Final answer:
When the interconnecting line set is longer than standard, consulting manufacturer guidelines is necessary to determine the correct adjustments, such as possibly increasing the refrigerant charge, for the system to function properly.
Step-by-step explanation:
If the interconnecting line set is greater than the standard length for a refrigeration or HVAC system, it might be necessary to consult manufacturer guidelines. This is crucial because increasing the length of the line set can significantly affect the performance of the system, potentially requiring adjustments such as a refrigerant charge increase to ensure proper operation. Manufacturer guidelines will provide the specific details and requirements for handling such alterations to the system design.