Which of the following is an indication of a potential refrigerant leak in a refrigeration unit?

Low suction pressure is indeed an indication of a potential refrigerant leak in a refrigeration unit. In a properly functioning refrigeration system, the suction pressure should remain within a specific range that corresponds to the refrigerant being used and the operating conditions of the system. A drop in suction pressure often suggests that there is insufficient refrigerant circulating through the system. This can occur due to a refrigerant leak, which allows the refrigerant to escape from the system, leading to lower pressure readings.

When a leak occurs, the system cannot maintain the required level of refrigerant, which impacts its ability to absorb heat effectively. As a result, low suction pressure can indicate not just a refrigerant leak but can also affect the overall cooling efficiency of the unit, potentially leading to other issues such as freezing at the evaporator.

High discharge pressure, normal motor amp draw, and ice build-up on the compressor may be symptoms or side effects of various operational issues but are not definitive indicators of refrigerant leaks. High discharge pressure can result from restrictions in the system or high ambient temperatures, normal motor amp draw shows that the compressor is operating as expected, and ice build-up is typically associated with other issues like airflow problems rather than directly indicating a leak.