Trans Air Manufacturing. “If system refrigerant level is low, you must fix leak and verify proper lubricant levels to maintain reliable system oper- ation,” he commented. “When working on the vehicle, make sure you return and properly reattach or reinstall AC com- ponents. Not properly affixing wiring harnesses can impact safe operation.” Mechanics may have little experience in maintaining bus air conditioning equipment. However, training on a few best practices may be all they need to save their district from costly failures. Parts procurement can also be a sensi-
tive topic. Purchasing OEM parts may be a best practice, but many fleet managers find them expensive and often with longer lead times than aftermarket parts. Tis is a source of continual debate with strong opinions as to their procurement. Lehnert said that utilizing OEM
replacement components can negatively impact safety and reliability. For example, electric fans that may look the same can have lower air flow or higher amperage, which can impact circuit protection and system performance. Some fleets, however, use both. “While the bus is in warranty period you must use manufacture parts,” says Will Nobles, fleet manager at Denver Public Schools in Colorado. “After that we put together RFP to ensure the quality of the parts meet the manufacturer’s spec and look for the best price on parts.” Trans-Air’s Lehnert, however, cautioned against this. “Great variation in industry supplier and traceability cause a lot of customers to be taken advantage of by counterfeit suppliers, negatively impact- ing the A/C system brand experience,” he said. “Who is liable if you replace a part that results in a system failure or safety issue? Will the parts supplier take the liability? Te school district?”
ADVANCED TECHNOLOGY A smart parts strategy and a robust maintenance program are key ingredients for any fleet manager who has air condi- tioning units in their fleet. Knowledge of equipment design and cooling capacities to suit their environment and buses is also important.
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Lehnert added that one trend in bus A/C is the availability of systems compatible with electric drives commonly found on newer replacement buses. Trans-Air offers electric A/C system options for hybrid and electric drive buses. Te scenarios with school bus A/C in South Carolina, Texas and Alabama show that the systems are critical and likely to be in even greater demand in the years ahead. As aging school fleets are replaced, A/C will likely be found on those newer buses.
Fleet managers will need to be aware of the maintenance challenges to keep those new buses operating with reliable air conditioning equipment, which benefits not only stu- dents but also their drivers.
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