate maintenance lapses, reduce confusion if service is needed somewhere else in the dealer network and keep unit in peak condition and on the road.
Sid Gnewikow is manager of technical service and warranty for Thermo King North America (https://na.thermoking.com), a world leader in transport temperature control systems for trucks, trailers, buses, rail cars and shipboard containers.
